Page 19 of 19 FirstFirst ... 9171819
Results 541 to 558 of 558

Thread: What do you think is the most likely explanation for the Fermi paradox?

  1. #541
    Join Date
    May 2007
    Location
    Earth
    Posts
    10,261
    Scientists can err, witness Lord Kelvin’s 1895 quote, and Felisa Wolf-Simon’s arsenic-using life. It’s certainly possible there will be both false positives (these have happened) and false negatives.
    Information about American English usage here and here. Floating point issues? Please read this before posting.

    How do things fly? This explains it all.

    Actually they can't: "Heavier-than-air flying machines are impossible." - Lord Kelvin, president, Royal Society, 1895.



  2. #542
    Join Date
    Dec 2011
    Posts
    3,317
    Quote Originally Posted by swampyankee View Post
    Scientists can err, witness Lord Kelvin’s 1895 quote, and Felisa Wolf-Simon’s arsenic-using life. It’s certainly possible there will be both false positives (these have happened) and false negatives.
    Sure.
    So the Fermi Paradox is just another false one then, eh? (Humour intended here).

  3. #543
    Join Date
    Mar 2004
    Posts
    18,353
    Quote Originally Posted by kzb View Post
    I don't remember it like that at all. I recall President Clinton announcing the discovery of life on Mars. And he was put up there at the request of NASA.

    Whilst I go along with what you say about publicity, the later backtracking must've been embarrassing for all concerned.
    Memory is far from perfect, and if I recall correctly, many news reports at the time missed important details.

    Here is a transcript of his statement:

    https://www2.jpl.nasa.gov/snc/clinton.html

    Some key bits:

    This is the product of years of exploration and months of intensive study by some of the world's most distinguished scientists. Like all discoveries, this one will and should continue to be reviewed, examined and scrutinized.
    [...]
    First, I have asked Administrator Goldin to ensure that this finding is subject to a methodical process of further peer review and validation.
    [...]
    Today, rock 84001 speaks to us across all those billions of years and millions of miles. It speaks of the possibility of life. If this discovery is confirmed, it will surely be one of the most stunning insights into our universe that science has ever uncovered. Its implications are as far-reaching and awe-inspiring as can be imagined. Even as it promises answers to some of our oldest questions, it poses still others even more fundamental.
    It was definitely an optimistic statement, but they were careful to include qualifiers.

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." — Abraham Lincoln

    I say there is an invisible elf in my backyard. How do you prove that I am wrong?

    The Leif Ericson Cruiser

  4. #544
    Join Date
    Mar 2004
    Posts
    18,353
    Quote Originally Posted by Selfsim View Post
    Let's also not forget about the notorious Richard Hoover episode who, in 2011, published a 'paper' in the crank Journal of Cosmology, wherein he claimed evidence in meteorites that life on Earth came from space, in this case, in the form of comet debris. (He's apparently made similar claims six times to date!)

    Then again in the same crank Journal, a 'Rhawn Joseph' published an article in January 2014, concluding that the martian (in situ) rock, dubbed 'Pinnacle Island', was in fact, a living organism.

    The pattern seems clear ... the fixation with 'life must be out there', (which of course provokes the Fermi Paradox), when combined with marginal scientific qualifications, (a BSc in Hoover's case), leads towards pareidolia driven delusions, a life of pseudoscientific crankdom, which then serves to perpetuate the accompanying fixation with the Paradox too (ie: Fermi's) ... which really never was one at all anyway(?)
    The pattern seems clear . . . if we're just discussing the nonsense published in a crank journal. That's no reason to condemn serious research (like that on ALH84001, which has been extensively peer reviewed), or serious discussion about issues like the Fermi paradox.

    Incidentally, we had an extensive discussion about the Journal of Cosmology on this board, and at one point one of their key editors popped in here with a negative comment (they were doing that a lot around the internet, see David Brin's experience with the Journal, for instance, where he tried to peer review a Rhawn Joseph article at their request). My recollection is that JoC initially got some publicity with a mention of one or another of their articles in some major newspapers. But it quickly became known as a crank journal and they later stopped getting mentions from serious news organizations.

    I did a bit of research myself, and it was clear that Rhawn Joseph played a major part in the site. The website formatting was essentially the same as a personal site he had built earlier. He had a lot of ATM science claims. If I recall, he had some steady state eternal universe idea, argued modern evolution was wrong, abiogenesis was impossible, and insisted on panspermia.

    Hoover's claims were very quickly criticized by the science community, and NASA made it clear he wasn't speaking for them. (I think also that he was retired at the time when the JoC article flap happened?)

