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Author Topic: Why does rotating mass cause frame dragging?  (Read 2479 times)


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Why does rotating mass cause frame dragging?
« on: 19/04/2011 23:30:02 »
@grahamshort asked the Naked Scientists:
Why does rotating mass cause frame-dragging in space-time?

What do you think?
« Last Edit: 19/04/2011 23:30:02 by _system »


Offline granpa

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Why does rotating mass cause frame dragging?
« Reply #1 on: 20/04/2011 21:32:50 »
why does a moving charge produce a magnetic field?

Offline yor_on

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Why does rotating mass cause frame dragging?
« Reply #2 on: 21/04/2011 00:19:50 »
Frame dragging :)

Now, why did you have to drag that one up? Eh, that was a joke. This is mainly mine speculations, but I hope I argue it reasonably well. Still, if you find me getting to 'wild', I will understand. I can't promise to be happy though, but I will try to understand :).

Anyway, you can see it several ways, as some 'friction' but as far as i know space has no friction classically (meaning where we 'live' and act normally, excepting some very weird QM phenomena). You can also see it as analogy to electromagnetism, maybe proving it to be a 'force' or a 'field', but gravity has nothing to do with EM fields, as I know.

Or you can do as I and think of SpaceTime as a jello. No, not as in having a classical friction but as in being one 'thing'. Inside this jello stuff moves relative each other, and rotates and just 'are'. The jello they are and exist in is gravity. There are no place in the universe you will be without a gravitational effect. You might find it equaling out, through 'uniform motion' following a geodesic 'free falling' weightlessly or, depending on how you define what 'frame of reference' you exist in, being 'still', but gravity will always be there even if undetectable.

Gravity is weird in that even though not 'touchable' it 'knows' where invariant matter is and adapt itself to that and motion. Mach had an idea of all matter in the universe being 'connected' so that the gravity we feel is the total sum of all matter in the universe, although the closer it is to you the more that 'near' matter will influence you. "Space tells matter how to move, and matter tells space how to 'bend'" said Feynman.

But for this we need that jello :) And then we need 'objects' moving. What makes those objects exist? 'Time' I would say, without our arrow of time there is no motion. SpaceTime becomes static. So is this jello a continuous 'stream of time'? Not according to the theory of relativity?

Comparing your own frame of reference to another frame of reference you will find that 'time' will differ, in that 'frames' motion relative yours, and in its invariant mass. And if we go to the other extreme, QM, a similar phenomena seems to exist, time simply becomes, ah, doubtful? Maybe able to go different paths simultaneously (Feynman's sum over paths) as well as 'backwards' and 'forward' :) and possibly all of it at the same 'time', no less :) But notice one thing, it all involves time being in 'motion', that is, some sort of 'arrows' even if acting as no arrow we know of.

Then we have what is called 'tunneling' and 'entanglements'. So extremely weird phenomena as they somehow 'make do' without time? Actually presenting us a causality ** without the chain. As if there was 'breaks' in the 'continuum' under certain circumstances, allowing particles to do things not involving 'time', and, neither involving 'distance'? Although that one makes a perfect sense to me. I mean, without time, why stare yourself blind at distance? Where will you find it? A distance is always a expression of time.

So time is the mystery here, time is what communicates 'relative motion'. And the jello dance to time. And there is something more to it, and that has to do with 'scales'. What we see at a QM level is not the exact same as what we see macroscopically. It's 'down there' you find 'tunneling' and 'entanglements', but as you climb up in scale things become more and more 'normal'. Until we get to invariant masses as in a neutron star, or a black hole maybe. And the same goes for 'relative motion', or better expressed, 'accelerations' close to the speed of light in a vacuum. There 'time' will start to 'act up' again, not the same way as in QM, but expressing that weird 'fluidity/plasticity' we saw there too. And 'distance' as a universal unchanging concept will also start to 'act up' depending on from which frame you look out on the universe. With motion 'distance' contract.

So Time will act differently, with our normal 'reality' existing somewhere in a (thought up) middle, scale-wise. Mach idea makes so much sense to me, using his view, just rearranging it slightly to gravity 'coupling' itself to what we call invariant mass/motion/energy we now find a universe where everything is a relation, and where all is connected in a way that somehow defies both 'times arrow' and 'distance', but also a place where time seem to be the redefiner of 'reality', that and scale.

So is time plastic?

Well, your own time will never differ, you can prove that by measuring your heartbeats to a chronometer, assuming you are of a exceptionally calm nature as you to prove it will have to visit black holes and move at 'speeds' close to light. So no, your time is not 'plastic' neither is mine, or anyone else's. But those 'frames of reference' sure is. so the universe or SpaceTime, or jello, if looked through the looking-glass of time, are definitely in a constant chaotic motion. And uniquely so for each observer.

But think of it as Mach did, everything being connected through 'mass' and you can see why if something rotates or 'move', relative something else, it has to have a influence. And then we don't need 'forces' for describing it, but we do need Einsteins concept, SpaceTime. ah well. Remember, pure speculation :)

But try this one for size.
and Mach’s Principle: exact frame dragging
by energy currents in the universe.
« Last Edit: 21/04/2011 00:37:04 by yor_on »

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Why does rotating mass cause frame dragging?
« Reply #2 on: 21/04/2011 00:19:50 »


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