Is existence faster than the speed of light?

  • Thread starter archen
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  • #36
ZapperZ
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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?

You can temper with them as much as you want, but unless it is a discussion based on established physics, you'll have to do it elsewhere, per our PF Guidelines.

Zz.
 
  • #37
Idjot
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archen, I understand your question. What I'd like to point out is that regardless of the rigidity of the "rope" and the speed of sound, ect., ect. ; If you're pulling one end of the rope and someone else is losing the other, you and your rope can essentially be treated as one body moving through space. If you pull the rope and it instantly jumps away from the other's hands it only means that a very long object is moving. With regard to velocity it'd be no different than pulling a six foot rope out of someone's hands. The rope only moves as fast as you pull it. Of course, the amount of energy required would be ridiculously larger to pull the longer rope. Might need a winch.
 
  • #38
Danger
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If you pull the rope and it instantly jumps away from the other's hands it only means that a very long object is moving.

Again, this is not possible. It will not jump away from the other's hands any faster than the pulling force can be transmitted from one end to the other, which is limited to the speed of sound in the rope.
 
  • #39
jtbell
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archen, I understand your question.

Please take note of the date on archen's original post that started this thread. Furthermore, according to the list of his postings in his profile, his last post on PF was on November 11, 2005! :rolleyes:
 
  • #40
Idjot
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Again, this is not possible. It will not jump away from the other's hands any faster than the pulling force can be transmitted from one end to the other, which is limited to the speed of sound in the rope.

I understand the whole "speed of sound" argument. It makes perfect sense. But it's simply not necessary to point it out when answering this question. My answer was "regardless of the speed of sound, ect. ect.". In other words, even if the pull was instantaneous, the rope would still be treated as just a long object moving at the speed your pulling it. I am answering the original question with regards to the idea presented. I'm sure the "rope" in the original question was intended to create a visual interpretation of a theory. I seriously doubt archen was inquiring about the physical characteristics of rope when "yanked" on.

Made for fun reading though.
 
  • #41
Idjot
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Please take note of the date on archen's original post that started this thread. Furthermore, according to the list of his postings in his profile, his last post on PF was on November 11, 2005! :rolleyes:

Yeah, I noticed the date after I replied. lol maybe he'll come back someday and read what he started.
 
  • #42
Danger
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My answer was "regardless of the speed of sound, ect. ect.". In other words, even if the pull was instantaneous, the rope would still be treated as just a long object moving at the speed your pulling it. I am answering the original question with regards to the idea presented. I'm sure the "rope" in the original question was intended to create a visual interpretation of a theory. I seriously doubt archen was inquiring about the physical characteristics of rope when "yanked" on.

I see what you mean, but this is a serious science site. We don't deal with scenarios involving 'if we ignore the laws of physics, this is what might happen'. The laws of physics are not ignored here.
 
  • #43
Idjot
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I see what you mean, but this is a serious science site. We don't deal with scenarios involving 'if we ignore the laws of physics, this is what might happen'. The laws of physics are not ignored here.

If you're going to take such an aggressive stance I suggest you consider that much of physics is based on theory. Many theories use imaginary objects for illustration. It's to be appreciated. And recognized. Otherwise you might miss the proposed theory altogether while knit-picking the props, as you seem to have just done.

Additionally, if you actually believed your present thrust then you naturally would have knit-picked the basic scenario itself first. 2 people 200,000 miles apart holding a rope? Where and with whose physics did you justify such impossibility before you noticed that the physics of pulling the rope quickly was the part that wasn't possible?

Nice try Dr. Danger.
 
  • #44
AlephZero
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2 people 200,000 miles apart holding a rope? Where and with whose physics did you justify such impossibility before you noticed that the physics of pulling the rope quickly was the part that wasn't possible?

The justification is that the same laws, principles, or theories, (call them what you like) apply whether the rope is 2 inches long of 200,000 miles long.

And THAT principle is one of the most fundamental principles of physics.

As for impossibility or irrelevance, there are plenty of man-made objects that look and behave pretty much ropes and are a of the order of 1,000 miles long. And experimentally, effects don't get propagated from one end to the other instantaneously.

The propagation delay is quite easy to measure in a rope a 2 feet long, for that matter.
 
