Is existence faster than the speed of light?

In summary: I mean the molecules of the rope are pushed along by the forces acting on them, but it takes time for the last domino to fall.
  • #1
archen
6
0
lets say theoretically you have a rope 200,000 miles long and it was pulled tighted with a person on each end one persons pulls the rope towards them instantaneously the rope begins to leave the other person wouldn't this conclude that something is faster than the speed of light?
 
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  • #2
archen said:
lets say theoretically you have a rope 200,000 miles long and it was pulled tighted with a person on each end one persons pulls the rope towards them instantaneously the rope begins to leave the other person wouldn't this conclude that something is faster than the speed of light?

Instantaneously? How do you think the force moves along the rope? What do you think holds the molecules of the rope together?

Zz.
 
  • #3
I would argue that your premise is flawed. Does it happen instantaneously? Not likely. Would if it the rope were a perfectly rigid body? Maybe. Do perfectly rigid bodies exist? No. There is some elasticity in the rope, and even if it is very small, think about it on an atomic scale. You pull on the rope. All contact forces are electrostatic. The atoms have to influence their neighbouring atoms, all the way down the line, to the other end. There is a definite propagation time associated with that. That's my take on it. Does anyone disagree, or have I stated anything that is incorrect?

Note also that a rope cannot be pulled perfectly taut, it will sag under its own weight. That doesn't relate much to your question, I just thought I'd point it out.

Edit: ZapperZ beat me to it in a much more succinct way, but I feel more confident now that he has hinted at the same thing I said.
 
  • #4
By the way, if you replace your rope with a steel rod the results are the same. Any effort to move the rod, moves through the rod at the speed of sound in the rod. If you apply forces great enough to create a signal which moves faster then the speed of sound in the metal you will deform the rod.
 
  • #5
Interesting! That suggests to me that the speed of sound in a solid material is tied to the natural frequency of oscillation of the atoms in the crystal lattice. Try to exceed that frequency, and you destroy the lattice, at least in one place. Am I right?

Edit: Or does it have to do more with the maximum allowed amplitude of said vibrations? :confused:

Edit2: Sorry for getting all excited like as if it was some sort of revelation, but the idea that acoustic signals are just mechanical vibrations, even when NOT in air (right?) was sort of there in the back of my mind, but brought out vividly by this example.
 
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  • #6
I am on thin ice here... Yeah, hitting the rod harder would induce larger amplitude sound waves. My thought was that if the impact strikes the rod at a velocity greater then the speed of sound in the rod the rod will be deformed. (Depending of course on the material which hits the rod!)

The true experts in this would be Gukul, I will yield to a post from him.
 
  • #7
ok let me clarify the rope was pulled tight and then sat down the person pulling is the only one hplding the rope now let's say we did this on a smaller scale even with a steel pole the pole being pulled away would be noticed almost instantly so what's to say that this extremely long pole doesn't react the same and if I am coming off as an idiot I am sorry I am actually very new to the whole physics scene I am teaching myself physics in a high school in an independant studies class and this is practically my project learning from the experienced
 
  • #8
Just like with the taut rope, the "pull" is transmitted along the steel pole at the speed of sound in steel. For short lengths, it may seem to travel instantly, but it doesn't. (Nowhere close to the speed of light!)
 
  • #9
Just think of the types of forces interacting which cause it to move

*hint* the atoms don't touch each other
:)
 
  • #10
You can imagine the analogy of a traffic jam in a highway; a car moves a little bumps into the next in front of it then that car begins to move and bumps into the next then...
 
  • #11
I guess what you're asking is equivalent to saying, "suppose i have a row of dominos 200,000 miles long. If i knock the first one over, then this will be noticeable at the other end instantly, hence something is faster than light."
It's not really the case because it takes time for the last domino standing on the other end to fall. Similarly with any rope, you're basically setting off a chain of dominos where the dominos are the molecules in the rope. So you can see it can't be instantaneous, even if at a small scale it seems that way.
If the rope were a rigid body, then the scenario would change to a row of dominos where the dominos are packed together (rather than being at a certain distance). In this case, if you want to make the last domino fall, you have to hit it hard enough so that the perturbation at one end reaches the other end with enough strength to knock down the last domino. Notice that this perturbation loses some of its strength with each domino it goes through because the dominos offer some resistance and push back in the other direction. For a 200,000 mile such chain you'd need considerable energy. Most likely, even if you hit it with enough energy, instead of making the last domino fall, the dominos in between will probably jump out of place to the side, so the perturbation never reaches the other end with enough strength. This is equivalent to the rope breaking. A better strategy would be to hit the first domino multiple times with less strength, so that you have a better chance to disturb the last domino. Of course this isn't instantaneous.
I would say if the rope were perfectly streched (maximum stretch), and you pushed it on one end, it would break. This is actually evident in the assumption that the rope is perfectly stretched. When we say that the rope is perfectly stretched we are saying that rope is streched as much as possible without having it break. Hence stretching it a bit more must cause it to break.
 
