Inconsequential gravitational quirk?

[drawkcab]

Hey, I'm new here and I'll state right here and now that I know little about physics, so bare with me and try not to laugh too hard

 

Just a thought on gravity that someone here could probably clear up pretty easily for me. Basically, I don't contend that this could explain gravity, I just think it may have some effect, however insignificant.

 

Most of you would know of cosmic radiation. It appears to rain down upon our planet from every conceivable direction in a constant bombardment. Most of you would also have heard of a force called radiation pressure. Have you guessed where this is headed?

 

If radiation is striking the Earth, then it is applying a pressure. While this pressure is constant on every surface of the earth nothing would happen, but if the radiation were slightly less from one direction, then the Earth would be pushed by the radiation striking it on the opposite side to the deficiency.

 

If cosmic radiation strikes the Earth from one direction, and it's force is absorbed, then there will be less exiting the Earth on the other side (as with x-rays: the rays that strike the bone don't continue through to the recording device while the rest do).

 

This lesser amount of radiation exiting a massive object will appear to have the effect of attraction between two bodies, but really, they are being pushed together, not pulled. Imagine radiation coming from a point A, and travelling to a point B. If one were to place two balls apart from each other in a straight line between points A and B, the radiation hitting the ball closest to point B would be diminshed by passing through the first ball. So, taking radiation pressure into account, the ball closest to A would begin to proceed toward point B. The other ball would too, but at a reduced velocity. If you further imagine that radiation is also travelling from B to A, then the balls will both travel toward each other.

 

This idea seems to be capable of encompassing everything I know about gravity (which isn't much). For instance, the more massive and/or dense the object, the greater the blockage of radiation, and the greater the force it exerts; the closer the objects are in proximity, the greater the force; the force would deplete with distance in a hyperbolic way; if two bodies moved past each other, the deficiency of the radiation between them would be constantly shifting and result in orbits (I think- It would take me ages to explain why I think this heh); if two bodies of different sizes were next to each other, the smaller of the two would be moved toward the larger at a greater rate since the larger blocked proportionatley more radiation from the smaller.

 

I realize of course that radiation pressure is weak, and would have an entirely unsubstantial effect on actual heavenly movements, but I just think it's interesting to think that gravity need not be considered an attraction per se. I am sure someone will blow this one entirely out of the water, but I'll appreciate the feedback regardless.

[insane_alien]

ok, for enough radiation to be striking the earth to cause the same acceleration gravity does would be phenominal like, atmosphere and oceans boiled away, land eroded everything dead kind of phenominal.

 

the total radiative imbalance(some guy worked it out) is a couple of mega newtons across the whole earth(this causes a very very very very tiny acceleration, it would take a few years to amount to 1 m/s . and get this, its AWAY from the sun. if it was radiation pressure i'm afraid we would be flying away from the sun pretty quickly by now.

 

also how would the sun hold itself together?

[Klaynos]

I'd assume the reason it's away from the sun, is that the sun kicks out so much

 

And as we're orbiting no other part of space is any more exposed to us as any other, and space is isotropic (the same in all directions)... Probably

[swansont]

Radiation pressure is the idea behind the solar sail concept, and you need a big sail and small payload to get any kind of noticable acceleration. The radiation pressure on the earth is very small compared to its mass, as i_a has noted. So let's check some numbers: I get a maximum acceleration of the earth of about 10^-16 m/s² from solar radiation. Solar power at the earth is 1.74 x 10¹⁷W, so that's ~ 600 MN/6x10²⁴ kg. This ignores the re-radiation from the earth, which makes the net effect much smaller. Whoa. Make sure you're hanging on to something after an eclipse is over, when that light slams into us.

 

(However, the radiation does have a measurable effect on the magnetic field of the earth, by deforming that magnetosphere. Diurnal variation of ~ 50 nT, IIRC)

[losfomot]

OK, so far, you're all focusing on the 'radiation pressure' aspect of Drawkcrab's post. Yet even he admits:

I realize of course that radiation pressure is weak, and would have an entirely unsubstantial effect on actual heavenly movements, but I just think it's interesting to think that gravity need not be considered an attraction per se.

 

And so I think that what he (or she) is looking for is a discussion on the idea that something may be pushing everything in the way that he describes. Radiation can be replaced by 'some form of energy' or even simply, 'something'.

 

This idea has intrigued me for a long time, I think I especially like it because it deals (at least partly) with a cause of gravity and not just the effect that Newton and Einstein describe.