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." — Abraham Lincoln

    I say there is an invisible elf in my backyard. How do you prove that I am wrong?

    The Leif Ericson Cruiser

  5. #545
    Join Date
    Dec 2011
    Posts
    3,317
    Quote Originally Posted by Van Rijn View Post
    The pattern seems clear . . . if we're just discussing the nonsense published in a crank journal. That's no reason to condemn serious research (like that on ALH84001, which has been extensively peer reviewed), or serious discussion about issues like the Fermi paradox.
    Somewhat agreed .. I'm obviously challenging the 'seriousness' of FP discussions about so-called 'issues' though. The FP is only a paradox for philosophical thinkers .. its largely irrelevant for scientific thinkers (the latter of which, includes the proper Astrobiology researchers I've encountered, who are doing great work).
    (Ie: one can't test against a believed-in standard .. so move on testing against one that isn't).

    Quote Originally Posted by Van Rijn
    Incidentally, we had an extensive discussion about the Journal of Cosmology on this board, and at one point one of their key editors popped in here with a negative comment (they were doing that a lot around the internet, see David Brin's experience with the Journal, for instance, where he tried to peer review a Rhawn Joseph article at their request). My recollection is that JoC initially got some publicity with a mention of one or another of their articles in some major newspapers. But it quickly became known as a crank journal and they later stopped getting mentions from serious news organizations.

    I did a bit of research myself, and it was clear that Rhawn Joseph played a major part in the site. The website formatting was essentially the same as a personal site he had built earlier. He had a lot of ATM science claims. If I recall, he had some steady state eternal universe idea, argued modern evolution was wrong, abiogenesis was impossible, and insisted on panspermia.

    Hoover's claims were very quickly criticized by the science community, and NASA made it clear he wasn't speaking for them. (I think also that he was retired at the time when the JoC article flap happened?)
    Yar .. it pops up occasionally elsewhere in my web forum travels .. and always gets the treatment it deserves. Its 'going-in' position/purpose is just outright anti-science (IMO).

  6. #546
    Join Date
    Nov 2009
    Posts
    318
    Aliens became too smart, developed nukes, waged wars, alien life was extinguished. As per main plot theme of 'Battlestar Galactica', it has all happened before, and it will happen again. Intelligent life in the universe will develop robots, weapons, so on that will either turn against them, or destroy them.
    Perhaps, Gods, angels, demons were in fact aliens. Why did angels and Nephilim exist at all? Were Adam&Eve from another planet or dimension? Was Jesus a human?

    Or... intelligent aliens are just too far from Earth.

  7. #547
    Join Date
    Nov 2009
    Posts
    318
    From:
    https://www.realclearscience.com/blo...nd_aliens.html

    "12. Aliens are already here and we just don't realize it. "

  8. #548
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    37,105
    Quote Originally Posted by Gomar View Post
    From:
    https://www.realclearscience.com/blo...nd_aliens.html

    "12. Aliens are already here and we just don't realize it. "
    "6. Space is big."
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  9. #549
    Join Date
    Dec 2011
    Posts
    3,317
    0. We don't have a clue that what we're looking for, is actually alien life.

  10. #550
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    37,105
    Quote Originally Posted by Selfsim View Post
    0. We don't have a clue that what we're looking for, is actually alien life.
    You mean that "life signs" would not be immediately obvious and recognizable to us over a distance that even the fastest thing possible takes many years to cross?

    What a concept!
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  11. #551
    Join Date
    Dec 2007
    Posts
    1,660
    I rather like the analogy of pacific islanders looking past their islands bay at the open ocean and asking 'is there anything but storms and sea out there?'... while five minutes sailing and a dive would bring them to a coral reef teeming with colour, variety, and life. IMHO we'd be better off simply exploring without fixating on such a narrow thing as our current understanding of life... but perhaps that is too big an ask, and as a people we truly do need a goal to aim at.

  12. #552
    Join Date
    Oct 2019
    Posts
    4
    Quote Originally Posted by marsbug View Post
    I rather like the analogy of pacific islanders looking past their islands bay at the open ocean and asking 'is there anything but storms and sea out there?'... while five minutes sailing and a dive would bring them to a coral reef teeming with colour, variety, and life. IMHO we'd be better off simply exploring without fixating on such a narrow thing as our current understanding of life... but perhaps that is too big an ask, and as a people we truly do need a goal to aim at.
    I always liked this quote from Arthur C. Clarke: “Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”

    I think the question of whether we are alone or not is important to us on a philosophical level. If we are indeed alone, then that means we're special somehow. If we are the only intelligent species in the Universe then that means it's just us and this unimaginably gigantic sandbox we can do anything we want with it.

