Slashdot Mirror
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."
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.
You mean that the sun and the moon together pull stronger than the sun alone?
Please correct me if I got my facts wrong.
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.
ffs, all Einstein did is put together a unified theory of the universe based on knowlage of the time. He knew it wasn't the absolute theory of the universe and that it would be modified as time went by. Stop trying to dis. the guy and appreciate what he did.
And energy, which has gravitational attraction (or so says Einstein). In this case, of about 25 grams distributed over a whopping huge volume.
Next theory please?
Exactly. There are almost certainly missing elements in the model for gravity, for quantum mechanics, and so on. Maybe sometime in the future someone will come up with a quantum - relativistic super duper theory that brings disparate theories together. Yes, some of that is what string theory is trying to do. In the end though, it is going to take a LOOONG time before advances in science can be applied to engineering. Finding new particles, finding dark matter, and finding where missing socks go have no real life application right now - and I can't even imagine one. Just as math was (and still is) far ahead of where science can go, science is far ahead of where engineering can go. The missing elements of models would be useful for abstract knowledge, but have no practical use right now or probably in the next century.
I submitted this story last night, and it didn't get posted.
Or, you could just do the test here on earth at night. Then the whole mass of the earth is between your apparatus and the sun.
I guess the reason that doesn't work is that thermal effects (like those that may be causing the Allais results) change everything at night, and it's too hard to distinguish a legitimate anomaly from some-thermal-effect-we-didn't-think-of.
Still, there's no need to go to Jupiter or even the moon; as a satellite in a higher and higher earth orbit checks the effect, the earth effects will drop off as 1/r^2 while the anomaly should remain constant.
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.
No, this makes perfect sense. Gravity has a "size", or more precisely, a magnitude. Well, it's a vector, so it has a direction too.
For instance, normal earth gravity has a "size" of 9.8 m/s^2. When the moon passes between you and the sun, they measured gravity getting 6e-10 m/s^2 stronger (that number comes from their paper).
What they are saying is with that level of acceleration, it would take an object about a day to move 2.24 meters (or 6-7 feet, roughly the height of an apple on an apple tree)
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.
shouldn't they also occur every time the earth is between the pendulum and the sun...say, every night
Problem is, there is a known effect that would change the gravitation acceleration on an object as the Earth's orientation changes with respect to the sun. During the lunar eclipse, though, there's very little change in the relative positions and orientation of the earth, the moon and the sun.
That is, I suspect it would be too hard to distinguish between any such Allias Effect from the Earth and solar (and in this case, lunar) tides.
Kinda sounds obvious to me. Just like tidal waves, the molten metals in earth gets pulled towards the sun and moon. This shifts the earth's mass upwards thus causing an increase in 'g'. Whats wrong with this theory? Has this already been proposed?
- Vinay
Fuck off - I'm not going to mod shit up simply because some dumbass says it should be modded up. I'm going to mod posts based off of what I think of them
That's a load of bullshit. Just because two problems are hard doesn't mean they're equivalent. I challenge you to give one reference about the equivalence of the three body problem and the halting problem.
Well, in Penteli mountain, there are verified gravitational anomalies (there are also a hell lot more noted in the Hellenic space by physicists).
Who mods this crap up? "NATO was interested" and "gravitational anomalies"?!? WTF!? I thought we were nerds here...
"Gravity hills" are nothing more than optical illusions, Penteli mountain included. Check out this link for more information. (shakes head at the state of "science" here on Slashdot... double shakes at the tin foil hat wearing mods...)
I would have to say that explosives are the most abused technology in all of history.