Any science freak out there can answer that?
#1
You know how and object, namely a fighter jet, traveling at high speed will produce a sonic boom when breaking the speed of sound, due to the Doppler effect, which effectively is the 'stacking' of the sound waves, all being heard at once, which is VERY loud!

What I was wondering was, if one was to (theoriticaly of course) build a contraption that would allow travel at and above the speed of light, would an effect analogous to the sonic boom occur?

I can only guess on that matter. I can imagine how photons behind the said device would not reflect against it, so it would be 'invisible' from behind, assuming you can manage see and object that can go 'round the earth 7.5 time per second.

In front of the device, photons would 'stack' and create a light so bright and friction created by all those photons would probably generate gargantuesque amounts of heat that would obliterate anything.

Hope someone out there has a less whacky :w00t: and more rigorous theory!

Cheers!
-D
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#2
Your theory sounds reasonable, but there's a few problems present.

One, I'm not sure that the currect laws of physics apply in such great speeds

Secondly, the mere existance of photons is, I believe, entirely theoretical, the same as gravitons, there are no evidence, not even indirect evidence as Electrons or Black Holes have.

Third, light is not known to be whether particles or waves, thus the effect could vary, I myself think it's actually a third thing which is neither particles nor waves, or perhaps both as it is impossible for something to be two different things which contradict each other.

There's also another I foresee, if something could go beyond the speed of light, adding the pressure of impact and the such, wouldn't the vessel just explode due to a nuclear reaction of the atoms coming in touch with the vessel are being seperated.
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#3
There is already a description of such effects. Cherenkov effect

The speed of light in any material is slower than a vacuum, so a particle moving faster than this spepd gives off radiation.

And yes, moving faster than light's vacuum speed is impossible from what peopel knowso far, unless you use some tricks such as wormholes which won't be developed for a long time
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#4
Well, the speed of light ain't that much of an absolute as some scientists claim it to be, it was successfully tested to slow and accelerate the speed of a photon, slowing it down to just above the speed of sound and accelerating it to around 10 times the speed of light (don't take my word on the acceleration, I'm not sure) so that quite ruins the entire thing of impossible to be above the speed of light as the speed of light itself can be modified.
"Turn the key deftly in the oiled wards, and seal the hushed casket of my soul" - John Keats, "To Sleep"
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#5
I am not a scientist but here is an uninformed hypothesis.

Objects traveling close to the speed of light become shorter and increase their mass. This plus the simple fact that objects moving at high speed are harder to see anyway may mean that as an object aproaches the speed of light (and it's power requirements increase exponentialy) it becomes nearly invisible anyway.

Also as objects become more massive they create greater distortions on space time which cause objects nearby to "curve" around it. When mass becomes great enough (such as a black hole) things that get too close get "sucked in" instead of curving around it. So light either curves away from the object or becomes trapped in the gravity well created by the object's mass. Again, the object would not be visible, other than the effect it has on nearby items.

Photons travel at the speed of light and are believed to have no mass and an object approaching the speed of light is becoming exponentially heavier. When the object passes the threshold and begins traveling at the speed of light does that incredible amount of mass spontaneously convert into energy? (Yikes!)

So to answer your question I believe you wouldn't be able to see the object at all. It either isn't there yet or has already passed by. :o
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#6
Quote:What I was wondering was, if one was to (theoriticaly of course) build a contraption that would allow travel at and above the speed of light, would an effect analogous to the sonic boom occur?

As far as I know this would be impposible to test because:

1. When objects start to near the speed of light they lose mass because their nuclei get excited and start emiting pions, and their electrons start to change their spin more often and start emiting low energy photons (infinitly redshifted). This means that somewhere just before the speed of light the objects would lose all their mass and we would be left with nothing to accelerate. :o

2. When objects near the speed of light it takes more and more energy to accelerate them, this need increase exponentially, until we would need an infifnite amount of energy to keep accelerating it (this would happen just before light speed). :wacko:

Quote:I can only guess on that matter.  I can imagine how photons behind the said device would not reflect against it, so it would be 'invisible' from behind, assuming you can manage see and object that can go 'round the earth 7.5 time per second.

Not only would anything directly behind the object not be able to see it, but it would be "censored" from them as an "event horison" would form beetwen them.
But the "weak forces" (gravity) from the object would still effect the obserever because the light can still theoreticlly reach him (it's just infinitly redshifted). :blink:

Quote:In front of the device, photons would 'stack' and create a light so bright and friction created by all those photons would probably generate gargantuesque amounts of heat that would obliterate anything.

