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Mysterious Force Affects Pioneer 10 & 11 Probes
JabbaTheFart writes "The Guardian is writing that something strange is tugging at America's oldest spacecraft. As the Pioneer 10 and 11 probes head towards distant stars, scientists have discovered that the craft - launched more than 30 years ago - appear to be in the grip of a mysterious force that is holding them back as they sweep out of the solar system.
Some researchers say unseen 'dark matter' may permeate the universe and that this is affecting the Pioneers' passage. Others say flaws in our understanding of the laws of gravity best explain the crafts' wayward behaviour."
The question is can we develop the technology to detect tractor beams all the way out there from here?
What's interesting about this is the craft went in different directions out of the solar system, which rules out something like the mass of an unknown body in the outer solar system affecting their flight.
Please read my Canon EOS tech blog at http://www.everyothershot.com
exactly what was AFFECTED?
They could just be hitting up against that big crystal shell that all the stars are painted on.
Smeghead every day of the week.
When you think about it, we know so little about deep space. Perhaps the Matrix doesn't go out that far? Clipping problems?
It is also thought that dark matter is at the centre of galaxies Could explain a lot of things, e.g. the expansion/contraction of the universe. Judging by the amount of "tangible" matter in the universe, there is no way to halt the expansion, and it will go on forever. However, if there is dark matter, it could hold enough gravity to halt expansion and force the big crunch. Lots of info on this sort of stuff here
It is neat to see things like this which challenge our understanding of relatively basic things like gravity. Part of me is still hopeful that we will find some holes in the relativity theory. More than a few scientists have pointed out other inconsistencies between observations and relativity. It would be nice not to be constrained by this whole 186,000 miles per second thing :)
It'd just be great if after all this time we actually find out something like it's not possible to leave the solar system without some sort of extreme propulsion system.
They're so far away the Matrix is accumulating significant floating point error.
Obviously, this is merely the result of the space craft leaving the singularity of our solar system, thereby moving outside of Einsteinian laws of gravitation and physics. It can now enter hyperspace... or would be able to if the puppeteers would hurry up and arrange for a hyperdrive shunt to get dropped off.
Sorry, just finished "Ringworld".
Ah yes, the good old "If you don't know, blame it on Dark Matter" strikes again.
-Kenneth Sundby-
Note to Hemos: The verb is spelled "affect". You know, with an "a". The noun is spelled "effect", but it's the verb needed in the title.
Sorry, don't mean to sound curmudgeonly and grumpy and so forth, but so few people get this right that I can't stand by and let it slide.
I'll put the cantankerous old grouch away now...
Daar is nie 'n lepel nie
From TFA They had been tracking the probes using the giant dishes of Nasa's Deep Space Network.
This doesn't quite quench my thirst for information: does this mean the probes are still sending radio waves/signals, or just irradiating passively?
Sigged!
I don't know about you guys, but if "something strange" were tugging at my "probe" using "mysterious forces," It would probably be bigger news than the science page of /. !
im not scientist, and surely these articles are written for the layman, but all of the articles i've read say "something more than the sun's gravity is pulling at the probes"
wouldn't the planets, especially jupiter, and saturn, and ALL of the misc tiny asteroids in the various belts, exert a pull on the probes as well? some sort of combined solar system gravitational force since the probes are well beyond the last planet?
doesn't seem that complicated to me, but im definately coming at it from a relatively uneducated perspective then who's saying something's wrong in the first place.
One thing that is rare for them to admit is not knowing why something happens.
According to my physikcs teacher, this is quite often the case. Physics describe how things happen, the question why they happen is left to the philosophers.
Life is just nature's way of keeping meat fresh.
Bit of an old story this.
wot no sig
This isn't news. The slowing-down effect has been seen before, on some other probe. I even remember
But expecting /. editors to recall that would be like expecting them to get effect and affect correct.
You cannot apply a technological solution to a sociological problem. (Edwards' Law)
Only if by "rare" you mean "all the time."
The Bush Administration is altering the laws of gravity in order to distract us from the situation in Iraq. A bill in Congress right now will nullify the law of gravity as we know it, taking away the rights of individuals to remain firmly planted on the Earth.
what can I say... the damn things snagged my sweater during take-off, and I didn't want to say anything...
Link to the Physics Web article: http://physicsweb.org/article/world/17/9/3
According to this paper, it could be drag from dust in the outer solar system.
Um, I'm way out of my area of expertice here, so forgive me if this is utter drivel.
