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Mystery Force Affecting Probes
imipak writes: "The BBC reports that after exchaustive investigations, NASA scientists have run out of possible explanations for the mysterious tiny course deflections experienced by the Pioneer and Voyager spacecraft as they head out of the solar system towards the heliopause. Could it be that there's something wrong with our theory of gravity? (Well, yes, we already know that...) or could it be Oort Cloud objects? The tenth planet? Informed comment, please!"
random Capitalization and Trolls?
That's all possible, but maybe it's just slashdot sucking so hard that NASA's toys are all getting sucked back to earth.
Even at 70 AU, the solar wind keeps the ISM out. That's one of the reaons in keeping contact with the spacecraft -looking for the heliopause, the boundary where interstellar space begins. It's distance is estimated at 75 - 100 AU but hasn't been detected yet. So it can't be the reason for the decceleration.
You're describing Le Sage gravity, and not only would things "slow down over time", circular orbits would in fact decay and all the planets would quickly fall into the Sun. It still doesn't work.
Anyway, distances in space are measured by rulers, by definition.
Hmm, not quite. Let me throw some comments in your general direction that may be relevant.Geometrically, there is a notion of "proper distance" along a path that is invariant -- that is, independent of coordinate system. You can measure that by laying rulers side-by-side along the path. No matter how you're moving or what coordinates you use, the number of side-by-side rulers connecting two points along a path will be the same, even though (due to length contraction or whatever) the distance you perceive (the coordinate distance in your frame) may not be the same.
Mathematically, this is easy to picture. If you look at a sheet of paper and draw a line between two points, the length of that line is an invariant. It doesn't matter how you rotate the paper around or what coordinate grid you lay down on the paper. However, if you do lay down a coordinate grid, the projection of that line onto a spatial axis may change depending on the orientation of that grid. In special relativity, the analog of "rotations" are Lorentz transformations; the analog of "length of line" is "proper distance" (i.e., the distance between two events in the frame in which they are simultaneous); the analog of "projection onto a spatial axis" is "coordinate distance" between the two events in whatever frame corresponds to the coordinate grid you've laid down. (In general relativity things are more complicated but I don't want to go into that just yet.)
So... as far as rulers go, a ruler at rest with respect to me will always measure proper distance between events I measure as simultaneous. Thus, that distance is "fixed". It doesn't matter if space is expanding or whatever.
As far as spatial distances expanding... this is where a spacetime picture is necessary. If I line up a bunch of rulers rigidly end-to-end to measure the distance between "point A" and "point B" in space, then I will get some distance (which will depend on what path I choose, of course). However, if spacetime (not just space) is curved, then those rulers will not be able to remain end-to-end rigid. Tidal forces will force them to drift apart. In fact, if space is expanding (described by spacetime curvature, rate of change of spatial geometry with respect to time), then I will be forced to add new rulers in between the old ones to fill the gaps if I want and end-to-end measurement along some path. The distance increases.
This is all oversimplified, of course; there is the whole question of "which points in space at one time" correspond to "which points in space at a later time", or indeed which events correspond to "space at a given time" all. Remember the relativity of simultaneity; which events occur "at the same time" -- i.e., which ones constitute "space at a given time" -- depends on the observer in special relativity, and is even more ambiguous in general relativity. You can slice spacetime up into "space" and "time" in any number of arbitrary ways.
You can "fix two particles at a given distance" by connecting them with some rigid ruler, but they won't stay fixed. Expanding space will force them to drift apart; relativity does not permit truly rigid bodies. I don't know what spatial "flux" might be, nor why we should care about it if it's not a physical observable. I don't think the conversation is quite esoteric enough to be completely uninteresting to the Slashdot layman, but maybe soon...Ok. All the cranks are coming out. I might as well join the party.
Let me start with a story about the planet that wasn't.
It seems at a lecture back on January 2nd, 1860, the French mathematician Urbain Le Verrier announced that the problem of observed deviations in Mercury's orbit could be resolved by assuming the existence of one or more intra-Mercurial planetoids. Over time, both before and after this announcement, various people claimed to have spotted such planetoids. One of them was named Vulcan, a name that was, about a century later, re-used in a well-known science fiction television show, which was how I got on to this damn story in the first place.
The planetoids, including Vulcan, were, in the end, proven fictional. Perhaps sunspots. Perhaps asteroids/comets on a near-sun trajectory.
In 1916, the General Theory of Relativity was put forth by Albert Einstein. E=MC. Energy and Mass are one and the same.
More precisely: The energy released by the sun causes a proven gravitational effect upon the orbit of Mercury.
My question, still unresolved, is:
When they took into account General Relativity with respect to these spacecraft, were they referring to time dilation effects, which makes sense given that they are dealing with a Doppler shift. Or, as wacky as it sounds, were they accounting for the gravitational effects of starlight?
Which also raises questions concerning "dark matter". Do scientists account for the gravitational effects of all the energy that has been radiated over the years?
After all, our piddling little sun puts out 3.86e26 Joules/second. E=MC² implies this is equivalent to 4.536e9 Kg/second. No offense, thats one heck of a lot of mass. Spread out over a very large spherical space. And the spacecraft is inside that sphere of energy, complicating the mathematics.
So: Anyone out there better with mathematics than I am want to take a crack at this? What effect does this sphere of radiated energy have upon the spacecraft? Complicating matters is that the energy in the vicinity of the spacecraft is proportional to the surface area of a sphere of radius r. The energy density increases as you go toward the sun, and decreases as you go away. Intuition makes it appear that there should be a small, but definite effect towards the sun.
Slashdot Readers
Hurrah! Please explain it for me, guys. I have a friend at NASA who would really like to know.
Okay, more seriously, what the hell are you talking about? It's all abstract voodoo. Have you seen an electron? No, you can't. Electrons and all your beloved particles are invisible. You can see the effects of them, I suppose. But are you really sure it's not fairies doing the real work? Are you really sure it's not God, setting up little games for us to figure out? I mean, if He plants bones in the ground to test our faith, it doesn't seem far fetched that He'd come up with other little games. Or maybe it's multidimensional strings?
You've never seen an atom, not to mention an electron... and certainly not quarks. All that makes you think that they exist is some model, which apparently has been consistent in predicting a wide range of experiments. It's a nice enough model that you have been able to internalize its metaphors, even with only indirect evidence.
But it's just a model made up of a bunch of equations and notions and assumptions. It isn't magic. It isn't Truth. And that model is not somehow endowed with some status that makes it somehow more The True Model than any other mathematical model. Atom theory predicts things good. Newton's theories predict things good. Aristotle was a idiot, and he didn't predict crap, but that's an aside.
So far, no model has predicted and explained everything. Maybe no such model exists, or maybe it does. Maybe many such models exist. You want underlying causes, but you won't get them, ever (unless maybe God is proven to exist). You can only get models. One after another, which by some really long chain of deduction end up in something you can directly sense. Or, at least, you think you can sense, because this all might just be a dream in the mind of Shiva.
It's just turtles, all the way down.
At large distances, the smaller terms get smaller. The higher order terms are inversely proportional to the radius raised to a power (larger than 2), so the larger the r the smaller the force. Even if you were to use the full blown field equations (tensors and all) you're still going to get this drop off.
Things really only get interesting at small radii and huge gravitational fields...like around black holes, neutron stars, and perhaps white dwarfs, those are the only places where the higher order terms start to become significant.
In other words, the answer to this mystery does not lie in general relativity, and more likely than not, has nothing to do with gravity at all...there would be too many other discrepancies in things like planetary orbits, if it were, in fact, a problem with our gravitational theories.
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Recent astronomical observations to seem to show that the cosmological constant may not be zero implying that there may be a very weak antigravity force, but it's not really detectable on scales that we can easily experiment with, and it has yet to really be confirmed, so for now, the issue remains unresolved.
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You have to be careful with comet orbits too. The gas ejected from comets when they are near the sun can definitely change their orbit. Such non-gravitational accelerations have been observed in nearly every comet to date.
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Well, yeah there are 5, but in most physics circles, electricity and magnetism are generally counted as one force. I suppose it's mostly for historical reasons, since E & M were unified such a long time ago. Ask most any physicist to list the known forces and they will almost always describe them as gravity, electromagnetism, the strong, and weak atomic forces, hence I called the new force, a "5th" force. *shrug*
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Heh. Yeah, I forgot. I hear that one two! :)
But usually it's amoung the particle physicists.
We astronomers don't tend to have to worry about
electroweak unification unless you're working in
cosmology.
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This troll also goes by Nemesis on the sci.physics.relativity newsgroup. He's a popular killfile item. He really likes to call people "prevaricating little lapdogs." This means he knows how to use a thesaurus and possibly a dictionary as well. He seems only capable of ad hominem attacks.
Math does not create physics.Ack! He doesn't seem to be able to tell difference between a map and the actual road.
from the Simpsons' Episode: $pringfield (or, How I Learned to Stop Worrying and Love Legalized Gambling):
Mr. Burns - "Quick, Smithers! We'll take the Spruce Goose. Hop in."
Waylon Smithers - "But that's just a model."
Mr. Burns, cocking a revolver - "I said, 'Hop in.'"
On the actual subject of the article: That is simply fascinating. I would like to see them add an experiment to the proposed Pluto probe to study this phenomenon further. Pluto-Kuiper Express
"You'll get nothing, and you'll like it!"
There exists the possibility that, if alien intelligence exists, they may not be able to do the things you describe.
Also, establishing direct contact with a race (humans) who have a long history of violent reactions to the unknown would be unwise. Perhaps "they" are testing the waters? Or testing our level of sophistication?
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We may not imagine how our lives could be more frustrating and complex—but Congress can. – Cullen Hightower
After all, what better way to make contact than to cause an unexplainable error? We'd be sure to notice it!
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We may not imagine how our lives could be more frustrating and complex—but Congress can. – Cullen Hightower
Math doesn't create physics, and nobody (sane) believes that it does. I do believe you're a troll, of course, but you do tap into some common frustration with the intangibility of modern (non-newtonian) physics.
The field of particle physics that you extol would not exist but for mathematical models.
If "mathematical what-if scenarios" are junk, how do you come up with a falsifiable hypothesis predicting the existense or behaviour of such-and-such subatomic particle? How do you design the experiment to falsify the hypothesis?
Math isn't physics. Math is a tool for modeling. You're a tool for trolling. You may have a legitimate beef with news media who report abstract theory as sensational fact, but I deride the legitimacy of your beef against physicists.
-Isaac
I am not a lawyer, and this is not legal advice. For Entertainment Purposes Only.
The acceleration is described as towards the Sun, not opposed to the motion of the spacecraft. Assuming those to directions are not so close together that they can't be distinguished, that would pretty much rule out drag.
I think the science instruments would also have detected a change in the velocity of the surrounding medium. It's precisely to detect the heliopause that they are being run.
As the probes travel farther and farther from the Sun, the masses of the planets, moons and asteroids move behind rather than in front of the probes. Of course, this has probably been considered, but I haven't seen it mentioned.
x = 4195835
y = 3145727
z = x - (x/y)*y
...and consequently, SlashDot is as good a venue as any to look for explanations.
Perhaps the stars really are embedded in a crystal sphere, and the perturbations are the gravitic effects of the sphere beginning to manifest. Watch for a sudden end to transmissions and soon afterwards the mother of all cracks in the sky... (-:
``But seriously, folks''
NASA don't know how our own sun works, so how can they be expected to predict behaviour even further away from the sun? How is it that a (ghasp) lone scientist with no resources can bullseye planetary magnetic fields before the fact, but NASA (besides many other large and well-equipped organisations) are several orders of magnitude wide of the mark?
Got time? Spend some of it coding or testing
A slap with a wet salmon to whatever fool modded this up as "Funny."
-Waldo
Clearly, this is due to the Springfield Effect. They have simply passed through new, undiscovered Springfield locations.
Mr. Teapot can answer all your questions.
Know what I like about atheists? I've yet to meet one that believes God is on their side.
There is a cult within the spacetime physics community led by a small but influential cadre of nerd physicists and mathematicians whose credo is "physics is math" and who think they are free to create physics simply by manipulating spacetime equations using what-if scenarios.
LOL! That reminds me of Logopolis episode of Dr. Who. This was where the Doctor and the Master visited this city where these people run "block transfer computations" which control reality.
Could it be that space has some resistance.... like dust... gases.. etc.
