A Mathematical Connundrum

[Flagg]

Okay, so I was sitting talking to my friend who is studying mathematics at university and he showed me a very basic diagram.

Basically he drew two circles and a line between the circles. He said imagine these two circles were planets and that they were 6 light years apart and that the line was a steel girder and was connected to both planets. Take the circle on the right as Planet B.

Now, if you pushed on the beam from planet B, would the force be felt on Planet A straight away? If it could, that would demonstrate that information could be sent to planet A and vice versa faster than the speed of light..does that not break the law of time immediately because of the distance.

If the force of the push was not felt straight away, why not? Does the steel girder shrink in size as kinetic waves travel through the girder? Does that mean the girder has shrunk in size?

This has really got me thinking, because such a construct could be compared to a dumbell with two weights on each end, and if you push on one end the other end immediately moves at the same time as it is in essence, one construct.

Does anyone have a viable explanation for this phenomena?

[JiGGaMaN]

Too many variables, plus if you try to do an experiment its not relevant to wat you are talking about because you arent doing it in a vacuum. Either way building a girder of that magnitude is impossible.

[RuhlFreak55]

i'd surmise that it wouldn't be felt immediately.....it's kind of a wave effect and with such distances involved i think there would be a lag.....granted i sure as hell don't know how to work that out on paper lol

[burt66]

Acting in unison isn't the same as traveling at the speed of light.

[Flagg]

But Jiggerman, with enough materials and resources you could build such a construct.

My question still remains...would the force of a push be felt straight away? If yes that proves the speed of light can be broken but that would also prove time could be broken.

However, if there is a ripple...that shows that objects cannot move in unison, even if they appear to be connected to each other.

[Flagg]

Acting in unison isn't the same as traveling at the speed of light.

I think it is, because if the effects were felt straight away, you could in essence send messages along such a construct. That message would be recieved immediately, from a planet that exists 6 light years in the future.

[Overhaulz]

A O------O B

If these two planets are connected then pushing from side A to side B certainly would be felt instantly as you're moving the entire object as a whole. Granted, information could absolutely be sent through such a contraption; imagine it just a giant telephone wire.

The problem is, that you somehow brought the speed of light into this, and it has no place here whatsoever. Simply communicating through a giant beam, or the push of the planets has absolutely nothing to do with the speed of light, nor would the push being felt be anywhere comparable.

[DSM4Life]

[KingTenderloin]

[novastepp]

are we talking about vibration, or are we talking about moving circle A near the beam and subsequently moving circle B?

[JiGGaMaN]

But Jiggerman, with enough materials and resources you could build such a construct.

My question still remains...would the force of a push be felt straight away? If yes that proves the speed of light can be broken but that would also prove time could be broken.

However, if there is a ripple...that shows that objects cannot move in unison, even if they appear to be connected to each other.

No, its definitely not feasible, but i dont think thats the answer your friend was looking for.

[JiGGaMaN]

Now, lets look at it on a smaller scale: If you pushed on a tree, could you feel it on the other side?

[novastepp]

Now, lets look at it on a smaller scale: If you pushed on a tree, could you feel it on the other side?

exactly, that's why i asked about vibration; you probably wouldn't feel me punch the tree.

now if you were to say theoretically, move/scoot the tree across the ground, you would feel that on the other end. is that what we're talking about here with these planets?

[RuhlFreak55]

exactly, that's why i asked about vibration; you probably wouldn't feel me punch the tree.

now if you were to say theoretically, move/scoot the tree across the ground, you would feel that on the other end. is that what we're talking about here with these planets?

yes nova......like spinning one end of a dumbbell clockwise from above, the other side will turn immediately to match....but i think that's just due to proximity....the force would travel down the rod/beam at some speed, like a force wave....so in such a drawn out set of distances you could observe this phenomenon that's not usually discernible in every day life.....i'm hypothesizing my ass off though, just instinct

[JiGGaMaN]

exactly, that's why i asked about vibration; you probably wouldn't feel me punch the tree.

now if you were to say theoretically, move/scoot the tree across the ground, you would feel that on the other end. is that what we're talking about here with these planets?

My theory is that his friend came up with this in attempt to prove to himself that he is a genius. I would suspect he is not.

[novastepp]

I see where you're coming from. distensibility, and other properties of elements would come into play. i doubt the element would be able to transmit any rotation at that length. in regard to unexplainable or uncomprehendable lengths and times, it is very hard to estimate.

[novastepp]

My theory is that his friend came up with this in attempt to prove to himself that he is a genius. I would suspect he is not.

hypothesis out of the rhelm we live is for people who actually examine those areas. not some kid who wants to use unidentified science he has yet to explore.

