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Slashdot: Chicxulub Impact Might Have Spread Life-Bearing Rocks Through the Solar System


Larry

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(As is usual with Slashdot articles, the entire article is a single paragraph.  But with lots of links to other material.) 

 

 

KentuckyFC writes

 

"Some 65 million years ago, an asteroid the size of a small city hit the Yucatan Peninsula in what is now Mexico, devastating Earth and triggering the sequence of events that wiped out the dinosaurs. This impact ejected 70 billion kg of Earth rock into space. To carry life around the Solar System, astrobiologists say these rocks must have stayed cool, less than 100 degrees C, and must also be big, more than 3 metres in diameter to protect organisms from radiation in space. Now they have calculated that 20,000 kilograms of this Earth ejecta must have reached Europa, including at least one or two potentially life-bearing rocks. And they say similar amounts must have reached other water-rich moons such as Callisto and Titan. Their conclusion is that if we find life on the moons around Saturn and Jupiter, it could well date from the time of the dinosaurs (or indeed from other similar impacts)."

 

 

 

Attempt no landings there.  :)

 

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yeah, but isn't it just tooooooo damned cold on those moons?

If these chunks bore life materials from earth, given all we know about earth based life, can anything survive and evolve in such extremes?

 

Edit, i remember this thing.. the Water Bear survived in space

article-0-152D53DC000005DC-559_634x556.j

 

 

~Bang

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Still, though.  I keep remembering reading an article where one of the topics was "The Fermi Question".  The article explained that the question basically looked at the theory that life on Earth was simply random chance.  Then extrapolates to examine just how many solar systems there are in the Universe.  And observes that pretty much no matter how remote you assume the chances for advanced-level civilization are, you still wind up concluding that simply in our Galxy, it must have happened thousands, if not billions, of times. 

 

And then observes that well, if our civilization was simply the result of random chance, then it should follow that half of these thousands or billions of civilizations must be older than ours.  And "older" doesn't mean older by a few hundred years, it means older on an astronomical time scale.  Millions or billions of years older. 

 

The Fermi Question is "Where are they?" 

 

The article points out that our planet, right now, radiates more RF energy than the sun puts out.  And every indication is that that will be increasing.  Exponentially.  And spreading outward, at the speed of light. 

 

That, even if you assume that Star Trek - style space flight doesn't happen, that advanced civilizations broadcast their presence. 

 

(The article's main thrust was to examine Humanity, and speculate that maybe there's something about us that makes us more unique among life forms, than we're assuming.  Perhaps something about us that makes our level of advancement a lot more unique than we theorize.) 

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yeah, but isn't it just tooooooo damned cold on those moons?

If these chunks bore life materials from earth, given all we know about earth based life, can anything survive and evolve in such extremes?

 

That Water Bear thing maybe?

article-0-152D53DC000005DC-559_634x556.j

 

 

~Bang

 

Yeah, the surfaces are too cold, but a couple of the moons of Jupiter/Saturn have liquid water under the icy surfaces. So while maybe not advanced or "intelligent" life, bacteria and simple life forms like exist at the bottom of our oceans is possible deep under the ice.

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yeah, but isn't it just tooooooo damned cold on those moons?

If these chunks bore life materials from earth, given all we know about earth based life, can anything survive and evolve in such extremes?

Well, Arthur Clarke imagined an "ecosystem" on Europa where liquid water could exist (on a planet with no atmosphere.) And one where evolution was much more cutthroat. (He imagined life evolving around undersea thermal vents, which brought heat and chemicals up from the planet's core. In such an environment, life might evolve, huddled around these fountains. In effect, the planet contained not one, but hundreds of ecosystems, each of them isolated by cold from the others.

No clue whether it's scientifically possible. But it sure as hell was poetic. :)

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----------

Although, possible counter-argument:

Can "life as we know it" (insert Spock line, here) develop in an ecosystem where (I assume) there isn;t enough sunlight for photosynthesis?

I don;t think you can have animals, even single-celled ones, without single-celled plants, first, can you? Wouldn't the same be true of sub-cellular "life", like viruses and bacteria? Don't they require a cellular host, to reproduce?

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Still, though.  I keep remembering reading an article where one of the topics was "The Fermi Question".  The article explained that the question basically looked at the theory that life on Earth was simply random chance.  Then extrapolates to examine just how many solar systems there are in the Universe.  And observes that pretty much no matter how remote you assume the chances for advanced-level civilization are, you still wind up concluding that simply in our Galxy, it must have happened thousands, if not billions, of times. 

