I guess you pass on Heinlein as well. Lazarus Long makes Louis Wu look like an monk!Ann wrote:I decided then and there that I would never read a book by Larry Niven again!
What makes the Earth habitable?
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Re: What makes the Earth habitable?
Chris
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Re: What makes the Earth habitable?
Sorry, Owlice. I'm sure I exaggerated that. Those who champion the idea of a Milky Way teeming with life tend to be the most enthusiastic SETI proponents. (But I realize that you can be very interested in SETI and still not believe that our galaxy is overflowing with life. Indeed, SETI is as legitimate as a science as any other, if you do it properly.)owlice wrote:Who made that statement? Where did it come from? What is your source for that statement?Ann wrote: the statement that our galaxy is teeming with life and that there are millions of civilizations in the MIlky Way should be much easier to prove.
I'm sorry; I must have missed this. I don't see from where such a statement comes. I've never heard a serious assertion that our galaxy is teeming with life, nor that there are millions of civilizations in the Milky Way. Speculation, yes. Stories that are science fiction, yes. But a flat-out statement that our galaxy IS teeming with life? No. A flat-out statement that there ARE millions of civilizations in the Milky Way? Please let me know what reading material I've been missing by pointing me to a source; thanks!
But I bought Astronomy Magazine a year ago or so because they had an article about the Drake Equation in it, and I was almost shocked by what author said in it. I had expected a balanced report on what we know and what we may assume. But while the article managed to sound scientific enough, it nevertheless ended up suggesting that very many of the factors of the Drake Equation are close to unity. That is, most G-type planets can be expected to have planets, and most solar systems can be expected to have at least one habitable planet, and practically every habitable planet can be expected to produce simple life form, and simple life forms can almost always be expected to evolve into complex life forms, and complex life can be expected to develop intelligence, and intelligent life can be expected to build technological civilizations.
Am I sure that the article said that? No, I'm not. It could well be that I thought that the article was way too enthusiastic about how much life we can expect to find in our galaxy, and because of my irritation I might mis-remember what the article actually said. (I don't have it any more.)
A person who was very optimistic about life on other planets in our galaxy was Carl Sagan. Surely he predicted that there was at least a million technological civilizations in our galaxy.
Another thing that irritates me, and that I have also found many times in magazines like Astronomy and Sky & Telesciope, is the assertion that astronomers used to be much more pessimistic about life on other planets in the past than they are now, because now they know so much more about the other planets that they have far more reason than before to be optimistic. I don't believe in that at all. Like I said, I vividly remember being told by a serious-sounding article from the 1960s that there was vegetation on Mars. I also vividly remember an article in my local newspaper from about 1970 where the reporter was shocked and horrified at learning that Venus was hot enough to melt lead. The reporter wrote that astronomers used to believe that Venus was clement enough to support simple life forms, and while that may well have been a misconception on his part, it was probably a misconception that was shared by many astronomically interested people at that time.
Ann
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Re: What makes the Earth habitable?
I haven't read much by Heinlein, but you're right, I don't much like him. But my real problem with Larry Niven's Ringworld hero was not so much his promiscuous sexual habits as the fact that he ended up killing almost all the (hundreds?) of women he had had sex with!Chris Peterson wrote:I guess you pass on Heinlein as well. Lazarus Long makes Louis Wu look like an monk!Ann wrote:I decided then and there that I would never read a book by Larry Niven again!
Ann
Last edited by Ann on Fri Jul 30, 2010 3:57 pm, edited 1 time in total.
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Re: What makes the Earth habitable?
I haven't read A Tale of Two Cities (and it's probably just as well that I haven't), but I have read Little Women. It was a very long time ago, so I don't remember much, but I think there were things I liked in it (or them? Were there more than one book?), and there were things I didn't like.rstevenson wrote:I'm pretty sure I could make A Tale of Two Cities or even Little Women sound just as ridiculous if I made as much effort as you've just made to trash Niven's Ringworld. But in making that effort you failed to address the point I was making in response to your slur of all science fiction for its lack of creativity regarding planetary orbits.Ann wrote:I decided then and there that I would never read a book by Larry Niven again!
Rob
I don't mean to slur all science fiction for its lack of creativity regarding planetary orbits. I'm sure you are right that if I had kept reading science fiction for longer than I did, and if I had put up with writers like Larry Niven, I might indeed have come across some very interesting creativity regarding planetary orbits. I ended up strongly disliking Ringworld because I was shocked that the hero would kill all his former lovers, but I really did think, all the same, that the Ringworld itself was a very creative and fascinating idea.
