Who wins?

[trenton]

I have a mate that works for PBMR at Pelindaba and I asked if they have a running nuclear reactor. Apparently so because next thursday he wants to show me the nice blue glow of the Cherenkov effect. This, he says, happens when a particle travels faster than light. Sort of like a photon boom.
I says, sorry sir, you have smoked your socks, nothing goes faster than light.
He says, google will decide.
I say deal, but if I am right I get 2l coke, I am wrong he gets 2l diet pepsi.
Wiki says the effect happens when a particle travels faster than light IN A MEDIUM, ie: in a fluid the speed of light might be .75c so a particle will be able to go faster in that medium, but not faster than a photon in a vacuum.
Who gets fat?
Who gets thin?

 

[rwenzori]

http://en.wikipedia.org/wiki/Cherenkov_radiation

While relativity holds that the speed of light in a vacuum is a universal constant (c), the speed at which light propagates in a material may be significantly less than c. For example, the speed of the propagation of light in water is only 0.75c. Matter can be accelerated beyond this speed during nuclear reactions and in particle accelerators. Čerenkov radiation results when a charged particle, most commonly an electron, travels through a dielectric (electrically insulating) medium with a speed greater than that at which light propagates in the same medium.

But also see these about the speed of light:

http://en.wikipedia.org/wiki/Speed_of_light#Quantum_mechanics

In quantum mechanics, certain quantum effects may be transmitted at speeds greater than c (indeed, action at a distance has long been perceived by some as a problem with quantum mechanics: see EPR paradox, interpretations of quantum mechanics). For example, the quantum states of two particles can be entangled, so the state of one particle fixes the state of the other particle (say, one must have spin +½ and the other must have spin −½). Until the particles are observed, they exist in a superposition of two quantum states, (+½, −½) and (−½, +½). If the particles are separated and one of them is observed to determine its quantum state then the quantum state of the second particle is determined automatically. If, as in some interpretations of quantum mechanics, one presumes that the information about the quantum state is local to one particle, then one must conclude that second particle takes up its quantum state instantaneously, as soon as the first observation is carried out. However, it is impossible to control which quantum state the first particle will take on when it is observed, so no information can be transmitted in this manner. The laws of physics also appear to prevent information from being transferred through more clever ways and this has led to the formulation of rules such as the no-cloning theorem and the no-communication theorem.

http://en.wikipedia.org/wiki/Speed_of_light#Travel_faster_than_the_speed_of_light_in_a_medium

Travel faster than the speed of light in a medium

Although it may sound paradoxical, it is possible for shock waves to be formed with electromagnetic radiation.[26] As a charged particle travels through an insulating medium, it disrupts the local electromagnetic field in the medium. Electrons in the atoms of the medium will be displaced and polarised by the passing field of the charged particle, and photons are emitted as the electrons in the medium restore themselves to equilibrium after the disruption has passed. (In a conductor, the equilibrium can be restored without emitting a photon.) In normal circumstances, these photons destructively interfere with each other and no radiation is detected. However, if the disruption travels faster than the photons themselves travel, as when a charged particle exceeds the speed of light in that medium, the photons constructively interfere and intensify the observed radiation. The result (analogous to a sonic boom) is known as Čerenkov radiation.

Forgive all the quoting - must be Telephrone's influence!

 

[Phronesis]

If I understand correctly:
Speed of light in a vacuum is c.
Speed of light is a medium is < c.

So lets say in the nuclear reactor the speed of light is 0.8c.
The Cherenkov effect implies that light will travel > 0.8c but still < c.

He forgot to mention "in a specific medium" I guess. So either you get fat or no-one gets fat.

 

[trenton]

I'll take that as sematics FTW then.