speed of light ? or faster?

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R1

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I have a question, <br />suppose we build a nonotube 3 Light-seconds long <br /><br />an explosion on each end of the tube moves it back and forth, <br />it's a signal between scientists on each end.<br /><br />when the tube is pushed by scientist A to signal scientist B on<br />the other end, don't they instanly receive the information and<br />notice the tube moved ?<br /><br />I know if you had a wire and sent a phone signal, you would need at<br />least 3 seconds to get the signal on the other end, because the electron signal<br />has to jump through each copper wire in the way.<br /><br />But this is totally different, doesnt scientist B immediately see that the nanotube has been pushed an inch in his direction instantaneously? and<br />beating the speed of light slow phone signal by up to 3 seconds?<br /><br />In other words dont send informationon a wire using slow speed of light<br />phone signals, just jerk the whole nanotube back and forth and<br />communicate instantlyandfaster than SOL<br /><br />or what are you getting ready to say, that the speed limit cant be violated<br />and the nanotube will actually break somewhere, separate by an<br />inch, and then rebuild itself chunk by chunk or atom by atom towards the other end at the speed of light?<br /><br /> <div class="Discussion_UserSignature"> </div>

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vogon13

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Mechanical disturbance (from explosion) travels thru tube at the speed of sound in that material. IIRC, for instance, speed of sound in steel is ~1 mile per second.<br /><br />Not sure the speed of sound in neutronium, but suspect even in that material it is drastically less than c.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

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yevaud

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Ever grabbed a garden hose by one end, and whipped it hard? You can watch the hose "sine-wave" down it's length. Same thing. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

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keysersoze

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ummm somthing 3 light seconds long would be larger than earth.... extremely larger than earth.. so how would u be able to construct it in the 1st place

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K

exactly

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Saiph

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john, that moving of the tube <i>is</i> a mechanical disturbance.<br /><br />We don't see delays in rigid materials here on earth merely because the beams and blocks and such are quite short compared to the speed of sound through the object.<br /><br />When you push an object, you exert a force upon a portion of it. In order for the rest of the object to move, that force must be exerted upon the next portion, and then the next, and then the next, down the line.<br /><br />This speed at which the pushing force travels between portions, is the speed of sound.<br /><br /> <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

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vogon13

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Tap it with a feather, or slam it with a nuke, its still a mechanical disturbance traveling at the speed of sound in that medium.<br /><br />Anything short of inflation phase of Big Bang is going to react just like I said.<br /><br />And that's the way it is, June 22, 2005.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

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taolung

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Right - what the others have pretty much said. Say you have your big long nanotube set up, and scientist A wants to ring the bell on scientist B's end. So he smacks the tube with a hammer. You'll get to watch the nanotube bend slightly as it shoots a "wave" down its length until at scientist B's end, it juts forward an inch to ring the bell.<br /><br />If you ever find some footage of a building demolition in slow motion you'll likely see the same thing. Explosives at the bottom of the building go off, the force pushing up on the building slightly. The top of the building doesn't move up at exactly the same moment - instead, you instead watch a ripple move through the concrete and steel, up the building, until it reaches the top, a few fractions of a second later.

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robnissen

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"This speed at which the pushing force travels between portions, is the speed of sound."<br /><br />I completely agree with everything that has been said here, but I have one clarification. The speed of the pushing force, is the speed of sound in the medium being pushed, it would have nothing to do with the speed of sound in the air. For example, if a long solid steel tube was hit with a hammer. The sound coming through the air of the hammer hitting the tube would arrive after the other end of the steel tube moved. But the sound of the hammer hit that propagated through the tube, would arrive at the other end at the exact moment the other end moved.