Oddly enough, it also seems that this deviation is not evident in the orbits of the planets.
Me? I just think that they've been slowed by local debris--though I'd like to believe in a gravitational constant.
-W-
"Is it all journey, or is there landfall?"
-W-
Is it all journey, or is there landfall?
--Ellison & van Vogt, 'The Human Operators'
Ok we are talking deep space, but they have passed the region where the solar wind, which is detectable goes subsonic and so the probes might now be traveling faster than very very tenuous medium around them.
"Because we are not employing at entry level, offshoring will kill our industry stone dead."
A few comments above we have, "So, let me get this straight. NASA has given up trying to explain this, they have no idea. So for informed comments, now we turn to ...
Slashdot Readers
Hurrah! Please explain it for me, guys. I have a friend at NASA who would really like to know.
I thought it was funny (so did several moderators).
And now we get this obvious troll, and it is moderated as insightful.
Not so funny anymore.
Steve M
Its funny (or sad) not flamebait!
Well it sure ain't funny. It may be a sad attempt at humor.
But I'm going with flamebait.
Steve M
This property is generally seen as a desirable property of the theory. In fact the only really good argument in favor of string theory is that it is the only known quantum mechanical theory which produces the observed behavior of gravity and is not known to have internal inconsistencies.
Why? He was bored...
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Sorry but I don't think the instrumentation on these probes really is advanced enough to gather what is needed to make an accurate or informed decision.
How so?
To start with, the main data of interest (probe positions and trajectories) doesn't require additional instruments to measure. They're looking at the timing and doppler-shifting of the probes' radio signals, and getting a very good estimate of their positions and velocities.
The record of the probes' trajectories over long periods of time is what suggests the effect and places limits on how it acts.
Secondly, there isn't anything *out* there to look at. At least a few of these probes have micrometeorite detectors and dust analyzers and radiation analyzers. That covers just about everything you'll run into. What extra instrumentation do you propose to add?
What kinds of instruments do you think would give us a better idea of what's going on than we already have?
Now, I can't remember the specifics, but the general equations we use when utilizing relativistic motion are actually still only approximations -- it's just that the third, fourth, etc. order terms of the equation are so small that you can ignore them.
The thing is - what happens over large distances? Well, the smaller terms will start to become very important. I've got to wonder if they forgot that the equations they'll typically use ARE approximations which are simplified for ease of use in calculations?
If I understand correctly, the approximations only cause problems in very extreme situations (sharply curved space, very high matter or energy densities, very oddly configured space, etc.). At the probes' location, space is so flat you could treat it with Newtonian mechanics and have a great deal of trouble finding discrepencies with observations.
Thus, I doubt that equation approximations are the cause of the problem in this case.
On the other hand, if I recall correctly there has been interesting speculation about the full versions of the equations allowing negative mass to be generated under some conditions. I'd have to study my relativity book a lot more thoroughly to tell if that's even remotely sane, though.
for instance if it were wrong, then (since we have a fairly good grasp of the distances involved, we would simply miscalculate the mass of a planet. And believe it or not we could probably go for quite some time convinced that jupiter was heavier or lighter than it was without finding a condradiction.
If we were only looking at the orbits of the planets about the sun, this would most certainly be correct. However, we've also observed the orbits of the moons of the various gas giants about their primaries, and measured with fanatical precision the paths of the probes we've sent to and past the gas giants. If the mass values for the gas giants were off, this would have very substantial effects on the orbits of their moons and on the trajectories of probes that have visited.
Good thought, though.
If they're slowing as they get very far from the Sun, that seems to imply that the force of gravity is not dropping of quite as fast as 1/r^2.
The problem is, as the article points out, we would have seen the effects of this on the orbits of the planets if this was the case.
I'm personally wondering about drift in the probes' radio sources throwing off the doppler measurements, but if this was happening they should have caught it already (you can directly measure the probes' positions by measuring the round-trip signal times to them at a few different imes during the year).
Informed comment, please!
Bullshit, informed? how do you know it's not a bunch of flying winged monkeys. Theories are only slightly better than guesses. Besides, Slashdot isn't exactly the best place to go for people knowledagable in the physics of bodies moving through uncharted portions of space. If you really want informed opinions, try and berate the people at NASA and JPL. Slashdot is more of a jack-of-all-trades thing, theres probably someone with the background similar to Stephen Hawking on here. But the only thing they can offer you is, their opinions and theories. Again, not necessarily better than my theory of tiny space going simians.
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Insert Witty Sig Here
There are already 5 forces by most count. Gravity, weak, magnetic, electric, and strong. Oh course, the forces have been unified in various ways, but in many circumstances it still makes the most sense to talk about 5 forces.
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I hope we shall crush in its birth the aristocracy of our monied corporations
And I'd be a Libertarian, if they weren't all a bunch of tax-dodging professional whiners.
Berke Breathed
Well, I always hear about electroweak, strong, and gravity myself. Guess it depends on the physics subculture one moves in.
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I hope we shall crush in its birth the aristocracy of our monied corporations
And I'd be a Libertarian, if they weren't all a bunch of tax-dodging professional whiners.
Berke Breathed
possibly theres enuf crap in space that the probes are running into small particles, thus losing speed on impact, and also from greater effect of gravity because of mass = probe + dust
But how well do we know what shape the galaxies have? If this effect were a result of "warped space-time" would it be large enough to detect in the images of galaxies? We know with a good degree of accuracy where the probe started, how fast it was moving, how much it weights, etc. So it is quite likely that we can make a more exact projection of where the probe should be than of how a galaxy should be shaped.
Just consider, we don't even know, really, how much "dark matter" there is in either our own galaxy, or in any of the nearby galaxies. But that could profoundly effect the shape of the galaxies. Those who argue that we know that the universe is flat on the order of a mega-parsec (or whatever) actually don't have that much evidence. Just how flat are they asserting it is? And on what fractal scale? (Consider: "How long is a coastline on a fractal scale?" to be the appropriate analogy.) Certainly is must be lumpy near each star or other massive body. The assertion of flatness then is either the assertion that a) that doesn't matter, or b) but it lumps the other way too, so it evens out. Normally we say that is isn't lumpy enough to make any difference, except when we do something like use gravitational lensing. But how exact is our knowledge?
Even things that are straigtforward projections from well known physical laws tend to be scoffed at if they are unfamiliar. Consider the early days of black holes. But they had been predicted in the 1800's (well, not their more peculiar features, but a star that was too heavy for light to escape from). If anybody had run a straightforward calculation (post Einstein) they would have come up with black holes. And they did, but the idea was so strange that nobody would believe it, and it was considered a purely theoretical curiosity. Perhaps there is another "theoretical curiosity" that will explain this. But it's likely to require being willing to accept that the universe isn't a simple as we like to think of it as being.
Caution: Now approaching the (technological) singularity.
I think we've pushed this "anyone can grow up to be president" thing too far.
Ok. But if it's stellar gas, then there's no reason to assume that it's uniformly distributed. Perhaps then the spaceship is acting as an air plane hitting an air pocket, and getting slightly refracted? (After all, it wouldn't take much.)
Caution: Now approaching the (technological) singularity.
I think we've pushed this "anyone can grow up to be president" thing too far.
The first possibility that popped up in my mind was that the value of G (the universe's gravitational constant) might need adjusting. This would cause local phenomena to agree with it, but would start to lose its accuracy at greater and greater distances. Thus, the deep-space probes can maybe get us a more precise measurement of G than has ever before been able to be measured.
I can't imagine the distances being great enough, but if they are, then, as the article hinted, the expansion of the universe might start coming into play. Basically, imagine a rubber membrane, with two dots fixed on it. Now expand your universe (stretch the membrane), and the dots move away from each other. The farther apart they are, the faster they move. This might be counteracted by a second phenomenon I haven't read about, but reasoned out several years back (any physicists in the audience? Am I off my rocker on this?). Basically, the universe is expanding, but the stars in the galaxies are not expanding with it due to gravity holding them in. Thus, to an observer, the stars in the galaxies should appear to be moving away from their respective galactic cores, as space expands out past them (this is why a meter stick stays a meter even after space expands, and we can measure space's expansion. If it weren't true, then we'd never be able to view space expanding, as our measurements would expand with it). Thus, we could have a combination of the distance appearing to push them away from us, but gravity retarding this effect by still holding it back some. Were it to stay in a stable orbit, it should appear to be moving inward as space "flows" past it.
Ah well. I need to study gravitational phenomena more after I graduate. After graduation is where you take the really cool physics courses anyway (I'm a physics major).
Finally, its possible that our redshift (IIRC, the article stated that they used the probes' redshift) measurements are being affected en route to Earth, or that our redshift-based position and velocity measurement system needs tweaking.
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Given enough personal experience, all stereotypes are shallow.
One of the big open questions of the day is: What is the shape of the universe?
Bent. Or was that time? I'll have to re-read Dr. Streetmentioner's work again.
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
Perhaps we should be careful. It may be Thread, which inhabits the Oort cloud around the Rukbat system, and very nearly destroyed the colonists on P.E.R.N.
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
I am extremely offended at your attitude. My father spent the last years of his life _skeptically_ examining all the evidence gathered throughout the THIRTY years the pioneer probes were operational.
The fact that you can sit in your armchair and question his objectivity, wonder, and *passion* for the mysteries of life makes me physically ill.
Any failing of science is OUR fault. OUR faliere to educate. OUR faliure to recognize our biases. OUR faliures to drag concieted shits like you out of the dark ages.
My (recently deceased) dad is on that paper.. he believed that it was most probably (b) (outgassing of some sort, possibly a malfunction/weakness common to both pioneer probes). No real evidence of that of course, and a "mysterious" force is more publishable ;) Still it is very spooky.
(g) and (h) were (in his opinion) the least likely.
Note that the paper was actually first released in April, and just revised today.
I take it these probes are mostly metallic, does our solar system have magnetic field? i.e. the combination of the magnetic fields of all the bodies in it.
Never trust a man in a blue trench coat, Never drive a car when you're dead
Could it be that there's just more mass in the solar system than we think? Wait, hear me out. I'm not talking about Planet X or a bloated G, I'm talking about ambient stellar gas.
Here's the deal: On the Earth, the gravitatinal forces acting on you at the surface all sum out to equal to the forces that would be exerted by a point source with the Earth's mass and a distance r, the diameter of the Earth. Though that ocean to your left and that continent to your right pull you in opposite directions, and the ground under your feet is pulling harder than the ground in China (um, unless you're in China, in which case, 'hi'), but it all sums out exactly right to a point mass at radius r.
Now, take that example and pose it to the solar system. Forget about the forc of solar wind blowing, and realize that all that wind has mass, and exists everywhere. It's pretty thin, but it's a lot thicker than the four hydrogen atoms per cubic meter in deep interstellar space. All that stuff, wispy as it is, has mass, and even though most of it is so godawful far away, the net gravitational effect of all of it is as if there were an additional point source inside the sun, with the mass of all the stray gasses and particles inside the huge sphere that has the sun as the center and the space probe on the outer surface.
What makes the math even more wonky is that, assuming a roughly even distribution of gas as inversely proportional (or inverse square, or even constant, doesn't matter in this case as long as it's uniform by uniform radius) to the distance form the sun, then the farther out the probe goes, the more mass there is behind it, and the farther back the point source goes.
If the density were uniform (it's not) then the effect of this force would actually increase as the probe got further away. As it is, it may be a constant force. For conceptualization's sake, if you had a well to the center of the earth and went to the bottom (forget magma, use the moon if it makes you feel better) you'd be weightless. Go halfway up, and you'd have a force of one-half g. Go to the surface and you are being pulled with a stronger force than you were when you were closer to the center.
Anyhow, HTML's bad for math, but I just wanted to get the idea out there. I don't have enough info on particulate density over the scope of the solar system and beyond to make any educated numbers anyhow. Hopefully someone out there does.
Kevin Fox
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Kevin Fox
All the scientists are wrong....
...Because some slashdot troll says so....
And of course you're qualified in quantum/astro/subatomic physics, right?
--Gfunk
Send lawyers, guns, and money!
Gravity is many orders of magnitude less powerful than the other fundamental forces, but at least in our experience gravity is also the only force that is always attractive. It is also one of the forces that has a measurable impact at distances beyond a few angstroms.