 

And then observes that well, if our civilization was simply the result of random chance, then it should follow that half of these thousands or billions of civilizations must be older than ours.  And "older" doesn't mean older by a few hundred years, it means older on an astronomical time scale.  Millions or billions of years older. 

 

The Fermi Question is "Where are they?" 

 

The article points out that our planet, right now, radiates more RF energy than the sun puts out.  And every indication is that that will be increasing.  Exponentially.  And spreading outward, at the speed of light. 

 

That, even if you assume that Star Trek - style space flight doesn't happen, that advanced civilizations broadcast their presence. 

 

(The article's main thrust was to examine Humanity, and speculate that maybe there's something about us that makes us more unique among life forms, than we're assuming.  Perhaps something about us that makes our level of advancement a lot more unique than we theorize.) 

My personal opinion on this is that I can only imagine these aliens in reference to humanity, so If we are most likely typical, then they are most likely typical. 

 

While millions of years of evolution could separate us, I think that intelligent life is typically curious so they would be almost as curious about us, as we are about them. and that most are likely already here and have been here the second our blue planet was on their radar.

 

Something tells me that no matter how advanced an alien civilization might be that some if not most would always want to check out any blue planet discovered and monitor it indefinitely.

 

I think that while as our ethics in regard to our scientific observation of natural environments has led to attempts at less and less interference in the environments we are observing, that an hypothetical aliens ethics would follow a similar course and follow the same principles.

 

As in they do not get involved in our affairs, and use all means available to keep it so.  But there are many here and probably many watching. 

 

Seeing them is something they mostly likely have control over up too a certain point, and they know what that point is, maybe its when a civilization ventures out of its own solar system, that some veils are lifted... who knows.

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As to the question, "where are they?" I think you really have to consider the immense distances involved, and also the very brief time humans have existed. You might also consider the possibility that a high percentage of technical civilizations manage to annihilate themselves (eg through nuclear war or overuse of finite resources).

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As to the question, "where are they?" I think you really have to consider the immense distances involved, and also the very brief time humans have existed. You might also consider the possibility that a high percentage of technical civilizations manage to annihilate themselves (eg through nuclear war or overuse of finite resources).

I really doubt that ever happens.

 

there is no nuclear war that would annihalate us, many people would survive in some bunker somewhere. 

 

It would take some rare major earth event like super volcano or asteroid and i dont think it will be long before we can protect, at the least, our very existence from even those. 

 

I think that whole factor of the drake equation is overused and sometimes cynically inspired. 

 

I think its a lot harder for races like ours to simply go extinct once we reach a certain level of tech.

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(As is usual with Slashdot articles, the entire article is a single paragraph.  But with lots of links to other material.) 

 

 

 

 

Attempt no landings there.  :)

So Europa is out. Phobos and Deimos are obviously out since we don't want demons teleporting in and then taking over earth. Where CAN we land?
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----------

Although, possible counter-argument:

Can "life as we know it" (insert Spock line, here) develop in an ecosystem where (I assume) there isn;t enough sunlight for photosynthesis?

I don;t think you can have animals, even single-celled ones, without single-celled plants, first, can you? Wouldn't the same be true of sub-cellular "life", like viruses and bacteria? Don't they require a cellular host, to reproduce?

Enough bacteria can change the entire planet.  See early earth.  Carbon eating (oxygen defecating) bacteria made life possible.  (Archaebacteria sp?) If oxygen fixing bacteria could exist somewhere else, photosynthesis could also begin.  It is not beyond belief that earth could be replicated out there amongst the stars.

 

But then again, we have such a small tolerance to classify "life".  Perhaps the carbon based life system is too rare.  We may be looking for signs that cannot and do not exist beyond our Goldilocks zone.  Respiration, for example, may have been naturally selected / evolved out of other beings.  Or perhaps these other beings merely exist at the conscious level now, having evolved to that state.

 

Fun conversation!

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Certainly, life could possibly be sustained on deep sea vents.  That is actually a popular idea of where life started on Earth.  Does Europa have deep sea vents or is it cooled all the way through?

 

With respect to Europa, the other thing that I've actually seen speculated due to the strong pull of G from Jupiter, and the way in which it changes, there might be enough energy there to sustain life (directly or through thermal actions).

 

It is an interesting question.

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The article points out that our planet, right now, radiates more RF energy than the sun puts out.  And every indication is that that will be increasing.  Exponentially.  And spreading outward, at the speed of light. 

