Earth-Like Planets In Our Neighborhood 171
goran72 sends in a story out of the Chicago AAAS meeting contending that Earth-like planets with life-sustaining conditions may be spinning around stars in our galactic neighborhood — we just haven't found them yet. "'So I think there is a very good chance that we will find some Earth-like planets within 10, 20 or 30 light years of the Sun,' astrophysicist [Alan Boss]... told his AAAS colleagues meeting here since Thursday. ... The images from those new planets, he added, should identify 'light from their atmosphere and tell us if they have perhaps methane and oxygen. That will be pretty strong proof they are not only habitable but actually are inhabited. I am not talking about a planet with intelligence on it. I simply say if you have a habitable world. ... Sitting there, with the right temperature with water for a billion years, something is going to come out of it. At least we will have microbes,' said Boss."
Re:Polluted by life? (Score:2, Informative)
The chances of genetic material from the earth reaching other habitable planets is next to nil because:
1) You are forgetting how astronomically tiny Earth is compared to...what is not Earth. Really not much material here.
2) There aren't actually any known habitable worlds other than ours (doesn't mean they aren't there, just that they probably aren't prolific)
3) The genetic material would be traveling so slowly compared to the distance to any planets out there that they might as well not even be moving.
Re:Polluted by life? (Score:2, Informative)
Mass of Earth is almost 6 sextillion metric tons. [nasa.gov]
Re:impossible dream? (Score:2, Informative)
REPORT ON THE INGREDIENTS OF THE EARTH'S CIVILIZATION AS SEEN FROM THE "WIKIPEDIA" SENT BY HUMANS
* 20% ---- Elitist mod-trolls
* 30% ---- Politics (a.k.a. sheeple herding)
* 35% ---- Religion-like (i.e. spirituals, rituals, TV, Paris Hilton, Web 2.0, Slashdot, pr0n, etc)
* 15% ---- Obsolete knowledge known as "science" and/or "technology"
CONCLUSION
Humans make good material for Soylent Green.
Re:impossible dream? (Score:5, Informative)
Now, to take the concept to the ultimate (but unreachable) conclusion: to reach such a velocity that an outside observer would record you as moving equal to the speed of light: To the traveler it would seem as if there was actually no distance traveled, and the journey took no time at all. What the traveler would observe is space and time folded between the origin and the destination... for a 10 light year journey, you would instantly travel to the destination, but 10 years later. The return trip would also be instantaneous, but 20 years would have elapsed at home since you have left. Thus, the speed of light is not violated. However, to cut your travel time to zero in a Newtonian framework, you would need to reach infinite speed in zero time, which would require infinite acceleration, which would in turn require infinite energy. That is impossible, so an object with a resting mass cannot travel at the speed of light (or beyond.) But you still have to take into account the fact that at relativistic speeds, space constricts while time dilates, allowing for what on the surface appears to be traveling faster than the speed of light, but actually is not.
Re:Polluted by life? (Score:4, Informative)
There have been spores tested, and the verdict is that they can survive at less than 10cm to an atomic explosion.
Citation needed.
A couple thousand degrees temperature will break up pretty much any chemical bond.
One atomic bomb can kill, at best, about 50000 people, in a dense city block less than 1 square kilometer.
Eh, what? Both of the bombs used in anger so far killed more than that (both directly by the blast and delayed deaths by radiation). And, mind you, those were small 10-15 kT devices. In todays strategic arsenals, you'll warheads ranging from a couple hundred kilotons to 1.2 megatons. And then of course, there's this little baby:
http://en.wikipedia.org/wiki/Tsar_bomba [wikipedia.org]
Re:Water alone wont cut it (Score:3, Informative)
however a stagnant pool of water won't produce even microbes in any prompt fashion on a cosmic scale. The moon is as big a contributor to life on Earth as its water, because of how the tide has stirred the water like no other planet we've discovered yet.
Obviously you are unfamiliar with the concept of thermal turnover.
No tide is necessary to mix a body of water. All you need is rotation.
Nice try, though.
Re:Question (Score:3, Informative)
It's all mentioned in the article. The Tsar Bomba created a fireball about 8 km in diameter, and the resulting mushroom cloud was 64 km high.
If we were they, we wouldn't hear them (Score:3, Informative)
"They could be in our equivalent of 1750 and we'd never hear a peep."
In fact, they could be our equivalent of 2009 and we'd never hear a peep.
Except for one or two exceptions, no radio signals from Earth are strong enough to be detectable at interstellar distances using the receiving technologies that we use for SETI.
The "exception" is ballistic-missile warning radar, which might be detectable, if it were at the wavelength being searched, and they happened to be looking in the right direction when the Earth happened to be rotated so that the radar pointed the right way. But there's no signal in radar, and even the carrier would be gone when they looked again to follow up, so to a SETI search, it would be tagged "noise"-- most likely a side-lobe of a transient terrestial source, possibly a satellite. (Unless they knew the Earth's rotational period, so they could look again when the signal was aligned their direction.)
Re:Question (Score:5, Informative)
This will give you some idea how large a nuclear blast is:
Ground Zero simulator [carloslabs.com]