Ann
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Re: What makes the Earth habitable?
Well, technically, they weren't women, but females of a different hominin species. And technically, it wasn't sex but rishathra, a ritualized, interspecies sexual practice (often used to seal contracts). And the decision to kill millions of "people" is part of a series of ethical dilemmas Wu faces in trying to save a world that contains hundreds of billions of sentient beings.Ann wrote:I haven't read much by Heinlein, but you are right, I don't much like him. But my real problem with Larry Niven's Ringworld hero was not so much his promiscuous sexual habits as the fact that he ended up killing almost all the (hundreds?) of women he had had sex with!
BTW, if you continue with the Ringworld series, you'll discover that not many were actually killed by the restabilization jets.
Chris
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Re: What makes the Earth habitable?
Note, however, the difference between "might be" and "is". Claiming that the galaxy might be teeming with life is a lot more reasonable than claiming that, based on what we know now, it does teem with life.Chris Peterson wrote:I've heard pretty serious claims that the galaxy might be teeming with life.owlice wrote:I'm sorry; I must have missed this. I don't see from where such a statement comes. I've never heard a serious assertion that our galaxy is teeming with life, nor that there are millions of civilizations in the Milky Way. Speculation, yes.
Ann appears to contend that a significant number of scientists claim galactic life-teeming as fact rather than possibility. That is what I think is a strawman construction.
Henning Makholm
Re: What makes the Earth habitable?
Chris, speculation is one thing, and I agree that speculating there are other planets which host life is reasonable. It's the claim that there is an assertion that this is so that I question. Of course there will be those who claim all kinds of fantastic things, but a credible, serious assertion, one that is accepted by many (or even some critical number)... that, I question.
This whole thread, and the earlier one on the color of the sun, makes me think of Santa Claus. Not everything kids believe when they are little, regardless of whether the belief was planted or grew out of children's limited experience with the world, is true.
Re: Heinlein, I read him until I got to a certain Lazarus Long story; I had thought before that that Heinlein had some serious issues of his own to work out, and after that, I was certain of it!
I still reread the Heinlein I've already read, but haven't sought out anything of his I don't already know since.
Ann, you're taking an article here, a journalistic exaggeration there, as evidence of a wide-spread belief, and then getting irritated about it. Instead of looking at the oddball articles, maybe concentrating on the larger share of writings would be a better idea? So long as there are more than two people on the planet, there will not be perfect agreement about everything, or possibly anything!! <g>
Henning, yes, exactly my point: this strikes me as a strawman argument, too.
This whole thread, and the earlier one on the color of the sun, makes me think of Santa Claus. Not everything kids believe when they are little, regardless of whether the belief was planted or grew out of children's limited experience with the world, is true.
Re: Heinlein, I read him until I got to a certain Lazarus Long story; I had thought before that that Heinlein had some serious issues of his own to work out, and after that, I was certain of it!
![Shocked :shock:](./images/smilies/icon_eek.gif)
Ann, you're taking an article here, a journalistic exaggeration there, as evidence of a wide-spread belief, and then getting irritated about it. Instead of looking at the oddball articles, maybe concentrating on the larger share of writings would be a better idea? So long as there are more than two people on the planet, there will not be perfect agreement about everything, or possibly anything!! <g>
Henning, yes, exactly my point: this strikes me as a strawman argument, too.
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Re: What makes the Earth habitable?
Sure. Of course, one person's speculation may be another's assertion. We certainly see that occasionally in this forum, where a few of our more credulous members are quick to repost any number of extremely speculative ideas as strong assertions!owlice wrote:Chris, speculation is one thing, and I agree that speculating there are other planets which host life is reasonable. It's the claim that there is an assertion that this is so that I question. Of course there will be those who claim all kinds of fantastic things, but a credible, serious assertion, one that is accepted by many (or even some critical number)... that, I question.
Chris
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Re: What makes the Earth habitable?
