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Gravitation Anomaly Measured
Rob Riggs writes "Is there a hole in Einstein's Theory of Relativity? A story in The Economist talks about an apparent gravitation anomaly recorded during solar eclipses. According to Chris Duif at the Delft University of Technology, the 'Allais effect' is real, unexplained, and could be linked to another anomaly involving a the Pioneer spacecraft. More detailed information can be found in the paper he has just posted on arXiv.org."
Where is Capn' Picard when he is needed
"Doing what i can, with what i have." ~ Burt Gummer
My wife had one of these after she went in for breast augmentation...
You mean that the sun and the moon together pull stronger than the sun alone?
Please correct me if I got my facts wrong.
Remember: there is no gravity. The Earth sucks.
It's good to use your head, but not as a battering ram.
My limited understanding of interstellar phsyics is that einstins equations have never really been solved for the third body problems. Am I wrong? If I remeber correctly we can only aproximate third body forces (tidal forces) even when using the newtonian model.
Well.. maybe. Or Maybe not. But Definitely not sort of.
Why is this being carried in the Economist? Shouldn't it be picked up by New Scientist or some other scientific (or pseudo-scientific) publication?
It's good to use your head, but not as a battering ram.
I would highly doubt that Einstein's theory is flawed, but then again, they did not study the effects of gravity during a solar eclipse back then.
Not only is this comment not "insightful" but it is just plain wrong. One of the original PROOFS for relativity involved measuring the amount that light is bent during a -- pay attention now -- solar eclipse. To quote the article you so carefully did not read, 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."
Next.
According to the article, earlier results include those measured with "so called paraconical pendula". It's shocking to think that we have allowed ersatz paraconical pendula to be used in place of the genuine articles.
Mr. President, we must spend whatever is necessary to close the paraconical pendula gap.
Who is John Cabal?
Einstein once said something along the following lines:
Testing theories is a very thankless task, because nature never says "yes." Usually nature says "no," meaning that a measurement contradicts a theories predictions.
Sometimes, nature says, "maybe," indicating that while the measurements are consistent with the theory.
But nature never says "yes," because your theory could be incomplete or erroneous but your instruments are either too inaccurate to detect the error, or you are not doing the right experiment.
Newtonian dynamics makes good enough predictions for alot of phenomena.
General Relativity is more precise in its predictions.
Given our difficulties in unifying it with quantum mechanics, it is likely that we don't have the right theory. As our instruments get more precise and we conduct more experiments, eentually we'll get a hint as to where we are going wrong.
For real confirmation, an experiment on one of the Jovian moons would do nicely.
Yes, I'm serious about this. This is fundamental to our understanding of physics, which is in turn fundamental to our understanding of the origins, processes and fate of the universe. A billion to put a pendulum on the Moon would be money well spent.
Sustainability and energy independence essay
"Photons have mass. "
They don't. They do have momentum though.
This could be a confirmation of one of the competing theories of gravitation: the "MOND" theory, that at very low accelerations, gravity gets stronger.
As I recall, MOND solves some of the more annoying problems of astronomy: missing matter, and the apparent need for a period of faster-than-light expansion early in the history of the universe.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
I wonder if Gravity Probe B will be able to measure this effect if it is still in working order next time an eclipse rolls around.
(Side note-- I never heard of this probe until I saw it in a magazine. Why not?)
But, given your first postulation, we have a problem:
Given: Photons are quantized light
Given: Light travels at c
Given: No massive particle can travel at or faster than c
Given: c is defined as the speed of light in a vaccuum
Postulated: Photons have mass
Therefore: Light has mass, as it consists of massive particles
Therefore: Light cannot travel at or faster than c
Therefore: The speed of light is less than c.
Therefore: c is less than c
ERROR: STACK OVERFLOW
Haec merda tauri est. Ceterum censeo Carthaginem esse delendam.
Too easy, give me another..
MOND evidently has problems; while dark matter can explain both galactic rotation curves and cosmological behavior, MOND is hard to make consistent with both. (And it's also, I've heard, extremely hard to make consistent with any relativistic theory of gravity.)
