5 ms·
We'd need to blast a radio signal at about 100 million watts for it to hit the closest star with the same strength that Voyager is sending to us right now. Som
by digitalsushi 7y ago
We'd need to blast a radio signal at about 100 million watts for it to hit the closest star with the same strength that Voyager is sending to us right now. Something like 4 light years away. If we consider how quickly signal strength decays, it's pretty easy to picture just how quiet we are. Our loudest tv stations are like 5% of that.
We think we're blasting a firehose off into space but we're spitting from a straw.
- mmhsieh 7y agogood points, but signal strength decay in the semivacuum of space really has to do more with the geometry of your emitter path vis a vis a fixed target (earth). so we get attenuation from the voyager but you can bet your sweet patootie that voyager is broadcasting our business to a gajillion other star systems even with a weak signal. in which case deflections from the intergalactic ambient hydrogen is the only hope of mankind that they don't invert the signal back to our solar system with our primitive space force.
- jhoechtl 7y agoWould be true for omnidirectional transmission. Much much less for a directed transmission.
- henryfjordan 7y agoYou'd have to know where the aliens are for that to matter!
- erik_seaberg 7y agoHitting a fixed target, from light-years away, with a signal stronger than cosmic background? Pretty sure a world-class team could get PhDs just for the attempt.
- dredmorbius 7y agoGiven the detection of exoplanets of approximately Earth mass orbiting in habitable zones, that's rapidly become tenable. Laser / maser signalling would probably be about the best we could do for now.