The probes are basically big lumps of metal moving at high speed through space.
How much do we know about the magnetic fields in deep space?
Could this be some fairly boring electromagnetic effect?
Quidquid Latine dictum sit, altum videtur (anything said in Latin sounds important)
Uranus!
...to the inevitable discovery of a monolith and a solar baby.
John Maynard Keynes: "When the facts change, I change my mind. What do you do?"
It's a SPACE STATION!!!
For those that would die defending it, Freedom
has a sweet taste that the protected will never know.
I have no idea whether the effect would be so big though.
Some (Majorana?) even thought some kinds of matter were radiating "pushing gravity", but I'm really leaning dangerously far out of the window by guessing that this is the way that a black hole a the center of the galaxy causes the anomaly in galactic rotation curve that is observed (that anomaly suggests more (gravitational) pull, too.)
Please note that the arguments derived from thinking about Pushing gravity might apply even if gravity is not considered pushing by the physics used.
I'm still trying to figure out what people mean by 'social skills' here.
No, this was explained more than a year ago.
That explains it - all of the scientists have forgotten the answer in the last 12 months! It's lucky that someone as intelligent as yourself is around to correct their error. I suggest you start writing letters immediately.
Don't worry, I've already written to The Guardian to tell them how stupid they are on your behalf.
Of course, I did briefly entertain the possibility that you might be an arrogant dick, but I quickly realised how absurd that was!
After reading the article I had a flashback about old computer games, where "mysterious force" would tug you back when you reached the end of the area.
:)
How funny it would be if our world ended after Pluto and the stars would only be 'a painted backcloth'. I wonder what kinda effect it would have on our society. Scientist would propably spend years trying to explaing the phenomena, until one day a human could travel to the edge and verify the obvious.
Or maybe the aliens that run our world on their supercomputer have not yet coded the rest of the universe. Let's wait for few more years and see if 'the mysterious force' has been removed
One thing that is rare for them to admit is not knowing why something happens.
Rare? It's what they do all the time! It's the very first step in every single research project, and most of the subsequent steps too.
Some religious preachers and journalists and Hollywood writers portray scientists as believing that they know everything. But for real scientists, wondering what happens is the very basis of their work.
You should read more Scientific American and less clueless tabloids.
Terrorists can't threaten a country's freedom and democracy. Only lawmakers and voters can do that.
Well, our understanding of the laws of gravitation _is_ better than the link in the article might suggest. Look: http://en.wikipedia.org/wiki/General_relativity.
Greetings from the physics department.
Has this effect been observed as to the Voyagers?
Excellent illustration (updated daily!) of all these probes and their vitals (trajectories, distance, speed, etc.) at Heavens-Above .
Bush Lies On the Record.
Setting your speed at "c" and it takes a while to get out of the Solar System. Set it at a few AUs per second and you can clear the solar system more quickly, but once you are out, it seems like you are not moving at all. Once you accelerate to a light year per second, things start moving a bit, especially the neighboring stars, but it is still pretty slow going on a galactic scale. If you want to get out beyond the galaxy, I recommend going perpendicular to the galactic plane and accelerating to a few thousand light years per second (ummm...that is rather fast, don't you think).
Doing this gives you a pretty good perspective on things. Once you are in inter-galactic space, if you aren't moving about a thousand light years per second, it seems like you aren't moving at all. For an even better perspective of mixing size and speed, try manually flying back to Sol. It seems easy, and you even decelerate a bit, but it seems like you are going kind of slow until you suddenly zip past Sol doing about 100 light years per second. Go back and try again.
Back to the original point, yeah the speed of light is fast, but on a galactic and/or universal scale, it isn't that fast. I too hope they either find some loopholes in relativity, or find some loopholes in the universe (such as Asimov's idea of Hyperspace), or we won't be going anywhere anytime soon.
Yeah, I know this is deeply in the realm of Science Fiction, but I'm kind of hoping that it becomes Science Fact someday...
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
I heard other things.
If you read TFA, you'll notice that they are talking about a force acting equally on *both* probes.
Claims that this is a new effect are a bit too early, though.
Occam's razor doesn't mean that scientists should stop investigating because there _may be_ a simple explanation. If there are interesting, unexplained things, one has to go down and calculate every traditional force(/space time curvature) which may act on the spacecraft; numerical simulations of the radiation pressure of the RTGs, taking the geometry of the space craft into account. Other external electromagnetic forces. Etc.pp.
