Skip to comments.Question: Real Time Transmission of Video - Space Travel
Posted on 06/22/2017 9:45:54 PM PDT by Vendome
So, here is the dumb question my brother posed:
If a ship leaves earth and transmits "LIVE" video as it travels deep into space, would the transmissions continue to be live and real time even as it traveled months and years away from earth?
At what point does that transmission actually delay or become part of the past?
Bonus question: Assuming the craft continues travel directly away from earth, if it stopped transmitting and then restarted transmitting would that now be real time?
Caveat: I don't know the distance that makes the transmission now a part of the past...
Albert Einstein maight have been able to answer.
Transmission will always be “live” when sent. It will be delayed by the time it is received by the transmission time which is the distance divided by the speed of light. (in the same units)
Note that on the news when the story is from somewhere else on the planet, there is often a delay before the “live” transmission starts, this is cause by the transmission delay which via a satellite is about .2 sec.
Every light second away from Earth(speed light travels in a second) would add a 1 second delay.
It takes around 13 minutes for a signal to reach mars and vice versa.
Around about where the moon is on average is one light second.
It would take 8 minutes ish for a signal to reach the sun. If it went out we wouldn’t know for 8 minutes.
When the spaceship is a bit over 186,000 miles from earth the video will be received 1 second after it was generated. Double that distance and the delay will be 2 seconds.
And so on.
Light and radio signals travel at about 186,000 miles per second. That’s really all you need to know.
Everything you see is “in the past”.
Your brother likes being a pot stirrer
Scientifically...the transmission is always live. The reception is current to the receiver
But to answer your question: yes, a transmission started in Earth orbit would become more delayed the further the craft travels. You wouldn’t notice it however because you would just assume it’s still “live”, there would be no way to tell unless you sent them a message and asked for a response, you wouldn’t see them get the message until however much time passed related to how many light seconds/minutes/hours/days away they were.
Transmissions are never “live”, if by “live” you mean instantaneous. There is always a delay due to the speed of light or even the speed of sound. The further away, the longer the delay. There is even a delay due to the processing electronics or even the hardware between your ears.
On the other hand, if you are getting the transmission from a source directly in the shortest possible time rather than from a stored version, perhaps that is “live”, even if the delay was years due to distance.
But if by “live” you mean in a manner that allows for interaction between the communicants, then that is an arbitrary definition determined mostly by the patience of the participants.
Glad to be of essentially no help whatsoever.
Agree with KC.
Interesting question, but what would be even more interesting to ponder is what would happen if a spaceship crew began to broadcast live video/audio as they launched, and then accelerated to near the speed of light. Since time passes much more slowly for the spaceship crew at near light speed than it does for those on Earth, would the Earthbound viewers see the broadcast keep slowing down as the craft approached light speed, until eventually it seemed to be running at a fraction of real-time? My guess is that this is precisely what would happen, but curious if anyone has other ideas.
Assuming that the speed of the space craft remains much less than the speed of light, the time within video will be stretched as distance from earth increases. So motion as viewed from the broadcast will be slowed.
The transmission would run at normal time and speed. It would just be delayed.
I think Art Bell is on at this hour.
only if you remained the same distance from the earth!
The speed of light is finite, so the transmission will not be perfectly "live" after the ship has traveled at all -- even one inch. There will be a delay, that will increase with distance. Stopping and restarting the transmission will not affect the rate of increase of the delay.
Think about this.
The speed of light, is the limit to how fast the spacecraft can fly.
But what if the spacecraft was to succeed in reaching 99% of the speed of light? So just 1% short of the speed of light.
The light beams (or radio waves) broadcast back toward base, would be travelling at the speed of light.
But what speed of light? Speed of light as measured relative to the ship which transmitted them? It is travelling away from earth, at 99% the speed of light. So would the radio/light waves be actually received here, at 1 percent of their original velocity?
Or would the radio waves be received here, at the speed of light here?
Is that conflict, what relativity is all about?
Anyway, that’s all. :D
No. Even if they accelerated to relativistic speeds, even reaching the speed of light. The transmission will continue in normal time for the viewer. It’s not going to just slow down or speed up because they are going the speed of light.
The transmission is being observed INSIDE their craft. Which is recording and sending that transmission. The transmission isn’t accelerating away. It’s travelling at its normal speed. The transmission would just be delayed the further they got from Earth.
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