Since the object would then be traveling so fast that it can't exist in normal time-space the photons would just ignore and go right through it!
On the other hand, according to quantom theory the object would be at the "end of time" and "see everything simotaniously" (although it would al be infinitly blueshifted). :w00t:

I'm still waiting for the demonstration of quantum gravity though! :whistling:




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#7
TaiDaishar,Mar 15 2005, 02:59 AM Wrote:Third, light is not known to be whether particles or waves, thus the effect could vary, I myself think it's actually a third thing which is neither particles nor waves, or perhaps both as it is impossible for something to be two different things which contradict each other.
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Quantum Physics says light has a dual nature. :shuriken:

TaiDaishar,Mar 15 2005, 02:59 AM Wrote:There's also another I foresee, if something could go beyond the speed of light, adding the pressure of impact and the such, wouldn't the vessel just explode due to a nuclear reaction of the atoms coming in touch with the vessel are being seperated.
[right][snapback]70752[/snapback][/right]

The vessel would have no atoms left and even if it had they would immediatly be converted to energy. ;)
It is a myth that the hair and nails grow after death! The skin shrinks, giving the illusion of their growth.

When J.F.K. was assassinated in 1963, it was not a federal felony to kill a U.S. President.

The leading cause of death to military personnel in peace time is drunk driving.

It would take more than 2.5 minutes to fall from the top of Mt. Everest.

0xDECAFBAD is a hex oddity, a coincidence of hexadecimal digits which just happens to hold some incidental semantic content to weird humans.
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#8
jahcs,Mar 14 2005, 07:41 PM Wrote:Photons travel at the speed of light and are believed to have no mass and an object approaching the speed of light is becoming exponentially heavier.  When the object passes the threshold and begins traveling at the speed of light does that incredible amount of mass spontaneously convert into energy? (Yikes!)
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Probably not. The mass just goes closer and closer to infinite, assuming you get enough energy to get it going that fast in the first place.

jahcs,Mar 14 2005, 7:41 PM Wrote:Objects traveling close to the speed of light become shorter and increase their mass. This plus the simple fact that objects moving at high speed are harder to see anyway may mean that as an object aproaches the speed of light (and it's power requirements increase exponentialy) it becomes nearly invisible anyway.

Also as objects become more massive they create greater distortions on space time which cause objects nearby to "curve" around it. When mass becomes great enough (such as a black hole) things that get too close get "sucked in" instead of curving around it. So light either curves away from the object or becomes trapped in the gravity well created by the object's mass. Again, the object would not be visible, other than the effect it has on nearby items.

That's how such objects would get detected. This would be extremely hard to test since the amount of energy needed to get somethign that heavy can't be easily made now by a long shot. The speed needed to get something black hole mass is lot of nines behind a decimal, more than 10 probably, since particles now from what I hear get up around 4 or so nines percent the speed of light and still are pretty light for everyday objects.
I may be dead, but I'm not old (source: see lavcat)

The gloves come off, I'm playing hardball. It's fourth and 15 and you're looking at a full-court press. (Frank Drebin in The Naked Gun)

Some people in forums do the next best thing to listening to themselves talk, writing and reading what they write (source, my brother)
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#9
TaiDaishar,Mar 14 2005, 06:24 PM Wrote:Well, the speed of light ain't that much of an absolute as some scientists claim it to be, it was successfully tested to slow and accelerate the speed of a photon, slowing it down to just above the speed of sound and accelerating it to around 10 times the speed of light (don't take my word on the acceleration, I'm not sure) so that quite ruins the entire thing of impossible to be above the speed of light as the speed of light itself can be modified.
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Hey, I was terrible at physics, so I'm not the best person to comment on this (we miss you, Pete!), but I'm pretty sure that if something had been successfully accelerated past the speed of light, I wouldn't be hearing about it for the first time here. You'd be talking about a radical new look at physics as we know it (at least from what I know about physics, which, like I said, is very little).

Forgive me for not taking you at your word here, but I would want to see some documentation before I would believe something like this.
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#10
Griselda,Mar 15 2005, 01:05 AM Wrote:(we miss you, Pete!)
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That was the first thing I thought of when I originally read this topic. I know a bit about physics, but not enough. This stuff interests me, but I don't know nearly enough about it to comment.

Get well soon Pete! You've always been great at sorting out these topics.
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#11
Daemon,Mar 14 2005, 04:00 PM Wrote:What I was wondering was, if one was to (theoriticaly of course) build a contraption that would allow travel at and above the speed of light, would an effect analogous to the sonic boom occur?[right][snapback]70749[/snapback][/right]

Well, if you're asking whether it's possible to create a shock wave (or, for that matter, a contraption) that travels faster than the speed of light, the short answer is: no. (Unless there are radical changes in our understanding of physics.)

