Faster than C?

[yevaud]

Now *there's* an interesting question: do Tachyons exist.<br /><br />I do recollect from my schooling (back in the Dark Ages, surely) that one hypothesis is that Tachyons may well produce decay products that might "appear," so to speak in our mundane, Einsteinian space. Something about tunneling through from superluminal...<br /><br />CR, Saiph, do either of you recollect this? <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>

 

[Saiph]

Nope. Though I suppose if heisenberg allows particles to exceed C (however briefly), it could work.<br /><br />I'm trying to remember what the "symptoms" of a tachyon are that would allow detection. <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>

 

[jatslo]

HELLBOY?

 

[ordinary_guy]

<blockquote><font class="small">In reply to:</font><hr /><p>I'm trying to remember what the "symptoms" of a tachyon are that would allow detection.<p><hr /></p></p></blockquote><br />Dunno...<br /><br />But I thought of this: when you play with the speed of light itself, lowering it through certain mediums, other particles can exceed the speed of light – and often do. When it happens, the particles give off a glow, photonic shockwaves of a sort, in a glow known as cerenkov radiation. The problem with tachyons (I think) is that you'd need a medium where C can go it's in-vacuum speed, then look in that medium for cerenkov radiation. It would be akin to looking inside a laser beam to catch non-coherent photons. Not real easy, but considering the minds that put together particle collision detectors, I have no doubt they could do it. <div class="Discussion_UserSignature"> <p style="font:normalnormalnormal12px/normalTimes;margin:0px"><strong>Mere precedent is a dangerous source of authority.</strong></p> <p style="font:normalnormalnormal12px/normalTimes;margin:0px">-Andrew Jackson (1767-1845)</p> </div>

 

[yevaud]

Well, it's known that the velocity of light can be altered, to a higher velocity. It's an aspect of the Casimir Effect. <br /><br />To my recollection, part of the experiment showed that it decreased interference (an averaging effect) with particle/anti-particle pairs. It increased the velocity of C by a few hundred KPS. Or something to do with altering Permissivity and Permiability. Don't quite remember.<br /><br />Been a long time since I was in school. Does this ring a bell for you?<br /><br />Dang. I really have to go back and hit my old textbooks... <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>

 

[jatslo]

That's what I was talking about in that other speed-of-light thread; however, I thought I invented the concept at the time. HELLBOY was supposedly pushed through by a tachyon ;o)<br /><br /><font color="yellow">or Cerenkov radiation [for P. A. Cherenkov], light emitted by a transparent medium when charged particles pass through it at a speed greater than the speed of light in the medium. The effect, discovered by Cherenkov in 1934 while he was studying the effects of gamma rays on liquids and explained in 1937 by I. E. Tamm and I. M. Frank, is analogous to the creation of a sonic boom when an object exceeds the speed of sound in a medium. The light is emitted only in directions inclined at a certain angle to the direction of the particles’ motion dependent upon the particles’ momentum. Thus, by simply measuring the angle between the radiation and the path of the particles, the particles’ speed may be determined. The effect is used in the Cherenkov counter, a device for detecting fast particles and determining their speeds or distinguishing between particles of different speeds.<br /><br />http://www.bartleby.com/65/ch/Cherenk-rad.html</font><br /><br />Why should there be a medium involved with a light boom?<br />

 

[ordinary_guy]

<blockquote><font class="small">In reply to:</font><hr /><p>Why should there be a medium involved with a light boom?<p><hr /></p></p></blockquote><br />I don't know if it's a requirement, I'm a little sketchy about theoretical stuff at that level – it enters the realm of "extended relativity." I suppose you could have spontaneous tachyonic-induced cerenkov radiation from a vacuum (say that 3 times fast), but it would likely be... <i>rare.</i> If you study a high-energy medium, you're "seeding" the phenomena, making the energy available and therefore more likely that you'd observe a connected phenomena.<br /><br />At least... that's my impression. <div class="Discussion_UserSignature"> <p style="font:normalnormalnormal12px/normalTimes;margin:0px"><strong>Mere precedent is a dangerous source of authority.</strong></p> <p style="font:normalnormalnormal12px/normalTimes;margin:0px">-Andrew Jackson (1767-1845)</p> </div>