 

 

 

I'd like to see the math to back that claim up. Do we have a a physics student who wants to integrate the Rayleigh-Jeans equation to calculate the radiation from the sun in RF frequencies?  :)

 

But that's off topic. No doubt the Earth is radiating signals that might be detected. Carl Sagan used this as the basis of his novel Contact and claimed that the first TV transmission strong enough to be detected by an extraterrestrial civilization was actually a broadcast of Hitler's speech at the 1936 Olympics. Maybe the extraterrestrials saw this and changed the channel for a few hundred years.  :)

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I'd like to see the math to back that claim up. Do we have a a physics student who wants to integrate the Rayleigh-Jeans equation to calculate the radiation from the sun in RF frequencies?  :)

 

But that's off topic. No doubt the Earth is radiating signals that might be detected. Carl Sagan used this as the basis of his novel Contact and claimed that the first TV transmission strong enough to be detected by an extraterrestrial civilization was actually a broadcast of Hitler's speech at the 1936 Olympics. Maybe the extraterrestrials saw this and changed the channel for a few hundred years.  :)

 

The point isn't where they are with respect to us in terms of are we a "channel" worth watching.  The question is why can't we "see" them.

 

If we are making and sending out a whole bunch of radio waves, why aren't we getting radio waves (and other electronic emmissions) from somewhere else?  You start to look for explanations, and you get things like:

 

1.  The evolution of intellligence life is actually very very very rare.

2.  Some how (for some reason?) we're in a "bubble" that prevents those signal from reaching us.

3. Our perspective of the universe is very off (oh, I don't know something like this is a simulation and not the "real" universe).

 

(and realistically, all 3 point to something being off with respect to our understanding (and that maybe related to the probability of the evolution of intelligent life))

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I'd like to see the math to back that claim up. Do we have a a physics student who wants to integrate the Rayleigh-Jeans equation to calculate the radiation from the sun in RF frequencies?  :)

 

But that's off topic. No doubt the Earth is radiating signals that might be detected. Carl Sagan used this as the basis of his novel Contact and claimed that the first TV transmission strong enough to be detected by an extraterrestrial civilization was actually a broadcast of Hitler's speech at the 1936 Olympics. Maybe the extraterrestrials saw this and changed the channel for a few hundred years.  :)

 

the point isn't whether anyone else is "hearing" us, it is whether or not we are hearing anybody else.   Our signals have only been going for 60 or 7 years, so haven't reached anything far from our solar system yet (far, in cosmic terms...70 light-years is still righ tnext door :)

 

but.. should't we be "hearing" broadcasts from these ancient civs?

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Still, though.  I keep remembering reading an article where one of the topics was "The Fermi Question".  The article explained that the question basically looked at the theory that life on Earth was simply random chance.  Then extrapolates to examine just how many solar systems there are in the Universe.  And observes that pretty much no matter how remote you assume the chances for advanced-level civilization are, you still wind up concluding that simply in our Galxy, it must have happened thousands, if not billions, of times. 

 

And then observes that well, if our civilization was simply the result of random chance, then it should follow that half of these thousands or billions of civilizations must be older than ours.  And "older" doesn't mean older by a few hundred years, it means older on an astronomical time scale.  Millions or billions of years older. 

 

The Fermi Question is "Where are they?" 

 

The article points out that our planet, right now, radiates more RF energy than the sun puts out.  And every indication is that that will be increasing.  Exponentially.  And spreading outward, at the speed of light. 

 

That, even if you assume that Star Trek - style space flight doesn't happen, that advanced civilizations broadcast their presence. 

 

(The article's main thrust was to examine Humanity, and speculate that maybe there's something about us that makes us more unique among life forms, than we're assuming.  Perhaps something about us that makes our level of advancement a lot more unique than we theorize.) 

I think you're jumbling a few things up here.

 

The bit about how many solar systems could support life sounds to me like the Drake Equation.  It's an interesting thought experiment, as it forces one to consider the magnitude of the number of stars out there, but it's essentially useless as an actual predictive tool because we have no way of knowing what some of the variable values are.

 

A Fermi Question is a question or problem where one can arrive at a numerical estimate by making a series of reasonable assumptions.  The Drake Equation is an example of a Fermi Question, although again, some of the variables are essentially unknowable, at least right now.  So the Fermi Question is not, "Where are they?", it's "How many active, intelligent civilizations are there in the universe right now?"

 

The classic example of a Fermi Question is, "How many piano tuners are there in Chicago?"

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I think you're jumbling a few things up here.

