# forget string theory...here's rope theory

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hey kids,

had this idea for a while now, when I say a while....I mean about 4 years, anyway as I am sure we all know, distances and movement in space is measured by lightspeed so if we wanted to get to the Sun it would take 8 minutes, Andromeda Galaxy would be 2 million years and well parts of the Hubble deep field would be 10 billion years.

Even sending a message to the Mars rovers takes what 20 minutes or so?

So here is my thinking and you can try it out at home then imagine it on a solar system then universal scale; please note this is just me explaining some thoughts, as far as I can tell it does and should work (even though it will never happen)

Right kids:

Part 1: Get some straight string about a metre long, lay it on the table between two points. Now pull the string at one end and you will see the string move all at once, therefore the effect of movement is instantaneously.

Part 2: Upscale your efforts, move into a room which is quite long and wrap a long length of string around a door handle so you are holding both ends with no slack in the string, right, now pull one end of the string and you will notice the other end in your other hand pulling away from you....notice its instantaneously!

Part 3: Imagine your in a field and at the other is a gate, imagine the string is some rope (to cope with the energy your placing on it) and imagine the rope is like that in Part 2 whereby it is wrapped around the gate and you are holding both ends, now pull on one end and you will notice the other end moving away!

Part 4: Forget 8 minutes, imagine your rope is wrapped around the Sun, again pulling on one end should see an instantaneous pulling away from you.

Part 5: Want to pull the 'imaginary handbrake' on Spirit or Oppertunity to stop them faling into some random crater on Mars, imagine the string wrapped around that distant handle, again, you should be able to communicate with the rovers without any time delay.

Part 6: Want to have a game of tug-o-war with some macho alien in M31, again imagine he / she / they have hold of your other end of rope....the pulling should be instantaneous, should it not?

So my point is this, although only parts 1&2 are possible the theory should work on a large scale surely? By having a direct link between 2 points across a distance then we can forget about lightspeed and time taken, the effect should be instantaneously.........dunno what implications a tug-of-war would have though especially with an Andromadae Arnie!

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we are going to have to have a long piece of rope :whip2: kev

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Part 1 is wrong, the effect is not instantaneous, just very fast. Sorry!

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Interesting concept. I never really thought of it that way.

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It would certainly be interesting to try it!

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Ok Chris, you go to the Andromeda end and I'll pull from here!!!

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why not instantaneously?.........as you move the string towards yourself by 1 cm, the pull from the farthest object towards you will be 1cm at the same time, its the same with your arm, your wrist and elbow move at the same time but they are seperated by about what 10 inches.........its like anything solid, move one end (say a ruler) and the other end moves at the same time provided it is in one definite direction.

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Is there a particle physicist or someone out there to explain what happens. Personally I reckon it might be like water - when you open a gate at the top of the pound you might think the level rises along the whole pound but what in fact happens is that a tiny wave comes down then bounces back and keeps on doing this imperceptibly.

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Ok Chris, you go to the Andromeda end and I'll pull from here!!!

I've got a man cold, so you go and I'll stay huddled under my duvet!

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This is how telephones work, push one electron at your end and it pushes one out at the other end of the line However it is still limited by the speed of light. On the universal scale its called the horizon problem, that everypoint we look in the sky at the CMB is the same over large scales, but at the speed of light which is the limiting factor cannot have transfered that information, in this case temeperature. This lead to inflation theory.

Some theorise tho that you can use a sort of "subspace" by creating a tachyon bubble around it to transmit information as they are all still connected no matter where they are. Thats going down the quantum and what is space made of line which could take a while to explain from scratch, but I guess you could make some form of "subspace" rope lol

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I think you're onto something EA. The ENERGY is not limited by particle physics is it?

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To see why this is wrong you don't need to be a physicist - try doing some fishing and you'll quickly realise that pulling a string does not create an instantaneous effect at a distance - I've lost more trout than I care to count for that reason. What Einstein showed in 1905 (among other things) is that there is no such thing as a perfectly rigid body: if you push one end of a "rigid" pole it actually takes time for the other end to move. The pole gets deformed by the applied force, and the deformation works its way very quickly - but not infinitely quickly - from one end to the other.

