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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...
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.
Yes. Syzygy is when the Earth, moon, and the sun are all lined up. Spring tides occur at this time. Spring tides are unusally high tides that occur during syzygy.
as i understand it it's the other way round - one of the possibilities mentions the moon "blocking" gravitation from the sun during an eclipse.
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.
Now there's a scrabble word if ever I saw one!
Hic iacet Arthurus, rex quondam rexque futurus.
Havent we had objects in orbit for 40+ yrs now, many positioned in just the right orbits to transit thru the moon's shadow? Satellites like the GPS series, whose positions are known and tracked to the centimeter?
Why hasnt this effect, if it exists, been noticed 1000's of times?
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.
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.
Apparently, you've never seen a scrabble word. (There are only two 'y's in Scrabble).
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.
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.
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
To answer your question, the effect, if it exists, hasn't been noticed because there are many other perturbing effects on the orbit. The most important, by decreasing magnitude, are: earth's gravitational attraction, moon attraction, oblateness of the earth (that is, the flattening at the poles), sun gravitational attraction, solar radiation pressure, tri-axiality of the earth (that is, the east-west irregularity in the gravitational attraction), albedo (that is, the pressure exerted by the sunlight reflected by the earth), dynamic solid tide (the gravitational effect of the earth's deformation caused by the moon's attraction), gravitational attraction by venus, gravitational attraction by jupiter, relativistic effects caused by the earth's gravitation.
So, you can see that there are so many other effects that it's pretty hard to separate each one. In particular, the effects of solar radiation and albedo change more or less randomly, so in the end, whatever cannot be explained otherwise in a satellite's orbit is normally attributed to "solar radiation".
It's only when a probe goes so far from the sun as Pluto that solar radiation becomes small enough for other perturbations to be measured.
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.
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 individual effect of each of the Sun or the Moon on the Earth is to cause two tidal bulges of the oceans/lakes/rivers of the Earth
(one facing the object, and the other on the opposite side). These lead to diurnal (24 hour cycle) and semi-diurnal (12 hour cycle) tides.
When the Moon and Sun are aligned together, you have Spring tides. Neap tides are caused when th e Moon and Sun are perpendicular to one another. There is also the Proxigean Spring Tide, when the moon is at its closest point to the Earth (perigee). This time is known as the "proxigee", and causes even higher tides than ordinary Spring Tides. Fortunately, these only occur once every 1.5 years.
The gravitational acceleration at the Earth's surface is 9.8 metres/second per second (towards the centre of the Earth).
The gravitational acceleration on Earth due to the Sun is 0.0059 metres/second per second.
Or about 5.9 millimetres/second.
The gravitational acceleration on Earth due to the Moon is 0.000033 metres/second per second.
Or about 0.033 millimetres/second.
Source: Space Talk Forum
These amounts are small, but research groups at one of the particle accelerator rings actually noticed a distortion in the targeting of the beams due to the stretching/squashing of the surrounding land caused by the changing positions of the Sun and Moon. This caused the beam to periodically go off target.
Intuitively, one would assume that gravity would be less when the Sun and Moon were overhead, and the pendulum would swing slightly higher and slower. Plus the behavior of the pendulum should vary according to the positions of the Sun and Moon.
If the "shielding effect" occurred with large objects, then it would also apply to Earth's ocean tides. The closest side of the Earth one should shield the opposite side, but the bulging effect can be explained by simple vector addition/subtraction.
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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.