Briefly faster than light, How charged particles shed excess speed

During my brief sojourn in this forum, I have never seen the topic of how charged particles shed velocity when they enter a medium where the speed of light is reduced below that in the previous medium.

This does happen and the suddenly excess kinetic energy is shed via Cerenkov radiation. The theory for this happening was described by the Russian physicist after whom it is named. I believe that the radiation had not been seen when the theory was published.

If you have ever seen a photograph of a nuclear reactor's internals while it was operational, the green glow visible is Cerenkov radiation. It can also be seen in underwater photographs of spent nuclear fuel casks.

I just thought that folks should be more generally aware of this phenomena, assuming that they were not just being shy.

Does the particle gain velocity if it re-enters the original medium ?

Nope. Since it sheds its kinetic energy by releasing Cerenkov radiation, it can't speed back up if it goes back to its old medium unless there's something there to give it more kinetic energy.

is possible the existence of inertial systems that run with speeds greater than light.the space and time connected in an only one entity:SPACE-TIME,that is generated by rotations of biquaternions that does transpositions from left-handed(positive space-time=forward in time,but that in reversion due breakdown of pt
run backward in time) and right-handed(negative space-time=backward in time,but that in the reversion due at the breakdown of pt run forward in time).these coupled of rotations in 8-D to 4_D lead ud to curvatures of the space by the time with differents degree of curvatures that imply a limit and constant speed of light,with anisotropy that generate the differents speeds for light.then there are values for c,greater than value obtained in michelson-morley experiences.also can to see the tunneling effect that does generated times imaginary-that are metrics derived of asymmetry of left-right handness rotations-that permit space-time positive and negative.then permit complex manifolds,that arte the negative and positive space-time continuos given non-linear fuctions,that are at the same time complex conjugated and reversion that only can occur by the motion of the time-that is the rotational asymmetry from left-handed to right-handed and vice-versa in the couplement pt to-pt=PT->p't'=pt=PT*
THEN IN THE TUNNELING THERE SUPERLUMINAL SIGNALS.

Cerenkov Radiation is akin to a sonic boom, a shock wave. It is known as the "blue glow" of reactor pools.

What's interesting about it, is that is all down to neutrons. These are not affected by electromagnetic fields. And they do travel faster than light in the medium, which is usually water. OK in water light is being absorbed and emitted, so you can't really talk about c. But note that the "speed" of light in vacuum is all down to the permittivity of space, which can be likened to "back EMF", if you've ever heard of that.

So the obvious question is whether the speed of light is only a limit for charged particles. Are there cosmic rays out there with velocities and energies higher than they ought to have? Spookily enough, the answer is yes.

By the by, UFO sightings often feature a "blue gow".



PS: Why did I put speed in inverted commas? You really don't want to know.

This post has been edited by Farsight on Oct 17 2006, 11:06 PM

Hi FS,
Quote "So the obvious question is whether the speed of light is only a limit for charged particles".
Do you think that this can be assumed from the above situation considering that 'c' in this case is actually a slower than 'c' in a vacuum? To me, when dealing with c in a medium other than in a vaccum, since there are many other properties associated with that medium than just it's affect on c. Permiativity and permiability (which is used in calculated c in that medium) must have affects on charge also, wouldn't you think?
Also, thanks for making me look harder into Cherenkov Radiation, I've never quite understood that phenomenon.
Just thinking out loud,
Ron

The Cerenkov radiation doesn't violate the speed of light in vacuum limit.