As for the "apparent need" for FTL expansion in the early universe, by which I assume you mean inflation, some very specific predictions of inflation are now verified by WMAP, including the structure of the acoustic peaks in the CMBR angular power spectrum.
Wacky as they may seem, dark matter, dark energy, and inflation are the mainstream theories right now for a reason: the alternatives so far simply don't work as well.
African or European?
Let's assume for the sake of argument for a second that gravity is a wave...
Could this be constructive interference caused by the collision of the gravity wavefronts from the sun and the moon when they are lined up just right?
Just a thought, the real explanation is probably much crazier.
Knowledge != Intelligence
The easy explanation as I was given to understand is that the photons propagate in spacetime, ie the wave that they are does. Spacetime is curved by gravity, hence the photons/waves curve with them. According to General relativity, they cannot have mass since they propagate at light speed. Any object with mass obtains infinite mass upon attaining lightspeed, which is impossible. Hence a photon has no mass. Of course, solar sails work so photons can exert pressure which might lead one to suppose they have mass. In sense they do, as energy and matter are equivalent. In the case of a solar sail, it is impulse that is being transferred. It depends on how you measure the presence of the photon. By the way, note that Duif does not cast doubt upon Einstein's theories per se. Rather, he invokes the presence of dark matter (although no one has ever demonstrated its presence unequivocally).
----- One learns to itch where one can scratch.
Given that light can be slowed down, what reason have we to assume that c is not some slowed-down light speed?
It is. You can get a very slight boost in the speed of light by suppressing quantum vacuum fluctuations (the Casimir effect).
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
If gravity is (very slightly) blocked by mass, then one would expect to have a different weight on the dark side of the earth than on the light side. It this observed? After all, if you're on the dark side, the entire mass of the earth should be shielding you (ever so slightly) from the gravitational pull of the sun.
According to modern definitions, the unqualified word "mass" refers to invariant mass (which for massive particles is called "rest mass", although that term makes no sense for photons which can never be at rest). Thus, photons are referred to as massless particles.
The kind of mass you're talking about is nowadays referred to variously as "mass-energy", "effective mass", "relativistic mass", or just "energy" when people feel like slurring the difference.
Photons are both influenced by gravity, and can influence gravity.
To understand how they are influenced by gravity, one must understand that according to general relativity, spacetime is curved, and bodies follow paths called geodesics which are paths of minimal distance. (Geodesics on a spherical surface, for example, are segments of great circles.) Photons travel along a special class of geodesics called "null geodesics" (Which don't exist in ordinary Euclidean spaces, but do in spacetime. They are essentially paths of zero "length" where length is defined a bit differently for spacetime.) Anyhow, massive bodies influence matter around them by curving spacetime. In curved spacetime, geodesics are no longer straight lines, but curved paths. Photons trajectories can thus be bent by massive object even though they have no mass, in contrast to Newton's theory of gravity which holds that massless objects do not participate in gravity.
Additionally, photons can influence gravity themselves. According to Einstein, it is not just mass, but momentum and energy that curve spacetime. (This is through a quantity called the stress-energy tensor, T, which can be represented by a 4x4 matrix). Since photons, although massless, have momentum and energy (this is allowed by special relativity, forbidden by Newtonian mechanics) they can gravitate as well.
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
Well, it's yer space-time warping by large gravitational fields innit.
r s/961102.html for a pretty good explanation.
Check out http://imagine.gsfc.nasa.gov/docs/ask_astro/answe
Once I was a four stone apology. Now I am two separate gorillas.
Although, despite all proposed conventional explanations fail to explain the observations either qualitatively or quantitatively, it is likely that the reported anomalies will turn out to be due to a combination of some of these effects and instrumental errors. The judgement of some of the experimental results is hampered by the lack of a statistical analysis and/or data of sufficient length. Nevertheless, there exist some strong data which cannot be easily explained away.