If you charge up a baloon with static electricity you can see just how strong the other major fundamental forces are. The number of electrons you're moving around is tiny, but it's enough to overwhelm every single proton, neutron and electron being pulled by gravity. The fact that gravity has a measureable impact isn't anything spooky, it's just the sum of a lot of very weak interactions with no opposing interactions.
Of course, we're still discussing this problem in a vacuum (pun intended, thank you). These researchers should have considered all this, and we're just having a fun time chatting about possibilities and shooting in the dark (OK, I'll go away now).
The interstellar medium (interstellar gas & dust) is much less dense than normal around our solar system due to the Scorpius-Centaurus Association superbubble and the Geminga supernova bubble. Perhaps we're seeing a slight increase in the ISM density -- of course these researchers should know all about this, so it's still a puzzle...
A hundred years ago, an unexplained force seemed to be affecting the orbit of Mercury, causing a wobble in its orbit that should not have existed in a Newtonian framework. Then in 1915, Albert Einstein developed the theory of General Relativity, describing the complex curvatures of our universe that could explain Mercury's path around the Sun.
You know... a lot of these problems occur when you take an approximation instead of the real thing.
Eg. Newton's laws are a 1st order approximation to the real thing.
Relativity gets closer.
Now, I can't remember the specifics, but the general equations we use when utilizing relativistic motion are actually still only approximations -- it's just that the third, fourth, etc. order terms of the equation are so small that you can ignore them.
The thing is - what happens over large distances? Well, the smaller terms will start to become very important. I've got to wonder if they forgot that the equations they'll typically use ARE approximations which are simplified for ease of use in calculations?
Simon
Coming soon - pyrogyra
an interesting idea, but relativistic effects keep us from being able to notice it at all even if it were happening. in this case, if light were slowing down, so does time, and the whole thing balances out.
But if the effect doesn't show up until somewhere past Pluto's orbit... (I know the probes aren't yet beyond Pluto's apehelion... but there's still an unexplained anomaly in Pluto's orbit, isn't there? And we haven't observed Pluto for a full orbit yet.)
If they're slowing as they get very far from the Sun, that seems to imply that the force of gravity is not dropping of quite as fast as 1/r^2. If the strength of gravity is higher than inverse square and great distances, perhaps that effect would explain the "missing mass" problem? There isn't really any missing mass. This effect makes it look like the galaxies are more massive than they really are.
Even if a thousand people (scientists) say something is so, does not make it so. False ideas have been taken as gospel many times in the past (the 4 humors, for example.) We work with theory, which in many cases cannot be concretely proven (like how acids and bases work) and, although 1000's of scientists say it is so, it may not, and often is not the case.
ok, IANAAstronomer but I would imagine the slowdown in gps satellites have to do with remenants of the earths atmosphere.
this question can be answered easily. do the planets/comets slow down over time?
bueller....bueller.....
--Fermat
The only problem with this analogy is that the precession of Mercury's perihelion occured in the area of the highest graviational field within 4 light years. This is where you would expect to find simplier theories to break down.
:-) The shape of galaxies - and interactions of galaxies in clusters and super-clusters, shows that the universe is "flat" on the scale of many millions of light years. If you equate that to the size of the earth, then 1 meter represents about 1 LY, and the helipause will easily fit within a postage stamp. Or maybe the period at the end of this line. Something definitely "flat" by any reasonable definition.
In contrast, the probes are in areas with a relatively small gravitational field. While the field is smaller than anything this side of Pluto's orbit, it's not that much smaller. (The contribution from the sun is lower, but the contribution from the entire Milky Way, and our gravitationally bound galactic cluster, is just as large.) A breakdown in the existing theory just doesn't make sense here - and even if it does break down, where does the energy come from?
As for the issue of the space of the universe... get a grip.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
Wind, on a galactic scale, is my loony guess.
--
If a tree falls on an anonymous coward yelling 'first post' in the forest, does anybody hear?
--| Earth Moves Around the Sun in an Ellipse? |-----
http://home.earthlink.net/~johnrpenner/Articles
Copernicus in his deliberations bases his cosmic system upon three axioms.
The first is that the Earth rotates on its own North-South axis in 24
hours. The second principle on which Copernicus bases his picture of the
Heavens is that the Earth moves round the Sun. In its revolution round the
Sun the Earth itself, of course, also revolves in a certain way. This
rotation, however, does not occur round the North-South axis of the Earth,
which always points to the North Pole, but round the axis of the Ecliptic,
which, as we know, is at an angle with the Earth's own axis. Therefore the
Earth goes through a rotation during a 24-hour day round its own N. S.
Axis, and then, inasmuch as it performs approximately 365 such rotations
in the year, there is added another rotation, an annual rotation, if we
disregard the revolution round the Sun. The Earth, then, if it always
rotates thus, and then again revolves round the Sun, behaves like the Moon
as it rotates round the Earth, always turning the same side towards us.
The Earth does this too, inasmuch as it revolves round the Sun, but no on
the same axis as the one on which it rotates for the daily revolution. It
revolves through this 'yearly day' on another axis; this is an added
movement, besides the one taking place in the 24-hour day.
Copernicus' third principle is that not only does such a revolution of the
Earth take place round the North-South axis, but that there is yet a third
revolution which appears as a retrograde movement of the North-South axis
round the axis of the Ecliptic. Thereby, in a certain sense, the
revolution round the axis of the Ecliptic is canceled out. By reason of
this third revolution the Earth's axis continuously points to the North
celestial Pole (the Pole-Star). Whereas, by virtue of revolving round the
Sun, the Earth's axis would have to describe a circle, or an ellipse,
round the pole of the Ecliptic, its own revolution, which takes the
opposite direction (every time the Earth proceeds a little further its
axis rotates backwards), causes it to point continually to the North Pole.
Copernicus adopted this third principle, namely: The continued pointing of
the Earth's axis to the Pole comes about because, by a rotation of its own
- a kind of 'inclination' - ; it cancels out the other revolution. This
latter therefore has no effect in the course of the year, for it is
constantly being annulled.
In modern Astronomy, founded as it is on the Copernican system, it has
come about that the first two axioms are accepted and the third is
ignored. This third axiom is lightly brushed aside by saying that the
stars are so far away that the Earth-axis, remaining parallel to itself,
always points practically to the same spot. Thus it is assumed that the
North-South axis of the Earth, in its revolution, remains always parallel
to itself. This was not assumed by Copernicus; on the contrary, he assumed
a perpetual revolving of the Earth's axis. Modern Astronomy is therefore
not really based on the Copernican system, but accepts the first two
axioms because they are convenient and discards the third, thus becoming
lost in the prevarication that it is not necessary to suppose that the
Earth's axis itself must move in order to keep pointing to the same spot
in the Heavens, but that the place itself is so far away that even if the
axis does move parallel to itself it will still point to the same spot.
Anyone can see that this is a prevarication. To-day therefore we have a
'Copernican system' from which a most important element has actually been
discarded.
The development of modern Astronomy is presented in such a way that no one
notices that an important element is missing. Yet only in this way is it
possible to describe it all so neatly: "Here is the Sun the Earth goes
round in an ellipse with the Sun in one of the foci."
As time went on it became no longer possible to hold to the starting-point
of the Copernican theory, namely that the Sun stands still. A movement is
now attributed to the Sun, which is said to move forward with the whole
ellipse, perpetually creating new ellipses, so to speak (Fig. 3). It
became necessary to introduce the Sun's own movement, and this was done
simply by adding something new to the picture they had before. A
mathematical description is thus obtained which is admittedly convenient,
but few questions are asked as to its possibility or its reality. It is
only from the apparent movement of the stars that the Earth's movement is
deduced by this method. As we shall presently see, it is of great
significance whether or not one assumes a movement - ; which indeed must
be assumed - ; namely the aforesaid 'inclination' of the Earth's axis,
perpetually annulling the annual rotation. Resultant movements, after all,
are obtained by adding up the several movements. If one is left out, the
whole is no longer true. Thus the whole theory that the Earth moves round
the Sun in an ellipse comes into question.
Source: Astronomy Lectures, Rudolf Steiner, Stuttgart, January 2, 1921.
http://gate.cruzio.com/~e0yes/astronomy/l2.html
--
Could it be a long term affect of magnetism? If the metal of the probes are reacting to the solar systems magnetic fields, wouldn't it possibly show up with the same symptoms[slowing down]? I'd think it would show this over long periods if the probe was being magnetically pulled back towards the solar system. But I'm not sure how far out the sun's magnetic field goes, or if there is a larger [if fainter] magnetic field based around the entire solar system.
Just a thought...
Ender
Nothing to see here
And they match what the GPS sats have been doing for years.
An early theory of gravity said it pushed in all directions at the same time but things with mass blocked it slightly. The attraction force is simply the delta of pushes from two sides not being equal. This was thrown out because things in space would slow down over time. However...
it appears that things do slow down over time. The deep space probes are not the only ones showing this. The gps sats are doing it and this is one of the problmes that gravity probe B is suppoed to help solve. I guess it means we have a wrong view of what keeps up stuck on this world.
NASA scientists have run out of explanations, but we're going to figure it out. Right here on Slashdot.
Heh heh heh,
But your obscure reference to the glory days of Usenet just whizzed over the heads of 95% of the Slashdot crowd - most of them aren't old enough to remember those times.
The universe just sucks.
(sorry)
--
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
The science return, perhaps? The recent FBC probes are neat, and produce lots of nice data, but, on a per-dollar basis, the Pioneers and Voyagers are unbeatable.
Voyager cost billions of dollars
Just under a billion, actually. This includes two flight articles, two launches, and operations.
In return, we got data on Jupiter, Saturn, Uranus, and Neptune; the Uranus and Neptune encounters are unlikely to be repeated for a very, very long time indeed.
[Cassini] cost over three billion dollars
This I agree with. Cassini is the last of the giants.
It's Protector Brennan, making slight alternations to make certain that the probes don't eventually travel to planets with possibly-hostile alien species, thereby alerting them to the existence of humans.
You cannot apply a technological solution to a sociological problem. (Edwards' Law)
Well, there's that hologram doctor... and the hot babe with the retractible ass ticklers in her arms... and its micro-wormhole generating technology that lets it communicate far further distances than simple subspace...
The probles don't *need* to be sophisticated. It's sufficient to use the doppler effect of the radio signals from the spacecraft to determine the speed of the craft, and the position can be determined by simple position in the sky. Distance can be determinedby delay between send and receive, which can be measured.
The RTG can't shield the neutrons... the sheilding would weigh more than the rest of the spacecraft.. Beyond Jupiter RTG radiation is that largest non-gravitational effect, larger than solar pressure even
.00000019% of the time. Effectively zilch.
Sorry, but effectively there aren't any neutrons. The P238 isotope used is used because it decays to U234 with the emission of an alpha particle and releases this energy fairly quickly, but not too fast - a half-life of 87.7 years. The alternative spontaneous fission only occurs
Another likely source of the accelerartion is neutrons (and other particles) from the radioactive power source that the probes carry. This effect is much larger than relativistic effects and is probably much larger than any new physics effects. The decay of these power sources over long periods is not well known, and hence their effect on perturbing the trajectory is not well known.
Huh? the RTGs' radioactive heat source is completely enclosed, the particles it generates do not have enough energy to penetrate the shielding and give up their momentum to the enclosure. Therefore, no net momentum change caused by the decay products, other than the known-to-be-miniscule contribution of individual neutrinos.
Not that it matters anyway, since the decays would happen equally likely in all directions, so even if the particles were released the net effect would be zero.
More ACBS...
well, im not a physisist, because i can't even spell, but I can deduce from obvious logic that space dust would have no effect by itself, but that a combination of solar wind pushing space dust into the craft could push it off course.
-- Betting on the survival of the media industry is a serious risk. I advise investing elsewhere.
no, space dust and solar wind is the simplest explanation
-- Betting on the survival of the media industry is a serious risk. I advise investing elsewhere.
What a sad, small world you live in.
My sense of wonder is enhanced by understanding, not undermined. Perhaps it's a failing of those who would rather substitute stereotypes for characterization, bromides for solutions, vilification for criticism, and ignorance for a sense of wonder.
Science, to steal from Carl Sagan, is a candle in the dark. And the dark is only more interesting than the light if you have the unbearable hubris to believe that your puny imagination is more interesting than the awesome complexity that is reality.