  • #45
Danger
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I would point out, as well, that a cable of some sort of 200,000 miles length is entirely possible in space. That would be an appropriate dimension for an interstellar hydrogen ram scoop.
 
  • #46
DaveC426913
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I think Idjot might be thinking we're being sticks in the mud about transmission of the force - that's it's a detail.

Idjot, this is not a trivial point - it is the whole point of the discussion.

To merely propose an infinitely rigid object in a thought experiment is to immediately violate SR. SR does NOT allow any matter or any information to travel at greater than c. Period. There's no grey area.

Our universe works the way it does because pulling on a rope takes time to transmit the force.
 
  • #47
Idjot
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You guys are totally missing the point. 'Suppose' there was something that spanned 3 light seconds in size and it's entire mass could move simultaneously in one direction. Forget the rope and the mere 200,000 miles for a second. Replace the rope with a star and replace the person pulling with gravity. Now maybe the concept can be examined instead of the layman's props originally used to illustrate it. It's really an interesting idea. A little harder to grasp this way, but for some it may be easier to be free of technical distractions involving rope and such.

The original idea was suggesting that if a large object can interact between two points faster than light could interact between the same two points, what does that really mean? It's obviously possible and happens all the time without breaking any laws. But the concept requires an unorthodox method of observation. Hence the props.

Unfortunately, as much as I appreciate the concept, nothing tangible is actually traveling faster than light in such scenarios. It's merely an interaction with a very large object that takes light a little longer to cross. Still worth a few more thoughts, though.
 
  • #48
Danger
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Man, you have got one convoluted thought process happening there. It has nothing to do with the original question. If you insist upon bringing in gravity, then you do in fact have the entire mass being pulled equally... once the gravitational wave has reached each part; and gravity propogates at light speed. You can still not have an instantaneous movement of all parts.
 
  • #49
JeffKoch
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The original idea was suggesting that if a large object can interact between two points faster than light could interact between the same two points, what does that really mean? It's obviously possible and happens all the time without breaking any laws.

But it can't, that's the point. The distant points on the large object can't interact more rapidly than the time it would take light to cross the separation distance. It's not possible, and it can't happen. That's not to say the object as a whole can't move with a uniform speed, but in that case the distant points aren't interacting and can't know anything about each other over timescales shorter than the light travel time between the points.
 
  • #50
Danger
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Nice summation, Jeff. :approve:
 
  • #51
Idjot
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The sun is about 1,000,000 km across. Light travels at less than 300,000 km/sec. At 1c it would take you more than 3 seconds to traverse the width of the sun. I know, I know. YOU can't travel at 1c but light can. Sorry bout that. Anyway, let's say point A and point B are a little over 1,000,000 km apart and point A is behind the sun's trajectory and in contact with it and point B is on the other side a few miles in front. With the sun so large it can lose contact with point A on one side and then gain contact with point B on it's other side before you can get from A to B at light speed. That's all this ridiculous argument is about. So, if a single bodies' mass can represent the "existence" in the original question then yes, existence can be faster than light. Doesn't really amount to much but that's the best interpretation of the original concept yet. You guys definitely win the rope diagnostics award, though.
 
  • #52
«John»
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well i have an idea that is very simular to this topic, if you move your leg, the exact second that you move your leg, the smallest (atom, quark, and whatever is smaller than that) of your leg moves instantaniously, right? i mean you can't move your leg without an infinite number of instantanious movements all at once, am i making any sence?
 
  • #53
Danger
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am i making any sence?

You're making sense in that we can understand you, but your assumption is incorrect. A leg is like any other material. The movement progresses from the muscle attachment point at or near the speed of sound. Luckily, it's a very short distance and sound is pretty quick.
 
  • #54
DaveC426913
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... let's say point A and point B are a little over 1,000,000 km apart and point A is behind the sun's trajectory and in contact with it and point B is on the other side a few miles in front. With the sun so large it can lose contact with point A on one side and then gain contact with point B on it's other side before you can get from A to B at light speed.
You do realize though that the sun, if put in motion will not move as a solid body? If a force is applied to it, that force will only propogate - once again - at the speed of sound of the mass involved. The movement of the Sun will ripple though its volume and no part of the Sun will travel at greater than the speed of sound.

Again, this is not a detail, this is critical to the question.

