In truth, this article over at NBC News says "the nearest aliens are probably between one and two-thousand light-years away," which really is 'right next door' if you think in terms of distance between stars and other objects in the galaxy and the larger universe, which is almost incomprehensibly vast. But there's always hope, right? :-)
Anyway, the reasoning behind the hypothesis that the nearest thinking aliens are actually pretty far away, at least by the way we measure distance in space and our (current) ability to traverse it, is pretty simple:
"Intelligence is less certain. The dinosaurs were a good design but didn't do well in school. But let's say that one in 100 biology-encrusted planets eventually coughs up some thinking beings. And, as per Frank Drake, let's also assume that any Klingons out there continue to hang out for 10,000 years before self-destructing (nuclear war, anyone?) or meeting some other woeful end.
Do the arithmetic, and you'll find that one in 100 million star systems has technically adept inhabitants. That's not much different than the fraction of jackpot tickets in this week's Powerball lottery.
So how close are the nearest signaling extraterrestrials? If we're going to pay good money to fire up the warp drive and visit some bumpy-headed aliens, how far do we have to travel? Well, the average distance between stars in our part of the galaxy is 4.2 light-years (the distance to Proxima Centauri). That is, for every cube of space that's 4.2 light-years on a side, you'll find (on average) one star. Now imagine a bigger box, 2,000 light-years on a side. It will contain 100 million star boxes, and one sophisticated civilization.
By this rough and ready calculation, the nearest aliens are probably between one and two thousand light-years away. In other words, no closer than the three bright stars of Orion's Belt. Sure, alien neighbors might be farther — or closer. But this order-of-magnitude estimate tells us that they're not next door. They haven't heard our news reports, and they're not likely to have any incentive to visit. They simply don't know we're here."
The article also notes that at the speed produced by our fastest rocket ships today it would take 20 million years to reach an intelligent alien society which likely exists about 2,000 light-years from Earth. Such a distance is simply too far away for us to travel to, given the limitations of our rocketry and plain old physics. Even if we were to invent a means of propulsion that matches the speed of light (something Einstein says is impossible to do), we'd still need 2,000 years of travel to reach our intelligent neighbors down the interstellar block, so to speak.
Add in that if the speed of light is the universal constant and something that simply cannot be exceeded in a conventional or linear fashion (and the possibility of traveling via wormholes, skirting the event horizons of black holes, or bending, folding or "warping" space is mostly science fiction at present), and we're kind of stuck. Even our earliest radio signals won't reach the nearest likely intelligent aliens for another 1900 years, give or take. Making things more maddening is the fact of math and it demonstrating there may be 10,000 intelligent societies in just our Milky Way galaxy alone. Unfortunately and unlike what the old commercial used to say about reaching out and touching someone, in this case it's much, much more difficult than it sounds.
Our nearest local star is 4.2 light-years, or over 24 TRILLION miles, away (at almost 6 trillion miles to the light-year). And that's right next door in terms of distance when looking at just our galaxy, let alone the universe and the 2 trillion galaxies within it. As it turns out, Earth is just a tiny dust particle plopped down into an Olympic-size swimming pool of water, with the next tiny dust particle way over on the other end of the pool, and that may not even be the true scale of the distances involved. Yeesh. ;-)
"Politics is just show business for ugly people."
Anyway, the reasoning behind the hypothesis that the nearest thinking aliens are actually pretty far away, at least by the way we measure distance in space and our (current) ability to traverse it, is pretty simple:
"Intelligence is less certain. The dinosaurs were a good design but didn't do well in school. But let's say that one in 100 biology-encrusted planets eventually coughs up some thinking beings. And, as per Frank Drake, let's also assume that any Klingons out there continue to hang out for 10,000 years before self-destructing (nuclear war, anyone?) or meeting some other woeful end.
Do the arithmetic, and you'll find that one in 100 million star systems has technically adept inhabitants. That's not much different than the fraction of jackpot tickets in this week's Powerball lottery.
So how close are the nearest signaling extraterrestrials? If we're going to pay good money to fire up the warp drive and visit some bumpy-headed aliens, how far do we have to travel? Well, the average distance between stars in our part of the galaxy is 4.2 light-years (the distance to Proxima Centauri). That is, for every cube of space that's 4.2 light-years on a side, you'll find (on average) one star. Now imagine a bigger box, 2,000 light-years on a side. It will contain 100 million star boxes, and one sophisticated civilization.
By this rough and ready calculation, the nearest aliens are probably between one and two thousand light-years away. In other words, no closer than the three bright stars of Orion's Belt. Sure, alien neighbors might be farther — or closer. But this order-of-magnitude estimate tells us that they're not next door. They haven't heard our news reports, and they're not likely to have any incentive to visit. They simply don't know we're here."
The article also notes that at the speed produced by our fastest rocket ships today it would take 20 million years to reach an intelligent alien society which likely exists about 2,000 light-years from Earth. Such a distance is simply too far away for us to travel to, given the limitations of our rocketry and plain old physics. Even if we were to invent a means of propulsion that matches the speed of light (something Einstein says is impossible to do), we'd still need 2,000 years of travel to reach our intelligent neighbors down the interstellar block, so to speak.
Add in that if the speed of light is the universal constant and something that simply cannot be exceeded in a conventional or linear fashion (and the possibility of traveling via wormholes, skirting the event horizons of black holes, or bending, folding or "warping" space is mostly science fiction at present), and we're kind of stuck. Even our earliest radio signals won't reach the nearest likely intelligent aliens for another 1900 years, give or take. Making things more maddening is the fact of math and it demonstrating there may be 10,000 intelligent societies in just our Milky Way galaxy alone. Unfortunately and unlike what the old commercial used to say about reaching out and touching someone, in this case it's much, much more difficult than it sounds.
Our nearest local star is 4.2 light-years, or over 24 TRILLION miles, away (at almost 6 trillion miles to the light-year). And that's right next door in terms of distance when looking at just our galaxy, let alone the universe and the 2 trillion galaxies within it. As it turns out, Earth is just a tiny dust particle plopped down into an Olympic-size swimming pool of water, with the next tiny dust particle way over on the other end of the pool, and that may not even be the true scale of the distances involved. Yeesh. ;-)
"Politics is just show business for ugly people."