Since i first heard from this effect i thought it might be some magnetic braking effect (all metals would be affected by this when they pass through changing (not spatially uniform) magnetic fields, like that of the sun e.g.). The idea is pretty simple, it would also explain why artificial probes are affected, but not planets, asteroids, etc., since the probes are made of metal. Maybe it's just a hint, that the changes in magnetic fields out there are (for some reason) stronger than we think.
But then something that obvious would probably have been looked into. It would be much easier to make a wild guess, if there was a list of effects already looked into and dismissed. (The paper is apparently slashdotted).
"By the way if anyone here is in advertising or marketing... kill yourself." -- Bill Hicks
Then again, crackpottery is relative, as MOBE2001 demonstrates by calling every other spacetime physicist one.
--
Win dain a lotica, en vai tu ri silota
There's another page somewhere which discusses crackpot theories... however, that page is written by MOBE2001, a crackpot himself (though he calls everyone else one), who loves to troll Slashdot with his "theory".
--
Win dain a lotica, en vai tu ri silota
You can't decry one model of the Universe until you have another one that explains experimental findings better. MOBE didn't do any experiments, he just mangled the definitions of physics terms. The burden of proof is on you, I mean MOBE.
Looks like he's got multiple Slashdot accounts, too.
--
Win dain a lotica, en vai tu ri silota
I can prove that these probes are being affected by the Frisbee Force, which pulls frisbees onto rooftops and under cars.
The only problem is, Who's building roofs and abandoning cars that far out in the Solar System?????I have the answer, but just as I was about to come public with it a little gray lawyer came to me and told me that it was the Intellectual Property of an Alien Race. Any attempt to reveal it would be met with litigation of galactic proportions.
Sorry guys, but the strong arm tactics of The Orion Grays and their Intellectual Property Laws have somewhat forced me into silence.
I'll give you a hint though...
...it has something to do with ò[NO CARRIER]
"Everything you know is wrong. (And stupid.)"
"Everything you know is wrong. (And stupid.)"
Moderation Totals: Wrong=2, Stupid=3, Total=5.
New Physics Theory Highlights:
Due to the fact that the size of the anomalous acceleration is of order cH, whereH is the Hubble
constant (see Eq. (56)), the Pioneer results have stimulated a number of new physics suggestions.
For example, Rosales and S anchez-Gomez [136] propose that aP is due to a local curvature in
light geodesics in the expanding spacetime universe. They argue that the Pioneer eect represents
a new cosmological Foucault experiment, since the solar system coordinates are not true inertial
coordinates with respect to the expansion of the universe. Therefore, the Pioneers are mimicking
the role that the rotating Earth plays in Foucault's experiment. Therefore, in this picture the
eect is not a \true physical eect" and a coordinate transformation to the co-moving cosmological
coordinate frame would entirely remove the Pioneer eect.
From a similar viewpoint, Guruprasad [137] nds accommodation for the constant term while
trying to explain the annual term as a tidal eect on the physical structure of the spacecraft
itself. In particular, he suggests that the deformations of the physical structure of the spacecraft
(due to external factors such as the eective solar and galactic tidal forces) combined with the
spin of the spacecraft are directly responsible for the detected annual anomaly. Moreover, he
proposes a hypothesis of the planetary Hubble's ow and suggests that Pioneer's anomaly does
not contradict the existing planetary data, but supports his new theory of relativistically elastic
space-time.
stvang [138] further exploits the fact that the gravitational eld of the solar system is
not static with respect to the cosmic expansion. He does note, however, that in order to be
acceptable, any non-standard explanation of the eect should follow from a general theoretical
framework. Even so, stvang still presents quite a radical model. This model advocates the use
of an expanded PPN-framework that includes a direct eect on local scales due to the cosmic
space-time expansion.
Belayev [139] considers a Kaluza-Klein model in 5 dimensions with a time-varying scale factor
for the compactied fth dimension. His comprehensive analysis led to the conclusion that a
variation of the physical constants on a cosmic time scale is responsible for the appearance of the
anomalous acceleration observed in the Pioneer 10/11 tracking data.
Modanese [140] considers the eect of a scale-dependent cosmological term in the gravitational
action. It turns out that, even in the case of a static spherically-symmetric source, the external
solution of his modied gravitational eld equations contains a non-Schwartzschild-like component
that depends on the size of the test particles. He argues that this additional term may be relevant
to the observed anomaly.
A proposal to modify the theory of gravity in order to provide an explanation of the Pioneer
anomaly has also appeared. Capozzielo et al. [141] discuss the possibility of determining the
stability and characteristic geometrical and kinematical properties of galaxies strictly based on a
minimal action whose value is on the order of the Plank constant.
Due to the fact that the size of the anomalous acceleration is of order cH, whereH is the Hubble
constant (see Eq. (56)), the Pioneer results have stimulated a number of new physics suggestions.
For example, Rosales and S anchez-Gomez [136] propose that aP is due to a local curvature in
light geodesics in the expanding spacetime universe. They argue that the Pioneer eect represents
a new cosmological Foucault experiment, since the solar system coordinates are not true inertial
coordinates with respect to the expansion of the universe. Therefore, the Pioneers are mimicking
the role that the rotating Earth plays in Foucault's experiment. Therefore, in this picture the
eect is not a \true physical eect" and a coordinate transformation to the co-moving cosmological
coordinate frame would entirely remove the Pioneer eect.
From a similar viewpoint, Guruprasad [137] nds accommodation for the constant term while
trying to explain the annual term as a tidal eect on the physical structure of the spacecraft
itself. In particular, he suggests that the deformations of the physical structure of the spacecraft
(due to external factors such as the eective solar and galactic tidal forces) combined with the
spin of the spacecraft are directly responsible for the detected annual anomaly. Moreover, he
proposes a hypothesis of the planetary Hubble's ow and suggests that Pioneer's anomaly does
not contradict the existing planetary data, but supports his new theory of relativistically elastic
space-time.
stvang [138] further exploits the fact that the gravitational eld of the solar system is
not static with respect to the cosmic expansion. He does note, however, that in order to be
acceptable, any non-standard explanation of the eect should follow from a general theoretical
framework. Even so, stvang still presents quite a radical model. This model advocates the use
of an expanded PPN-framework that includes a direct eect on local scales due to the cosmic
space-time expansion.
Belayev [139] considers a Kaluza-Klein model in 5 dimensions with a time-varying scale factor
for the compactied fth dimension. His comprehensive analysis led to the conclusion that a
variation of the physical constants on a cosmic time scale is responsible for the appearance of the
anomalous acceleration observed in the Pioneer 10/11 tracking data.
Modanese [140] considers the eect of a scale-dependent cosmological term in the gravitational
action. It turns out that, even in the case of a static spherically-symmetric source, the external
solution of his modied gravitational eld equations contains a non-Schwartzschild-like component
that depends on the size of the test particles. He argues that this additional term may be relevant
to the observed anomaly.
A proposal to modify the theory of gravity in order to provide an explanation of the Pioneer
anomaly has also appeared. Capozzielo et al. [141] discuss the possibility of determining the
stability and characteristic geometrical and kinematical properties of galaxies strictly based on a
minimal action whose value is on the order of the Plank constant.
Someone you trust is one of us.
Could this be attributed to coriolis force ? The solar system is not at rest within the galaxy, nor the galaxy is at rest withing the local group, and so on... An object staying on its trajectory may not appear to do so locally. I figure that they thought of this force and included it in their calculations, but what if more frames of references where embedded than currently accepted ? One could argue the universe itself is rotating (the same way a black hole can apparently rotate). Of course it would have to rotate very fast to have any kind of impact on a probe or such a tiny object so it's probably not it, but shuld coriolis force be dismissed altogether as an explaination ?
lone
Is it possible that the whole solar system is moving away from a fixed point and the probe is actually traveling a straight line which makes it appear to be moving off course?
Jon
All we need to do is look the way the universe is expanding to realize that something is amiss in our understanding of the forces that interact with gravity.
It's not a major shock to see that we do not have a perfect grasp of our outer solar system. For all of our cleverness the past century we are still a young species, and there are quite a lot of things that we just don't know. Something in the outer solar system has to be disturbing the Oort cloud every once in a while or we would exhausted our supply of new comets a few billion years ago.
Perhaps negative energy somehow interacts with gravity wells to clump matter, like drops of water on an oil slick? Maybe if the politicians ever get their heads out of their rear ends and start investing in further development of space we can scrape together enough money to send a probe to find out what's going on.
We might even learn something in the process.
Get off my virtual lawn, you damned virtual kids!
It's gnomes, not elves... Sorry, but I couldn't resist. I'm way too big of an SP fan to let it slip.
The higher, the fewer.
In other words, all objects in the universe emit gravitons, and these exert a force on objects that they weakly itneract with. When you have two objects near each other, they shade each other from the cosmic background graviton flux. As a result, instead of each object having the same force on them from all directions, they now have less force on them from the shaded direction. So the two objects fall towards each other. The force is, coincidentally, proportional to inverse square of distance.
However, a small correction factor is required. The thinning effect of a nearby object is not proportional to the amount of matter in it exactly, because the object shades itself from gravitions. Therefore the correct formula is an integral of an inverse exponential with respect to how deeply the gravitons have passed through the material.
The effect of "self-shading" from gravitons implies that the force law must be corrected so that the gravitional force is smaller than the inverse square of distance for smaller distances. Conversely, as you get further away, the correction is positive relative to the inverse square law.
This theory also helps to explain so-called missing dark matter, and of course it explains the expansion of the universe. It also has strong implications for black holes and the big bang, because it implies that the force of gravity is bounded by the total mass of the universe multiplied by a weak interaction factor. It explains lots of other strange things too.
Could someone pass this on the NASA please?
the probes are affected by the slashdot effect!
Good questions. The only comment I have is that unfortunately gravity waves do not cancel each other out when a "wave" meets a "trough". I put this exact question to none other than Dr. Robert Forward (many years ago at a seminar on advanced space propulsion methods), and his answer was (IIRC) "Gravity waves don't do that because they have a much more complicated structure than light or sound waves."
Naah. Sounds like you simply lost your ability to let your imagination run free.
Well, this was probably the first possibilities they thought of. Anyhow, the phenomenom doesn't have to be caused by a "force".
The problem with NASA's calculations is that they all involve objects in space that are either drifting or in some sort of orbit,etc -- but they haven't taken into account other space craft that would be wizzing by along the way. In fact, if one of our little probes were to pass close enough to a large transport, it may well get slingshotted not just out of it's course path, but to places completely unfathomed by our dear NASA engineers.
I was visited by a little green man last night who promised to tell me all the secrets of the universe for a buck and a quarter. I told him all I had was two bits, to which he replied that he'd only be able to tell me why our space probes aren't sticking to their projected paths. I took note of his advice, but can't say that I believed much of what he told me. I was just about to shred the notes that I took, lest they be discovered in my posession and I be taken for a lunatic, possibly even a danger to our society as we know it. I will have to weigh further what to do with this transcripts, .... damn, I spilled coffee all over them! ..nevermind.
It's caused by the Starship Enterprise traveling forward though time from the late 1900s. After the loop around the sun it moved forward in time, and left a ripple here in our time that is effecting the probes. Duh.
Coder's Stone: The programming language quick ref for iPad
And no, it is not spacetime curvature. Spacetime curvature is an abstract representaion of the effect of gravity, not the cause.
Sorry, that's mistaken. Let me clear this up for you: according to relativity, the effect known as gravity is caused by spacetime curvature. Mass bends spacetime and, by extension, mass causes gravity. Assuming that Einstein's equations are indeed correct, this doesn't necessarily mean that this is exactly what is actually happening(ie. that there is such a thing as spacetime that is being bent by the presence of mass). It is an elegant model that we use to explain the mathematics which are correct. Let me say this again, the mathematics may be correct, but our interpretation may be off.
-----
"Goose... Geese... Moose... MOOSE!?!?!"
Higher Logics: where programming meets science.
There is only one little problem with this, nothing can move in spacetime. Spacetime is frozen from the infinite past tot he infinite future, by definition.
;-) I'll let you in on a little secret about science: any field which uses mathematics to explain anything is using a mathematical model. By definition, models do not necessarily have any grounding in reality. But it is absolutely unquestionable that the models can accurately describe the observed physical phenomena. Otherwise, why would they be adopted? Can you tell me with a straight face that Einstein's equations don't accurately describe gravitational effects? You can't.
I'm sorry, where exactly does it say this? If matter can't move in space-time, then I think Einstein would have noticed that none of his thought experiements were even possible.