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R1

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well thanks to everyone for your inputs,<br />it's really interesting and helpful for my thinking. Thanks to all of you.<br /><br />here's another thought. if scientist A pulls the nano string (rod) instead<br />of pushing it to signal scientist B, are you trying to say the<br />nano string/rod will break or stretch?<br /><br />I know one of the posts mentioned an explosion when buildings are demolished<br />in slow motion it takes a while for the disturbance to reach the opposite end,<br />but the nano string these scientists have are approximately one atom in<br />diameter, maybe a few at the most, so it's really almost massless over<br />a lot of intervals.<br /><br />So I can understand a disturbance sent to scientist B's bell by poking them<br />with the nano string a little better now, <br /> <br />but is it the same case if scientist A were to pull instead of push? what if they told<br />you their nano string is unstreachable and unbreakable?<br /><br />if 600,000 miles makes this nano string too massive, would it help them if<br />they only used a 1.5 light-second long nano thread? (200,000 miles)<br /><br />would the mass of the nano-thread between 1 and 5 atoms in diameter<br />amount to anything per 1000 miles?<br /><br />I mean the transatlantic cable at the bottom of the sea must really weigh a lot,<br />but intead of inches in diameter or however thick it is, scientist A and B<br />are using a nano tube (string) only 1 or 4 or 5 atoms in diameter, built in a super<br />strong and rigid straight line in the cold outer space.<br /><br />but anyway what's the answer, the thread will either have to stretch or break or not move at all, (no matter how massless and strong the nanostring is?) ?<br /><br />thanks everyone. <br /><br />(ps. no I dont know how it would be built, but I wish this thing would at least work<br />on paper first. maybe a robot spider could build the string atom by atom, <br />getting refueled every now and then with whatever atoms it needs to build it)<br /><br /> <div class="Discussion_UserSignature"> </div>

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vogon13

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Dreams die hard, sorry. You were thinking superluminal, and physics of matter limits concept to speed of sound in material. <br /><br />All matter available to you is atomic, ie. nucleus and electrons. Mechanical disturbance transmitted thru the electron clouds around each atom (simplified view here, quantum mechanical interpretation of all this exceeds needs of this thread). Each electron has to deflect sequentially from one end of your chain of atoms to the other. Takes time. Rather more than you hoped.<br /><br />I still have no idea what the speed of sound in neutronium is, but I bet its large. But not larger than C. Disturbance in neutronium would be transmitted via quark/ strong nuclear force effects, I suppose, but am clueless to go beyond that.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

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cosmic_hotshot

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what about those things they call leptons. dont remember where but they are supposedly capable of going faster thatn light

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nacnud

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No leptons are a classification of subatomic particles, all closly related to the electron. The name "lepton" comes from the Greek, meaning "small" or "thin". <br /><br />There are three flavours of leptons and each lepton has an associated nutreno. The three flavours are electron/anitelectron (positron) the muon/antimuon and the tauon/antitauon.<br /><br />There has never been any reason to think that leptons could move faster than the speed of light.

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raghara2

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Of course such thing could hapen if material would do quantum teleportation of the required force. Such thing could be in future computers, imagine CPU that would work faster than light in vacuum.<br />It might be so powereful that it would need just two CPUs for runing the lastest game.

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lunatio_gordin

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I hate the look on people's faces when they ask me what i'm reading and i have to say "physics." no average people want to understand it, they think you have to be albert einstein himself to have a clue...

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taolung

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<blockquote><font class="small">In reply to:</font><hr /><p>if scientist A pulls the nano string (rod) instead <br />of pushing it to signal scientist B, are you trying to say the nano string/rod will break or stretch? <p><hr /></p></p></blockquote><br /><br />Yep. It'll stretch as much as the material allows. Everything has some elasticity, even steel, rocks, and other apparently solid things. As soon as that elasticity gives, it'll break.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>what if they told <br />you their nano string is unstreachable and unbreakable? <p><hr /></p></p></blockquote><br /><br />It's a moot point, since such a thing can't exist... but to play along, my guess is you wouldn't be able to move it. It's sort of like asking if you could move a rock without moving it. For the string to propegate movement, it physically has to stretch. I dunno, I may be wrong...

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