  • #12
simon009988 said:
You can imagine the analogy of a traffic jam in a highway; a car moves a little bumps into the next in front of it then that car begins to move and bumps into the next then...

another thing to add is that you could think of the passangers as the atoms and the cars could be the repulsive magnetic force of the electrons; so the atoms themselves do not touch but the magnetic field "kinda" do.
 
  • #13
This brings up a curious scenario. If i had a rope about a light year in length with one end hanging 6 feet from the ground, even though it is not attached to anything or being pulled by any force at the other end, i would easily be able to climb up on it a good deal. :smile:

(even if it was considerably shorter than a light year, we can probably estimate how long such a rope would need to be in order to allow me to hang from it a certain amount of time)
 
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  • #14
It seems to me that the initial question "is existence faster than the speed of light?" has been overlooked by the the initial writer and subsequent responses.

Whilst the question, can anything travel faster than the speed of light? has been answered and has made for interesting reading, the question is existence faster than the speed of light is another concept altogether.

Existence is relevant to the observer and the interactions that the internal and external stimuli effect upon the brain. I am aware of things existing around me, but only as they have occurred in the past (the question of what existence means if nothing exists to observe it is a philosophical one). However, what of the awareness of my own existence?

One could argue that existence itself must travel at the speed of light based on the electrical interactions within the brain. But what if the signals are being created by the subconscious before the actions begin? Even at the atomic level, existence must precede an action. If this is the situation, then could it be possible for thoughts to be created before they are thought? If so, then what are the implications for organic computers (if we go down that path) and artificial intelligence?
 
  • #15
warp darkmatter said:
It seems to me that the initial question "is existence faster than the speed of light?" has been overlooked by the the initial writer and subsequent responses.
Whilst the question, can anything travel faster than the speed of light? has been answered and has made for interesting reading, the question is existence faster than the speed of light is another concept altogether.
Existence is relevant to the observer and the interactions that the internal and external stimuli effect upon the brain. I am aware of things existing around me, but only as they have occurred in the past (the question of what existence means if nothing exists to observe it is a philosophical one). However, what of the awareness of my own existence?
One could argue that existence itself must travel at the speed of light based on the electrical interactions within the brain. But what if the signals are being created by the subconscious before the actions begin? Even at the atomic level, existence must precede an action. If this is the situation, then could it be possible for thoughts to be created before they are thought? If so, then what are the implications for organic computers (if we go down that path) and artificial intelligence?
Unfortunately this is the physics forum, here we must talk of physics. I do not see any evidence of physics in your response.
 
  • #16
possibly, however I was attempting to answer the question, nothing more. The beauty of physics is that it refers to all interactions of matter and energy. Philosophy is still an important part of the processes of our understanding the universe, if you want lengthy mathematical desciptions based on these ideas (all they are) they can be provided but id prefer to save that for my job and enjoy the general discussion. Thinking outside the boundaries of mathematical equations keeps my mind active and alert.
 
  • #17
(Nothing) is faster than the speed of light, To pun a fact, It's everywhere in the Universe.
 
  • #18
agreed, but does everything obey our current understanding of the laws of physics? until we discover a successful Theory of Everything, things that can't be directly observed such as the complexity and of existence must still be dealt with carefully. I find it very difficult to imagine anything being able to cheat its way around the boundaries of c, however, we know so little of the interactions of matter, particularly at Plancks length. Do not all the laws of physics break down within a singularity? what happens then at planks length when the proposed extra dimensions come into play?
 
  • #19
warp darkmatter said:
agreed, but does everything obey our current understanding of the laws of physics? until we discover a successful Theory of Everything, things that can't be directly observed such as the complexity and of existence must still be dealt with carefully. I find it very difficult to imagine anything being able to cheat its way around the boundaries of c, however, we know so little of the interactions of matter, particularly at Plancks length. Do not all the laws of physics break down within a singularity? what happens then at planks length when the proposed extra dimensions come into play?


Not only should there be a successful theory of (EVERYTHING) but there should also be a successful theory of (NOTHING)
 
  • #20
archen said:
lets say theoretically you have a rope 200,000 miles long and it was pulled tighted with a person on each end one persons pulls the rope towards them instantaneously the rope begins to leave the other person wouldn't this conclude that something is faster than the speed of light?

the forces propagate though the material at <c, I have heard some claim that it is at the speed of sound (in that material) but I don't know and I am not willing to do an experiment
 
  • #21
warp darkmatter said:
It seems to me that the initial question "is existence faster than the speed of light?" has been overlooked by the the initial writer and subsequent responses.
As stated, that's seems to be a meaningless question, at least from a physics point of view. I think, as evidenced by the example submitted, that the OP meant to write something like "Does something exist that travels faster than the speed of light?"
 
