Does General Relativity explain this?

Question

Long ago -- probably in 1990 or 1991 -- I saw in a magazine a picture -- In that picture -- a feather and an apple were dropped at the same time in vacuum -- the picture is like this -- at top of the picture the feather and the apple are at the same position -- then probably after 5 sec another picture is taken and superimposed on the old one -- so now there are 2 feather/apple duo stacked on top of the other -- and -- like that there are many instances -- and at the last instance it was seen that feather is a bit closer to the ground than the apple -- some thing which means there is more force between the feather and the earth -- than -- between apple and the earth -- does einstiens general theory of relativity predict this -- I dont claim to have a theory which rivals GR -- I know nothing about GR -- while free I read some popular science books on physics -- just being curious -- the magazine where I saw the pic was "span" -- it is an american magazine published in India

Answer 1

In a perfect vacuum, the apple and the feather will both fall at the same rate. If the feather hits bottom first, it was either released first or did not quite as far to drop as the apple did.

Answer 2

If a real apple was put into a real vacuum, then moisture would evaporate pretty fast from the apple and its mass would change as it fell. So this would not be a simple case of a solid object falling in a vacuum.

So -- I expect the apple and the feather would not fall at the same rate, simply because the mass of the apple is decreasing.

If I was doing this experiment I would use a billiard ball and a feather!!

Answer 3

Not knowing the particulars of the experiment, I can only speculate on why the feather leads the race...but GR is not one of them.

GR does indicate gravity affects time lapse rate ...an effect called time dilation. And GR indicates space itself is warped under gravity. But those effects require enormous gravitational pull, like from super galaxies, to see even the slightest bit of measurable differential. Certainly the mass differentials between a feather and an apple would not be measurable.

Perhaps the release mechanisms are not exactly in sync; so one object gets released at a slightly different, but measurable, time. It would be interesting to see the results of multiple releases where the feather and apple were released alternately from both release mechanisms.

Answer 4

You don't have to use GR!!!

This is a trivial matter. Use newton laws of motion and the weight formula:

F = m * g

m *a = m * g

a = g

So the acceleration, and thus the velocity if the bodies start in the same initial position it's the same for all objects, independent of their mass.

In the every day picture, we don't appreciate this effect because there is always air resistance to falling objects. This resistance might depend on the mass of the object.

Good Question...

Answer 5

Im no expert myself either put I have explained what I understand about relativity several times. E=m*c^2 means energy can be turned into matter and vice versa. It takes a lot of energy to equal a little mass. The speed limit of the universe is c, the speed of light. This is because as you approach the speed of light your mass, resistance to acceleration, increases exponentially. That means it would take an infinite amount of energy to accelerate to the speed of light. As you get close to the speed of light time slows down. If you were going nearly the speed of light and you were shining a flashlight ahead of you then shouldn't the light be going nearly twice the speed of light? Time slows down so the light seems to be going ahead of the spaceman as if he were standing still and not barreling through the universe at 99% the speed of light. This allows light to be going the speed of light no matter if your on the space ship or watching from afar. And since energy and mass is the same substance energy has a gravitational pull. This is why light curves around the sun or can't escape a black hole, it is affected by gravity and creates gravity. No real math either, wasn't that fun =)

Answer 6

If dropped from the exact same height at the exact same time, they should hit the ground together, at the same time. If the feather hit first the test was not controlled properly.

Answer 7

What you saw is trick photography. What you describe is neither indicated nor contradicted by relativity. I can think of interjectional causes that could produce the result, but I have seen a photograph that appears to display what you describe, and I am aware of the cinematic technique that produces it. It is just some pretty camera work.

Answer 8

If a difference like that was observed in the experiment you saw, my first guess would be static electricity. It would not be affected by vacuum and would affect an object of low mass more than an object of high mass.