posted
Yeah well, other people have offered convincing arguments about their ideas and have been wrong too. Take Martin Bernal's "Black Athena" for example... He was determined to prove that Ancient Greek culture came from Egypt... He's been proven wrong time and again, but it was convincing, for a while.
------------------ "Goverment exists to serve, not to lead. We do not exist by its volition, it exists by ours. Bear that in mind when you insult your neighbors for refusing to bow before it." J. Richmond, UB Student
posted
Oh, Black Athena...now that brings back some memories. It represents one of the poorer aspects of advocacy as history. Or as one review put it "An ideologically motivated atrocity of fake scholarship."
Regardless, it certainly added something to the historiography, even if it was only to be refuted by other books like Not Out Of Africa or Black Athena Revisited.
posted
It doesn't really take into account the apparent size of the universe, which is either really, really big, or infinite. So unlikely stuff could still happen somewhere, but far enough away that I'm still not going to run SETI@home.
A few things, though:
"Our solar system is the perfect distance, 25,000 light-years, from the centre of the Milky Way. Any closer, and we would have been clobbered by exploding stars or zapped by radiation from a black hole by now. Too far out, and there wouldn't be enough metal-creating stars to have formed the planet in the first place."
The part about the metal sounds right, but you'd have to get closer to the center of the galaxy for frequent problems with radiation and black holes.
"We're extremely fortunate in having Jupiter in the neighbourhood. Its gravity acts as a shield, sweeping up 99 per cent of the cosmic debris that could otherwise collide with Earth and destroy life (the asteroid it did let through 65 million years ago extinguished the dinosaurs)."
It's probably let quite a bit through, actually, since it's big, but not that big...it's orbit will still leave plenty of room for lots of stuff to get close to the earth. Besides, since gas giants form commonly, the likelihood of getting a planet similar to Jupiter isn't that low.
"And as the third planet in, we're perfectly positioned: Earth neither boils like Venus nor freezes like Mars."
Isn't Mercury really cold, though? The orbit and rotation of planets has a lot to do with the surface temperature too.
"Our moon is relatively large for a planet this size...there is now evidence that it was formed by an impact on the young Earth - yet another happy ``accident'' in the planet's history."
Of course, moon-sized planets that come near earth-sized planets have a chance of being caught in each others' gravity anyway, although that's also not especially likely. More likely is two smaller moons of an earth-sized planet crashing into each other to create a larger one.
We can also hope that some of those way-distant intelligent life forms had the courtesy to travel the universe and terraform/build some planets, but that's hoping for a bit much.
------------------ Frank's Home Page "So, anyways, this is the 24th century. Starfleet officers have injections once a month or so so that they don't go getting each other pregnant. How would it be a problem for my character and Joral to be rocking the casbah?" - Fabrux
[This message has been edited by The Shadow (edited March 26, 2000).]
posted
That link won't work now that it's tomorrow, by the way.
Anyway, this is an argument that has been around for a long, long time. The problem is that we still don't know what constitutes average for a planetary system. If we judged it on simple statistics, the average planet would be huge, hot, and very, very close to its star. (Forgetting for a moment that current detection methods only allow us to see the really odd planets.)
At any rate, Frank, the points the article brings up are sound. For life similar to our own, at least, you need to be at the right distance from the sun, and you need a big moon. Why? Tides. Without them, the oceans would be one big stagnant pool. Yucky. Though, of course, we can't say that such a planet couldn't have life, as there's plenty of life in big stagnant pools right here on Earth. Also, of the five planets that we can call terrestrial, two of them have large moons. (Earth and Pluto, to be precise.) Again, we need more data! So, uh, everybody grab a telescope.
Also, Mercury can only be considered cold if daily highs of 800 degrees celsius require a coat and mittens. Of course, with no atmosphere, it gets down to several hundred below at night. So it depends on when you go.
------------------ "What did it mean to fly? A tremor in your soul. To resist the dull insistance of gravity." -- Camper Van Beethoven
posted
Moons that big are pretty hard to come by actually , except when you name is Pluto Most of the times, something that big turns into a ring or a few tiny moons.
Don't ask why, I just saw it on Discovery
------------------ "When You're Up to Your Ass in Alligators, Today Is the First Day of the Rest of Your Life." -- Management slogan, Ridcully-style (Terry Pratchett, The Last Continent, Discworld) -------------------------------------------------------------------------------- Prakesh's Star Trek Site
posted
Well, in regards to Pluto, it isn't so much the size of the moon, but its size relative to the planet.
Yes, stagnant pools are very bad for advanced forms of sea-going life as we know them on this planet. Without tides, the water wouldn't circulate and a great many things would die.
------------------ "What did it mean to fly? A tremor in your soul. To resist the dull insistance of gravity." -- Camper Van Beethoven
posted
Well, stagnant pools would kill higher forms of life on Earth, maybe, but life adapts to its environment, and probably get around that.
As long as life has water, its very possible to exist anywhere.
------------------ "Goverment exists to serve, not to lead. We do not exist by its volition, it exists by ours. Bear that in mind when you insult your neighbors for refusing to bow before it." J. Richmond, UB Student
posted
But I was specifically talking about life as we know it. Though it should be noted that lots of things do live in stagnant pools, but nothing we would call particularly "advanced".
------------------ "What did it mean to fly? A tremor in your soul. To resist the dull insistance of gravity." -- Camper Van Beethoven
posted
Consider the underwater volcanic vents. One can find a great deal of life by these suckers. And I wonder to what extent such vents might add some kind of currents to water devoid of moon induced tides thereby decreasing stagnation.
posted
Well, they certainly stir the water up a bit, and the existance of such life on Earth argues strongly that life can exist just about anywhere. But tides are a specific phenomenon that takes a bit more to produce than a few spa jets.
Again, I'm not saying that life in any form can only exist under certain narrow conditions. The past decade or so has shown that there is life here on Earth living under conditions we might find on Mars or Europa. Certainly not an exceedingly narrow condition. I'm just saying that there is some weight to the argument that to evolve advanced lifeforms, you need tides to stir things up as it were. Of course, all it takes to disprove this is one example. I imagine that extraterrestrial life will prove charmingly destructive to our various theories about what it should be doing.
------------------ "What did it mean to fly? A tremor in your soul. To resist the dull insistance of gravity." -- Camper Van Beethoven
Saiyanman Benjita
...in 2012. This time, why not the worst?
Member # 122
posted
If the pool was stagnant, then life would not have the need to evolve. It would be accustomed to its own environment, wouldn't it? The movement through the tides and geological phoenomena is what forces the life to evolve. How would land life create itself, if it wasn't forced to? Tell me if I'm wrong, I have no real study in this field.
------------------ Man it's a real shame when folks be throwing away a perfectly good white boy like that.
posted
Well, it depends on what you believe in... Does evolution occur when there's a force involved to cause change, or does life constantly evolve and change, making it more efficient to its environment? Personally, I believe the latter, and therefore think that Tides aren't necessary for life.
True, water movement is necessary, for current Earth-life anyways, for oxygen. But, if life does bring about itself, it will evolve to its environment, stagnant or not, and find ways around natural obstacles. Does anyone else understand this?
------------------ "Goverment exists to serve, not to lead. We do not exist by its volition, it exists by ours. Bear that in mind when you insult your neighbors for refusing to bow before it." J. Richmond, UB Student
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