[RuhlFreak55]

I see where you're coming from. distensibility, and other properties of elements would come into play. i doubt the element would be able to transmit any rotation at that length. in regard to unexplainable or uncomprehendable lengths and times, it is very hard to estimate.

ah, didn't think of that.....lol not like it was practical to begin with but that's true on a planetary scale i don't think we know of any materials that could withstand the forces involved

[RuhlFreak55]

i love this kind of stuff......it's why i switched my econ major to physics now......who cares if it may not make me money...my finance degree and bodybuilding can do that...i just love astrophysics

[novastepp]

i love this kind of stuff......it's why i switched my econ major to physics now......who cares if it may not make me money...my finance degree and bodybuilding can do that...i just love astrophysics

i admittedly don't know much, but the theory behind it all is VERY intriguing. i enjoy learning/reading about astrophysics, and other similar principles.

[soulstealer]

This is just stupid.... if I push the damn steel girder I merely apply an amount of force to the apposing planet my end of the steel girder didn't hit your planet theres no faster than light travel...if I move it an inch you get hit with an inch... durr durr =p

[RuhlFreak55]

i admittedly don't know much, but the theory behind it all is VERY intriguing. i enjoy learning/reading about astrophysics, and other similar principles.

well perhaps we will travel to another galaxy one day on a ship i create the engine for

[JiGGaMaN]

i love this kind of stuff......it's why i switched my econ major to physics now......who cares if it may not make me money...my finance degree and bodybuilding can do that...i just love astrophysics

You lied to me. you told me you had a degree in economics.

[RuhlFreak55]

This is just stupid.... if I push the damn steel girder I merely apply an amount of force to the apposing planet my end of the steel girder didn't hit your planet theres no faster than light travel...

the crux of the question is whether the force travels instantaneously which would indeed mean faster than light travel because the force has to travel the distance of the girder to act on the other planet.....i think it's more of a wave thing though....not that in any way don't believe in faster than light travel....i've believed it's possible since i was 5.

[RuhlFreak55]

You lied to me. you told me you had a degree in economics.

nah this was a recent development getting back into the physics thing....and i'm still getting my finance degree which is similar to econ in most respects.

[soulstealer]

the crux of the question is whether the force travels instantaneously which would indeed mean faster than light travel because the force has to travel the distance of the girder to act on the other planet.....i think it's more of a wave thing though....not that in any way don't believe in faster than light travel....i've believed it's possible since i was 5.

Assuming that the object is 100% rigid and without give then enough force on my end to move it one inch will move it one inch on your end... my end has not traveled 6 light years my end traveled one inch.... no this is just silly... no faster than light travel here..

[soulstealer]

In fact if I took a 10' pole and moved it one inch I moved it one inch that was not supersonic speed because its force traveled over a 10' distance...

[RuhlFreak55]

Assuming that the object is 100% rigid and without give then enough force on my end to move it one inch will move it one inch on your end... my end has not traveled 6 light years my end traveled one inch.... no this is just silly... no faster than light travel here..

i just explained the force has to travel through the connecting rod to act on the other planet....so if the instant planet a moves planet b moves then that force has traveled faster than the speed of light between the two points.

[JDawg1536]

i just explained the force has to travel through the connecting rod to act on the other planet....so if the instant planet a moves planet b moves then that force has traveled faster than the speed of light between the two points.

It sounds difficult to explain, but seems simple enough to comprehend. The object (rod) is present in both places at the same time, so any force applied to it would be experienced at the same time. A light source however, would not be present in both places, neither would said "information". They would have to travel 6 billion light years, whereas the pole would not.

Ive been reading this book- http://www.amazon.com/Universe-Rober...3265136&sr=1-1

No references to anything like this, but the universe is full of crazy mind boggling stuff.....

[JDawg1536]

i just explained the force has to travel through the connecting rod to act on the other planet....so if the instant planet a moves planet b moves then that force has traveled faster than the speed of light between the two points.

It would take a physics degree and some damn good wording, but I think the concept of force would be simple enough to comprehend. Since the rod is present in both places, I dont really think the "force" is traveling at all. But then again, I'm no doctor.

[JiGGaMaN]

ok so the speed of light is 1,079,252,848km/hr x 24hours in a day x 365 days in a year x 6 years you need 5.67255297 × 10^13 km's of steel. I think you would need quite a bit of force to feel something on the other end.

[JDawg1536]

ok so the speed of light is 1,079,252,848km/hr x 24hours in a day x 365 days in a year x 6 years you need 5.67255297 × 10^13 km's of steel

Then just imagine Lexington Steele is the acting force.

[Tock]

If it's a steel girder, then you'll have to take into account the elasticity of the metal. Consider both elasticity and inertia, and you'll end up with a long metal stick that stretches/compresses at one end while the other end tends to resist any movement at all. If the girder is long enough, the motion will be dissapated into heat energy, and nothing will be felt at the other end.