And here's a point not covered in the paper: if these experimental effects occur when the moon is between the pendulum and the sun, then shouldn't they also occur every time the earth is between the pendulum and the sun...say, every night? If this effect is due to a large mass's ability to block gravity, then surely someone should have detected this effect from the earth blocking the sun's gravity by now!
On the other hand, if the effect is because moon cheese acts as a form of Cavorite, well, then I can't help you with that.
This is just wrong. The Newtonian prediction gave an angle of deflection which is half that of the Einstein prediction. The experimental prediction decided in favor of Einstein.
The General Theory of Relativity consists of sixteen coupled differential equations that can be reduced to ten, which when just written out would take hundreds of pages. It is so complex that there are research programs just categorizing possible solutions.
Analytical solutions only exist for two cases: the overall case that describes a homogeneous universe, and the Schwartzschild case that describes a spherical body. There is also a linear approximation that gets gravity waves.
It's a bit premature to say that GR has a hole in it, because nobody has ever explored it fully. Perhaps this will lead to a solution of GR for this case, or perhaps not.
Until he was told to move his pendulous mass
Faith: n. -- That human impulse that drives them to steal appliances when the power goes out
I thought running Eclipse on my Sun workstation was just ironic.
For years, it has been believed that electric bulbs emit light, but recent information has proved otherwise.
Electric bulbs don't emit light; they suck dark. Thus, we call these bulbs Dark Suckers.
The Dark Sucker Theory and the existence of dark suckers prove that dark has mass and is heavier than light.
First, the basis of the Dark Sucker Theory is that electric bulbs suck dark. For example, take the Dark Sucker in the room you are in. There is much less dark right next to it than there is elsewhere. The larger the Dark Sucker, the greater its capacity to suck dark. Dark Suckers in the parking lot have a much greater capacity to suck dark than the ones in this room.
So with all things, Dark Suckers don't last forever. Once they are full of dark, they can no longer suck. This is proven by the dark spot on a full Dark Sucker.
A candle is a primitive Dark Sucker. A new candle has a white wick. You can see that after the first use, the wick turns black, representing all the dark that has been sucked into it. If you put a pencil next to the wick of an operating candle, it will turn black. This is because it got in the way of the dark flowing into the candle. One of the disadvantages of these primitive Dark Suckers is their limited range.
There are also portable Dark Suckers. In these, the bulbs can't handle all the dark by themselves and must be aided by a Dark Storage Unit. When the Dark Storage Unit is full, it must be either emptied or replaced before the portable Dark Sucker can operate again.
Dark has mass. When dark goes into a Dark Sucker, friction from the mass generates heat. Thus, it is not wise to touch an operating Dark Sucker. Candles present a special problem as the mass must travel into a solid wick instead of through clear glass. This generates a great amount of heat and therefore it's not wise to touch an operating candle.
Also, dark is heavier than light. If you were to swim just below the surface of the lake, you would see a lot of light. If you were to slowly swim deeper and deeper, you would notice it getting darker and darker. When you get really deep, you would be in total darkness. This is because the heavier dark sinks to the bottom of the lake and the lighter light floats at the top. The is why it is called light.
Finally, we must prove that dark is faster than light. If you were to stand in a lit room in front of a closed, dark closet, and slowly opened the closet door, you would see the light slowly enter the closet. But since dark is so fast, you would not be able to see the dark leave the closet.
Next time you see an electric bulb, remember that it is a Dark Sucker.
Speak before you think
Makes perfect sense.
All they're saying is that if 'g' were of the magnitude of this effect, then it would take a day for an apple to fall from a tree.
d=0.5*g*t^2
Pick a reasonable height for a tree, use 1 day for t, and solve for g.
Roughly, we're talking about something on the order of 10e-9 m/s^2
You have violated Robot's Rules of Order and will be asked to leave the future immediately.
If gravity is blocked by mass, it would be a simple thing to simply observe a pendulum at night time and compare that to daytime.
The earth would block much more solar gravity than the puny little moon.
