OT: Radios

[CRations]

If, while traveling at the speed of light, I turn on a radio will it work? And if the radio does work, what would I hear?

CR

[Kwik E Mart]

ORIGINAL: CRations

If, while traveling at the speed of light, I turn on a radio will it work? And if the radio does work, what would I hear?

CR

Yes. Disco.

[Nikademus]

no. Country.

[dorjun driver]

It will work, but there will be no one to see it.
Or something...

[Nikademus]

If a man talks in a forest and there's no woman around to hear him.....is he still wrong?

(my fav.) [:D]

[Grfin Zeppelin]

ORIGINAL: Nikademus

If a man talks in a forest and there's no woman around to hear him.....is he still wrong?

(my fav.) [:D]

Absolutely.

[jcjordan]

Yes & it'll be endless loops of the best of Boxcar Willie, Zamphir Master of the Pan Flute & Slim Whitman.

[wdolson]

I could give a serious answer, but the smart ass comments are too good.

Bill

[Justus2]

ORIGINAL: CRations

If, while traveling at the speed of light, I turn on a radio will it work? And if the radio does work, what would I hear?

CR

It may work, but unfortunately all you will hear is the crash when the idiot in front of you (also travelling at the speed of light) decides to hit the brakes while you look down to turn the radio on.

[danlongman]

You won't be able to make out anything but your windows will be rattled by the booming
bass of the young punk in the pimped out Honda Space Civic who pulls up beside you at the stop light (which is always red because of doppler shift)

[KenchiSulla]

Yes, beam me up Scotty...

[zzodr]

This was done in the intro to the movie "Contact" [;)]
well, sort of..

[CRations]

Ya'll are too much![:D]

I was figuring if I heard anything on the radio it would be older-style music - maybe polka or big band. [;)]


CR

[wdolson]

If you were traveling at the speed of light, time would essentially stop and you would hear nothing. Another way to look at it would be the radio waves would be traveling exactly the same speed you were.

If you were traveling a little less than the speed of light, you would pick up radio, but it would be stuff broadcast after you left (you would be going slower than the radio waves), but it would be dramatically downshifted in frequency to a point where you would probably need a computer to speed it back up again, and collecting an hour's worth of programming would take a few years.

If you were able to exceed the speed of light, with some kind of drive only known to science fiction today, you would outrun the radio and most likely hear nothing while you were traveling, but when you stopped, you would be able to pick up broadcasts from many years ago, depending on how far away you were. The radio waves would also be very diffuse, the strength of the signal declines at the cube of the distance (the signal is radiating out from Earth in a sphere), so you would need a super sophisticated receiver to be able to pick up anything. Radio noise put out by our sun would probably drown out much of the signal after some distance. You might be able to pick up a bit of a radio hot spot where Earth was when the broadcasts you are picking up were sent, but all you would be able to do is pick up that something was transmitted.

SETI tries to pick up coherent radio patterns in signals from other stars. So far they haven't found anything definitive. They do have some pretty sophisticated receiver arrays (and would like to build even more sophisticated arrays). I doubt you'd be able to pick up anything coherent with commercially available equipment even if planets around nearby stars were broadcasting.

And always remember 285,000 miles per second, it's not only a good idea, it's the law. [:D]

Bill

[LoBaron]

Your radio would be unable to reach the speed of light, as anything else with rest mass > 0.
If it was able the radios´ movement through time would stop, without time, no signal.

You are able to reach 99% of the speed of light though, and if you listen to the radio at that speed,
what you hear would depend very much on the position(change) of the radiostation relative to your axis of movement.

The effect on light wavelengths will be pretty similar to the Doppler Effect for sound.

If for whatever reason the radiostation moves at 99%C as well with exactly the same vector as your radio, you
would notice anything different than if you listen to the radio right now.

I could give a serious answer, but the smart ass comments are too good.

Bill

Damn it, I only read that after I typed the above. Now its too late to back off. Too late.