Then, there will probably be a traditional explanation of the effect. If not send some probes out too further investigate the effect. After all, experimental physics is not only about testing the theory's POV, it is also about exploring the world and finding new effects.
You can have wrong calculations by theoreticians even in such fields where there is a fundamental theory capable of explaining everything. (This includes nearly every field of physics today - except nuclear/particle physics and astrophysics).
Nouvelles de jeux et technologies en français. TC
As it happens, The Economist recently ran an article addressing some of these issues. The article also provides context and perspective that should be of interest to those participating in this discussion. For convenience, the full text is reproduced below; it is also accessible online (may require paid subscription).
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Gravitational anomalies
An invisible hand?
Aug 19th 2004
From The Economist print edition
[Image]
An unexplained effect during solar eclipses casts doubt on General Relativity
"ASSUME nothing" is a good motto in science. Even the humble pendulum may spring a surprise on you. In 1954 Maurice Allais, a French economist who would go on to win, in 1988, the Nobel prize in his subject, decided to observe and record the movements of a pendulum over a period of 30 days. Coincidentally, one of his observations took place during a solar eclipse. When the moon passed in front of the sun, the pendulum unexpectedly started moving a bit faster than it should have done.
Since that first observation, the "Allais effect", as it is now called, has confounded physicists. If the effect is real, it could indicate a hitherto unperceived flaw in General Relativity--the current explanation of how gravity works.
That would be a bombshell--and an ironic one, since it was observations taken during a solar eclipse (of the way that light is bent when it passes close to the sun) which established General Relativity in the first place. So attempts to duplicate Dr Allais's observation are important. However, they have had mixed success, leading sceptics to question whether there was anything to be explained. Now Chris Duif, a researcher at the Delft University of Technology, in the Netherlands, has reviewed the evidence. According to a paper he has just posted on arXiv.org, an online publication archive, the effect is real, unexplained, and could be linked to another anomaly involving a pair of American spacecraft.
Three different types of instrument have been used to detect the Allais effect. The first are conventional pendulums, such as the one Dr Allais used originally. The second are torsion pendulums, which work by hanging a bar that has weights at each end from a wire. As the wire twists back and forth, the bar rotates in pendulum-like motion. The third are gravimeters, which are, in essence, very precise scales. All of these instruments measure the acceleration due to gravity at the Earth's surface, a quantity known as g. The Allais effect is a small additional acceleration, so tiny that it would take an apple about a day to fall from a tree branch if it were the only gravitational effect around.
Allez, Allais
Dr Duif has examined various conventional explanations for the Allais effect. He finds the most obvious suggestion--that it is a mere measuring error--unlikely, because similar results have been found by many different groups, operating independently and, in at least one case, without knowledge of Dr Allais's results.
He also discounts several explanations that rely on conventional physical changes that might take place during an eclipse. One of these is that the anomaly is caused by the seismic disturbance induced as crowds of sightseers move into and out of a place where an eclipse is visible. That seems unlikely, given that one of the experiments with a positive result was conducted in a remote area of China while another that had a negative result took place in Belgium, one of the most crowded parts of the planet. Dr Duif also considered the possibility that, because the moon's shadow cools the air during an eclipse, this cooler, and thus denser, air might exert a different gravitational pull on the instruments. This change could, he reckon
And why wasn't it seen until now? And why did it start effecting the two craft at the same time? Provide a few more details of the radiation pressure hypothesis, or better a few links and I'll be more apt to believe you. Until then I remain skeptical. The Pioneer Anomaly has been around for a little while, long enough to generate more than a few ( Google Search of Citebase)) papers written to try to explain the anomaly. Dismissing them all out of hand in two sentences is NOT good science, but then hey, this is Slashdot, what do I expect?
What if it is just turtles all the way down?
Guess what? Science is _based_ on not knowing everything.
Scientists not admitting they don't know everything? Well, gee, I thought they even told you exactly what they don't know yet and/or are trying to find out, each time a new experiment is performed. Whenever a new particle accelerator is built, whenever a new probe is sent into space, whenever someone builds a bigger telescope, whenever they bury some sophisticated particle detector deep, they'll conveniently tell you exactly which part of the unknown they're trying to probe.
If anyone believed we already have the absolute truth already, we wouldn't need those. In fact, we could just as well shut down the existing ones and send everyone home. Nothing left to discover, no?
But that's not the case.
The whole idea of science is that we don't know everything. If you want absolute truths, those are that-a-way, through the door marked "religion". Science is in the other direction.