  • #22
warp darkmatter said:
agreed, but does everything obey our current understanding of the laws of physics? until we discover a successful Theory of Everything, things that can't be directly observed such as the complexity and of existence must still be dealt with carefully. I find it very difficult to imagine anything being able to cheat its way around the boundaries of c, however, we know so little of the interactions of matter, particularly at Plancks length. Do not all the laws of physics break down within a singularity? what happens then at planks length when the proposed extra dimensions come into play?

However, there is a problem with providing that scenario as AN ANSWER to the original question. You are answering the question using an unverified, speculative, hypothetical, and still unagreed upon answer. It is the intent of this forum that when a straightforward question is asked, a straightforward STANDARD physics answer should be given.

While we understand that physics explores the unknown and things that we still do not understand, we need to make a clear separation between that and standard, accepted physics answers. If we don't do that, this forum WILL deteorate very quickly into a free-for-all speculative garbage that will make it no different than other unmoderated open forums.

Zz.
 
  • #23
However, there is a problem with providing that scenario as AN ANSWER to the original question. You are answering the question using an unverified, speculative, hypothetical, and still unagreed upon answer. It is the intent of this forum that when a straightforward question is asked, a straightforward STANDARD physics answer should be given.

ok, thanks. will abide by this and leave the philosophy for where its appropriate. It is difficult sometimes to provide a straightforward answer considering the potential complexity (or logical simplicity) that surrounds some of these problems. (my responses were also questioned based themselves in regard to the answers of others, not answers)

While we understand that physics explores the unknown and things that we still do not understand, we need to make a clear separation between that and standard, accepted physics answers. If we don't do that, this forum WILL deteorate very quickly into a free-for-all speculative garbage that will make it no different than other unmoderated open forums.

have read a lot of speculation on other threads on this forum already, some of it quite challenging and refreshing. However, i do respect your thoughts (we don't want astrologers now do we!).
 
  • #24
-Job- said:
This brings up a curious scenario. If i had a rope about a light year in length with one end hanging 6 feet from the ground, even though it is not attached to anything or being pulled by any force at the other end, i would easily be able to climb up on it a good deal. :smile:
(even if it was considerably shorter than a light year, we can probably estimate how long such a rope would need to be in order to allow me to hang from it a certain amount of time)
Check into the 'space elevator' threads.
 
  • #25
I'd say, if the speed of sound in a rope at some temperature is S m/s, then the other end of the rope wouldn't start to come down until the sound wave got there. So if the rope has length L meters, then it would take at least L/S seconds for the rope to start coming down. Of course because a rope stretches, and even if this stretching is very minimal, if the rope is very long, in a fair amount of time it will have stretched significantly, so my end would come down a bit. If it were a wire instead of a rope, then this probably wouldn't be significant. If the speed of sound in the wire is anywhere around 300 m/s then, in order for me to hang from the ground for 10 minutes, i would need a wire of about 10(60)300 = 180 Km. :smile:
 
  • #26
-Job- said:
I'd say, if the speed of sound in a rope at some temperature is S m/s, then the other end of the rope wouldn't start to come down until the sound wave got there. So if the rope has length L meters, then it would take at least L/S seconds for the rope to start coming down. Of course because a rope stretches, and even if this stretching is very minimal, if the rope is very long, in a fair amount of time it will have stretched significantly, so my end would come down a bit. If it were a wire instead of a rope, then this probably wouldn't be significant. If the speed of sound in the wire is anywhere around 300 m/s then, in order for me to hang from the ground for 10 minutes, i would need a wire of about 10(60)300 = 180 Km. :smile:

I would not want to be under 180 Km of wire falling at 32 feet per second squared.
 
  • #27
Jay-qu said:
the forces propagate though the material at <c, I have heard some claim that it is at the speed of sound (in that material) but I don't know and I am not willing to do an experiment

Well i don't think so, u might not have heard abt theory of relativity yet. It says if some phenominon the sun just disappears (obviously along with its mass), the force that keeps Earth in its motion will also seize, as said by Newton it 'd be instantanious but Einstien said it will ony happen when it could be seen what means when the light reachs the earth. Conclusion: forces propagates at c.
Oh and by the way when u mentioned material it think u confussed it with a light light wave (passing through a glass material)
 