[g0dsend]

Is there anyway to tell? Im no physicist but wouldn't it take 3 light years to see that the girder is pushed from the center?

[Kärnfysikern]

Okay, so I was sitting talking to my friend who is studying mathematics at university and he showed me a very basic diagram.

Basically he drew two circles and a line between the circles. He said imagine these two circles were planets and that they were 6 light years apart and that the line was a steel girder and was connected to both planets. Take the circle on the right as Planet B.

Now, if you pushed on the beam from planet B, would the force be felt on Planet A straight away? If it could, that would demonstrate that information could be sent to planet A and vice versa faster than the speed of light..does that not break the law of time immediately because of the distance.

If the force of the push was not felt straight away, why not? Does the steel girder shrink in size as kinetic waves travel through the girder? Does that mean the girder has shrunk in size?

This has really got me thinking, because such a construct could be compared to a dumbell with two weights on each end, and if you push on one end the other end immediately moves at the same time as it is in essence, one construct.

Does anyone have a viable explanation for this phenomena?

You cant build a perfectly rigid rod. If you push the rod on one end the push will propagate through the rod with a fixed speed, the speed of sound in the material at hand. Only a perfectly rigid rod would have a infinite speed of sound and such a thing is unphysical.

Information of any kind can not propagate faster than the speed of light, unless you send it through a wormhole. But thats allowed by the general theory of relativity.

[IronReload04]

wow guys, this is so ****ing simple its not even funny.

the two planets are connected. They are in unison. push the beam and the force is felt instantly, everything is connected. similarly, if you take 2 soccer balls, connect them with a beam, push one, the other moves instantly

THE DISTANCE IS IRRELEVENT

the light will take 6 years to reach the other planet.

[Kärnfysikern]

wow guys, this is so ****ing simple its not even funny.

the two planets are connected. They are in unison. push the beam and the force is felt instantly, everything is connected. similarly, if you take 2 soccer balls, connect them with a beam, push one, the other moves instantly

THE DISTANCE IS IRRELEVENT

the light will take 6 years to reach the other planet.

Not quite that simple, you have to consider how fast waves propagate through materials. Pushing at one end of a rod is nothing else than creating a wave in the material, but we dont percieve it as that of course since the speed of sound in rigid materials is far greater than we can notice. In steel its over 5000meters per second. But if you where to build a 10km long steel rod and push one end of it, you would not notice it on the other side until 2 seconds later.

[Kärnfysikern]

Look at it on a micro level. A solid is just atoms/molecules packed close togheter.

For the entire rod to move, one layer of molecules has to move, transfer the force to the next layer so that it moves and so on. There is a finite speed by which that can happen. The maximum speed of sound in any theoretical material is of course lower than the speed of light since the molecules are keept in place by the electromagnetic force, and forces propagate through the EM field with the speed of light.

[RuhlFreak55]

You cant build a perfectly rigid rod. If you push the rod on one end the push will propagate through the rod with a fixed speed, the speed of sound in the material at hand. Only a perfectly rigid rod would have a infinite speed of sound and such a thing is unphysical.

Information of any kind can not propagate faster than the speed of light, unless you send it through a wormhole. But thats allowed by the general theory of relativity.

that's exactly what i was thinkin but don't have the background yet to explain it thoroughly

[Flagg]

Okay guys, ive been mulling this over all day and I think the answer is this:

If you moved the girder one meter from Planet B in a motion toward Planet A, the movement WOULD be felt immediately at Planet A end. The whole "compression wave" is nonsense, the girder itself is one whole single object so would move in unison. Nothing is travelling faster than light as the girder is already touching A, and it is only travelling at the speed that the initial push initiated. Time exists at the same rate and speed everywhere, simultaenously.

To suggest that the effect wouldn't be felt at the other end immediately has to impossible.

Another way to look at this could be...imagine the the girder was hollow and completely filled with peas from one end to the other. Imagine each pea is one inch long. Now if you pushed the back pea along 1 inch, the pea at the other end would fall out, and this would happen no matter how long the tube was. If there was some sort of wave, then that would mean there would be always be a space which means somehow, a pea has ceased to exist.

To suggest that there would be some sort of compression wave would then dictate that you could never make an object greater in length than one light year, an example could be a starship. That would mean that a part of the star ship would be motionless while another point was moving, which of course would be impossible.

Johan, I just used a steel girder as an example before, but for the sake of purposes lets say its made of an unbreaking element that has no elasticity and that the girder falls short of just 1 inch on Planet A. The question is the same, if you pushed the pole one inch from B would the pole touch Planet A straight away? I think it would.