In science at most we might have a good enough approximation for stuff we're able to measure already. And for a given class of problems.
E.g., Newton's mechanics are accurate enough for everyday stuff: things weighing between milligrams and thousands of tonnes, at relatively slow speeds. If you move away from that in any way, the approximation is no longer enough, and more detailed theories become necessary. That's why we have relativism, quantum mechanics, astrophysics, and so on.
We do _not_ however have an explanation for stuff noone has measured before, or for problems which didn't even exist before.
E.g., for what happens at sub-atomic particles under a certain size. That's why we keep building bigger accelerators. 'Cause we have no clue what happens there, why or how. We're trying to find out, 'cause so far noone measured anything in that range.
E.g., for exactly the problem in this article. Noone before had measured what happens when you chuck a rock (or a spacecraft) far enough outside the solar system. It's a new problem, and, yes, the scientists are very open about it: noone has a clue what's happening there or why.
But that's ok. That's how science work.
What will happen is that we devise new experiments, measure some more, and then we'll have enough data to make a better theory. One which will allow us to chuck spacecrafts better.
See, for all its "absolute truths" and the knee-jerk jumping to point fingers at scientists, that's one thing that religion can't do: eventually tell you _how_ to do something right.
Everything you see about you, such as the electronics in the computer you typed that on, didn't happen because someone shrugged and said "uh... guess because God wanted it to be so". It came to be possible because some scientists openly admitted what they don't know yet, and proceeded to measure and devise theories.
(And someone will point out that engineers were also needed to make an actual device based on those theories. Indeed. Personally I just think of engineers as a branch of science. The applied kind of science, as opposed to the theoretical kind. Still science either way.)
Theories which don't just explain why something already happened, but how to make it happen again. And how to control it when you make it happen. How to make it happen slightly differently.
But again, it invariably started with someone saying "well, we have no bloody clue why _that_ happens. We'll need to measure some more and do some serious thinking."
A polar bear is a cartesian bear after a coordinate transform.
As it happens, The Economist ran an article in 1997 addressing some of these issues. The article also provides context and perspective that should be of interest to those participating in this discussion. For convenience, the full text is reproduced below; it is also accessible online (may require paid subscription).
----
A space oddity
Sep 24th 1998
From The Economist print edition
A tiny error in the paths of two spacecraft may require the rewriting of some of the laws of physics
OUT in the far reaches of the solar system, beyond the orbits of Neptune and Pluto, something strange is going on. Two space probes, now speeding away into the interstellar void, are not behaving as they should. They appear to be experiencing an unexplained extra tug from the sun--raising the possibility that there is something amiss with the laws of gravity.
Physicists are used to predicting spacecraft trajectories with great accuracy. For the Pioneer 10 and Pioneer 11 probes, launched towards Jupiter in 1972 and 1973 and now heading away from the sun in opposite directions, they have done it with the help of a piece of computer software called the Orbit Determination Program (ODP). This calculates how the gravitational influence of the sun and the planets--suitably tweaked to fit with the general theory of relativity--affects each probe's motion.
At the same time, by analysing radio signals from the two probes, precise measurements of the Pioneers' actual trajectories can be made. As each craft zooms away from the solar system, the radio waves it transmits back to earth are slightly stretched out, causing a change in frequency (known as a Doppler shift) that depends on the craft's speed relative to the earth. With enough number-crunching--taking into account the motion of the earth around the sun and its wobbles as it spins on its axis--the position and acceleration of each Pioneer can then be worked out.
The trouble is that the predicted and measured trajectories do not match. Instead, there seems to be an additional pull (in effect, an acceleration) in the direction of the sun that is not predicted by the ODP. The anomaly is almost imperceptible: about one ten-billionth of the acceleration due to gravity at the earth's surface (at that rate, an apple would take a day to drop to the ground from the branch of a tree). But that is still big enough to raise questions.
Send for the detectives
Astronomical discoveries often hinge on the analysis of wobbles, discrepancies and errors. The existence of Neptune was deduced from minute deviations between the predicted and observed orbits of Uranus. An anomaly in the orbit of Mercury provided one of the first clues that the laws of gravity as described by Newton were incomplete, which, in turn, led Einstein to general relativity. So John Anderson, one of the members of the Pioneer 10 navigation team at the Jet Propulsion Laboratory in Pasadena, California, says he feels a professional responsibility to make his sums add up. His latest attempts to explain the anomalous acceleration will be published next month in Physical Review Letters.