Spacetime is really an abstract math trick.
I don't know why you're getting all your panties in a bunch.
Are there such things as gluons, quarks, neutrino's, time dilation as described in the Standard Model? Is there even such a thing as energy? What is energy? It's a mathematical construct, just like space-time. Are you saying that just because it's mathematical, that energy doesn't exist? How else would you explain the effects commonly attributed to energy? Whether there actually is an entity called space-time may always remain a mystery. Fortunately, that fact almost completely irrelevant. It's just a model, and will always be so. A correct model at that (until proven otherwise).
Also, you're just substituting one man's word for another's. I don't see how the one quoted paragraph you provided in any way constitutes any kind of proof that space-time doesn't exist, or that Einstein's theory is impossible. I could just as easily find someone who will say with absolute certainty that the Sun revolves around the Earth. That doesn't make it so.
-----
"Goose... Geese... Moose... MOOSE!?!?!"
Higher Logics: where programming meets science.
Oops... slight oversight on my part. Time dilation isn't described in the Standard model.
-----
"Goose... Geese... Moose... MOOSE!?!?!"
Higher Logics: where programming meets science.
All these craft are still within the heliopause and will be so for a long time. They're moving outward faster than the solar wind, which means they're flying into it. The vacuum of space is only mostly a vacuum, remember, so the combined impacts of many little atoms will add up over time. The Pioneer craft, in particular, have been out there 20+ years, so the culmulative effects have had time to add up, and these would tend to slow the crafts over time. This effect is not negligible, or solar sails wouldn't work.
Also, as probably a lesser effect, there's all the virtual particles that are springing up in front of the craft and getting run into before they can meet their natural antipartners. These also will register as mass impacts and tend to slow the vehicles.
The first cause in particular will only get worse when the first craft hits the heliopause. At that point, it will no longer be plowing along with, but faster, than our Sun's wind, but head on into new solar winds. I wonder how much more difficult this makes it to come up with enough energy for eventual real interstellar travel.
Just a late night thought or two... but it doesn't seem unreasonable.
--
--
I don't want to rule the world... I just want to be in charge of mayonnaise.
- Spacetime curvature is produced by mass-energy
- Trajectories of free-falling objects (satellites; planets; binary neutron stars...) are "straight lines" (geodesics) in this curved spacetime
- "Gravity" is the force we impute to explain the bending of these "straight line" trajectories into, i.e., orbits
Thus (contrary to your comment above) spacetime curvature is caused by matter, and indeed has "gravity" as its effect. I could not agree more - and I too will believe in wormholes when and only when I see (observational evidence of) one. However, physical theories developed with the language of mathematics have proven remarkably fruitful in guiding observations. One of the best examples of this is Einstein's near-prediction of the expansion of the universe, several years before it was discovered by Hubble. (Failing to predict this expansion was Einstein's self-termed biggest mistake.) Exactly correct! Redshifting of light is redshifting of light, and the universe was smaller, denser, and hence more gravitationally bound in the past.Or did you mean to discredit the theory?
Cheers,
Renard
ps Apologies for staying off-topic; I have no idea what's causing the anomalous "acceleration" of the Pioneer probes.
I'm not sure what planet you're on because you seem to be trying to write an anti-science diatribe and yet much of what you say is no different from the view of a scientist.
---- SIGFPE
Quite a harsh statement. My guess is that we should seek an answer in meta-physics, that introduce-another-dimension-stuff, or call it "space and matter and energy are consequence of undetectible lower level entities". Maybe one can adjust gravitational laws.
--
Bizar technology?
Pardon my doofyness but a certain piece of obviousness is just begging to be laid out. Theories are like lossy data compression: You never get a perfect rendition. In fact, if "reality" could be said to contain an infinite amount of information everywhere (I mean, what sets the resolution of a definition, some mythical objective reality or simple satisfaction? How many words are enough?) then any theory made about it must always be infinitely deranged. So mysteries, while easily ignored-to-forgetting from the comfort of your livingroom/office/customary-groove (in fact one might say that an act of intentional ignorance is the bedrock underlying any useful theory. Ignoring the irrelavent.), should be considered the norm to a degree proportional to your elsewhereness.
But seriously, I want to see an actual point-by-point calculation accounting for radiation pressure, gas leaks, and all that before I'll imagine something affecting our space probes that doesn't affect the planets.
What about all the photons (radio waves) we've been sending back and forth between the Earth and the probes, that's got to add up at least a tiny bit.
All kings is mostly rapscallions. -Mark Twain, The Adventures of Huckleberry Finn
Sure, that's what ALL the scientists said about the Earth prior to Magellan.
--
Sleep is just a poor substitute for caffeine, anyway. -Bob Lehmann
nt
Gravity at short ranges is being tested now (on scales of, like, inches) as a test of some superstring theories.
If gravity does not have a 1/r^2 dependence, things get really messy, really fast. First of all if you have to introduce a new length scale into the universe (such as a length within or beyond which a different law applies) then you have basically introduced a new constant of nature.
Secondly, it means that GR is wrong in some fundamental ways, so you have to work very hard to recover the successful tests of GR while still scrapping the guts theory itself.
Finally, remember that we HAVE tests of gravity at the ranges we're talking about -- Pluto's orbit is pretty well-determined, and Neptune and Uranus are out there, and Earth and Mars turn out to put very strong constraints on this, too (see the article for details, p.77); galaxies attract each other about the way we expect; there are plenty of long-period binary stars with this sort of separation that have been studied; etc.
I'm not saying that there's no way that gravity itself could be the culprit in the anomolous position of the craft; I'm just saying that the nature of gravity is pretty tightly constained by observation, so throwing stuff off like "it's different at large distances" opens a whole can of worms that have to be shoved back into some new theory.
I think what the article means is that we don't see the planets slowing down and moving closer into the Sun.
A quick search of google produces 0 results for "Elquibre drive"
Funny, they didn't include my first thought on what might be causing it: (i) our understanding of the heleopause is incorrect.
It may be that the heleosheath is not a hard boundary, but rather has a mix of both solar winds and interstellar gasses for a much wider region than is presently thought. In other words, it could be that there is no true heleopause at all. If that was the case, our little space probes could have been heading "upwind" against largely stagnant gasses for some time now, slowing them.
Of course I have absolutely no evidence for this, but it is a missing hypothesis.
Brings back memories of sitting up all night at a terminal cluster reading Usenet...
-- ;-)
Kuro5hin.org: where the good times never end.
If you can only wonder at the unknown, friend, I pity you; your world is a truly impoverished place, where joy is ignorance's handmaiden. Give me the wonder that comes with understanding nature's elegance any day.
...in view of the old saw that the staple of British SF is the MUF (Mysterious Unknown Force) that it's the BBC reporting this.
There is no reason to suppose gravity gradients are even across large distances (>20 A.U.) If you pour over your references, you'll see that at no point, from the General Theory on up, does any theorist take into account the possibility that between strong influences (astral bodies), spacetime must be smooth. in fact, it is perfectly reasonable to suppose that there are variations large enough to account for these variances in trajectory. The universe is not beholden to your 'rubber sheets and marbles' analogy for gravity.
Nobody rejected the companion star idea, it's just very hard to carry out a survey for a 20th magnitude brown dwarf in a highly eccentric object. Try diffrentiating that from the hundreds of thousands of other faint objects in motion on the celestial sphere.
"Fringe science" is not ignored by most scientists, it's just that a one-off, realistically unrepeatable observation is not good scientific method.
In order to prove that anomalies occur, we must disprove theories.
.3333333(cont), and 2/3 = .6666666(cont), and .333333 + .6666666 = .9999999(cont)
.99999999999999999999(cont)
So,
If 1/3 + 2/3 = 1, and 1/3 =
1 !=
Thus, since 1 != 1, we have an anomaly.
But wait, all math is based on the concept of a point. A point is defined as something that is "assumed" to exist. Thus following maths own principles, math is only assumed to exist.
Thus we have now proved anomalies, and Green is black, and The Mummy Returns will get 10 oscars.
I can program myself out of a Hello World Contest!!
Has been building a log table in secret and that has thrown the mass distribution off.
_O_
_O_
.|< The named which can be named is not the true named
Something that must be taken into account with these phenomena is that the pull of gravity from the sun and the planets is negligible out where these two probes are. And since neither of these probes are all that massive themselves small 1-2 ton objects massing within 10,000 km of the probe would cause its course to alter slightly. The closer it comes to one of these objects the larger the deflection of its course. And the probes probably do not have the instrumentation sensitive enough to be able to detect these 1-2 ton masses that it passes near.
For god sake Jim, I DON'T HAVE THE POWER!
"Mary had a crypto key, she kept it in escrow, and everything that Mary said, the Feds were sure to know."
First - my apologies to anyone who didn't shout this post down. I got so sick of the shouters that I had to reply before making sure I'd read all 11 other replys.
Lover's Arrival, The, is 100% correct about science's attitude to these sort of things.
I work with a guy who is studying Pathology at the moment. He is so excited about the work he gets to do on work experience, he thinks the scientists he works with are the be all and end all of medical research.
Essentially the story is that all the testing they do is on computer models. Organic material is tested against the introduction of various chemicals and compounds in a computer simulation and those results are taken as gospel.
He tells me that the programs are perfect and everything has been taken into account. Then I ask him about things like ectoplasm and the recorded phenomenum of observation & expectation effecting the results of scientific experiments. He bows his head, looks sheepish, says nothing to me, and then tells everyone else "Ben's really out there, you know".
True, the guy is only a scientist in training, but he is getting his "we are perfect" attitudes from his mentors. He knows all the things I'm talking about, but is willing to forget about them or suppose they are made up so they don't get in the way of a good Pathology test.
Get the Hell off my planet, you slimy mobster Bush!
(e) is my favourite. Not that it works of course. I just happen to be working on funny gravity stuff.
Mode (3) smart-aleck mode. Press * to return to main menu.
nuff said.
Mode (3) smart-aleck mode. Press * to return to main menu.
(1) What you described is called "vacuum energy", and is actually one of the suspects. However, current physics has a problem : the predicted vacuum energy is 10^(120) (that's 1 followed by 120 zeroes) larger than the actual measured vacuum energy (called the cosmological constant by some people). With respect to the Pioneer 10 acceleration, the predicted VE will be too big, the measured VE will be too small.
(2) Not likely. Small things can theoretical deflect the probe. However you run into two showstoppers (i) things are too small to make any difference (ii) the things will deflect the probe, averaged out, in an "isotropic" way (what this means is that, on average, there will be no net deflection).
(3) Possible. But this uneven distribution will be detected long before. It's discussed in the paper that I listed in another post here. The punchline is that such things will also cost deflection of the planets, and we don't see that.
Hope this helps.
Mode (3) smart-aleck mode. Press * to return to main menu.
Check out the JPL final paper on this.
:
Possibles are
(a) Heat Ejection (b) Gas Leak (c) Clock Drift (d) Anomalous objects (pretty dead, despite BBC giving prominence) (e) modifications to gravity (f) solar radiation pressure (g) systematics of observations (h) antenna radiation pressure
Let the armchair speculation begin. (But remember to read the paper to check your answers!) Have Fun!
Mode (3) smart-aleck mode. Press * to return to main menu.
Screw what's affecting space probes that NASA can't figure out, how about some informed comments on a cure for cancer? Clearly there's a slashdotter somewhere just waiting to spill out the answer to that if you just ask.
Outdoor digital photography, mostly in New Engl
This is a common misconception. You are thinking of the characteristic length scale for strong interactions, which is inversely related to the characteristic energy scale of strong interactions. However, the gluon is massless, and thus the strong force has infinite range.
The really cool (or aggravating, depending on your field of interest) thing about the strong force is that its strength actually increases according to some ungodly exponant with increasing range (the potential is somewhat complex, so I'd be lying if I quoted an actual number). Thus, the only allowed states for objects with "color charge" turn out to be "color neutral" combinations.
One consequence of this is that you can't ever make a free quark, because the strong potential just keeps going to infinity. And if you try, you eventually get above the quark pair-creation threshold, so whatever combination of quarks needed to return everything to color neutrality just falls out of the quantum field.
Quantum mechanics: the dreams that stuff is made of.
They slow down for the same reason my car slows down if I let off the gas pedal.
Perhaps space isn't as empty as we thought it was. How many collisions with molecule-sized particles does it take for a craft to slow down?
