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Space and Astronomy Thread |
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#3126 |
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The only way I could see human beings able to interact with other intelligent beings is if 1) They came here, or 2) we build large space ships/societies in the FAR FAR future that people just lived on traveling through space, kind of like nomads (think Battlestar Galactica). And then it would just be sheer coincidence that they bumped into each other. God help those poor aliens if that happens.
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That aside, I have been wondering about how rare the various features of our solar system are. Earth having a large moon, for example, may turn out to be crucial. Apparently it arose from a collision in the early solar system. Presumably from computer simulations we can now estimate how common such collisions are. Similarly the chances of having a Jupiter that is distant from its sun rather than close in. If it's true that life first arose on Mars and migrated to Earth, and if it turns out that it has to happen like that, how common is it to have two planets in the Goldilocks zone? Is it possible we are at the end of a long line of astronomically unlikely events? (Although most of the time I think life is common and intelligent life - or even multi-cellular life - is rare.) |
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#3127 |
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Join Date: Sep 2011
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I would think that on a planet where single-celled lifeforms exist, multi-cellular lifeforms are inevitable, given enough time. Whether you'd end up with simple sponges and the like and nothing more I'm not sure. Not every rung of the evolutionary ladder is equally spaced, so to speak.
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#3128 |
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I would think that on a planet where single-celled lifeforms exist, multi-cellular lifeforms are inevitable, given enough time.
Of course that's begging the question. We don't know if it is like pregnancy, which always takes nine months (more or less) because it involves a set number of events that have to happen in order, or if it is random. It seems mitochondria arose because one cell didn't properly digest another, which seems very unlikely in itself rather than something quickly inevitable once the precursors were around. That it apparently only happened once (that we know of), adds to my suspicions. This despite the entire surface of the planet being covered in simple single-cellular life that it could have happened to. Nor do I think it inevitable that multi-cellular life on any given planet would become intelligent. The dinosaurs didn't. And again, I'm talking about within the lifetime of the universe, which is what we have to work with. There's no "given enough time" here. And let's not forget we need heavy elements like carbon to make life, and those take time to forge, so you don't even get the whole universe lifetime. I'm being optimistic here. I'm saying the Great Filter lies behind us, and colonising the galaxy will be easy from here on in. Someone has to be first. |
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#3129 |
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Of course that's begging the question. We don't know if it is like pregnancy, which always takes nine months (more or less) because it involves a set number of events that have to happen in order, or if it is random. It seems mitochondria arose because one cell didn't properly digest another, which seems very unlikely in itself rather than something quickly inevitable once the precursors were around. That it apparently only happened once (that we know of), adds to my suspicions. This despite the entire surface of the planet being covered in simple single-cellular life that it could have happened to.
I completely agree with you about intelligent life though. The Earth is about 4.5 billion years old, yet homo sapiens have only been around for a few hundred millennia... and you still rarely meet an intelligent one.
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#3130 |
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Hubble has detected the most distant galaxy yet discovered.
For now at least - just wait until the James Webb Space Telescope is launched. ![]() http://phenomena.nationalgeographic....least-for-now/ http://phys.org/news/2016-03-hubble-...-distance.html |
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#3131 |
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As I understand it, simple single-celled life arose on Earth almost immediately conditions were suitable. Complex, nucleated single-celled life took a couple of billion years. Multi-cellular life took roughly another billion. May be it is inevitable, but those are long time spans, even compared to the age of the universe. If it usually takes 20 times as long, there just hasn't been enough time.
Never mind the Eukaryotes, which require speculation and hand waving. The transformation of chemistry into biology seems unknown. |
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#3132 |
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The Lottery is known, but we can't pick the right numbers. Still people win.
I am not a biochemist. |
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#3133 |
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Join Date: Oct 2011
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Yet we still can't replicate this process.
Never mind the Eukaryotes, which require speculation and hand waving. The transformation of chemistry into biology seems unknown. You have written three hand waving statements without any reference to what you are talking about. |
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#3134 |
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Join Date: Oct 2011
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You have written three hand waving statements without any reference to what you are talking about.
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#3135 |
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Quote:
Always wanted to be a prof
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#3136 |
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Join Date: Apr 2005
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Quote:
Yet we still can't replicate this process.
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#3137 |
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Inactive Member
Join Date: Sep 2012
Location: A Sound Expert
Posts: 13,881
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Did someone say "dinosaurs were not intelligent" ?
What a stupid thing to say., for many, many reasons. |
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#3138 |
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I think that's the difference between trying it in a few test tubes in a few labs over a few years, and trying it in every drop of ocean over an entire planet over a few million years. Something vanishingly rare in the former could be common in the latter.
All those factors put together mean that there are still so many unanswered questions which need to be addressed, e.g. where and in exactly what conditions did life evolve. |
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#3139 |
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Join Date: May 2004
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Hubble has detected the most distant galaxy yet discovered.
For now at least - just wait until the James Webb Space Telescope is launched. ![]() http://phenomena.nationalgeographic....least-for-now/ http://phys.org/news/2016-03-hubble-...-distance.html |
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#3140 |
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Join Date: Feb 2014
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Quote:
Did someone say "dinosaurs were not intelligent" ?
What a stupid thing to say., for many, many reasons.
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#3141 |
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Join Date: Apr 2005
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Quote:
Did someone say "dinosaurs were not intelligent" ?
What a stupid thing to say., for many, many reasons. |
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#3143 |
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How Richard Nixon saw the future of the space programme 46 years ago
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#3144 |
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Join Date: Feb 2014
Location: The Sixth Circle of Hell
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Why Mercury is so dark and a very mysterious mountain on Ceres.
![]() http://phys.org/news/2016-03-mercury...-revealed.html http://news.discovery.com/space/aste...oto-160307.htm |
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#3145 |
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Location: Osaka
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Why Mercury is so dark and a very mysterious mountain on Ceres.
![]() http://phys.org/news/2016-03-mercury...-revealed.html http://news.discovery.com/space/aste...oto-160307.htm |
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#3146 |
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Join Date: Mar 2013
Posts: 3,063
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Why Mercury is so dark and a very mysterious mountain on Ceres.
![]() http://phys.org/news/2016-03-mercury...-revealed.html http://news.discovery.com/space/aste...oto-160307.htm Nobel prize please... |
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#3147 |
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Forum Member
Join Date: Jun 2006
Posts: 19,567
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Total eclipse of sun in progress right now. It is live on a number of sites.
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#3148 |
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Join Date: Nov 2008
Location: London
Posts: 4,020
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Hello? Dark because it's so close to the sun? Obvious!
Nobel prize please... |
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#3149 |
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Join Date: Feb 2014
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Posts: 20,174
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"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff."
http://phys.org/news/2016-03-interstellar.html |
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#3150 |
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Join Date: Feb 2014
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