No, my point isn't that a significant number of scientists claim galactic life-teeming as fact rather than possibility. I don't think that is the case at all. My point is, rather, that there is a lot of speculation as well as discussion that life is common in the universe, but a lot less discussion about the possible uncommon-ness of the Earth. I googled "life is common in the universe" and got 12,600 hits. I googled "life is rare in the universe" and got 1,410 hits.Henning Makholm wrote:Note, however, the difference between "might be" and "is". Claiming that the galaxy might be teeming with life is a lot more reasonable than claiming that, based on what we know now, it does teem with life.Chris Peterson wrote:I've heard pretty serious claims that the galaxy might be teeming with life.owlice wrote:I'm sorry; I must have missed this. I don't see from where such a statement comes. I've never heard a serious assertion that our galaxy is teeming with life, nor that there are millions of civilizations in the Milky Way. Speculation, yes.
Ann appears to contend that a significant number of scientists claim galactic life-teeming as fact rather than possibility. That is what I think is a strawman construction.
I can't help noting that no one here has so far commented on my claim that we have reason to think that the Earth is rare. Personally I believe that the Earth is like a lottery winner, which, just out of pure coincidence, happened to win all the necessary characteristics that work together to make a planet very suitable for life. I also think that this "habitable planet lottery" is a very big lottery, and that there are few winners.
Any comments on my list of factors that help make the Earth habitable, a list I made in an earlier post?
Ann
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Re: What makes the Earth habitable?
How it is even logically possible for there to be a lot of discussion of A without there being the same abount of discussion of not-A? You cannot discuss one possibility without at the same time discussing the other; otherwise it would not be a discussion of the question at all.Ann wrote:No, my point isn't that a significant number of scientists claim galactic life-teeming as fact rather than possibility. I don't think that is the case at all. My point is, rather, that there is a lot of speculation as well as discussion that life is common in the universe, but a lot less discussion about the possible uncommon-ness of the Earth. I googled "life is common in the universe" and got 12,600 hits. I googled "life is rare in the universe" and got 1,410 hits.
Henning Makholm
Re: What makes the Earth habitable?
:: hopes someone brings her an unbirthday cupcake this afternoon ::Henning Makholm wrote: How it is even logically possible for there to be a lot of discussion of A without there being the same abount of discussion of not-A? You cannot discuss one possibility without at the same time discussing the other; otherwise it would not be a discussion of the question at all.
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Re: What makes the Earth habitable?
Naaaah. Didn't think so.Any comments on my list of factors that help make the Earth habitable, a list I made in an earlier post?
Ann
P.S. You're right, Owlice, it isn't my birthday. So I don't mind that unbirthday cake.
P.P.S. What do you people think of the mediocrity principle? Do you agree that the Earth can't be very special because the mediocrity principle says that we can't, amen?
Color Commentator
Re: What makes the Earth habitable?
Ann, I have Zingers; they're not cupcakes, but I'm happy to share them with you!
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Re: What makes the Earth habitable?
It seems quite apparent that nobody feels any particular need to champion the position you want to oppose.Ann wrote:Naaaah. Didn't think so.Any comments on my list of factors that help make the Earth habitable, a list I made in an earlier post?
How is that our fault, again?
And there's another strawman.P.P.S. What do you people think of the mediocrity principle? Do you agree that the Earth can't be very special because the mediocrity principle says that we can't, amen?
Henning Makholm
Re: What makes the Earth habitable?
Mmmmmmmmmmmmmmmmmm!!!!owlice wrote:Ann, I have Zingers; they're not cupcakes, but I'm happy to share them with you!
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Ann
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Re: What makes the Earth habitable?
Life is like a box of chocolates, you never know what your going to get.owlice wrote:Ann, I have Zingers; they're not cupcakes, but I'm happy to share them with you!
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We are all winners. I personally beat 2.5 million to the Egg. How Many did you Beat?Ann wrote:I can't help noting that no one here has so far commented on my claim that we have reason to think that the Earth is rare. Personally I believe that the Earth is like a lottery winner, which, just out of pure coincidence, happened to win all the necessary characteristics that work together to make a planet very suitable for life. I also think that this "habitable planet lottery" is a very big lottery, and that there are few winners.
tc
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Re: What makes the Earth habitable?
The momentum of discoveries is ALL going in the direction of life being abundant in the universe:Ann wrote:I can't help noting that no one here has so far commented on my claim that we have reason to think that the Earth is rare. Personally I believe that the Earth is like a lottery winner, which, just out of pure coincidence, happened to win all the necessary characteristics that work together to make a planet very suitable for life. I also think that this "habitable planet lottery" is a very big lottery, and that there are few winners.
