Speed of a ray of light is different in different mediums and it reduces as it enters a denser a denser medium.
suppose we have a glass slab and now a light ray enters into the slab, as a result its speed will decrease... so again if we give energy to this ray and increase its speed to that of the light in vaccum and then again if we change the medium from glass to vaccum...
what will happen?
2006-09-21 00:35:40 · 7 answers · asked by go4sambhav 1 in Science & Mathematics ➔ Physics
If I 've understood your question correctly. You mean if we could boost a ray of light whilst it was in the glass so that its speed increased when it emerged its speed would have to increase again and so it would be going faster than the speed of light ?. Sadly light is sneaky stuff. If you could somehow "give energy" to the ray in the glass it would respond not by changing speed but by changing its frequency (or wavelength if you prefer).
Look at it another way.
Putting aside the practical difficulties, you could fire a ray of light into a glass block and whilst it was still inside fire the glass block out of a gun. You might think that the ray in the glass is now travelling at the speed of light PLUS the speed of the glass block,
but the ray would respond by increasing its frequency (because higher frequency means higher energy) and slowing down !!! How so ? Because higher frequency light travels more slowly in glass.(If you recall your lessons in optics, the refractive index of a glass changes with the frequency of light ). When it emerged from the block it would increase its speed by just the right amount to get back to the speed of light in a vacuum.
As to whether anything can travel faster than light. Yes it can. Mother nature does it all the time. Einstein called it "spooky action at a distance" and didn't believe it was possible. But the experiments have now been done that prove he was wrong. It occurs when two quantum "particles" remain entangled no matter how far apart they are (they could be on opposite sides of the universe). "Prod" one particle of the pair and the other reacts instantaneously. Weird but true. The bummer is that its a random process and can't be used to transmit information.
2006-09-23 08:30:06 · answer #1 · answered by black sheep 2 · 0⤊ 0⤋
It is theoretically impossible to build a machine that can travel anywhere near the speed of light, because as an object's velocity nears the speed of light its mass tends towards infinity. You might not notice it but actually, you have more mass (a negligible increase, fortunately) when you are moving then when you are completely still in space. As a result, when a body of matter nears the speed of light its mass will increase so much that its power source will no longer have sufficient energy to move it, making light-speed travel impossible under currently accepted physics.
2006-09-21 23:29:54 · answer #2 · answered by hjh 2 · 0⤊ 0⤋
The easiest and laziest answer is NO, but history has taught us not to believe everything as fact until we have tried and failed. Remember how long it took the theory of relativity to be proven in out space? But it was however proven. Even the great Bill Gates once suggested that mankind shall never again need more than 704kb of memory. That was 1981 and today you can buy a hard drive of 800 Gig!
So can we ever achieve more than speed of light? Conceivable, maybe not, but definitely practical. 1 + 1 = 2 (speed of light + speed of light = 2 speed of light).
2006-09-21 00:51:31 · answer #3 · answered by kope k 2 · 0⤊ 0⤋
"They've gone straight to...Ludicrous Speed!!"
Newton and Einstein disagree when it comes to this. Newton says that if the sun were to wink out of existence in a microsecond, then its planetary bodies would instintaneously lose their orbit and fly off into the cosmos. Einstein would say that's impossible. He'd say the sun would wink out, then the "gravity wave" (which could not go faster than light) would travel to the planets at the speed of light, then they'd lose their orbits. If the sun blows up tomorrow then we'll know.
2006-09-21 00:48:35 · answer #4 · answered by Anonymous · 1⤊ 0⤋
Theoretically, no - it is believed that the speed of light is the greatest speed possible, and that it is not physically possible to ever reach a speed faster than that.
While the differing densities of objects can alter the "speed of light" I understand the maximum speed of light that most scientists refer to would be the speed of light through empty space.
2006-09-21 00:44:48 · answer #5 · answered by Dwight 2 · 1⤊ 0⤋
Let me add to that that nothing that travels in glass can go faster than light in glass. So, while something travelling in vacuum might go faster than light in glass, it cannot surpass light speed in glass. But check the Wikipedia page: it has interesting notes on things that seem to travel faster than light and on slowing down light in media.
2006-09-21 00:51:21 · answer #6 · answered by TGV 1 · 1⤊ 0⤋
what about cerenkov radiation that particles emit when travelling faster than the speed of light?
2006-09-21 01:32:26 · answer #7 · answered by benabean87 2 · 0⤊ 0⤋