Dr Anderson and his team start by considering all the possible forces that might be acting on the Pioneer craft but have not been included in the ODP. Could any of them account for the slight acceleration towards the sun? Gas leaks, and the minuscule push provided by infra-red radiation from the crafts' electricity generators, were ruled out. Both would be too feeble, and would be unlikely to press in the sun's direction anyway. Similarly, the pressure exerted by sunlight, and the force exerted by the emissions from each probe's radio antenna, were dismissed: again, both are too weak, and they would tend to push the probes away from the sun, not towards it.
Next, the gravitational influence of objects
It is most certainly not radiation pressure from the RTGs. If you would care to read the original 54 page article gr-qc/0104064 at http://arxiv.org/ you would have noticed that the original authors took serious effort to account for the radiation pressure from the RTGs and could make it in no way large enough to account for the anomaly.
Hmm, I've read about this on Slashdot before, and I'm pretty sure I've read about Modified Newtonian Dynamics before.
The gist is this: MOND is an alternative to the "dark matter" explanation. It makes a modification to newton's laws of motion, whereby gravitational strength.
The equation F = ma is well known, but with MOND the gravitational inverse square law changes to an inverse linear law when the acceleration due to gravity falls below a critical value, which is very small (i.e. you get pretty far away from the source of gravity).
This explains most of the observed behavior that is currently explained by dark matter, including the rotation of galaxies which seem to defy newton's laws. Unfortunately, there's still no derived theoretical basis for MOND; as of now it's a rather arbitrary explanation with equations that just seem to work pretty well, and many physicists do not take MOND seriously. Then again, "dark matter" seems just as silly.
A more in-depth explanation is available here.
Interestingly, the MOND critical value for the acceleration (a0) turns out to be the speed of light divided by the age of the universe.
-CausticPuppy "Of all the people I know, you're certainly one of them." -Somebody I don't know
MOND
/.
Well, it's what some physicists may be thinking, anyway. I suspect that the Guardian article is meaning to hint at this, as well. For those who don't know, MOND is a modification of standard Newtonian Dynamics that has to do with very small accelerations. I'd actually really, really like to see a MONDian calcuation of what the forces should be on those probes and see if it matches their current paths.
Wow. I think this is the second time I've advocated MOND (a theory which I just barely consider reasonable, and no where near verified) on
I couldn't tell if you were experimenting with poor-man's cryogenics or looking for the orange sherbet.
have in the past given clues to as yet undiscovered physics. Under Newtonian physics, it was thought that there would be another planet inside Mercury because of anomolies in Mercuries observable orbit. The theoretical inner planet was called Vulcan. It has since been shown that Mercuries motion can be more accurately described with Einstein's special relativity.
Surely in vain the net is spread in the sight of any bird -- Proverbs 1:17
The key issue here is that the verb "to effect" is meaningful and useful, and we are rapidly losing it through ignorant misuse. One can advocate a descriptive rather than prescriptive approach to language, but that isn't the same as defending actual errors in widely-understood words. Saying "effect" when you mean "affect" isn't like saying "ain't" when you mean "isn't", it's like saying "Austria" when you mean "Australia".
The article talked about ideas for potential successor craft. All I have to say is I hope that they are a LOT faster!
Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
I like the following explanation of the anomalous acceleration. No dark matter/20 dimensions/new gravity theory needed here. A small amount of dust in the kuiper-belt that transfers momentum with the probe should be enough to explain the slowdown. Look at: http://www.newtonphysics.on.ca/Anomalous/Accelerat ion.html
True that. Admitting uncertainty is the first step of science..."we don't know for sure why this is, so we'll propose a hypothesis, test it, and if the results don't clarify anything, we'll propose another one."
I don't know why people are shocked, or take it as a sign of supernatural causes every time a scientist "isn't sure." They're never sure. If they were sure, they wouldn't be scientists. Science takes a certain amount of confidence in a possibility, but being "sure" is the first step towards fudging data that's inexplicable. The universe is infinitely large and thus infinitely complex, and we'd only been empirically studying it for a few thousand years. Most of our in-depth insights have taken place in the past 200 years, and many clarifications and exceptions have taken place in the past 50, and even the past 20.
Scientists have a notoriously matter-of-fact attitude that leads some people to believe that science believes itself to be infallible. It doesn't. But due to the need for strict controls, even on language, to avoid confusion between scientists, even false and preposterous assumptions need to be stated matter-of-factly. Scientists don't claim to have all the answers...they just claim to have some very realistic (and repeatable) ones.