[timo]

This idea has intrigued me for a long time, I think I especially like it because it deals (at least partly) with a cause of gravity and not just the effect that Newton and Einstein describe.

If I understood you correctly then you want to replace a gravitational field with some unknown source of radiation which, in contrast to the gravitational field that pulls (whatever that might mean and whyever you think so), pushes objects together. And the reason is that you replace mere effects (gravitational fields and their impact on objects) with a real cause - some unknown radiation that pushes? I think I prefer my "little green gremlins eat space between massive objects"-hypothesis for a cause. It´s a bit less abstract than some unknown form of energy.

[D H]

I think I prefer my "little green gremlins eat space between massive objects"-hypothesis for a cause. It´s a bit less abstract than some unknown form of energy.

 

I like it! Can I extend your hypothesis a bit? I conjecture that the little green gremlins not only eat space but also eat a little green light (they are green, after all). This will result in giving far distant objects a reddish tinge, a red shift, if you will.

[CanadaAotS]

If I understood you correctly then you want to replace a gravitational field with some unknown source of radiation which, in contrast to the gravitational field that pulls (whatever that might mean and whyever you think so), pushes objects together. And the reason is that you replace mere effects (gravitational fields and their impact on objects) with a real cause - some unknown radiation that pushes? I think I prefer my "little green gremlins eat space between massive objects"-hypothesis for a cause. It´s a bit less abstract than some unknown form of energy.

 

*gives Atheist an award for "Best Cause of Gravity Theory* lol

All we have to do is knock the little green gremlins out, and woohoo! anti-gravity is within our grasp!

[m4rc]

Interesting idea. I've tried to think of how to experimentally test your speculation with the accepted theory. I'm convinced that both models predict that the force of gravity would vary as the 1/distance squared

 

The main difference sems to be that in your model of gravity that if mass blocked this radation, then the force of gravity would depend on mass in a different way. Instead of being proportional to the mass the amount of radiation blocked by the mass would follow a exponential decay relationship. In reality, the force of gravity is proportional to mass F=GM1M2/d^2.

[losfomot]

If I understood you correctly

You misunderstood me.

then you want to replace a gravitational field with some unknown source of radiation which, in contrast to the gravitational field that pulls (whatever that might mean and whyever you think so), pushes objects together.

I never suggested a gravitational field that pulls, although I certainly don't count that possibility out.

And the reason is that you replace mere effects (gravitational fields and their impact on objects) with a real cause

I'm not trying to 'replace' the effects, I just would like to see a cause as well. We may never be able to say, undeniably, this is how gravity works. But we can certainly discuss possible causes of gravity... can't we?

some unknown radiation that pushes? I think I prefer my "little green gremlins eat space between massive objects"-hypothesis for a cause. It´s a bit less abstract than some unknown form of energy.

I like it Let's go with that one!

[timo]

You can theoretically discuss about "real causes" for gravity. But the issue is: If you find two or three causes that lead to the same effects how are you going to distinguish them? And in case we agree that you cannot: What´s the point in looking for explanations beyond investigating the effects? The standpoint of physics is pretty simple on this issue: Physics tries to explain how things work, not why they do so.

[D H]

That, in a nutshell, is the problem with string theory.

[kkris1]

Interesting idea. I've tried to think of how to experimentally test your speculation with the accepted theory. I'm convinced that both models predict that the force of gravity would vary as the 1/distance squared

 

The main difference sems to be that in your model of gravity that if mass blocked this radation, then the force of gravity would depend on mass in a different way. Instead of being proportional to the mass the amount of radiation blocked by the mass would follow a exponential decay relationship. In reality, the force of gravity is proportional to mass F=GM1M2/d^2.

 

Yes, I think you are right.The problem is you stopped too early. If you calculate this exponential decay you'll find out that for small attenuation of energy you can get the same equation F=GM1M2/d^2 . Check my post (attachement) regarding it.

As for classic gravity theory imagine infinite row of uniform spheres of radius r/2 and mass m touching one another. You'll find out the force acting upon first sphere from infinite number of such spheres (and infinite mass) is quite finite and equals: F=(Gm^2/r^2)*pi^2/6 from which most contribution comes from second sphere. Happy calculations. Kris

[Jacques]

Hi, the pushing gravity model is develloped here: http://metaresearch.org/

That model need faster than light particle.

I prefer the Gremlin eating space model.!