we say the light speed is constant every were but i think light speed same as sound speed depent on some characteristics of media. why does some particles in Accelerators move with speed more than light ?
2007-01-14 00:18:43 · 9 answers · asked by davood s 1 in Science & Mathematics ➔ Physics
the speed of light is 3x10^m/s in a vacuum. In air, water, glass,or any other substance the speed will be less than this. Particles in an accelerator do not travel faster than the speed of light. In fact, it would take an infinite amount of energy to accelerate a particle with mass to the speed of light.
2007-01-14 00:23:39 · answer #1 · answered by ? 2 · 0⤊ 0⤋
Refractive index of the glass cause light to travel with slower speed.
There is impossible for an object or particle to travel faster or same with light speed. When object is accelerated, its mass will increase as this was concluded by Einstein with his famous equation E = mc^2.
But it is important to realise that the speed of light is not a "speed limit" in the conventional sense. An observer chasing a beam of light will measure it moving away from him at the same speed as will a stationary observer. This leads to some unusual consequences for velocities.
2007-01-14 09:27:32 · answer #2 · answered by li mei 3 · 0⤊ 0⤋
The speed of light (c) changes in glass because the density(as measured by the index of refraction) of the material in which it is traveling changes.
I certainly wouldn't say that c is constant everywhere. Light outside the Swatzchilde (spelling?) radius slows conciderable when going away from a black hole.
Sorry, I don't know much about particle accelerators and the speeds inside.
2007-01-14 08:39:39 · answer #3 · answered by wizzardx3 2 · 0⤊ 0⤋
Light is also a form of energy and we know that energy is conserved what ever be the medium.Now consider a case of light entering a glass slab.Surely a glass slab is more denser than air.Now considering light as a beam of particles it undergoes collisions with particles in glass more than it does in air.This is why light is offered more resistance in glass than air and it's speed slows down.
Now let's transfer to your question that properties of medium control light speed.I also think so but although elasticity,optical density and other factors affect the speed of light in a medium the change in the speed of light is very small and as compared to the speed of light(3x10^8 m/s) it is negligible and we neglect it.Thus it is promptly said that light speed does not change at all.
I hope this would be a satisfactory answer.
2007-01-14 08:36:00 · answer #4 · answered by Somsurya 2 · 0⤊ 0⤋
The speed of light *in vacuum* is the same everywhere and is independent of one's reference frame.
Light is an electromagnetic wave. When it is propagating in a medium such as glass, the electrons bound to the atoms react to the oscillating electric field of the wave by shifting their orbitals slightly in the direction opposite the E field (since their charge is negative). This oscillating charge distribution is a form of electrical current (called a bound current) that contributes self-consistently to the overall electric field of the wave. Since electrons have mass (inertia), the effect is to slow the wave propagation speed.
More energetic particles from an accelerator can zip through the solid entirely unimpeded, traveling faster than light *in the medium*
2007-01-14 12:51:59 · answer #5 · answered by Dr. R 7 · 0⤊ 0⤋
Glass is a denser substance than air and when light hits it it slows down. The index of refraction for glass is 1.52 (depending on the type of glass) If you take the speed of light 3 x 10^8 and / by 1.52 that is how fast it travels.
2007-01-14 08:29:16 · answer #6 · answered by Robert O 2 · 0⤊ 1⤋
While passing through glass from air the wavelength of light decreases and frequency remains unchanged as a result velocity decreases as Velocity=frequency*wavelength.
2007-01-14 09:16:35 · answer #7 · answered by Tariq M 3 · 0⤊ 0⤋
Because the refractive index of glass is more than 1. Only tachyons move faster than light and they have not been detected yet.
2007-01-14 08:32:41 · answer #8 · answered by ag_iitkgp 7 · 0⤊ 1⤋
Bcoz GLASS has got different medium(rarer or denser0 and differebt refractive index as compared to Air or Water
2007-01-14 08:49:06 · answer #9 · answered by Anonymous · 0⤊ 1⤋