Hey freaks: now you're ju
I'm not a rocket scientist, but I wonder if this is one of the effects of passing through the heliopause. It sounds like Pioneer 10 and 11 are too weak to send any actual data these days, so they can't really report if they're coming in contact with the expected particles, for instance.
Then again, it appears that this effect has been noted since at least 1998, so it's hard to say what's really going on. I will note that the two spacecraft are spin-stabilized, so maybe there's some weird frame-dragging-esque effect going on. I guess the effect hasn't been as noticeable on three-axis stabilized craft, though that's kind of expected since they would more frequently be using thrusters to change orientation (which would probably slightly affect trajectory too).
Let's see...in the past few weeks we've...
Sounds to me like it's time to sell your Reynolds Wrap (aluminum foil) stock soon, 'cause our alien overlords are f---ing around with us now that we've found their planet. Pretty soon, you won't need tinfoil hats to protect you from their mind control beams. You see, they won't waste time on tinfoil hat types -- because they make the best treats for their pet Glargian devourers.
Those who sell their stock, while soon to be enslaved to the Zarlanian Horde, will at least know they had money to live it up before the invasion began in earnest.
IronChefMorimotoWhat are you smoking? You make it sound like the explanation is on page 95 of the bible.. "And lo, the angel gabriel spake unto the herdsmen, and said: Take thee every herb bearing fruit... and the mysterious force effecting Pioneer 10 & 11 is from God doing his Silver Surfer impression."
Who modded this troll insightful? For shame. Parent post has zero redeeming value.
If science thought it knew everything, scientists wouldn't do experiments.
Galileo? Darwin? Helloooo? Earth to creationists... Stop picking fights with us. Science is not religion. If you think the world isn't big enough for both, go read St Thomas Aquinas (cliff notes: he philosphised that REASON and FAITH were BOTH part of the human mind and that each had it's sphere of relevance, eg, faith won't stop a bullet, but reason can help you design a flak jacket).
For the religious apologists, I held back the flamage, so beat it. And in case parent REALLY thinks this is beyond the ken of science, dude, the friggin' story has two educated guesses as to why it happens. Seriously, do you think you're making converts by posting that ignorant crap?
"A witty saying proves nothing." ~Voltaire
"d'Oh!" ~Homer
No, actually scientists state what they know, usually accompanied by how they know it, and how anyone can test the theory. That's what makes them scientists. Don't confuse a journalist spewing dumbed-down reports with a scientist.
>>>many times it's from the limited understanding we have and they have trouble with that.
If by "have trouble with that" you mean, "scientists like to learn and discover", you sure have a crooked way of saying it. If you mean "every time a scientist finds an unknown, they get all pissed off and make up lies to tell everyone, because they are heathen scum", then grow up. Science is here to stay.
Science as a school never said that reason precluded faith. It's the religious types who keep that torch lit, and cry when it burns them. Grow up.
"A witty saying proves nothing." ~Voltaire
"d'Oh!" ~Homer
An article at physicsweb.org says:
When the craft were at distances of between 20 and 70 astronomical units, researchers found that the Doppler frequency of microwave signals that were bounced off the craft drifted at a small, constant rate
The casimir effect cannot exist, as I understand it, on large scales like that. Its a force that results from the interesting effects of bringing two conductive surfaces so close to one another that only certain wavelengths of virtual parties can exist between the plates, whereas all wavelengths exist on the other sides of the plates. As a result, there is vacuum pressure pushing the plates together.
Its worth mentioning that yes, this could be used to extract energy from the vacuum, although no one has figured out (a) how to do this on a large enough scale to be useful and (b) whether it would take more energy to position the plates than you could extract (see below).
Logically, the energy to seperate the plates from one another should equal the energy gained by their collapse together due to vacuum pressure, so that should mean this is no net-gain.
"Stumble before you crawl"
:P
Abbot: Your holiness, our physics research team has discovered the reason for the heretofore unknown force on the Pioneer probes.
Pope: I KNEW we'd get to the bottom of that!
"A witty saying proves nothing." ~Voltaire
"d'Oh!" ~Homer
The original paper on the anomolous acceleration came out, I think, in 1997 (I reviewed it in a graduate astrophysics class I was taking around then). The authors did a good job of discussing some of the possible explanations for the discrepancy, including leaks from the craft, dark matter, 'modified newtonian dynamics' (MOND), and others which I can't remember. None of the explanations they came up with really explained the magnitude or direction of the effect that was observed.
