hawking - and radio signals
ffawkes
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He's backing a new search for extraterrestial life and mentions it may be watching these lights of ours.
By lights presumably he means radio and tv signals we have been beaming out over the last 80 years
Anyone know, if a radio signal gets turned on, then later turned off, does it carry on transmitting itself across the vacuum of space? Could an episode of coronation street broadcast in 1980 be received and translated by the inhabitants of planet zog circling alpha centauri?
By lights presumably he means radio and tv signals we have been beaming out over the last 80 years
Anyone know, if a radio signal gets turned on, then later turned off, does it carry on transmitting itself across the vacuum of space? Could an episode of coronation street broadcast in 1980 be received and translated by the inhabitants of planet zog circling alpha centauri?
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What they would pick up would be a jumble of all the electromagnetic, radio, TV etc signals emanating from Earth......they'd find it difficult to pick out individual programmes !
Exactly, christ i live on earth and i cant always pick up radio 2
Hmm. Presumably my tv antenna is picking up a jumble of signals too, but a cheap tv tuner can separate them out...
But your aerial is (usually) pointing at a single transmitter site radiating just a single service on each UHF frequency.
However there are multiple transmitter sites across just the UK let alone the rest of the planet transmitting signals on the same frequency. Someone out in space will see all of those multiple signals mixed into one big mush.
If we do make first contact, could we get e.t. to tape some old doctor who's
Anyway this article answers your question quite well:
http://zidbits.com/2011/07/how-far-have-radio-signals-traveled-from-earth/
"Because of this inverse square law, all of our terrestrial radio signals become indistinguishable from background noise at around a few light-years from earth.".
So that means almost no star systems within likely detection range given that the nearest star system is 4 lght years away. Of course the article goes on to make the point that those are accidental leakage. There are things you can do if you want to help a signal go further.
Right now. Cool innit?
- sign on UFO 5AUC3R5
http://physics.stackexchange.com/questions/11940/if-you-view-the-earth-from-far-enough-away-can-you-observe-its-past
"I'd have to say yes - at least theoretically. If there was an observer (not you) 27 light years away, he could see your birth. Awesome as it sounds, it isn't practically feasible. For one thing, the observer would need a large enough telescope to observe you. If the telescope isn't large enough, the resolution would be low, and the observer wouldn't be able to make out things far away. To get an idea, the size (diameter of mirror for instance) of the telescope that'll enable you to see an object of about 10m at that distance is about 10^8km while the diameter of earth is about 12800 km." (which is 10^3).
So gawd knows how big the telescope would have to be to get useful images from 50 million light years away
This is why we had to wait until a spacecraft with a camera was oribiting the moon before we could see pictures of the Apollo gear. We don't even have the technology to see things a couple of metres across on the moon.
http://hubblesite.org/reference_desk/faq/answer.php.cat=topten&id=77
Of course, and I did say "good enough". The principle stands.
An alien race were watching a soap opera that aired orignially years earlier but the broadcast was stopped before the last episode so the aliens came and demanded to see it or they would destroy the planet.
In the end they had to act out the final episode themselves to please the alien overlords.
Somewhere, an alien civilisation could be watching lost episodes of Dr who, hopefully they are recording them, then in years to come, the BBC can ask them for a copy.:D
http://www.reddit.com/r/explainlikeimfive/comments/2jxquk/eli5if_you_had_a_telescope_to_let_you_see_the/
and (irritating accent not withstanding):
https://www.youtube.com/watch?v=SgM2cF4WSnw
This guy reckons the telescope would need to be 4 light years in diameter.
But yeah, it's a cool idea, that's for sure. Maybe one day we'll be able to make telescopes using force fields instead of glass. It'd still be a nasty hazard to shipping though
I fear that if there are aliens out there they may see an episode of The Only Way is Essex or Made in Chelsea and react the same way as the aliens did in Futurama. But this time there will be no way to undo the damage and i think they will just blow up our planet
Their grasp of our language would be limited, and they'd think we were all homicidal maniacs. So, what should we turn the power up on to give them a better impression? Strictly? Definitely not X factor:D
I opened this thread thinking someone must have hacked his wheelchair:o
........... if you wanted to continue to do that unmolested ....... where would you 'programme' the scientists to look for extraterrestrial life? Deep Space.
This pretty unique jewel of a planet has attracted intense interest throughout our history - and the sooner people wake up to that fact - and stop wasting money on SETI projects looking for a 'needle in a haystack' in Deep Space - the sooner we can 'move on' and 'evolve' beyond the petty religious squabbles we seem to be obsessed with (ISIS etc) - and concentrate on living in harmony with each other, other species(alien included) and protecting this wonderful planetary jewel with which we have been gifted.
So true even Vogon Poetry is better than that.
Sadly though it's almost certain alien life is just too far away and planet earth is like a grain of sand on a 20 mile long beach.
I think that they would be able to pick up the signal, but I very much doubt that they would be able to decode it, unless they had a television set, which would be rather unlikely, so it would just be noise. It might appear as an intended signal but if they could decode it, it would be amazing.
It's all very well inviting the aliens, but what if they took a liking to the earth or humans for food or something!
Surely that would only work if you could travel FTL.