 

The bit about how many solar systems could support life sounds to me like the Drake Equation.  It's an interesting thought experiment, as it forces one to consider the magnitude of the number of stars out there, but it's essentially useless as an actual predictive tool because we have no way of knowing what some of the variable values are.

 

A Fermi Question is a question or problem where one can arrive at a numerical estimate by making a series of reasonable assumptions.  The Drake Equation is an example of a Fermi Question, although again, some of the variables are essentially unknowable, at least right now.  So the Fermi Question is not, "Where are they?", it's "How many active, intelligent civilizations are there in the universe right now?"

 

The classic example of a Fermi Question is, "How many piano tuners are there in Chicago?"

 

Granted, I'm going from memory from a 30 year old op-ed.  But as I remember it, the article was distinguishing between what it called a Fermi question (their example was "how many golf balls will fit in a car?"  the question doesn't specify what kind of car, or whether you're referring to the trunk, passenger compartment, or both, or the dimensions of a golf ball.  The goal is to make reasonable assumptions about all of these things, and come up with an estimate), and what I thought they were labeling as the Fermi question. 

 

I chose to leave that part out of my post, cause it was too complicated already. 

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I'd like to see the math to back that claim up. Do we have a a physics student who wants to integrate the Rayleigh-Jeans equation to calculate the radiation from the sun in RF frequencies?  :)

 

But that's off topic. No doubt the Earth is radiating signals that might be detected. Carl Sagan used this as the basis of his novel Contact and claimed that the first TV transmission strong enough to be detected by an extraterrestrial civilization was actually a broadcast of Hitler's speech at the 1936 Olympics. Maybe the extraterrestrials saw this and changed the channel for a few hundred years.  :)

 

The sun emits (estimated) 3.846 × 1026 watts per second.  This is from some guys that I love reading discussions about these types of topics.  Check them out:

 

http://www.physicsforums.com/showthread.php?t=223449

 

There is no way conceivable that the earth could emit as much as the sun, in any spectrum of EM.  It's not physically possible.  Earth could explode and still be drowned out by the sun's emissions.  We locate new planets by observing miniscule dips in luminosity of distant stars...as the planet crosses in front of the star.  Earth would be no different to anyone else out there. 

 

Assuming a species is out there somewhere, and assuming they are listening to the radio EM spectrum, assuming they understand what we're saying / implying, if they sent a response yesterday we won't know for 70 years.  Assuming they want to respond and be found.  Or their armada is en route as we speak and this discussion is moot.

 

Either way, I'd love to read that article Larry referenced.

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Formally, what he is talking about is the Fermi paradox.

 

http://en.wikipedia.org/wiki/Fermi_paradox

 

But he's got the basic idea, right.

Cool, thanks for posting that.

 

Larry, I get what you were saying, I was just trying to disambiguate a few things. I hadn't heard of the Fermi Paradox though.  Considering that Fermi Questions (not to be confused with the Fermi Paradox) are also sometimes known as Fermi Estimates or Fermi Problems, I would say Enrico Fermi has far too many similar things named after him.

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Either way, I'd love to read that article Larry referenced.

Actually, the article (an editorial in Analog science fiction magazine), after introducing this paradox, then went on to examine a possible theory to explain why perhaps humans are more unique than we imagine. Since the author can only compare humans against other terrestrial creatures, that's what he did.

And he observed that current theories seem to suggest that Man has been the top of the food chain for a very long time. Probably for a lot longer than we've had any tools at all. He questioned how we managed to achieve this point, seeing as how it's pretty much accepted that any unarmed human who takes on any animal bigger than a bunny rabbit is gonna get his flat omnivore teeth kicked down his throat.

And it observes that man is (or was) what is called a "cursorial hunter". A hunter which hunts by chasing it's prey until the prey literally collapses from exhaustion.

The article observes that it's pretty much assumed that modern man is in nowhere near the physical condition of his knuckle-dragging ancestors. And yet, every year, thousands of modern humans compete in marathon events, for fun, where the slowest participants post performances which would kill a cheetah within a mile or two.

Wolves hunt the same way.

The article explained that there are things about being a cursorial hunter which are different from other life forms.

They hunt in packs. (They pretty much have to. Remember, they at least CAN hunt things which are bigger and tougher than they are.)

They often spend a great deal of time hunting something, and then come up empty. They chase an antelope into exhaustion, and then something else is sitting on the corpse, when they get there.

But, when they succeed, they have far more food than they can possibly eat. These two factors encourage sharing.

The article's theory was that perhaps only cursorial hunters will tend to develop the ability to cooperate towards a common goal. Things which are necessary for large scale projects or advanced societies.

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