A little while after the paper was released a researcher pointed out, in a short, concise, article, that assymmetry in the way radiation from its ever-weakening energy sources (the RTGs mentioned) reflected from the craft, especially from the main communications antenna produced an acceleration of roughly the right magnitude and in the right direction.
It would have been great if MOND had provided the explanation (MOND has been proposed as an alternative to the bulk of the dark matter content in galaxies - not as an alternative to the content in the rest of the universe, though): I like observations which throw a wrench in our usual way of thinking about the universe - it makes things much more exciting. =;-)
#include "cunning_plan.h"
I think it is all the bad music and talk shows being broadcast for the past 10-15 years. That would hold anyone back.
Q: Why are pioneer 10 & 11 moving off course?
A: Because dark matter sucks.
A2: Because intersteller space sucks.
A3: Because SCO sucks less, the farther away you get from it.
I'm going to be here all week people, and the 10:00am show is completely different once I get my coffee.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
Couldn't it be continuously hitting against clouds of dust?
How close are these probes relative to the Oort cloud? I would think that what we are witnessing is that the probes lack the velocity to escape and will eventually become part of the Oort cloud.
"I bow to no man" - Riddick
So, we have to raise the Yamato, outfit her with a Wave Motion Gun, and go out there and whup that ass!
I didn't think the house band in Hell would play this badly.
Yep, Space Barnacles.
the major advances in civilization are processes which all but wreck the societies in which they occur - A.N. White
"Space, it seems to go on and on forever. But then you get to the end and a gorilla starts throwing barrels at you."
Affect and effect are two different verbs, with related but quite different meanings.
Affect is the more common. To affect something is to alter it, usually but not always in a harmful way.
Effect is less common. To effect something is to cause it to happen. I noticed people starting to use this more commonly about eight years ago. Soon afterwards, people started to use the verb "to effect" instead of the verb "to affect", unaware of the difference in meaning. The difference is so strong that these people often end up saying the opposite of what they mean.
here is a good reference.
http://www.spacedaily.com/news/voyager1-03c.html contains some interesting data that may be a clue:
:-) ).
"The location of the heliopause, which marks the outermost edge of the solar system, is a subject of scientific speculation. In two papers recently published in the journal Nature, scientists debated whether Voyager 1 has already reached the termination shock, a sign that the heliopause may be near. The termination shock is caused by a reduction in the speed of the solar wind as it slams into cooler plasma at the edge of the solar system and is similar to the sonic boom that occurs on Earth when an airplane crosses the sound barrier."
So my guess (IANAAP) is they have lost their (solar) wind in the back they had and hence the decceleration. It may not be so simple, though. Perhaps the space on the inside of the heliopause sphere is constantly "sweeped" by solar wind and therefore might have lower density then surroundings (picture: we are in a kind of a solar bubble!
There is a way to put my hypotesis to test: check the temperature readings for signs of friction, or perhaps even cooling.
gaining mass by gathering dust?
bj
My point is that "affect" and "effect" sound similar but have different meanings, although etymologically they are related. Similarly, "Austria" and "Australia" sound the same and have the same etymology (they both mean "South-ia"), but are in fact two different countries in different hemispheres.
If you say that Austria thrashed the USA at cricket today, you haven't made a "grammatical error", you've made a factual error. The headline of this article is a factual error. Pioneer 10 and 11 were effected by NASA, whatever they may have been affected by since.
Humankind's challenge is to evolve into something that can cross interstellar distances and colonize other solar systems efficiently. How this is to be accomplished (biomechanoid, or some other exotic technologies which are beyond our understanding) is an exercise left for future generations. Arthur C. Clark thought the same in The City and the Stars (et al) with the massless mind "Vanamonde" and his peers.
If such a species had already evolved, and FTL was available to it, we would be a sitting duck (assuming that we had desirable resources). As it stands, there is a great deal of time that must pass for such a species to reach us (hopefully).
The time required for interstellar colonization is nature's way of forcing us to be thorough and consistent, and to make many of our errors early on, perhaps before the effects upon our survival become critical.
Of course, this outlook for our initial stages of colonization must span hundreds of thousands of years. We might end up wiping ourselves out due to our infantile handling of the global ecology long before then.
But it's nice to have goals.