  • #28
.:JimmY:. said:
Well i don't think so, u might not have heard abt theory of relativity yet. It says if some phenominon the sun just disappears (obviously along with its mass), the force that keeps Earth in its motion will also seize, as said by Newton it 'd be instantanious but Einstien said it will ony happen when it could be seen what means when the light reachs the earth. Conclusion: forces propagates at c.
Oh and by the way when u mentioned material it think u confussed it with a light light wave (passing through a glass material)

I think a rope satisfies the criteria of been a material... and I have previously had a big discussion about the speed of gravity - its finite, c more specifically which means it would take 8 mins till we fell out of orbit - the same time that it would take for us to notice that the sun isn't there.
the forces that take place in the example I answered don't propagate at c, because it is one particle colliding with the next on an atomic level - for the force itself to propagate at c then the particles would have to move at c - hence impossible
 
  • #29
Jay-qu said:
I think a rope satisfies the criteria of been a material... and I have previously had a big discussion about the speed of gravity - its finite, c more specifically which means it would take 8 mins till we fell out of orbit - the same time that it would take for us to notice that the sun isn't there.
the forces that take place in the example I answered don't propagate at c, because it is one particle colliding with the next on an atomic level - for the force itself to propagate at c then the particles would have to move at c - hence impossible

Take a 200,000 mile long rope and ask two persons to hold its opposite ends, this is the basic appratus. well the radius of Earth is 3964 miles, can u calculate how many time would that rope wrap around the earth. And with all due respect, it doesn't seem to make any sense.
but talk but electric current, if "somehow" u can transmit an electron across a 200,000 mile wire, it would definitely take some time befor u can detect it on the other end
 
  • #30
Integral said:
By the way, if you replace your rope with a steel rod the results are the same. Any effort to move the rod, moves through the rod at the speed of sound in the rod. If you apply forces great enough to create a signal which moves faster then the speed of sound in the metal you will deform the rod.


This is probably a noobish question but why is the limit the speed of sound? In that regard, what is the concept that relates speed of sound with speed of light (so that I might read about it)?

Gracias
 
  • #31
jhe1984 said:
This is probably a noobish question but why is the limit the speed of sound? In that regard, what is the concept that relates speed of sound with speed of light (so that I might read about it)?
Gracias

Figure out what "sound" is and how it moves in various medium (gas, solids). You'll see that at best, it can only approach the speed of light.

Of course, there are always anomalous exceptions to this that requires us to redefine the things we actually measure as "moving". This happens with the NEC experiment of apparent superluminal group velocity of light. And it may be happening with the speed of sound also that may allow an apparent "superluminal" effect.

http://physicsweb.org/articles/news/9/11/1/1

However, in a common, standard medium, one encounters no such effects.

Zz.
 
  • #32
Sound is the transmission of vibrations through a medium. The speed is dependent upon what that medium is, but is always the fastest mechanical action that's possible. While you can physically force something through faster than sound (such as a bullet or aeroplane), you can't create movement of the medium itself above sonic speed.
Light is an electromagnetic wave phenomenon, whereas sound is mechanical. There is no correlation.

edit: Oh, hi Zapper. How do keep sneaking in like that?
 
  • #33
Any thing instantaneous is virtually. Example: If someone was 1000 feet apart, and they sent an instantaneous message to you, then what would happen if someone in the middle of you two received that message? They would have received it before it was sent.
 
  • #34
There's no such thing as 'instantaneous' when it comes to propogation of a signal. The limiting factor is light speed. Even quantum entanglement can't deliver a verifiable signal faster than that.
 
  • #35
Physics

Quote:
Originally Posted by warp darkmatter
It seems to me that the initial question "is existence faster than the speed of light?" has been overlooked by the the initial writer and subsequent responses.
Whilst the question, can anything travel faster than the speed of light? has been answered and has made for interesting reading, the question is existence faster than the speed of light is another concept altogether.
Existence is relevant to the observer and the interactions that the internal and external stimuli effect upon the brain. I am aware of things existing around me, but only as they have occurred in the past (the question of what existence means if nothing exists to observe it is a philosophical one). However, what of the awareness of my own existence?
One could argue that existence itself must travel at the speed of light based on the electrical interactions within the brain. But what if the signals are being created by the subconscious before the actions begin? Even at the atomic level, existence must precede an action. If this is the situation, then could it be possible for thoughts to be created before they are thought? If so, then what are the implications for organic computers (if we go down that path) and artificial intelligence?
Unfortunately this is the physics forum, here we must talk of physics. I do not see any evidence of physics in your response.

What exactly is our essence? Electrons pumped through a neural pathway. What is the exact composition of these electrons? In what form are they triggered and in what manner are they received? What is not physics about this? How do we define thought? Many new formulae would be created through understanding of these things to harvest better answers from the world around us.

It's not eccentricity but who says we have to wait until the labrats discover these things before we tamper with them ourselves?
 

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