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If you can't blind them with brilliance, baffle them with bull.
While this news report is very likely just a measurement error, we must be reminded that the last time we discovered an error in a celestial body's trajectory we reinvented the notion of the universe.
One of the big open questions of the day is: What is the shape of the universe? Euclidean, hyperbolic, a torus--we aren't sure. It is thought that each of these geometries would profoundly affect an object moving across the universe in a different way. These NASA probes could in a sense be the moving laboratory that we need to understand what exactly our universe looks like.
Robert
http://wso.williams.edu/~rmcgehee
Clever, but why don't we observe this in the orbit s of planets and (I presume) comets? It would be a pretty good astronomy dissertation topic to check all the known comets and asteroids in orbits similar to those of the spacecraft to see if any of them show the effect. If not, the spacecraft are probably leaking gas.
Yeah, right. Ahahahahahahahahahahahahaha
Voyager is more advanced than anything that NASA has produced lately. Pathfinder was a joke, not to talk about the failures that followed. It is doubtful whether with "faster, better, cheaper" Goldin in power, NASA would manage to build another Voyager, let alone a more advanced probe. I'm happy that they keep listening to it at all.
But if we get something decent built in the next decades, we might as well send a probe to 550 AU and use the sun as a gravitational lens for SETI. Talk about alien TV stations ..
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Oh jeesh.
I remember a science fiction story in some anthology that placed a futuristic Disneyworld on Pluto. A reborn finance minister was growing up his new body there, he had temporary gills and it was all oceans and desert islands. It got bombed and the fake sky fell. Nothing vaguely comical about the story.
But you're right. Disneyworld. Pluto. World. Mickey's dog. Bah, I didn't get that for YEARS. Ack what an awful pun.
The solution is left as an exercise for the reader.
ROTFLMAO! Those damn pussy gnomes. Could this be the same force that has caused my underpants to expand over the last few years?
Spacetime curvature, in Einstein's theory, is not described as being the cause or the effect of gravity. Rather, the theory postulates that spacetime curvature IS gravity!
You are the weakest link.
This Bible prophecy site reported the same thing in 1998. They referenced a Washington Times report. This Space.com story reported the same thing in November last year.
Well, I guess the final JPL report is newsworthy.
Note: I don't frequent the online Bible sites, but I knew I had heard this years ago and the referenced site turned up near the top of my Google search!
I'm sorry - that was cheap.
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In spite of the suggestions and all the tests that I have made, I have not cavato a spider from the hole.
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In spite of the suggestions and all the tests that I have made, I have not cavato a spider from the hole.
This article may or may not be the one that prompted this thread, but read to the bottom http://news.bbc.co.uk/hi/english/sci/tech/newsid_4 60000/460095.stm
and you find
"Earlier this year, scientists were puzzled by what was described as a mysterious force acting on the probe. It led to speculation that there was something wrong in our understanding of the force of gravity.
Eventually the effect was tracked down to the probe itself, which was unexpectedly pushing itself in one particular direction."
someone mod this up.
And that was one of the most important creative leaps that led to quantum mechanics that gave us electronics, computing, and hence Slashdot. Almost as if my miracle, the equations worked! After some eighty years, we still don't admit that particles are waves, but it is one heck of a model. In principle, physics is not about what is real, it is about models of the nature. (Insert your favourite definition of reality from the Matrix here.) Physics does a lot of things purely systematically, but new theories like wave mechanics require those what-if ideas that may seem stupid at the first glance. The validity of a model can usually be tested by experiment, and if it fails then we can be certain that the idea was 'stupid' indeed. We can only let Nature judge which models are better.
I agree that ultimately physics should be about particles - or rather whatever the fundamental objects turn out to be (strings? a very elegant _model_ but maybe nothing more). The problem is, before we get there, we want to be able to model the larger scales as well. We can quite safely model the largest scale of the universe without worrying about the underlying forces between individual particles. Maybe that model (i.e. General Relativity for now) isn't absolutely accurate, but it's better than having to wait for a theory of everything - which BTW may never come up.
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Escher was the first MC and Giger invented the HR department.
For each of the other 3 forces (weak, strong, electromagnetic), we have discovered a "carrier" particle for that force.
The strong force is carried by particles called "gluons" while the weak force is carried by "weak bosons". The electromagnetic force is carried by "photons". These have been detected in particle accelerators. Scientists have a name for the carrier particle of gravity - "graviton", but it has never been detected - yet.
The strong and weak force have a relatively (no pun intended) limited range. The strong force has a range of only about 1x10^-15 meters. On the other hand, gravity and the electromagnetic force have infinite ranges. Perhaps we're wrong about the gravity force, considering we don't even have a carrier particle. Maybe its strength isn't an inverse squared relationship for infinitely long distances - or it's simply an approximation.
Too bad I don't know nearly enough about experiments testing the gravitational constant and how well we've applied it to extrasolar objects.
"The universe seems neither benign nor hostile, merely indifferent." --Carl Sagan
A slashdot story with "probe" in the title. That's just asking for trouble.
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Crudely Drawn Games
Newton could not explain any of his laws of motion physically, so he invented calculus to explain it for him. Was Newton a crackpot nerd physicist with a hard-on for math? Well... maybe, maybe not. But there is no doubt he was/is one of the greatest physicists of all time. The only way we can progress in the field is by creating an experimantal model to hypothesize against; i.e. a mathamatical model.
Black holes? They have a 99% chance of existing, and most likely there is one at the centre of our own galaxy. Sure, they are a mathematical creation, just a limit taken to zero, but it makes it no less valid. Do you doubt neutron stars? Brown and white dwarves? Same thing, but just different initial conditions on the equations.
I don't mean this as a berating, but why do we feel to have a competition amongst the nerds/geeks? Comp-sci better than Math worse than Mech Eng. almost as good as Physics type nonsense. Again, no offense intended, but as a physics/astrophysics major, I tend to have a little departmental pride ^_^
I read it - and I agree that you should post a link if you're sincere that it's all been solved.
Looking for freelance Actionscript (Flash/Flex) or ColdFusion work and/or freelance developers. Email me, put Slashdot
http://www.holoscience.com
I believe NASA, or ESA, or someone like those guys should really send 2 or 3 probes out there specifically made so that their trajectory can be very precisely monitored, but also made in order to minimize other possible factors, like gas tanks leaking and that sort of stuff.
Probably something like an advanced GPS satelite, without any propulsion means, as passive as possible, should be used.
ESA has an interesting project, not directly related to this, but witch perhaps will help a lot in revealing more about gravity nature.
Instead of dumping our money in ISS, space agencies should endeavour in less expensive and more productive stuff... like this one.
We could also send a probe to Pluto, never visited before, before it's atmosfere gets too cold due to it's orbit getting the planet too far away from the sun. Now that all missions targeted there have been canceled this would be an extra objective for the mission, witch could make it more feasible and less expensive.
Obviously this is only me thinking... few persons seem to agree.
You cannot proceed from the informal to formal by formal means
Oh, unenlightened one, if only you had read the informative web page of the person you are responding to, you would REALIZE that most of the major figures in 20th century physics are crackpots! Here is a portion of the list of liars taken from the aforementioned page:
The problem with you, and all the people in the list above, is that you are all weirdos who believe in "time travel!" That is, one-directional time travel into the future. Clearly this is impossible!
Ha! Fools! Ahahaha! HAHAHAHAHA! Fools, all of them FOOLS!
--
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Ikaruga scoreboard (supports netranking)
Anyway, just remember the guy/gal/thing next time you have moderator points :-)
Funny, a misunderstanding of the heliopause was my first choice as well. If the kuiper belt objects are mainly frozen gasses that condensed out of gas at that distance, what's the expected vapour pressure at that distance and temperature for whatever didn't condense?
The reports indicate that the probes are slowing more than expected - a higher than expected gas density could easily cause the slowing measured.
Liquor
Liquor
Sanity is a highly overrated commodity.
That's no tenth planet... that's a battlestation!
You see? You see? Your stupid minds! Stupid! Stupid!
Um, my whole point was that you already have an answer from NASA scientists. It's in the BBC article. The answer is "we don't know." That's the best you're going to get right now.
If you REALLY want to know, you look elsewhere, but if you kinda want to know and your boss is looking, it's Slashdot all the way.
I'm not saying /. isn't a useful source of information. It's great inasmuch as it collates news items from a number of different sources, so you don't have to read all those sources yourself. (You do have to be aware of the lack of fact-checking in the stories posted, but that's another rant for another time.) What I'm questioning is the usefulness of asking for answers here, when NASA scientists have already tried everything they can think of, and haven't come up with an explanation.
Never take moderation advice from sigs, including this one.
I know, I shouldn't feed the trolls, but since you brought it up, I was already at the karma cap, so I can hardly be karma whoring. In fact, since the +3 came first (which didn't net me anything, since I was at the cap) then the -2, my net karma change was -2. Hardly karma whoring, wouldn't you say?
Never take moderation advice from sigs, including this one.
You'll see lots of speculation by people who have no idea what they're talking about, but at least that won't get modded up. You'll also see lots of speculation by people who have a very slight idea of what they're talking about, and even though that speculation is little better, it will get modded up by other people who have a slight idea of what they're talking about, because it sounds plausible.
Maybe a legitimate space scientist or two will post with something that might actually be useful. Maybe--possibly--that will get modded up. More likely it won't, because it will be over most people's heads, or because he came too late to the conversation (say, two days from now) when no one's going to use mod points on the story.
Assuming your characterization of the BBC story is accurate (/.ed, can't get to it right now), and assuming that the BBC story itself is accurate--both of which are nontrivial assumptions--why wouldn't the quoted "NASA scientists" be the informed comment you're looking for? Is anyone here going to give you a better answer than the "we don't know" you got from the NASA scientists?
(Don't mind my ranting, I'm just in an anti-/. mood today.)
Never take moderation advice from sigs, including this one.
off by 1 error
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in this age of communication i'm just not getting through
Not to argue with your essential point, but I assume when you say average, this refers to the mean (add em all up and divide by n). This is genreally considered a misleading way of representing salaries, because if the director/ceo gets a million dollars a year and his 9 other employees only get 1 dollar per year, it looks like the average salary is $100,000.
For a better represenation of a company's salaries, we want to know the median (what's the guy in the middle getting).
Just another annoying statistics lesson.
One of the things that cries out in this story is an explanation from the NASA scientists: why their apparent "mystery force" which can be detected on spacecraft a few billion kilometres away is not noticed in Doppler and gravity observations of bodies billions of light-years apart, on the galactic scale.. a new type of force, one that doesn't work on the micrososmic or macrocosmic scale, but sort of "in the middle"? Doppler observations led to the discovery of the expansion of the universe, and since then a very accurate figure for that expansion. Why have no astronomers ever reported such findings? Sorry, but lately whenever I see "NASA scientists" being quoted my heart sinks. They are becoming well known for launching half-baked ideas into the mediasphere (life on Mars, etc.)This looks like another.
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The heliopause, mentioned in the article, is the point where the Sun's solar wind is offset by that of other stars and deep space.
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All opinions presented here aren't mine.
To overcome this unknown force NASA should put a web server on board the spacecraft and then link to it from /. The hits received from the /. effect would greatly overcome any unknown force.
Pinky: "What are we going to do tomorrow night Brain?"
Pinky: "What are we going to do tomorrow night Brain?"
Brain: "I would tell you Pinky but this 120 char limi
Are you saying Australians and New Zelanders are altering the course of the probe on purpose? :)
-- [ta]
Maybe it's that Cadre of Stealth Chickens that keeps forcing me to read this page. They don't call them stealth chickens for nothing.
Uninnovate - Only the finest in engineering.
"Aye, ye know...it's all due to them damn metric system. Dammit, we used the english system again"
-Daniel S. Goldin, Head of NASA, two weeks later
There's a lot of "fringe science" that goes on that NASA typically rejects outright.
One of the most recent is a claim by a scientist that our Sun has a large failed-star as a neighbor, that our system is really a binary system. In theory, if some kind of brown dwarf existed, it could be affecting the probes. NASA, and most space scientists reject the very idea that our sun has a neighbor, simply because it's presence should be more obvious. I'd tend to agree (even though I'm nowhere close to being a space scientist). But it's a possibility, and maybe now that NASA has probes that are being affected by gravity in unknown ways, they should consider the idea.