[LoBaron]

Ah yes, posted 3 minutes too late. Relative to Bill. [8D]

[CRations]

ORIGINAL: wdolson

If you were traveling at the speed of light, time would essentially stop and you would hear nothing. Another way to look at it would be the radio waves would be traveling exactly the same speed you were.

If you were traveling a little less than the speed of light, you would pick up radio, but it would be stuff broadcast after you left (you would be going slower than the radio waves), but it would be dramatically downshifted in frequency to a point where you would probably need a computer to speed it back up again, and collecting an hour's worth of programming would take a few years.

If you were able to exceed the speed of light, with some kind of drive only known to science fiction today, you would outrun the radio and most likely hear nothing while you were traveling, but when you stopped, you would be able to pick up broadcasts from many years ago, depending on how far away you were. The radio waves would also be very diffuse, the strength of the signal declines at the cube of the distance (the signal is radiating out from Earth in a sphere), so you would need a super sophisticated receiver to be able to pick up anything. Radio noise put out by our sun would probably drown out much of the signal after some distance. You might be able to pick up a bit of a radio hot spot where Earth was when the broadcasts you are picking up were sent, but all you would be able to do is pick up that something was transmitted.

SETI tries to pick up coherent radio patterns in signals from other stars. So far they haven't found anything definitive. They do have some pretty sophisticated receiver arrays (and would like to build even more sophisticated arrays). I doubt you'd be able to pick up anything coherent with commercially available equipment even if planets around nearby stars were broadcasting.

And always remember 285,000 miles per second, it's not only a good idea, it's the law. [:D]

Bill

I found myself staring at the answers you & LoBaron supplied much like a deer looks at oncoming headlights. [:D]

So if I was in a rather long spaceship with the radio in the front and a radio antenna (sending Polka over the air waves within the long spaceship) would that work? Can light travel at the speed of light in a capsule traveling at the speed of light? I mean - if I'm traveling in a car doing 65 mph and I toss a ball up and down it goes up and drops back in my hand because everything in the car is doing 65 mph. So the same thing for radio waves traveling in a ship that is traveling at the speed of light?

Now I'm curious.

CR

[Erkki]

Yep, the light inside the ship would travel at the speed of light even if the ship itself would be at 0,9999999c. To an outside observer the light inside the ship would be traveling at 1c and the ship at 0,9999c.

However thanks to the Doppler effect, to the ship, the view of the outside world would be compressed to very high frequency gamma rays from a point directly ahead and very low frequency radio waves directly behind. Any signals sent from Earth would take a looong while to reach the ship, and would arrive from behind at extremely low frequency pretty much regardless of original transmission frequency.

[wdolson]

Light always travels at the speed of light relative to the frame it's traveling within. Hence the reason the theory is called relativity. If you are in a craft traveling near the speed of light, light will travel within the craft at the speed of light.

This is why a lot of Physicists resisted the theory of relativity when it was introduced. It's hard to get to your mind around it when you first encounter it.

Bill

[LoBaron]

ORIGINAL: wdolson

Light always travels at the speed of light relative to the frame it's traveling within. Hence the reason the theory is called relativity. If you are in a craft traveling near the speed of light, light will travel within the craft at the speed of light.

This is why a lot of Physicists resisted the theory of relativity when it was introduced. It's hard to get to your mind around it when you first encounter it.

Bill

This.

Just a small graph I put together. (Don´t tell anybody, I´m at work...)

It shows the difference between the observations of a person in a spaceship compared to an observer watching an accelerating spaceship
depart.

The major difference:
For the observer outside the spaceship, the distance the beam of light has to travel between the mirrors gets longer and longer the
faster the spacship moves relative to the observer.

For the observer in the accellerating spaceship the distance remains always the same.

How can it both happen?

Because time is no absolute value. The only absolute value is C, the speed of light. This implies that time moves slower within the
spaceship the closer it moves at C, to compensate for the difference in percieved distance the light has to travel.

Try to get your head around this and you´ll understand a large part of special relativity.