Are we really alone - the "Rare Earth" hypothesis
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Why we might really be alone in the universe
Simply stated, the Rare Earth hypothesis suggests that the very unique conditions of Earth that allowed complex life to arise and flourish are exceptionally uncommon — and they’re unlikely to widely occur throughout the universe.
Ward and Brownlee postulated that many fortuitous features of Earth, our Sun, and the solar system led to our highly favorable and surprisingly stable ecosystem. While some of these properties had been widely discussed in astronomy circles before, others had scarcely been mentioned.
The Rare Earth hypothesis focuses on numerous aspects of Earth and its environment that played a role in allowing complex life to develop. Some of the key factors Ward and Brownlee felt were critical to the formation of complex life included:
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A planet that exists in a favorable part of the right kind of galaxy, where significant amounts of heavy elements are available and sterilizing radiation sources are located far away.
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An orbit around a star that has a long lifetime (billions of years) but does not give off too much ultraviolet radiation.
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An orbital distance that allows liquid water to exist at or near the planet’s surface.
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An orbital distance that is far enough away to prevent the planet from becoming tidally locked to its host star.
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An orbit that is stable around its host star over cosmic timescales.
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A planetary tilt that allows for seasonal atmospheric changes to be mild, not severe.
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A solar system that includes gas giants capable of preventing debris from polluting the inner solar system, reducing the odds of major cosmic impacts and subsequent mass extinctions.
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A planetary mass large enough to both retain an atmosphere and allow for liquid oceans.
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A moon large enough to help stabilize the tilt of the planet’s axis.
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A molten planetary core that generates a significant global magnetic field, largely protecting the surface from solar radiation.
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The presence of oxygen, and the right amount of oxygen, at the right time for complex life to utilize it.
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The presence of plate tectonics, which build up land masses, create diverse ecosystems, cycle carbon into and out of the atmosphere, prevent a runaway greenhouse effect, and help stabilize the surface temperature worldwide.
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It’s still a numbers game. If one of a million systems has a planet in the Goldilocks zone, and if one of a million of those has the right chemical makeup, and if one in a million of those has… Then we have millions of other planets with life…
The distances are still the problem.
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They’ve written down a bunch of stuff that is necessary for one type of creature to develop. Who knows what alternatives there are with different starting conditions?
Humans can’t even agree whether eggs are healthy or not. I’d take our proclamations regarding anything more complex with a large grain of salt
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as the an anthropic principle states, if certain conditions are necessary to support awareness at the level where the aware creatures think about this stuff, then those conditions can be arbitrarily rare. They could be one in a trillion trillion trillion, and it still shouldn't make us wonder how it ever happened, or think that it should never happen. A trillion universes could have begun and ended without it happening once, and how could we say differently?
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as the an anthropic principle states, if certain conditions are necessary to support awareness at the level where the aware creatures think about this stuff, then those conditions can be arbitrarily rare. They could be one in a trillion trillion trillion, and it still shouldn't make us wonder how it ever happened, or think that it should never happen. A trillion universes could have begun and ended without it happening once, and how could we say differently?
@Horace said in Are we really alone - the "Rare Earth" hypothesis:
as the an anthropic principle states, if certain conditions are necessary to support awareness at the level where the aware creatures think about this stuff, then those conditions can be arbitrarily rare. They could be one in a trillion trillion trillion, and it still shouldn't make us wonder how it ever happened, or think that it should never happen. A trillion universes could have begun and ended without it happening once, and how could we say differently?
Right, so we're essentially lottery winners telling everybody else not to waste their money on a ticket because there's absolutely no chance they'll win, even though somebody wins sooner or later.
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Ultimately, we're either alone or we're not and we'll find out someday. The only way we're going to know is to get out there and get looking... We need the water, minerals, and real estate anyway...
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If we really knew how life started we would be recreating creation in the lab, at least the Chinese would.
And we would use the recipe to create all sorts of wonderful new creatures.
For example we would have creatures that eat carbon and supply free electricity for your car.
But since we are still clueless this won't happen any time soon.
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If we really knew how life started we would be recreating creation in the lab, at least the Chinese would.
And we would use the recipe to create all sorts of wonderful new creatures.
For example we would have creatures that eat carbon and supply free electricity for your car.
But since we are still clueless this won't happen any time soon.
@Copper said in Are we really alone - the "Rare Earth" hypothesis:
For example we would have creatures that eat carbon and supply free electricity for your car.
Trees?