Go Lakers!
Based on what criteria? The processing power of its computer? The sophistication, compactness and sensitivity of its instruments? The Voyagers were marvels of 1970s technology, but current probes can definitely do more for less.
The difference between Voyager and current proposals is that Voyager cost billions of dollars, while most probes nowadays come in at under $400 million. Voyager had about a dozen instuments, most probes now have at most five or six. Voyager was exploring areas of the solar system that we had never been to before, so everything was new, and major discoveries were dropping into our laps. Mars still has surprises in store, but they are more subtle than volcanos on Io, or braided rings around Saturn.
There is one last superprobe still to go; Cassini is the biggest probe ever launched, with a dozen instruments. It also cost over three billion dollars. We will not see its like again.
Lets make no bones about it i am a complete idiot. Having said that maybe there is an effect when an object with mass moves away from a gravity field similar to a conductor moving through a magnetic field. Might be interesting to ....say.....weigh... the space probes to see if they are any heavier. Momentum must be conserved (I think) so maybe with decreased velocity mass has incresed in some way thus messing up calculations.
1. I really like this quote from the article:
"Our analysis strongly suggests that it is difficult to understand how any of these mechanisms can explain the magnitude of the observed behaviour of the Pioneer anomaly," the team says.
I interpret this as "our reasearch sez we're completely baffled."
2. I swear, it's drag from the ether. You don't witness this with planets, because they have a much higher mass/frontal area ratio.
3. Maybe the universe is expanding/contracting at different speeds in different locations. Um, assume that we are remaining the same size, that means the rest of the universe is contracting with respect to our solar system. This was the basis for a Sci-Fi short story I read once. One solar system was shrinking while the rest of the universe was expanding. They found out when they sent astronauts up, and one of them dropped a sapphire and it was huge. Anyone know the title/author?
4. Basis for a Voyager episode: different time scales in different parts of the universe. If time is moving more slowly out there (in a gradient of course), then the probe would still "think" it was going the correct speed, but it would in fact seem to be going too slow for us.
5. Um, how does the special theory of relativity take into account the fact that gravity does affect time? Never mind, they probably already thought of that...
Thanks for listening!
It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
--Scott Adams
either that or the whole universe is leaning slightly to one side, like a bad pool table
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Barnaby Mannerings (heh) http://www.wasd.co.uk
..Barny
Uh, how is this off-topic? Somewhat funny on-topic humour, posted early on in the thread. +1 funny or at worst +0 ignore...
If I was the guy who moderated this down I'd fear metamod...
An anomaly in the space-time continuum. Adjust shield harmonics to compensate. QED.
Anybody want a peanut?
being shot at by the Klingons, and they keep missing! (See Star Trek V for details)
If you smoke after sex, you're doing it too fast.
First of all, the poster obviously didn't read the article.
Secondly, if our velocity has changed, then so has our orbit, which would be Bad. In other words, its effects would be -- and I'm euphemizing here -- a heck of a lot more obvious than a couple of probes straying from their expected courses.
I believe it is the poster that needs to Think Different(TM).
This obviously proves that the Creationists were right all along. Our projections weren't perfect, therefore the Universe was created 6000 years ago.
Sorry but I don't think the instrumentation on these probes really is advanced enough to gather what is needed to make an accurate or informed decision.
I would not mind seeing a mission equiped so they could determine what really is out there. In other words, ditch the hardware needed for planetary observations, use the slingshot effects of gravity and get a probe out there pronto.
It would probably be a better use to understand what goes on out there than visit the disney planet.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
This IMPORANT INFORMATION should be DISSEMINATED etc etc...
With apologies to Robert McElwaine, and everyone else.
OK,
- B
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http://www.bradheintz.com/
- updated
Jedi:"You will alter your course."
Probe:[ continues course ]
Jedi:(under breath) "Oops."
[ Jedi waves hand in front of probe ]
Jedi:"You will alter your course."
[ back on earth... ]
BBC News:"Mystery force tugs distant probes"
Ewige Blumenkraft!
Ewige Blumenkraft!
The probes are getting diverted by CowboyNeal's inverse hyperbolic gravitational shift field.
Ryan
"All your base are belong to this file I send in order to have your advice."
On Slashdot?!? I'm sure it'll be here, but good luck finding it.
Display some adaptability.
gravity is a byproduct of matter moving through space and as such the biggest concentration of matter is located at the sun, and it is moving fast through the galaxy, and the galaxy is moving through the universe. This will be called theorem 1.
Theorem 2 - Matter is actually an influx of dimentions. We take the substring theory to a new level and say instead of having dimentions rolled up inside of matter (quarks), they are constantly interacting in one another. The universe which we percieve to live in is just another dimention which these multidimentions exist inside of. The main idea is that the interactions of dimentions with this universe is a benign one, but when moving, it causes an.. interaction with this dimention thus causing "matter" to be in "existance". Thus matter is just a byproduct of the interactions, but the interactions of this universe and the others cause gravity.
Theorem 3 - Time is also a byproduct of the dimentional interaction with this universe. There can be no time with no space and vice versa. But that really isn't part of the theorem. The theorem goes as follows. Each rotating force in this universe has "fields" of force around it, or a certanty field in which it is the main driving force. Each galaxy has a center (massive black hole) in which everything rotates around it. Each solar system has a sun (red dwarf or whatnot) that is the main gravitational force. Each atom has a nucleous, ect. Once outside the main force, it will ahere to the rules of the greater force outside of it.
Hense, out of all my theorems, theorem 3 is the cause for the deflection. After getting too far away from the sun (ordos clouds or whatever they're called), it will be under the influence of the galactic center. The problem with this is the incredible distance, the relative speed of the probe to the center (remember that solar systems rotate around this center, if the probe is leaving the solar system, it is either traveling faster or slower than the solar system in relative speed.
So basically think of it like... Lauching something from a satelite in orbit horizontally (not to or away from the planet). The increased speed will make it change orbit, or fall to the earth. That or dark matter :P
Come on people its because of the fact that Earth is the universe's insane asylum. Obviously the rest of the universe isn't going to let us out that easy. Abductions are just when someones treatment is over. Have a good day and keep in mind what I say.
Written from The House of the Venerable and Inscrutable Colonel
Could be that scientists have underestimated the power of gravity, and as such, the planets, and Sol have stronger influence than thought, and thus, the probes may be closer to the limit of Solar gravity escape velocity than originally calculated.
Could even be that their paths are actually a parabola... That once they reach their apogee, may actually fall back into a very distant Solar orbit...
=== The price of freedom is eternal vigilance
I find a particular comment in the BBC article somewhat curious... It claims that the orbits of the planets in our own solar system do not seem to exhibit any effects comparable to that of the four probes in question:
"It would be apparent in the orbits of the planets around the Sun - which it is not".
Now, someone please correct me if I have this wrong, but don't estimates of the physical properties' of planets *derive* from the behavior of those planets under the assumptions of our best current understanding of gravity?
So, how can we claim that the planets do not seem affected by this "mystery force"? If we use the orbital radius and centripetal acceleration of a planet to calculate its mass, we can't then use that calculated mass to "prove" that the THEORY of gravitational attraction as we know it applies perfectly.
why on earth is this modded to Troll? I think it was a interesting post, probably not todays best post, but by no means a Troll.
You're modding me down because the truth hurts. Your favorites gurus are either frauds or crackpots and you can't stand it. Trying to stop this stuff from coming oput is like the music industry trying to stop people from copying music. It can't be done.
Thanks to the moderators who modded me up.
Perhaps this observed acceleration is actually us "decelerating". Could our close proximity to a large source of gravitation (the sun) lead to such an observation?
We need to, er, Think Different(TM) about stuff like this.
Didn't today's earlier story regarding anti-matter/matter creation answer this question. The existence of anti-matter is quite obvious to the naked eye.
link?
Rot-13 my address to e-mail me.
"So I hurry back to little earth / For another life another birth"
My spelling is not to be trusted :-)
Alcubierre's warp drive
And here is the link to NASA's research:
http://www.grc.nasa.gov/WWW/PAO/html/warp/
Go to Ideas based on what we'd like to achieve to read about it.
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Two witches watched two watches.
Which witch watched which watch?
Troll?!
Here is the link to NASA's research:
http://www.grc.nasa.gov/WWW/PAO/html/warp/
They list several ways to do it.
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Two witches watched two watches.
Which witch watched which watch?
Actually, the more massive the probe, the more gravitational attraction there would be between the 2 objects in question. Remember, WE attract the Earth too, just not at any detectable level. However, any additional mass in the probe would negate this ... /me tried to pull out inertia equations from the brain graveyard...
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
"Pioneer 10 was launched towards the outer planets in 1972. It is now well beyond Jupiter but still in radio contact with Earth."
I'm just amazed the damn probe still works. Pioneer 10's engineers must be very proud of it's longevity, and I wish more people would give NASA credit for their fantastic successes. (And let's get our butt back to the moon and mars!)
Clearly, the probes have crossed the Warp Field Barrier out past Pluto. Gravity pulls different out there, away from the disturbing influence of the Sun.
Now all they need to do is fire up their Warp Bubble Generator(TM)and haul ass for Alpha Centauri at C^3 (That would be cube of lightspeed, for you Sociology/English majors). Hooya!
informed content? do you mean like super-string theory or oort cloud objects?
before you guys get too carried away, try reading this:
Notorious Spacetime Crackpots.
Bored with your projects?
Try Einsteinium
God bless those Albino Ninjas...
- John Keats
I have many times had this aesthetic argument with math and physics students. It took a long time, but we eventually came to the following consensus on the aesthetics of science:
Scientific fact, in and of itself, is as completely devoid of artistic interest, as any fact is. The mere cold fact of the way in which paint was arranged on a piece of canvas to create the Mona Lisa is devoid of aesthetic value. Only a human interpretation of the meaning of this arrangement of paints can yield aesthetic worth. Therefore, for example, while the theory of relativity is, in and of itself, without merit as art, by an interpretation of its implications to humanity, it can gain meaning. The exciting thing about it is that we DON'T understand it completely. We can make all manner of wild romantic ponderings on its meaning with regard to light-speed travel and all sorts of fantasies. It's only because we don't understand it that we can make these ponderings, however. If we had a complete and thorough "scientific" knowledge of its (or "the theory of everything"'s) meaning and nature, light-speed travel or time travel, for that matter, would be either 1) recognised as impossible or 2) as matter-of-fact as travel at greater than the speed of sound.
The only reason science is interesting is because it entails mystery (if it didn't, there would be nothing more to investigate) and uncovers new topics for us to consider in wonder. Unfortunately, while it does this, it disproves the things that we used to wonder at (like a 6,000-year-old earth and Thor weilding his thunderbolts from the clouds). The end result is that the only things that we have to wonder at any more are so incredibly abstruse that only scientists can explore them. The common man used to be able, as the above poster noted, to look up into the stars and wonder even what they might be. Unfortunately, these wonders within the reach of the common man have already been explained. The worm holes, dark matter and Uncertainty which remain the wonders of today are somewhat beyond his grasp.
I think this is all summed up in a quote from David Hume:
The anatomist is useful to the painter"
The scientist investigating the human body and the artist who depicts it work hand in hand to create the final product. This is perhaps a consensus to be made between scientific and artistic aesthetics.
So let me get this straight. You know this ONE GUY who doesn't understand what the scientific method is about, and you generalise this to ALL SCIENCE??? ("Lover's Arrival, The, is 100% correct about science's attitude to these sort of things").
This ONE INDIVIDUAL that you know isn't a scientist (not at this stage anyway). Not everyone who calls him/herself a scientist is necessarily one (just as most Christians are not Christians). There is a lot of real science out there, and your claim that with the somewhat naive notions of this one individual you can with a brush of the hand ignore the works of thousands of real scientists quite frankly makes me sick.
Maybe it's simply the resistance of interstellar dust that slows the spacecrafts down. During its travel, it must have bumped into billions of particles that slow down the spacecraft. Although there may be only a few particles per cubic meter, after the billions of km's the spacecrafts have travelled, I can imagine that they add up and become significant.
Added to that, there may be more gas in the outer regions of the solar system.
My karma ran over your dogma
You know, most scientists do look at the world with eyes of wonder. It's the wonder that arouses their curiosity and leads them to be explorers.