- 1) the radio telescope discovery of complex hydrocarbons in space
2) the Miller–Urey creation of 22 amino acids "in a test tube"
3) the discovery of the simplicity of DNA replication
4) the discovery of prokaryotes 700 million years after the formation of the Earth
5) the discovery of prokaryotes both deep below the ocean & under the earth
6) the discovery of more than 100 billion galaxies in the observable universe
7) the discovery of earth-like planets around other suns
Can Ann give even ONE example of any discovery that suggests that life might somehow be rare in the universe?
Last edited by neufer on Fri Jul 30, 2010 11:57 pm, edited 1 time in total.
Art Neuendorffer
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Re: What makes the Earth habitable?
I did, but you ignored it. Here it is again...Ann wrote:I can't help noting that no one here has so far commented on my claim that we have reason to think that the Earth is rare.
"As for your initial question, and the title of this thread, I can only reply, "Who knows?" A data set containing only one point makes a poor chart." In case I was being too cryptic, let me explain. While we now have quite a few hints that there are at least the conditions that might lead to life on other panets and moons in our own system, and while we have lots of "candidates" for Earth-like planets elsewhere, we have so far only one planet with verifiable life -- some might even say intelligent life -- on it. Earth. One data point. Ergo, not enough data. Any discussion about how rare that is reduces to a discussion of belief. We simply don't know.
Rob
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Re: What makes the Earth habitable?
You are talking about the expectation that life exists elsewhererstevenson wrote:As for your initial question, and the title of this thread, I can only reply, "Who knows?" A data set containing only one point makes a poor chart." In case I was being too cryptic, let me explain. While we now have quite a few hints that there are at least the conditions that might lead to life on other planets and moons in our own system, and while we have lots of "candidates" for Earth-like planets elsewhere, we have so far only one planet with verifiable life -- some might even say intelligent life -- on it. Earth. One data point. Ergo, not enough data. Any discussion about how rare that is reduces to a discussion of belief. We simply don't know.Ann wrote:I can't help noting that no one here has so far commented on my claim that we have reason to think that the Earth is rare.
simply based upon the ONE fact that life exists on Earth.
Based upon the sum total of ALL the discoveries which I have stated above I believe
that we can confidently conclude beyond a reasonable doubt that life is abundant in the universe.
Art Neuendorffer
Re: What makes the Earth habitable?
Neufer, You really are growing on me. Your not a Barnacle are you?
Tc
![Wink :wink:](./images/smilies/icon_wink.gif)
Tc
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Re: What makes the Earth habitable?
I believe you are right Art. I even hope you are right. But I don't think you are right -- or wrong.neufer wrote:Based upon the sum total of ALL the discoveries which I have stated above I believe that we can confidently conclude beyond a reasonable doubt that life is abundant in the universe.
Rob
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Re: What makes the Earth habitable?
Belief. That is quite possibly the elephant in the room.rstevenson wrote:Earth. One data point. Ergo, not enough data. Any discussion about how rare that is reduces to a discussion of belief.
Someone seems to have decided that if intelligent life is abundant in the universe, that would be an argument that God does not exist. And, conversely, if life on Earth is truly unique, then it must be due to divine intervention. I don't find either inference to be particularly persuasive, but the idea makes some of us wary of approaching a debate that could turn out to be a preamble for a pointless and unproductive atheist/theist shouting match.
Henning Makholm
Re: What makes the Earth habitable?
Did not the great man input this info, into to his equations? Or was it the other way round? (You work out who).Henning Makholm wrote:Someone seems to have decided that if intelligent life is abundant in the universe, that would be an argument that God does not exist. And, conversely, if life on Earth is truly unique, then it must be due to divine intervention. I don't find either inference to be particularly persuasive, but the idea makes some of us wary of approaching a debate that could turn out to be a preamble for a pointless and unproductive atheist/theist shouting match.
tc
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Re: What makes the Earth habitable?
It might be interesting to see what values each of us who are interested in this discussion get when they run the Drake Equation interactive. Mine works out to 798,400 -- a bit on the high side compared to most of you, I imagine. That's mainly because I'm optimistic about the life span of an intelligent species.
For some, this version of the equation might be more suitable.
Rob
For some, this version of the equation might be more suitable.
![Laughing :lol:](./images/smilies/icon_lol.gif)
Rob