In fact, the supplies the answer the OP is looking for:

One side of the sun and the other side of the sun are not causally connected to each other at the same point in time. There is absolutely nothing in the universe you can do to one side of the sun that the other side of the Sun can be affected by in any less than 3 seconds.


The answer to the OP's question is thus:

Inasmuch as existence has any meaning in the physical world, it does not travel faster than c. There is absolutely nothing you can do or measure - even in principle - to show that two parts of the universe are connected to each other, at any speed faster than c.

On a cosmic scale, parts of the universe that are more distant from us than light has reached since the Big Bang are causally disconnected from us - they are forever cut off from us, and are treated and beyond the scope of science. In every way thayt is meaningful, they do not exist.
 
  • #55
Idjot
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You do realize though that the sun, if put in motion will not move as a solid body? If a force is applied to it, that force will only propogate - once again - at the speed of sound of the mass involved. The movement of the Sun will ripple though its volume and no part of the Sun will travel at greater than the speed of sound.

Let's see here. What force are we talking about? I left the "yanking human" behind a few posts ago and went to Gravity, so I guess I'll have to answer you with: No I did not realize that the force of Gravity reacting upon the Sun will have to propagate through the Sun at the speed of sound before the whole mass moves. So gravity is like a tow rope. Hmm... rope.

Nope. You still don't get it.
 
  • #56
DaveC426913
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That's right, it's us who aren't getting it...


While Idjot's thread has deviated dramatically from the OP, which is what we're answering here, I'll correct one element in it:

"...the force of Gravity acting upon the Sun will have to propagate through the Sun at c ..." (but note, you'd have to subject the Sun to a pretty big insult in order to create a gravity wave, the OP is really more about mere mechanical transmission of forces)
 
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  • #57
Danger
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I am so close to giving up here.
Alright, Idjot... let's try it this way. Envision the atoms in a material as cars lined up at a stop sign. If someone rams into the back of the last one, is the first one going to move at the same time?
 
  • #58
DaveC426913
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I am so close to giving up here.
Well, remember, this is the OP's question, not Idjot's. If Idjot takes umbrage with this answer, and wants to go off in a new direction he can always open a fresh thread.
 
  • #59
Danger
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Well, remember, this is the OP's question, not Idjot's. If Idjot takes umbrage with this answer, and wants to go off in a new direction he can always open a fresh thread.

Agreed. Perhaps it would be suitable for a Mentor to split this thread off as of the 'resurrection' post into a new one.

And maybe lock it... :uhh:
 
  • #60
Idjot
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C'mon guys, I'm only playing around here. My sarcasm runs deep. This thread is just fun to play with. Give me a break. Even if the rope was already taught and the B guy let go of it the propagation would still delay the motion of it. I'd love to demonstrate the delay in an Earthbound way because as well as we know it, I don't think anyone's actually proved it. Imagine being the astronaut that pulled the rope. How long would you be waiting for the rope to actually move? That's what's really come out of this. The awareness that a noticeable delay in movement would happen right in front of your eyes after you pull on the rope.

Many would not believe it without seeing it. I'm really on your side here, "in learned synchronicity with you". It's just that you don't seem to grasp this simple concept...

Existence continues... but at what velocity lol
 
  • #61
Idjot
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What if the Sun was already moving? Let's say around 72,000 km/hr? Could it still come in contact with A and B before light? What about CMBR? Is that moving? Could we measure the acceleration of a body being "pulled" by gravity by CMBR? Can we measure light by the G's we experience? Now THAT's convoluted. I'm done w/ this one.
 
  • #62
Danger
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Idjot, your humour was neither recognized nor appreciated for the simple fact that it wasn't obvious. We have had far too many people here who say that sort of stuff in earnest.
 
  • #63
Idjot
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Well I wasn't exactly cracking jokes. What I mean by playing around is that I made a conscious decision to debate from a seemingly opposing viewpoint. I wasn't actually passionate about this idea at all. In fact it was for this reason that I chose to champion it, so-to-speak. I proposed challenges to make things more interesting. The sarcasm was just to get the blood flowing a little, if you know what I mean. You got to admit it was fun.
 
  • #64
Danger
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You got to admit it was fun.

Yeah... in an irritating sort of way. :biggrin:
 

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