The "speed of light" is a bit of a misleading term with historical origins, since it represents a fundamental limit on the speed at which any information can propagate. It's a basic principle of all current physical theories (both classical and quantum) that causal effects can't propagate faster than the speed of light (EPR paradox, tachyons, geometric illusions, wormholes, and Star Trek, notwithstanding).
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#12
Daemon,Mar 14 2005, 06:00 PM Wrote:You know how and object, namely a fighter jet,  traveling at high speed will produce a sonic boom when breaking the speed of sound, due to the Doppler effect, which effectively is the 'stacking' of the sound waves, all being heard at once, which is VERY loud!

What I was wondering was, if one was to (theoriticaly of course) build a contraption that would allow travel at and above the speed of light, would an effect analogous to the sonic boom occur?

I can only guess on that matter.  I can imagine how photons behind the said device would not reflect against it, so it would be 'invisible' from behind, assuming you can manage see and object that can go 'round the earth 7.5 time per second. 

In front of the device, photons would 'stack' and create a light so bright and friction created by all those photons would probably generate gargantuesque amounts of heat that would obliterate anything.

Hope someone out there has a less whacky  :w00t:  and more rigorous theory!

Cheers!
-D
[right][snapback]70749[/snapback][/right]

Your model will not transfer. The speed of sound is faster in iron that it is in air, while speed of light, as Thecla points out, is not quite the same sort of thing. It is either a wave or a partical or both. Sound is quite simply a pressure differential, or a measure of agitation of molecules in a material. There is no sound in outer space if you presume space to be a vacuum. Nothing to rub together. "In space, no one can hear you scream."

Traveling through a copper wire sound can go very quickly, approaching the order of magnitudes of "the speed of electricity." Through fluids, it goes much more slowly, and attenuates more quickly. Air is a fluid.

The sonic boom you see and hear is driven by the nature of air, a mixture of gases. The vapor cone is the result of compression of the suspended fluid droplets in air.

In air, sound's speed is roughly 760 MPH at sea level. (CHanges with altitude and temp.) AKA Mach 1. You can travel many times the speed of sound. Bullets have been doing it since the meeni ball at least. The North American X-15 flew about Mach 7. It was an experimental airplane/rocket plane in the 60's. The F-15 can fly about Mach 2+.

No one has demonstrated that one can travel many times faster than the speed of light. The difference in orders of magnitude between the speed of sound in air and the speed of light being 186000 Miles Per Second

are something like

7.6 x 10^2 mph versus 6.48 x 10^8 mph (1.8 X 10^5 mph x 3.6 x 10^ 3)

Many models do not scale across six orders of magnitude. Even the equations on lift get interesting when you start looking at high mach numbers and for that matter, in a plasma. I don't know enough to discuss light moving in a vacuum in this case: in anything greater than a vacuum, friction becomes a significant limiting factor.

Even at mach numbers (in air) of 3 or 4, the temperature of the material, the leading edge in any case, typically experiences heat in hundreds of degrees Celsius. OK, increase that by six orders of magnitude. AT mach 4,000,000 what ever your were trying to propel became vapor or pure energy a while back.

What material will not deform, or for that matter vaporize, under the "light speed mach experiment" you propose? The Mach wave you are looking for is an atmospheric phenomenon, to say nothing of the issue of mass, and the energy to drive anything that fast. Remember the Columbia, and how relatively slow (to the speed of light) it was going? It burned to a crisp rather quickly.

There were some experiments a few years back regarding hypervelocity projectiles travelling on the order of Mach 12-17. As far as I know, they have not been put into practical use, partly because the ballistics at Mach 17 are considerably trickier than at more pedestrian Mach numbers.

Mach in the Millions? Not any time soon.

Occhi

For what it's worth, your idea of a light wave in a vacuum is intriguing from a "what if it worked that way?" perspective Taradox is that you and I can only see things in space time withing the speed of light. As soon as it was "down doppler at > Speed of LIght, it would be invisible to us mere observers on Terra Firma.
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#13
maniajk,Mar 15 2005, 04:50 AM Wrote:Quantum Physics says light has a dual nature. :shuriken:
The vessel would have no atoms left and even if it had they would immediatly be converted to energy. ;)
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Quantum physics only applies in incredibly small scales of around 50 microns (Very small, can't remember the exact thing) and even then the object discussed would have to be near the absolute Zero in temperature (aka 0-1 Calvin degrees).

Quantum physics say that if an object doesn't leave a sign in his path (aka touched something etc') it can be in two places at once and that's why the small scale and low temperature, the smaller it gets the less chances of said object to interact with any other atom in the air and thus leave no sign.