I think the arrogant assumption that we know it all frequently comes from non-scientists who have an axe to grind. The average scientist has far too much experience with failed hypothesis to think that they know it all. (And, of course, it's only the non-scientists who think that a failed hypothesis indicates a failure. I'll bet there are folks at NASA who are beside themselves with delight over this puzzle.)
Sorry, Arrival, if you stopped gazing at the stars with wonder. I seriously doubt that anyone at NASA ever did.
Shame on me for responding to such an obvious troll, but the contrast was hard to resist.
I remeber reading that the majority of the universe is made of "Dark matter" or things like black holes that we can not obverve directly because they are not emissive. If this is the case, then the changes in course could be small cumulitive effects from lot of dark matter gravitational interactions... Or maybe they just forgot to convert from pounds to kilograms again.
Isn't it obvious... The universe is flat, and these probes are just heading over the giant matterfalls at the edge of our solar system. I've heard stories of creatures from "out there" as well...
after reading through your past comments I have concluded you are a troll http://slashdot.org/users.pl?op=userinfo&nick=Ayen de%20Rahien
http://Lenny.com
4 great justice!
Furthermore, it couldn't have been some other type of temporary force. That rules out the possibility that a "tractor beam" might have deflected the probe. It also rules out the possibility that the emission of energy in the form of radio waves had any effect on the probe's trajectory, since that emission would not have been constant over time.
The slowdown in the probe's acceleration has been constant over time. The observed difference between the predicted acceleration and the observed acceleration should be reducible to a constant. If this is true, the slowdown should be proportionately the same early in the probe's voyage as it is now. A wild card here is that the probe might not have been always headed away from the sun. I'm not sure. Maybe they used a gravity slingshot or something to send the probe into deep space.
The continuing slowdown of the probe indicates that this force does not depreciate over the distances so far observed. This contrasts with the strong and weak nuclear forces, which both depreciate over smaller distances. Gravity does not depreciate over any known distance. We might assume that this hypothetical force is like gravity in not depreciating over any distance. At this point we could analogize this force to gravity. Maybe this new force is like gravity in other ways, too.
The probe is slightly off-course, but not much. Thus, the force is not as powerful as gravity.
This is just speculation. Maybe it's crazy. It will be interesting to eventually learn the answer. Is it really a new force?
I am not a lawyer. Do not take my words as legal advice. If you need legal advice, consult an attorney.
Is this some strange definition of news with which I am not familiar? They ran essentially the same story back in 1998. -- MarkusQ
The problem is not that we don't know what mysterious force is affecting our probes, the problem is that we assume too much and expect regularity in things irregular.
A space venture such as these reflects travel over vast distances. Try putting your car on autopilot and have it drive for millions of miles on the path you have created for it, no really, try it.
What if a small piece of debris hits your probe? What if a magnetic breeze brushes across its nose? What if the thrust is not perfectly aligned? Though we attempt to correct these events with the allmighty fudge factor, the simple reality is, that in a chaotic system, seemingly irrelevant anomelies can result in significant deviations from the expected outcome.
Can NASA do better in predicting the unpredictable? Probably. How much better? Can we ever produce something that behaves exactly as we planned every time? Well, I can't, but then again, I don't work for NASA.
aliens dont want us to know they exsist if they are more intelligent and they dont want us to reach them, the best way is to slow down our probes and let us think its a freak accident
aliens dont want us to know they exsist if they are more intelligent and they dont want us to reach them, the best way is to slow down our probes and let us think its a freak accident!
There are some flaws in your theories...
First and foremost are the laws of physics, specifically the speed of light. It can not be exceeded by a physical object and still maintain atomic integrity. This plainly makes travel over any significant distance impossible.
Ok, so because the speed of light has not yet been achieved by the human race, aliens cannot exsist? Did I miss something here or are you telling me that the human race has to be "the most intelegent" life ever? Maybe, we are slower than (alien) life form and they are moving at many times the speed of light.
"Well, what about our own solar system?" you may ask. Please. Do you really think there are little green men coming down to abduct farmers in the midwest? This is reality, people, not the X-Files. Quit dreaming.
What does this have to do with the article?
"You can believe in a higher power - as a matter of fact you should " Why should I? I can believe anything that I want. And im sorry, but people that attempt to force this theory that I should believe in a higher power upon me are the reason that I cannot believe in a higher power.
Points to consider in favor of extra terrestrial life:
1. We would have to be very conceeded if we believe that we are the only ones that can be alive in this huge expanse of our universe.
2. Elements that we say are required to sustain life here on earth are in huge abundance in various other planets that we know of, let alone in pockets of gassesous clouds through out space.
3. The human race and varous other animal and plant life here on earth have proven that we can adapt to and overcome any obsticles to our survival.
Just because we havent seen aliens doesnt mean that they are not there. Just because I havent seen God, doesnt mean he isnt there.
System error: User not found.
Has anybody thought about the probes leaving the Sun's exterior corona? Earth itself and most of the solar sistem is subject to intense solar winds and electro-magnetic radiation, could this force percieved by NASA be the absence of these?
Only the incompetent solve problems by appointing blame.
I don't know though. Remember that Einstein's entire throery of relativity was based upon a simple equation in some math that most of us can't understand, and don't really try, anyway. Also remember that time is an element of physics AND math, not one or the other, but both. You can't truly understnad physics or astronomy without understanding how numbers go together!!!
The probe just wants attention
In the spirit of Carl Sagan (billyuns and billyuns of years ago), the cosmos was a large mix of "gahses" and "stooff" and empty space. Then came Barbara Striesand.
--Entropy happens.
Everytime I hear theoretical physics discussions my mind starts to wonder...
When you look at matters of scale in theoretical physics and how we're now able to see inside the basic components of atoms; you have to wonder if God created His universe by a freak physicial breakthrough in a corporate lab, had time to observe us, then change our destiny and get a carptenter's wife pregant then mysteriously stop directly influencing our lives not soon afterward?
Maybe our universe is sitting in a dustbin as a spent experiment in some superuniverse. What happens to His creation when they take the trash out?
Just a thought.
--Theology + Physics = KABOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOM
You know they have a problem with math sometimes. I'd check to see that everything was in metric this time and that no units are getting confused. Probably something silly like that, silly until the probes come crashing back to earth.. wait!! that's it.. they are using the probes as new weapo ... thud..
. echo -e \\04 >
What about CowboyNeal did it?
Its probably running Windows CE Outer Limits Edition. If you think about it, it makes total sense. My computer runs Windows 98 and it does some of the strangest things, yet nobody raises an eyebrow.
The mystery force is time and the continual creation and disturbances that are inherent with its existence. As time expands or more precisely as time divides and multiplies thus expanding the universe, shockwaves are created that are producing anomalies in our measurements of what should otherwise be constants. My theory is that time can be seen as essentially a three dimensional particle that is dividing off in fours from existing particles of time. As these particles of time collide and form densities, which lead to matter, possibly all matter, they are affecting matter surrounding them similar to how we disturb our environment as we move through the atmosphere and collide into the particles that surround us. So as time expands the universe there may be shockwaves that tremble across space, which is, actually time that has manifested to such a density as to not create actual visual matter but is a wave or atmosphere of time sloshing through the universe. As the density of the universe changes with each passing moment, and the exponential growth of the universe due to the staggering amount of time particle division and growth, these fluctuations create slight distortions in the fabric of space and time that NASA doesn't yet understand the mechanics of. Time can be seen as a dividing cell, those cells group to form objects of matter, as these cells of time (particles) divide and the massiveness of the universe and the density of time that fills it continues growing, time forms an expansion that creates a motion outward or forward, time moving forward. It is my theory that we, our planet, the universe; all things are made of time. Different densities lead to different forms, but we all exist in the ubiquitous soup of time, our lifespan is a measurement of the object existing in time as being a part of time, I suggest we are an element made of a complex density of those particles, that we are Dimensional Morphogenetic Time entities. Due to the complex relationship of all these particles of time existing within the various densities of forms we are, have built, and that exist, different objects will behave differently as they course through their trajectory and meet and deflect off the various atmospheric densities of time that surround us or the object, in this case the Pioneer or Voyager spacecraft. The real fabric of reality is time. I would even like to suggest that the theory of everything and of creation have forgotten to take into account the moment that must have existed prior to the formation of the super string or the formation of the universe. As we learn to understand the relationship of time to our existence we will learn to look into the levels of reality and existence that we are being flung about. The satellite cannot be accurately measured because we must continue to look deeper, to understand more, if the measurements were predictable and constant we might lose our desire to better understand why.
My opinion (note) is that the key to solving the problem lies in the assumption that the speed of light is a constant. I believe it is not. Measurements of the speed of light have shown a consistent drop in the measured speed (in general) up until the atomic clock was adopted as the standard for time measurement. The rate of the atomic clock is dependant on the speed of light, so obviously the measured speed would remain constant. Apparently our days are also getting shorter by a miniscule amount every year according to the atomic clock. Perhaps our days are remaining the same length, but the atomic clock is slowing down? Just some thoughts. Call me a crackpot if you like. Actually that would be kinda cool!
Actually I did follow his link and his logic seemed pretty sound.
If you have a counter-proof then why don't you share it with us?
Isn't gravity the simplest explanation?
According to Einstein, everything is relative, including time.
Black holes supposedly have a gravity field so powerful nothing can escape them, not even light or time.
So, isn't it possible that there's an unknown gravity field outside the solar system that is not a black hole yet is so powerful it's actually slowing down time relative to the earth?
Couldn't it be that the probes are not slowing down but they just appear that way to us because of relativity and that the probes are in fact still going strong? Or am I missing something?
-- This sig for rent.
No more 'oort fields' or whatever. That 'tenth planet' one was nice, though. But...
Whenever there is a track meet, someone shoots a gun into the air (sometimes its a real gun.). It would possibly have the speed to break the earth's gravity (atmosphere), so maybe it got shot.
OR, for all you BASIC programmers out there
probe_speed = 60
atmosphere_edge = 100000000 (made up number for demonstrational purposes)
atmosphere_edge / probe_speed = time_to_next_world
track_bullet_speed / atmosphere_edge = bullet_time
If bullet_time > time_to_next_world then
msgbox "We have found our solution. It was a track meet bullet."
IF Else : msgbox "I guess we'll bever know..."
End If
There. Now run basic, get yer answer, and find out what the answer is, kay?
atmosphere
I see a little silhouetto on the window/
Voy'ger 2! Voy'ger 2! Can you say 'Course Disruption'?
Geez, ignore this. Slashdot's forums are annoying ^_^
Warning: EXCESSIVE SARCASM
"1 4m 4 1337 #4xz0r!"
Janus
using namespace slashdot;
troll::post();
It could also be that the Sun's own gravitational field is bending the light enough so that the NASA folk report an error of the actual trajectory that they see. Remember, Earth is pretty deep inside the gravity well of the sun. Also, notice that since the Earth orbits Sol, and that the probe is in the plane of the ecliptic, the sun will swing by and block out the probe signal from time to time, also... it will distort the crap out of the observed constellations and hence, maybe cause an error or two in calculations. This is all null and void, of course, if the sun is "behind" us in regards to the probe. Can anyone find this out? Me thinks that the NASA folk probably already checked this... they're a smart bunch.
I don't think the likely explanation has to do with exotic physics at all. It is true that we've never sent anything out of the solar system before, and hence this is uncharted territory... Newtonian gravity seems to work pretty well on the local level (never mind this inflationary universe stuff, that doesn't really affect us in the Milky Way), so I don't think it's that. My opinion is this: It is either that the NASA people didn't take into account the distortion effect (gravitational lensing or what have you) of the sun's own gravity, or... There's lots of stuff floating around in the ecliptic of the solar system--dust, planets, but lots of dust. Wouldn't that give the solar system a different index of refraction than perhaps interstellar space? There's not much dust per unit volume, but there's a lot of distance between here and the probe... Anyone in agreement here?
There are probably many problems with this theory, but... I believe it was General Relativity that predicted the existance of gravity waves (ripples in space-time caused by variations or movement in mass). As another poster has already stated, the solar system and galaxy are moving across the 'fabric' of space at incredible speeds. Now, the reason that we don't notice these gravity waves on or around earth is because of the sun's gravity well. So, it strikes me that if we're moving through space at high speeds, not only would the sun create a gravity "wake," but we would also be traveling though other gravity waves. Seems to me like that might fit. We even get to keep General Relativity a bit longer. Maybe, maybe not. Let me know where my theory errors are.