If relativity is right then it is impossible to propagate energy (or any kind of information) at greater than light speed. Of course relativity might be wrong, but then you've got to explain why it's so darned good at explaining the precession Mercury, bending of starlight, half-lives of muons, spectra of pulsars, etc etc etc.

Andrew

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I stand corrected... Thank you acey!

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Fair enough...........but whats the fishing part got to do with it, I think the pull of the fish would counteract your attempts at getting it to come to you, I am talking about no opposition at the other end......

Anyway, I think if I had a theoretical solid pole long enough to reach the sun, I could push something in that region and it wouldn't take 8 minutes to happen...........although we wouldn't see it for 8 minutes, so your kinda right Acey, seeing it would take 8 minutes but the effect would have happened a lot quicker!

(lights well slow hee hee!)

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sorry ed...

from waves and diffraction...

the wave equation for a sting under tension T and linear mass density p is...

d2y/dx^2 - (p/T)d2y/dt^2=0

d2y/dx^2 - (1/c^2)d2y/dt^2=0

so c^2=T/p

ie the propogation speed of a wave on a 1d string is the square root of tension/density....

this mean the wave takes a certain time to propogate...

sorry ed, just remebered waves and diffraction from last year...

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sorry ed...

from waves and diffraction...

the wave equation for a sting under tension T and linear mass density p is...

d2y/dx^2 - (p/T)d2y/dt^2=0

d2y/dx^2 - (1/c^2)d2y/dt^2=0

so c^2=T/p

ie the propogation speed of a wave on a 1d string is the square root of tension/density....

this mean the wave takes a certain time to propogate...

sorry ed, just remebered waves and diffraction from last year...

Well, that's easy for you to say!

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yeh, I agree that it will take time to get through the structure of the item your using..........I aren't querying that...

I was just pointing out that 'theoretically' it could be possible to communicate over large distances via a solid mechanism in a very quick time

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Take a rope from here to the next star out from the sun. Give it a pull and given the elasticity in the rope you might have to pull for a long time before the rope is stretched out enough to pull the thing at the other end - at which point you may have the biggest bungee rope in the Universe - Boing!

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Just hope you dont let it slip lol that would most deffinately smart!

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I was just pointing out that 'theoretically' it could be possible to communicate over large distances via a solid mechanism in a very quick time

By "theoretically" you mean "if special relativity is wrong", or else by "quick time" you mean "less than light speed" - in which case a light beam is quicker and a lot easier.

But ponder this. Let's say you've got a rope between here and the Virgo cluster, attached to suitable points at either end. The cluster is receding from us due to Hubble expansion - so does this mean that the rope will undergo increasing tension? And could the resulting energy be used? Let's ignore the actual speed involved and assume it's an extremely stretchy rope (able to extend by millions of miles per second!). The point is that it's usually said that cosmic expansion is experienced only by things that are not physically bound - the solar system and our own bodies don't expand, and there isn't expansion between our Milky Way and the Andromeda Galaxy, because their gravity is strong enough to eliminate the effect. So what about a rope? Seems a bit of a paradox.

(The relevant maths this time is the Friedmann equations - but they assume homogeneity. Hence I don't think anyone really knows the answer to this one).

Andrew

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aye special relativity is wrong..............

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Now Im a newbie but isnt the light from place B at x light years away not actualy in that place any more it having moved in the x years by some distance. That means the string would be bent and if you pull you just pull out a bit of the bend.

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I think some people are focusing too much on the 'elasticity' of the rope...........forget the stretch (its a theoretical solid rope, with no stretch in it).............its solid; hence doesn't warp right!!

So the question still remains, forget the possible moving structure inside the rope, or pole.......just think about the possibility of moving something at a distance that is all....I think its an interesting scenario that's all.

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There's no such thing as a perfectly solid object. All everyday solid objects are just bunches of atoms held together by electromagnetic forces and as such obey the speed of light limit.

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I aren't arguing with that..........I am being completely theoretical!

A bit like Christianity, loads of people believe in it, but do we know what actually happened? Just believe in this for a while without all the aethist view points!

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