Can something move faster than light?

[IDMclean]

Concider this, if you will.

 

You have two different Space-Time "bubbles" Seperated by perfect vacuum. Within these bubbles, we have massed/charged particles. Now lets say that the Space-time bubble was attached to the massed/charge particles. So that Space-time was depenent on Mass-Energy density.

 

Now lets say that these two seperate space-time bubbles can have seperate velocities, relative to their progenitor Mass-Energy Density.

 

If a ray of light were to pass through these bubbles, it's observed velocity, no matter it's direction of origin or departure would always appear to be c. Light is it's own contained Space-time bubble, that reacts poorly to space-time curviture.

 

Now lets say one bubble is moving at c, and the mass-energy within it was moving at [math]v = H_0D[/math] relative to the mass-energy of the other bubble. The light emitted will, as said before, travel at c. Near as I can tell, this does not violate anything, explicitedly. Any comments?

 

We have relative Super-luminal objects, I believe unless I missed something big here.

[Shekhar]

I even know a person personally who has written a theory of transmitting data at a speed greater than light !!

 

If he does so in practical,he will sure win the Nobel Prize !!!

[Jay-qu]

of course they would, but it is forbidden by the current laws of physics..

[Superstar]

Can someone explain to me what an AFTER IMAGE is? and is it as fast as light or beyond light?:naughty:

[Jay-qu]

I would suggest reading some of the above posts more thoroughly.

 

The way I think you mean it is that when an object moves (at any speed, will be below lightspeed!) an observer wont see where the object is, but where it was d/c seconds later, as the object moves faster this effect becomes more pronouced and it could happen that the image you see of an object is no-where near the actual object. In effect the object has 'left' its image behind.

[CraigD]

Can someone explain to me what an AFTER IMAGE is? and is it as fast as light or beyond light?:)

An image is something formed by many quanta of light – photons - allowing us to “see” such things as physical objects. The study of this is called optics. The optical instrument most of us are most familiar with is the human eye.

 

The term “after image” is not an optical one. The usual meaning of “after image” is an image that persists on the light-sensitive part of the eye – the retina – after the photons are no longer striking it. A common example is when one looks at the flash on a camera, and continues to see a spot where the flash appeared several seconds after it’s no longer there. It’s the result of the nerves in your retina – rods and cones – continuing to fire, sending impulses to your brain, because they have been “overloaded” by the bright flash.

 

The photons travel at the speed of light – about 300000000 m/s. Nerve impulses travel much slower – about 50 m/s. Neither travel faster than the speed of light.

[Superstar]

Thankyou CraigD for your insight. Your explanation was very easy to understand.

[munch]

I remember reading an article recently, might have been in Science News, about some physicists were able to send light through a gel of some sort faster than light. Basically the reverse of light slowing down in air or water.

 

The weird thing is, they could make a light pulse exit the medium before it entered.

 

They did point out that you couldn't transmit information this way, and that's what kept it from breaking any laws.

 

I'd post a link if I could, but it's too late for me to look tonight.

 

Forgot to add that positrons are just electrons moving faster than light, or backwards in time, whichever you prefer. Same thing is true for all anti-particles.

[Turtle]

Science is always ammendable. Here's a story about some folks making those ammendments to the question "can something move faster than light?".

:

 

http://www.signonsandiego.com/news/science/20060622-9999-lz1c22cause.html

 

“Anyone who thinks they can talk about quantum theory without feeling dizzy hasn't yet understood the first word about it,” said the late, great Danish physicist Niels Bohr who, incidentally, invented much of the theory.

 

“People know how to calculate with quantum mechanics, but that's not to say they know what it means,” agreed Sheehan. “Quantum mechanics is like poetry. The poem is right there, for everyone to see, but it has many different interpretations.”

 

Sheehan offers a couple of scenarios to ponder:

 

First, imagine a large boulder at the top of a hill. The boulder begins rolling downhill. Now freeze the action with the boulder midway along its descent. Call this the boulder's present. At this point in time, Sheehan says the boulder is being influenced both by its past (when it was atop the hill) and by its future (when it will come to rest at the bottom of the hill). The boulder's current position midway down the hill cannot happen without the effect of both the past and the future.

:)

[Boerseun]

First, imagine a large boulder at the top of a hill. The boulder begins rolling downhill. Now freeze the action with the boulder midway along its descent. Call this the boulder's present. At this point in time, Sheehan says the boulder is being influenced both by its past (when it was atop the hill) and by its future (when it will come to rest at the bottom of the hill). The boulder's current position midway down the hill cannot happen without the effect of both the past and the future.

I don't know whether this analogy can clear anything up.

I mean, imagine if you've got an endless hill? In other words, in the line of this analogy, the boulder won't have a 'future'. But it sure would keep rolling, wouldn't it? A rolling boulder is only rolling because of its velocity. Increase v, and the boulder could conceivably go into orbit. If in a stable orbit, it'll be there forever and won't have any 'future' to talk of. But it still orbits. :)

[Jay-qu]

I dont think that analogy is valid.. the only way you could freeze it half way is if you know where it will stop, which cant be done because it requires knowing the future..

[Turtle]

I dont think that analogy is valid.. the only way you could freeze it half way is if you know where it will stop, which cant be done because it requires knowing the future..

 

I think that's the point. IF you could freeze/stop the boulder, which you can't, and so making the certain future in essence traveling faster than light. :rolleyes:

 

The author gives another example as well & the entire article better describes what they think than my second-hand interpretation.

http://www.signonsandiego.com/news/s...1c22cause.html

[udhitsharma]

no.

if it is so then the mass of the body would become infinite.

[Qfwfq]

I even know a person personally who has written a theory of transmitting data at a speed greater than light !!

 

If he does so in practical,he will sure win the Nobel Prize !!!

If I found out how, I wouldn't even bother with the Nobel, it's peanuts compared to the jackpot of many lotto type games where you only need to guess a few measley little numbers... :)

[IDMclean]

Of course, Qfwfq, are you assuming a causality break. Just because the velocity of light is higher relative to your inertial frame does not mean it's going to travel back in time or anything. Most assume that if something goes faster than c that they will travel back in time, given the negative energy stuff.

 

However there are senarios in which causality is preserved and a tachyon is just a body traveling at speeds higher than your frame's light.

[Qfwfq]

It is an immediate consequence of Lorentz covariance, not an assumption.

 

Most assume that if something goes faster than c that they will travel back in time, given the negative energy stuff.

This is certainly a common misinterpretation, due also to confusion about RQFT and PCT, but it isn't what my point was based on.

 

Indeed, if a body were to travel at v > c, it wouldn't make sense to say it would go back in time, nor that it would go forward. Rather, for some (perfectly ordinary) observers it would go from place A to place B and vice versa for others. For some it would have infinite velocity, going instantaneously. As the notion of causality implies a "before" and an "after", superluminal causality would exchange these according to observer, hence the paradox.

[Bagpi]

It may sound dumb, but do we not need to qualify (faster than light).

What if.............there was an extremely long something with very little mass a wave or (standing wave)?? (I am on thin ice now) perhaps. What might happen if it was given a gentle nudge. Would there instantaniously be a corresponding move at the other end, ie communication faster than light.