As for the vessel converted into light, I'm very skeptical about that, Einstein's Theory of Relativity still applies and in order to create energy from mass I believe you'll need to travel at the square value of the speed of light (E=MC^2) and Occhi's explaination as to what would happen are far more likely, although you can say if it was in a vacuum or some material was found that could stand such high temperatures then such a thing won't happen and at least this obstacle is removed.
"Turn the key deftly in the oiled wards, and seal the hushed casket of my soul" - John Keats, "To Sleep"
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#14
I can only say this,

Fools! This has already been accomplished by our well esteemed friends at Starfleet.
It's called a warpfield! :P
I would expect a world-wide launch of this new technology any time soon.

... aaaany time now.. any ti.. <turns old and grey and shrivels away>

->|<- poof.

(awaits the inevitable flame that a warpfield is NOT this and that following a 3 page description of what a warpfield -really- is and how it applies to our daily social interaction)
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#15
Thanks for your insights on the matter everyone! :) Thorough stuff!

I knew I somehow had bypassed laws of physics and such... My understanding of this topic is very limited, although I have great interest in it.

I'll be sure to post further far-out ideas and questions here! :P

-D
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#16
Thanks Daemon. This thread was fun.

I always enjoy reading the replies of folks who sidestep the "what if" in this type of topic and go straight to "Nope, it ain't gonna work."

What if we made a ship that could withstand incredible amounts of heat?
What if we had an engine that could propel said ship at, or extremely near, the speed of light?
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#17
TaiDaishar,Mar 15 2005, 09:11 PM Wrote:Quantum physics only applies in incredibly small scales of around 50 microns (Very small, can't remember the exact thing) and even then the object discussed would have to be near the absolute Zero in temperature (aka 0-1 Calvin degrees).
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No. 50 microns is not small. Nor is it small emough for quantum effects to occur. Near absolute zero temperatures are also not required. Perhaps what you are thinking about is the superfluidity of helium at those temperatures, which is a quantum effect.

TaiDaishar,Mar 15 2005, 09:11 PM Wrote:Quantum physics say that if an object doesn't leave a sign in his path (aka touched something etc') it can be in two places at once and that's why the small scale and low temperature, the smaller it gets the less chances of said object to interact with any other atom in the air and thus leave no sign.
[right][snapback]70787[/snapback][/right]

I think what you're talking about here is Quantum entanglement, which Einstein called "spooky effect at a distance". This is where it is possible to have two particles (unobserved) which are linked such that when the wavefunction of one is collapsed by being observed (touched) the state is equivalent to the other particle. There is a lot more to quantum mechanics that this. Such as the Bohr model of the atom, and the photoelectric effect.

TaiDaishar,Mar 15 2005, 09:11 PM Wrote:As for the vessel converted into light, I'm very skeptical about that, Einstein's Theory of Relativity still applies and in order to create energy from mass I believe you'll need to travel at the square value of the speed of light (E=MC^2) and Occhi's explaination as to what would happen are far more likely, although you can say if it was in a vacuum or some material was found that could stand such high temperatures then such a thing won't happen and at least this obstacle is removed.
[right][snapback]70787[/snapback][/right]

All you need to do to convert mass into light is to annihilate it with antimatter, or any nuclear reaction converts mass to energy. Neither of these require travelling any higher than the speed of light. As for a material the would survive the energy levels here, it's rather fanciful. Atoms and even nuclei should break down under the vast quantities of energy required to accelerate matter to this speed. Even should the materials not hit anything(unlikely, as space is not a true vacuum), the mass increase would gravitationally crush the material under its own mass.

But yeah, Cerenkov radiation is the only real example of this sort of thing, and it does behave rather sonic boomish-ly.
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#18
Ok, I have read a bit about Cerenkov Radiation, I understood just enough to know what the guy was talking about! :)

So the 'stacking' of the light is the constructive interference of the polarized molecules that were in the way of the charged beta particle.

If I got it right....that is... ;)

I took the info off that site: http://www.cakes.mcmail.com/cerenkov/cerenkov.htm

Cheers!

-D
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#19
Here's one other way to look at this problem. I'm sure everyone has heard about how with black holes there's a point at which light can no longer escape. At that point, the light either gets sucked directly down into the hole OR it goes into an unending orbit at this point (since it can't escape, it's stuck there). Thus, whatever light gets stuck like this would be trapped forever. As more light would accumulate, it would all get stuck at this same point (since the light all goes at the same speed). I'm oversimplifying here, to be sure (so please don't go to the trouble to point out the faulty or poor assumptions that go into this thinking :) ), but at least this is one way you might try to think about this, in a simple way without a lot of math.

What you propose is akin to this sort of thing. IF you could somehow produce light at a point with something moving the speed of light, it would probably all collect and overlap, just like that region outside a black hole.

That said, it is impossible to do something like this for a variety of reasons already mentioned in this thread and, as you add more layers to the complexity of the physics formulations you use, more and more problems crop up. So don't expect this any time soon.

But at least it's a good thought game. :)
-TheDragoon
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