ChatterBank0 min ago
What would happen if you listened to the radio at the speed of light?
What would happen to a radio signal if you accelerated to the speed of light? Would the radio programme go backwards?
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Relativity means that it would take you an infinite amount of energy to reach the speed of light.
And, from what I remember from university in the mid 1970s, electromagnetic radiation, such as radio waves, would still be travelling at the speed of light relative to you no matter how close to the speed of light you manage to reach.
If that seems simply wrong, then once you deal with the physics of extremes such as velocities close to the speed of light, temperatures close to absolute zero, distances at a sub-atomic level, etc. then what seems common sense in everyday life quite simply doesn't work.
And, from what I remember from university in the mid 1970s, electromagnetic radiation, such as radio waves, would still be travelling at the speed of light relative to you no matter how close to the speed of light you manage to reach.
If that seems simply wrong, then once you deal with the physics of extremes such as velocities close to the speed of light, temperatures close to absolute zero, distances at a sub-atomic level, etc. then what seems common sense in everyday life quite simply doesn't work.
What about the time question? A clock on a speaceship going at the speed of light would appear to go more slowly than one on Earth. When you return to Earth the clock from the spaceship would be behind the one on Earth.
So SpodoCommodo you seem to be saying that I could end up listening to the radio at normal speed while the clock appears slower. So the radio news could end up being in advance of the clock? So I could end up hearing tomorrow's news?
So SpodoCommodo you seem to be saying that I could end up listening to the radio at normal speed while the clock appears slower. So the radio news could end up being in advance of the clock? So I could end up hearing tomorrow's news?
padanarm,
A clock on a speaceship going at the speed of light would appear to go more slowly than one on Earth
it would only appear that way to a person on earth, for the person on the spaceship all the clocks on earth would appear to go more slowly. The two people are moving relative to each other so in the grand scheme of things it could be said the spaceship is stationary and the earth is traveling at the speed of light away from it
get your head round this :)
http://www.phys.unsw.edu.au/einsteinlight/jw/m odule4_twin_paradox.htm
A clock on a speaceship going at the speed of light would appear to go more slowly than one on Earth
it would only appear that way to a person on earth, for the person on the spaceship all the clocks on earth would appear to go more slowly. The two people are moving relative to each other so in the grand scheme of things it could be said the spaceship is stationary and the earth is traveling at the speed of light away from it
get your head round this :)
http://www.phys.unsw.edu.au/einsteinlight/jw/m odule4_twin_paradox.htm
I think that helps, Chuck. So the radio is like the clock - it would appear to broadcast normally to the crew of the spaceship. It would only be a problem when they got back to Earth and compared the clock and radio from the ship with the one on Earth.
The spaceship clock would seem to have slowed down. The radio would be broadcasting from the same time to the crew of the spaceship.
So to the observer on Earth the radio would appear to be broadcasting from the past?
The spaceship clock would seem to have slowed down. The radio would be broadcasting from the same time to the crew of the spaceship.
So to the observer on Earth the radio would appear to be broadcasting from the past?
Everything we observe (depending on distance from the source) is from the past; light (electromagnetic radiation including radio waves) sound, even our senses of touch and smell are perceived after a slight delay.
As for radio waves transmitted from a source moving closer or further away relative to the receiver, these are subject to the Doppler effect. That's how radar and laser speed detection works.
Moving away from a broadcast the pitch of music would be lowered and the signal would be delayed more as distance increased but neither of these phenomena would be observed by the receiver due to the time and distance dilation of relativity.
A moving transmitter would however be a completely different story. In this case Doppler shift and the increasing delay in the arrival of the signal would be observed by the stationary receiver. A transmitter moving away at the speed of light would simply disappear from our observable universe.
As for radio waves transmitted from a source moving closer or further away relative to the receiver, these are subject to the Doppler effect. That's how radar and laser speed detection works.
Moving away from a broadcast the pitch of music would be lowered and the signal would be delayed more as distance increased but neither of these phenomena would be observed by the receiver due to the time and distance dilation of relativity.
A moving transmitter would however be a completely different story. In this case Doppler shift and the increasing delay in the arrival of the signal would be observed by the stationary receiver. A transmitter moving away at the speed of light would simply disappear from our observable universe.
mibn2cweus says "Moving away from a broadcast the pitch of music would be lowered..."
I don't think so. Most, if not all, music is broadcast on FM. The carrier wave would appear at a different frequency on a spaceship moving relative to the transmitter, but, once you had re-tuned your radio, the music would be normal.
Also "A moving transmitter would however be a completely different story". No, it is the same story whether the transmitter or the receiver moves.
I don't think so. Most, if not all, music is broadcast on FM. The carrier wave would appear at a different frequency on a spaceship moving relative to the transmitter, but, once you had re-tuned your radio, the music would be normal.
Also "A moving transmitter would however be a completely different story". No, it is the same story whether the transmitter or the receiver moves.
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