Then again, we would need a pendulum which is attracted to solar gravity because every pendulum on earth which swings, is doing so because of the gravitational attraction of the Earth.
Pay attention... pendulums on earth fall towards the EARTH, NOT THE SUN.
And another thing:
if you allow a pendulum to swing freely for 24 hours, the reason its path will trace out a circle, is *because of inertia* and the earth is rotating. THE PENDULUM IS NOT SWINGING TOWARDS THE SUN'S GRAVITATIONAL FIELD.
Are there any economists here who can explain this more clearly?
No one has a right to their *own* opinion. They have a right to the TRUTH.
I'm inherently skeptical of any paper first heard of via a website. Call me old fashioned, but I'd rather wait for peer review to run its course and read this in something like the Journal of the AAS. Having said that, I read the paper and it's considerably less sensational than the summary suggests. The author considers it possible, if not probable, that the effects can be ascribed to a combination of experimental error and theorists not having taken into account the circumstances of the situation. He suggests that further research would be useful, but I've never read a paper that didn't...
"'I pass the test,' she said. 'I will diminish, and go into the West, and remain Galadriel.'"
- JRR Tolkien.
The mobius strip by some definitions has only one side, what does this mean in terms of kinetics? Newtons third law states that every action has an equal and opposite reaction this is okay in a euclian universe, in a non eucldian the equal and opposite reaction is paradoxical because it is not a straight line - it is curved. If it is curved, eventually it will curve right back on itself and no longer be opposite.
The univese might be shaped like a klien bottle and be both inside of itself and outside of itself in terms of time. Help I'm stuck in a loop - help I'm stuck in a loop.
Just some zany ideas.
Laters
It's called an elephant's trunk whereas it is in fact, an elephant's nose, a nose by any other name would smell as sweet
what is light has mass, and that mass is contained in too equal and oppositely charged particals? like one half mass, one half negitive mass, this might explain wavelengeth and many other things, Just a thought..
AcrazyPhysicsPoet
We all must band together against the asome power of cheese
This also could explain why astronomers can't find the missing dark matter.
No one has a right to their *own* opinion. They have a right to the TRUTH.
Well, in Penteli mountain, there are verified gravitational anomalies (there are also a hell lot more noted in the Hellenic space by physicists).
:)
For example, you put your car in neutral in the outskirts of the mountain and instead of gravity to pull it down, it is tractored upside. Expert physicists claim there is another energy in the mountain area that is more powerful than the gravity itself, thus creating the effect.
NATO was interested (and presumambly is still) in that particular area. It's part of Greece's x-files
I've asked my girlfriend many times about involving a third body, but she consistently refuses.
The paper is talking about effects on the order of 0.5*10^-10 m/s^2. I don't know how anyone could measure this with a pendulum. Also, the paper doesn't show that this effect isn't accounted for by Einstein's theory. I think they need to solve the equations for the Earth/Moon/Sol system before saying that the effect disproves the theory. The only theory they talk about is Newton's theory, eg. a = gm/r^2, which we already know doesn't hold for the scales that they are talking about.
Seems to me like the effect is most likely due to someone walking their dog a couple blocks away.
More interesting is how everyone wants to prove that Einstein's theory is wrong. Seems to me like a bit of brain-envy.
Nice try, but this article only goes about 0.5*10^-10 of the way to convincing me the chuck the field equations.
The effect is there on the GPS clocks. Its clear that something funny is going on but only some times and so far the experiment hasn't been consistently duplicated which is the traditional hallmark of bad science so I expect this problem isn't getting the attention it deserves. I also expect this is the last major breakthrough in basic science that could be done in a basement and its clear that if you can explain what the heck is going on, some people in Stockholm will give you a prize
You think of The Economist. Where else will you find the all latest scientific breakthroughs?
Sorry, no - Casimir effect has nothing to do with C.
The Casimir effect is a measurable attractive force (really a repellant force from the opposite sides) between two parallel plates that are very close together.
