Or any old TV shows?
It seems unlikely that a TV signal would be powerful enough to be able to travel through space and stay coherent for decades on end.
Wouldn’t the signal degrade dramatically over 50+ light years?
I don’t see why it would degrade without significant interference once it got into space. I think the bigger problem would be getting a 1960s antenna signal out of the atmosphere.
My guess is that no, they’re not. If they were, and had the technology to receive/transmit such signals, wouldn’t we be picking up their reruns?
The closest star is only 4.2-4.3 light years away, so I guess if there were aliens there they could have sent a signal back. However, we have no idea if there are aliens and if so where they would be.
This IS a reference to that Amazing Stories episode right?
The signal would not be a beam straight to their planet. It would be an expanding sphere. It would diminish as the square of the distance. By the time it had traveled a few light years, it would barely be detectable.
We beat this question into the ground with no solid answer in this thread.
Perhaps they asked themselves the same question as did we:
Is there other intelligent life in the universe?
Once our TV broadcasts reached their receivers, they knew the answer to be no.
Actually, it would not be an expanding sphere per se Even the first commercial broadcast transmitters used antennas that limited their transmission to close to horizontal. It was obvious that broadcasting more than a few degrees “up” was a waste of power.
Any alien would see a sequence of stations as the earth turned. You can think of them as viewing “a time zone at a time” as the horizon broadcasts “beam” (actually a disk) swept over them. On a given day, their star might be located over “6:30 am” in the sky, and they would see the entire world’s 12:30am and pm broadcasts offerings [they would be viewing disk from opposite sides of the earth at once) come over the horizon a few at a time, as the Earth turned, and then wink out. Over the course of a year, as the earth revolves around the sun (but “high noon” remains directed centrally) the “time slots” they saw would change by 4 minutes each day.
I wish I could provide a diagram. It’s simpler than it sounds.
Since this is the straight dope, here is a site with a few details and maths to give an idea about the chances of such
-blink- an event occuring;
http://www.faqs.org/faqs/astronomy/faq/part6/section-12.html
quote
*It should be apparent then from these results that the detection of AM
radio, FM radio, or TV pictures much beyond the orbit of Pluto will be
extremely difficult even for an Arecibo-like 305 meter diameter radio
telescope! Even a 3000 meter diameter radio telescope could not
detect the “I Love Lucy” TV show (re-runs) at a distance of 0.01
Light-Years!
It is only the narrowband high intensity emissions from Earth
(narrowband radar generally) that will be detectable at significant
ranges (greater than 1 LY). Perhaps they’ll show up very much like
the narrowband, short duration, and non-repeating, signals observed by
our SETI telescopes. Perhaps we should document all these
“non-repeating” detections very carefully to see if any long term
spatial detection patterns show up.*
So not quite as likely as you might think at first.
SF worldbuilding at
http://www.orionsarm.com/main.html
Given that there are only a small number of TV frequencies and a large number of stations on each one, any signal received at a great distance would be a jumble of mixed programs, and thus very difficult to sort out.
This would be very difficult to do, even if the TV signals passed unhindered through the atmosphere. Perhaps we should periodically send out very high-amplitude blasts of radio, just to see if anyone answers. Or not.