 

[serak_the_preparer]

Ordinary_Guy,<br /><br /><i>The problem with tachyons (I think) is that you'd need a medium where C can go it's in-vacuum speed, then look in that medium for cerenkov radiation. It would be akin to looking inside a laser beam to catch non-coherent photons. Not real easy, but considering the minds that put together particle collision detectors, I have no doubt they could do it.</i><br /><br />Those other media in which Cerenkov radiation is generated are not, however, the underlying medium of the universe, space-time itself. Perhaps the presence of supraluminal phenomena in the vacuum of space would not be revealed by Cerenkov radiation, as it is in other cases? In which case, I would expect such phenomena to reveal themselves through a shock-wave in space-time itself. That is, gravity-waves. Perhaps when our gravity-wave detectors become good enough, we'll begin seeing strange things out in the universe?

 

[ordinary_guy]

<blockquote><font class="small">In reply to:</font><hr /><p>Perhaps the presence of supraluminal phenomena in the vacuum of space would not be revealed by Cerenkov radiation, as it is in other cases?<p><hr /></p></p></blockquote><br />That is quite possible. I still lean toward the cerenkov measure: tachyons would be a mathematical imaginary mass (negative square root) – just as cosmological "dark energy" may be – but it's still a type of mass and still subject to laws that govern mass.<br /><br />My personal reality check: just as Newtonian physics gave way to relativistic physics, at those levels, special relativity may give way to something else. Cerenkov radiation may not be possible from tachyonic phenomena.<br /><blockquote><font class="small">In reply to:</font><hr /><p>In which case, I would expect such phenomena to reveal themselves through a shock-wave in space-time itself. That is, gravity-waves.<p><hr /></p></p></blockquote><br />That is a <i>cool</i> idea. You may be on to something there.<br /><blockquote><font class="small">In reply to:</font><hr /><p>Perhaps when our gravity-wave detectors become good enough, we'll begin seeing strange things out in the universe?<p><hr /></p></p></blockquote><br />We see plenty of strange stuff already... high-resolution gravity wave detectors – the next generation or two of LIGOs – might be the thing we need to help sort some of it out! <div class="Discussion_UserSignature"> <p style="font:normalnormalnormal12px/normalTimes;margin:0px"><strong>Mere precedent is a dangerous source of authority.</strong></p> <p style="font:normalnormalnormal12px/normalTimes;margin:0px">-Andrew Jackson (1767-1845)</p> </div>

 

[lampblack]

I have trouble enough propelling myself from bed every morning. The notion of traveling faster than the speed of light seems extremely unlikely from this perspective.<br /> <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[serak_the_preparer]

<i>I still lean toward the cerenkov measure...</i><br /><br />Sorry I've taken so long to respond. I am a slow-speed web-surfer.<br /><br />About the Cerenkov radiation. I wonder if there are enough particles available in the interstellar medium to become excited by the shock-wave, and then to de-excite, emitting sufficient photons to be detected? In certain regions of space, you are probably right, and a tachyon ripping through would produce the effect.<br /><br /><i>Cerenkov radiation may not be possible from tachyonic phenomena.</i><br /><br />This is what I was also thinking. They may not be physical in the same sense as stuff stuck on the other side of the light-barrier. In fact, I rather doubt they would follow all the same rules.<br /><br /><i>You may be on to something there.</i><br /><br />What does imaginary mass do to gravity? Especially mass traveling faster than light? Another interesting question.<br /><br /><i>... high-resolution gravity wave detectors – the next generation or two of LIGOs – might be the thing we need to help sort some of it out!</i><br /><br />There used to be some extensive gravity threads on a previous incarnation of Space.com's Space Science forum. Lots of interesting stuff about LIGO and the other gravity-detectors. Our first detectors look to be a bit too crude to be very useful. But, as you say, the next generation, or the one after that, may show us some interesting things.

 

[jatslo]

That cracks me up, lampblack.