According to QED, there is no absolute zero-energy vacuum - all space, no matter how empty, has energy that spontaneously forms particle/antiparticle pairs that pretty quickly annihilate (see Hawking Radiation, Quantum Foam, etc., Fenyman Diagrams, etc.). These pairs, frequently being wavelike, come in a whole bunch of frequencies.
So, place two plates parallel to each other and real close, and the only frequencies of waves that can fit in there are those with wavelengths that are whole-number fractions of the distance between the plates. On the outside of the plates, however, an infinite number of frequencies can occur, so there is a greater force/pressure outside the plates than inside, so they are forced together.
Interestingly, unlike gravity and magnetism, which follow an inverse-square law, the Casimir effect follows an inverse-hypercube (4th) law, so it gets much stronger than gravity or magnetism when you get really close, but falls off much faster. Source
-T
Proponents of Process Physics claim that Einstien's original case for general relativity was built on a misinterpretation of critical 19th century experimental data and contend that the consequential abandonment of the ancient notion of Æther was wrong headed.
From their perspective, gravity should not be seen as a force field but rather as the cummulative effect of all massive bodies continuously absorbing/dissipating Æther. Locally the earth sucks most of the Æther and we experience the resulting downwards pressure.
-- Our systemic servants do not good masters make.
Wow, Syzygy really is a word. Somehow, I don't remember that one from the decade-old high school science corner of my brain. That's almost as good as Xyzzy.
-jim
There are two possibilities which immediately come to mind. Does anyone know of research about these:
Don't forget, there is still the unexplained slowing down of extra-solar space probes. There are things going on; things we don't understand.
Mys-TEER-i-ous things (with waggling fingers)...
i'd hit it so hard, if you pulled me out you'd be the king of britain [bash.org]
these are the voyages of the fast-food chain McDonalds. It's continuing mission, to explore new countries, to create a race of fat people, to go boldly where no fast-food chain has gone before.
Most of the posts are supposing the physicists doing this are real dumb. That in itself, is stupid. I think one or two have interesting points (e.g. "Einstein is Saf e") and most of the others are way off base. The paper is a summary of research by other people. The problem being discussed was noticed by Allais 50 years ago when he ran a month long pendulum experiment (three drops per minute I believe) that happened to intersect the time of an eclipse. The paper goes over a number of possible reasons for error and includes some as yet unpublished data on experiments intended to uncover them. The possibilities are c reative and followed up scientifically, for example one is done in remote China with nobody within 200 meters. All tests showed the suggested errors to be miniscule, although the paper does suggest that a combination of them might just cover it.
It would appear that a significant anomaly has been detected by various experiments and that professional scientists are taking it much more seriously than say cold fusion. It also is clear that there is a lot still to learn about gravity and that NASA is one of the groups that is working hard to figure out why its space probes don't move as expected. Some people even think gravity moves 20 times faster than light and other stories. It is not a shut case yet. In the paper mentioned in the post, they are saying that most people couldn't in the past solve the problem because they were thinking in terms of the Moon "shielding" the Earth from gravity, which the paper does not believe. They think it is more like an extra horizontal force that sometimes occurs during eclipses (of which there are different kinds including variations of angles). So all the posts about shielding are off base.
NASA has suggested that if experimental error really can't be the culprit, it might be caused by the same thing that apparently is accelerating Voyager more than expected.
I'd like to quote from a NASA article on the people who built Gravity Probe B.
I think that is cool. It says to me we have a good chance about learning a lot more about gravity and lots of other fundamental physics in the near to medium term future.
The paper also notes that one more individual experiment will not solve it; many simultaneous and comprehensive experiements are needed over the next few eclipses. It also suggests that it might be interesting to investigate "gravitational lensing by relativistic dark matter" although I cannot tell if that suggests we are in the midst of a river of high speed dark matter or what, something invisible passing between the Earth and Moon? Somebody with astrophysics degree please finally step in. Sounds like it might be interesting to have the ISS get involved too!
Links:
NASA decrypting the eclipse ('99)
Gravitational Anomalies - Literature List
In Search of Gravitomagnetism (NASA Gravity Probe B)