h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I have been reeding Einstein related things recently,and if I didn't get it all wrong,he states that gravity is just the bending,curving of the "fabric" of space.
But does the space itself really has a "fabric" of some kind ? I mean,don't get me wrong,I admire Einstein and his works,but isn't there a particle or something that can explain gravity,rather than a idea of "fabric of space" ?
Is it proven that space has a fabric,really ?

Depends upon the meaning of 'fabric' I guess. It can mean 'stuff that other stuff is made of'. The things you work with when you fabricate something, if you see what I mean.

You could say that brick and mortar are the fabric of a house, for example. So he could be meaning something similar - the stuff that space is made up of.

Admittedly I haven't the faintest idea if that's actually what he meant, but I thought I'd throw the idea in anyway.


Geggs

Nothing is a strange concept in physics. Even when there is no particulate presence in space there is not necessarily 'nothing' there.

In essence there needs to be a medium for stuff to happen - what is the mechanism by which opposite charges attract and like charges repel? Also with magnetism?
These are speculated to occur by particle 'exchange' and this is what sets up the fields of electromagnetism.
Some similarly speculate that a similar particle exchange occurs with gravitation although that is a lot more controversial I believe.

So space itself is not 'nothing' and is composed of EM fields, gravitational fields etc. and massive objects within these distort them.

Einstein was just giving it a nice easy to understand word by calling it 'fabric'. Plus as I'm sure he would have been happy to admit, when you ask what the 'fabric' is made of I'm sure he would have said 'dunno.'
It's all very theoretical and conceptual and so I'm going to stick my neck out and say that the fabric of space is made of 'stuff'

He meant black velvet, obviously.

I'd say what he meant was that space isn't merely nothingness as we believed. Rather that is has certain qualities that can be manipulated. Any massive object manipulates the space around it, warping it. So space is not a nothing but a something.

There have been talk of gravitons as mentioned earlier. However I don't think they could explain how gravity bends light, or could cause such a things as the precession of Mercury's orbit. The warping of a space fabric could.

This convo seems disappointingly slow - perhaps because there's nothing much to talk about?

- - - -

Not having much in the way of real science, I haven't commented until now but perhaps it wouldn't go amiss at this stage?

I have a sort of a scheme in mind that goes somewhat along Xanatic's black velvet...

Looking at illustrations similar to this one:

http://www.ws5.com/spacetime/

We could say that it is a two-dimensional representation of my concept.
Four dimensionally, the fabric would be a space-sized block of a very, very fine weave of black velvet which is made of some substance (?) that is elastic to an extreme.

The weave is of a fineness that allows the smallest particle there is (known or otherwise) to pass through, with some small distortion, in any direction.

The particle in the above illustration, being a planet, on passing through between the weave, distorts the fabric rather more, while once it's passed the fabric shrinks again, towards recovering its original shape.
The distortion (and recovery) is proportional to the distance from the particle, is instantaneous and affects the whole of the fabric, right to the very edges, though at that distance the remnant distortion is pretty small.
The largest body there is will pass through too.

In that illustration, only the immediate environs are relevant, not as far as the edge of the flat surface. there would be a gentler curve extending very much further out, in all directions. A fuller picture would show that web getting progressively finer further from the planet - right to 'all the edges' of space (not unlike like a sort of inside-out spider's web).

Now add the third dimension (if you can - I can't) and then the fourth...

Now add a moon to the planet and try to imagine the resultant distortions, in all directions, out to the very edges - if indeed there are edges. You might try also, to imagine the interactions between each of the 'individual' distortions.
Now add a few more planets and their moons, a sun - add more sun-systems up to and including galaxies.

The resultant picture looks, maybe, rather like gravity - illustrations similar to this one have been made with gravity in mind.




Please note that there's no attempt here to account for the planet passing through without having its atmosphere wiped off. Nor indeed, for any other anomaly, real or imagined.

It's just an account of one man's try at understanding something about it all.



If you don't like it, yikes it - or say so & I will.

Rod

Try this:

http://www.youtube.com/watch?v=CD5tBIqJU4U

Oolon you are correct to be wary. Fabric is of course the classical conception of "space-time" but "reality" doesn't appear to be "classical".

http://www.xkcd.com/1158/

Clive - your post6:
(I've been away for a week but) nice one!