Everyone seems to be operating under the assumption that a force is acting to push the probes closer. What better describes what is going on is that the probes are no longer being influenced by an outward force (perhaps solar wind). So lets say theoretically that the sun's gravity as we observe it is Gsun. But with this additional force now detected, we're really seeing Gsun = Gactual - Fnew.
The laws of physics don't just stop working. More likely, we just aren't observing the phenomenon correctly.
There are big problems with all of these techniques.
Worm holes: the problem is described in the article -- even if it can be achieved from an engineering perspective, and even if the theory is correct, you need to travel to your destination by conventional means to open the wormhole up in the first place.
Alcubierre's warp drive: several problems exist; primarily what is referred to as "negative energy" in the article can be thought of more easily as "negative mass". It's quite likely that no such entity can exist in our universe, we certainly have no idea how to produce it. And you need a lot of it, too. Second, the control problem referred to in the article is much more serious than it sounds. The problem is that the apparatus to control the warp effect would, essentially, need to operate on the unwarped universe outside of the travelling region; based on our current understanding, if the region were travelling at or faster than light, then the rest of the universe would be causally isolated from it, so whoever was travelling inside the warp ship would not be able to control it.
Negative mass: probably can't exist. There's no evidence to support it.
Millis space drives: these have less problems, but aren't actually FTL drives; they're "reactionless" traditional drive systems. This allows you to accelerate to significant fractions of c, but you'll take a while to get there.
Austria is that island where the toilets flush backwards, no?
Austria is an island, in the sense that it's surrounded by Europe.
I'm not sure about Austrian toilets, but I'm afraid they may resemble German toilets.
-kgj
-kgj
Just a thought, but if light were to move faster than the constant we asign to it, wouldn't objects moving away from us appear to slow down?
The probes are temporary swapped out, while the Universe Emulator is loading necessary modules for areas outside of this Solar system. :)
Hyperom.com
One of my favorite demonstrations from Physics class was when my teacher accelerated a ring of (non-ferrous!) aluminum into the cieling (nearly broke a light fixture) using an electromagnetic field.* This was the same day as he showed various non-ferrous pendulums being slowed to a stop in a fixed magnetic field due to eddy currents created in side the pendulum.
Moral of the story is that, even absent influences such as gravity and friction, a fixed magnetic field can change (slow) the velocity of a non-ferrous metallic object. Granted, though, you have a point about the fast drop in intensity with distance for magnetic fields...
*I don't remember how the device was constructed, or if the teacher even bothered describing it in detail. All I remember is that it plugged into 110 V AC, had a button he'd press, and it buzzed rather loudly while the button was pressed. The aluminum ring was shot into the acoustic tiles in the 20-foot ceiling hard enough to damage the tile, and the teacher admitted that he had actually broken a light fixture in a previous semester. Since then he aims more carefully.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
God has got to be the most flimsy belief that has come about since the idea that gods caused volcanos. (how else could such massive forces erupt from the earth?). It's like inventing truth for the sake of making the world make sense to youi or your paradigm.
Religion is a bunch of bull crap invented to make people feel better about not understanding the universe and the laws that govern it.
Point: Just because you don't understand something doesn't mean there isn't a shred of truth in it. Dark matter is a POSSIBLE explanation to the differences that we see between what we understand and observe, but is not the only explanation.
While that would make a nice and simple explanation, I think that this paper is flawed, since it does not take into account the different density of the kuiper belt in the directions the Pioneers are headed. The kuiper belt is most concentrated around the ecliptic (the plane the planets are moving in as well), and Pioneer 10 is more or less within that plane, while Pioneer 11 is about 17 degrees above it, which should make a difference. Oh, and they got the mass of the spacecraft wrong, it's 258kg without fuel (some should be left), and they're assuming 241kg. Their speculation about dust particles is not very credible, as the pioneers would not survive many of those breaking them down at the observed rate.
Yes, we have detected dark matter. I agree that the galactic rotation curves, etc., are indirect "detections" only, but gravitational lensing is pretty damn direct. Light rays from distant objects are being bent by some large, dark, gravitational masses. These masses, particularly in galaxy clusters, have been mapped out and show differences from the the galaxy distribution themselves.
I agree with your other statements at some level, even taking to account the lensing results.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
Tell that to the neutrino guys I've worked with.
Neutrinos have non-zero rest mass, and hence are known and detectable dark matter. (It's worth noting, though, that they're "hot" dark matter, and "cold" dark matter is more like what you're complaining about. Neutrinos also only account for maybe 20% of the needed dark matter.)