    If we aren't alone, that too has meaning. On one hand, it means we aren't special and that there are others like us (meaning intelligent). Then there's the huge amount of questions that come up: what's the other species like? what do they eat? what was their history? what do they believe in? what do they eat for breakfast? what do they think of Seinfeld?

    To go back to the OT. I think we're alone, at least in this galaxy. I think the conditions required to sustain intelligent life are very restrictive, and we here on Earth just got unimaginably lucky to exist. Also, I think we're one of the very species to exist, simply because the Universe is so incredibly young at this point. I read that the Universe will continue to generate stars for trillions of years, and we're only 13.7 billions years in.

  13. #553
    Join Date
    May 2009
    Location
    42.798928,10.952804
    Posts
    467
    a few novels tried to imagine a human civilization accostumed to the huge expanse of time and space of a galaxy-wide civilization... that's nonsense: even if such a galactic civilization could cope with interstellar travel of a few people per century, it exhausted its own energy sources much sooner than contacting another earth... same same as living on a remote south pacific island and expecting to buy cigarettes one 20-pack each time...
    Last edited by Barabino; 2019-Nov-05 at 08:21 AM.

  14. #554
    Join Date
    Apr 2005
    Posts
    2,489
    Quote Originally Posted by Spyrith View Post
    I always liked this quote from Arthur C. Clarke: “Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”

    I think the question of whether we are alone or not is important to us on a philosophical level. If we are indeed alone, then that means we're special somehow. If we are the only intelligent species in the Universe then that means it's just us and this unimaginably gigantic sandbox we can do anything we want with it.

    If we aren't alone, that too has meaning. On one hand, it means we aren't special and that there are others like us (meaning intelligent). Then there's the huge amount of questions that come up: what's the other species like? what do they eat? what was their history? what do they believe in? what do they eat for breakfast? what do they think of Seinfeld?

    To go back to the OT. I think we're alone, at least in this galaxy. I think the conditions required to sustain intelligent life are very restrictive, and we here on Earth just got unimaginably lucky to exist. Also, I think we're one of the very species to exist, simply because the Universe is so incredibly young at this point. I read that the Universe will continue to generate stars for trillions of years, and we're only 13.7 billions years in.
    Not so sure about this. Current ideas imply there are rather special conditions for evolving and sustaining intelligent life.

    Firstly, it needs a large spiral galaxy. All systems in a dwarf galaxy are subject to periodic extinctions due to GRBs.

    Then, there is the level of metallicity. This needs to be within a certain range, not too low and not too high, but metallicity is increasing as the universe ages. This means the rate of formation of suitable systems will start to decline and more or less stop at a certain age. It's nowhere near that age yet, in fact the "productivity" of our own galaxy is still increasing, but at some point in the far future it will.

  15. #555
    Join Date
    May 2004
    Posts
    1,875
    All systems in a dwarf galaxy are subject to periodic extinctions due to GRBs.


    Do you have a reference to that? It seems counterintuitive. It's not like life can spread away from a GRB that happens to be nearby. And if the dwarf is one thousandth the size of the giant, GRBs should be one thousandth as frequent.
    SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS

  16. #556
    Join Date
    Apr 2005
    Posts
    2,489
    Quote Originally Posted by Tom Mazanec View Post
    All systems in a dwarf galaxy are subject to periodic extinctions due to GRBs.


    Do you have a reference to that? It seems counterintuitive. It's not like life can spread away from a GRB that happens to be nearby. And if the dwarf is one thousandth the size of the giant, GRBs should be one thousandth as frequent.
    There was a paper on arxiv a few years back which argued this.

    In a dwarf galaxy, all locations are within range of a GRB. In a large galaxy, as time goes on, regions evolve which are outside the range of GRBs. Thinking about this now, I am not sure if this really holds together though !

  17. #557
    Join Date
    May 2004
    Posts
    1,875
    Seems unlikely. Why would, say, the Orion Arm be immune to GRBs? They can happen just about anywhere.
    SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS

  18. #558
    Join Date
    Apr 2005
    Posts
    2,489
    Quote Originally Posted by Tom Mazanec View Post
    Seems unlikely. Why would, say, the Orion Arm be immune to GRBs? They can happen just about anywhere.
    The incidence of GRBs is inversely related to metallicity. As a spiral galaxy evolves, the metallicity increases first in the inner region and spreads outwards. There is a metallicity gradient in the MW from centre to edge of disk.

    There are also considerations of stellar density and supernova frequency affecting habitability, and those also have a correlation with galactic radius.

    So maybe it is some kind of balance with GRB frequency (correlates with inversely with metallicity) and other factors all contributing.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •