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Last time I looked into this the current estimate is that there are on average 10 planets per star, so we have 1-4 trillion planets in our galaxy, and there are

by mkempe 9y ago

Last time I looked into this the current estimate is that there are on average 10 planets per star, so we have 1-4 trillion planets in our galaxy, and there are 10 trillion planets in Andromeda. The Universe is teeming with galaxies, which are teeming with planets. Given what we know now it is likely that they are teeming with life (organisms in a process of self-sustaining and self-generated action) as well.

DmenshunlAnlsis 9y ago
The majority of those planets are unsuited to anything we can imagine being alive, or only suitable for very simple unicellular life. Most of those plants are gas giants, or blazing hot gas giants. Some are rocky, but many of those are in orbits like Mercury, which would alternately bake and freeze them. Of course, part of the reason for this might be our detection methods, but as of now, we’re not finding. I hope like Earth, Venus, or Mars, while we find a lot of Jupiter’s. Maybe we’ll disocver that something like bacteria is ubiquitous, but that doesn’t imply much for our prospects of finding intelligent life. For all that we know life is common, but multicellular life is incredibly rare, or maybe it isn’t rare, but intelligent life is.
- dugluak 9y ago
  Wondering if giants like UY Scuti have planets and how big.
  - mkempe 9y ago
    Red supergiants are necessarily no more than about 25 million years old; they keep ejecting a lot of material, forming nebulae; and then they end as supernovae. So, unlikely to have sufficient time and relative calm to form and maintain planets.
- binalpatel 9y ago
  There's this great article I came across a few weeks ago: https://www.theatlantic.com/science/archive/2018/03/human-existence-will-look-more-miraculous-the-longer-we-survive/554513/ https://www.theatlantic.com/science/archive/2018/03/human-ex... About how we may expect life to be more prevalent than it is because our own existence is so miraculous. Though the other side is - if the universe is so large, with so many planets, then there may be a chance that there's life out there that's just as incredibly lucky as us.
- mkempe 9y ago
  Are you arguing? I only mentioned life, not degrees of complexity of life. Ponder this: how early did life appear on Earth? what later cataclysmic events did it survive through the next several billions of years? how many living organisms are there on Earth at the moment? Finally, how you imagine life can exist or can appear is not equivalent to the facts of life on Earth, let alone in the entire Universe.
- Brockenstein 9y ago
  I've always liked to entertain the idea that highly advanced intelligent life is an evolutionary dead-end. After all if human beings drive themselves to extinction in the next 10,000 or 50,000 years what did our intelligence get us? It didn't enable us to survive better than other species. And what if a lot of intelligent species run into this problem? Where the level of knowledge and power they amass far outstrips what they've evolved to responsibly handle. And the result is intelligent species often manage to destroy themselves before they become wise enough to avoid that.
  - magduf 9y ago
    It's interesting how insightful, thoughtful comments like this get modded down to hell on HN because they offend someone's religious beliefs. You're right, all evidence so far does point to us driving ourselves to extinction eventually, and the way things are going, it's likely to be a lot less than 10k years. And the idea of other intelligent species running into this problem isn't a new idea, it's long been a theory among searchers of extraterrestrial life, called the "great filter theory".
    - perl4ever 9y ago
      The idea that humanity is sinful and unworthy and the end of the world is near or at least inevitable has a very long and deep religious background. Yet these themes frequently crop up among those who are making a point of the inferiority of religious thought. I have a certain distaste for how much people apparently love to think in terms of labels rather than substance. I often think downvoting is overdone, though.
      - magduf 9y ago
        >The idea that humanity is sinful and unworthy and the end of the world is near or at least inevitable has a very long and deep religious background. Really? I haven't seen that at all. If you're talking about Christianity and the whole "end times" stuff, that's a little different: that isn't humanity "driving itself to extinction", that's some deity deciding that humans are bad and proactively eliminating them. I don't see that as the same thing at all. In fact, why I said this seemed to be offending peoples' religious ideals is that I think the idea of humans making themselves extinct directly counters this religious idea that a deity is the one in charge of humans' fate. To them, if humans are all eliminated, it can't possibly be because humans did it to themselves (as this is what they'd call a "humanistic" or "secular" idea), but could only happen because their deity made it so. And conversely, as long as humans are "good" enough (meaning they worship the deity enough, nothing about them wrecking their environment or obliterating themselves with nuclear weapons) then the deity will protect them from their own mistakes.
- kwoff 9y ago
  Just about "alternately bake and freeze" (no opinion on the rest): Mercury does spin (slowly, every 60 earth days; previously was thought to be tidally locked), but on the other hand it's not tilted with respect to the "ecliptic plane" (the plane in which the planets orbit around the sun). It turns out it has water ice at the poles: https://www.space.com/18687-water-ice-messenger-discovery.html https://www.space.com/18687-water-ice-messenger-discovery.ht...
- perl4ever 9y ago
  There are billions of galaxies though, so even if we are the only planet out of billions in our galaxy with complex life, there could still be billions of civilizations out there! For that matter, the typical planet with life could be too large and have too thick an atmosphere for space travel or astronomy and thus never have any idea the rest of the universe exists. That wouldn't necessarily mean life was limited to single cells.

by mkempe 9y ago

DmenshunlAnlsis 9y ago

The majority of those planets are unsuited to anything we can imagine being alive, or only suitable for very simple unicellular life. Most of those plants are gas giants, or blazing hot gas giants. Some are rocky, but many of those are in orbits like Mercury, which would alternately bake and freeze them. Of course, part of the reason for this might be our detection methods, but as of now, we’re not finding. I hope like Earth, Venus, or Mars, while we find a lot of Jupiter’s. Maybe we’ll disocver that something like bacteria is ubiquitous, but that doesn’t imply much for our prospects of finding intelligent life. For all that we know life is common, but multicellular life is incredibly rare, or maybe it isn’t rare, but intelligent life is.

dugluak 9y ago
Wondering if giants like UY Scuti have planets and how big.
- mkempe 9y ago
  Red supergiants are necessarily no more than about 25 million years old; they keep ejecting a lot of material, forming nebulae; and then they end as supernovae. So, unlikely to have sufficient time and relative calm to form and maintain planets.
binalpatel 9y ago
There's this great article I came across a few weeks ago: https://www.theatlantic.com/science/archive/2018/03/human-existence-will-look-more-miraculous-the-longer-we-survive/554513/ https://www.theatlantic.com/science/archive/2018/03/human-ex... About how we may expect life to be more prevalent than it is because our own existence is so miraculous. Though the other side is - if the universe is so large, with so many planets, then there may be a chance that there's life out there that's just as incredibly lucky as us.
mkempe 9y ago
Are you arguing? I only mentioned life, not degrees of complexity of life. Ponder this: how early did life appear on Earth? what later cataclysmic events did it survive through the next several billions of years? how many living organisms are there on Earth at the moment? Finally, how you imagine life can exist or can appear is not equivalent to the facts of life on Earth, let alone in the entire Universe.
Brockenstein 9y ago
I've always liked to entertain the idea that highly advanced intelligent life is an evolutionary dead-end. After all if human beings drive themselves to extinction in the next 10,000 or 50,000 years what did our intelligence get us? It didn't enable us to survive better than other species. And what if a lot of intelligent species run into this problem? Where the level of knowledge and power they amass far outstrips what they've evolved to responsibly handle. And the result is intelligent species often manage to destroy themselves before they become wise enough to avoid that.
- magduf 9y ago
  It's interesting how insightful, thoughtful comments like this get modded down to hell on HN because they offend someone's religious beliefs. You're right, all evidence so far does point to us driving ourselves to extinction eventually, and the way things are going, it's likely to be a lot less than 10k years. And the idea of other intelligent species running into this problem isn't a new idea, it's long been a theory among searchers of extraterrestrial life, called the "great filter theory".
  - perl4ever 9y ago
    The idea that humanity is sinful and unworthy and the end of the world is near or at least inevitable has a very long and deep religious background. Yet these themes frequently crop up among those who are making a point of the inferiority of religious thought. I have a certain distaste for how much people apparently love to think in terms of labels rather than substance. I often think downvoting is overdone, though.
    - magduf 9y ago
      >The idea that humanity is sinful and unworthy and the end of the world is near or at least inevitable has a very long and deep religious background. Really? I haven't seen that at all. If you're talking about Christianity and the whole "end times" stuff, that's a little different: that isn't humanity "driving itself to extinction", that's some deity deciding that humans are bad and proactively eliminating them. I don't see that as the same thing at all. In fact, why I said this seemed to be offending peoples' religious ideals is that I think the idea of humans making themselves extinct directly counters this religious idea that a deity is the one in charge of humans' fate. To them, if humans are all eliminated, it can't possibly be because humans did it to themselves (as this is what they'd call a "humanistic" or "secular" idea), but could only happen because their deity made it so. And conversely, as long as humans are "good" enough (meaning they worship the deity enough, nothing about them wrecking their environment or obliterating themselves with nuclear weapons) then the deity will protect them from their own mistakes.
kwoff 9y ago
Just about "alternately bake and freeze" (no opinion on the rest): Mercury does spin (slowly, every 60 earth days; previously was thought to be tidally locked), but on the other hand it's not tilted with respect to the "ecliptic plane" (the plane in which the planets orbit around the sun). It turns out it has water ice at the poles: https://www.space.com/18687-water-ice-messenger-discovery.html https://www.space.com/18687-water-ice-messenger-discovery.ht...
perl4ever 9y ago
There are billions of galaxies though, so even if we are the only planet out of billions in our galaxy with complex life, there could still be billions of civilizations out there! For that matter, the typical planet with life could be too large and have too thick an atmosphere for space travel or astronomy and thus never have any idea the rest of the universe exists. That wouldn't necessarily mean life was limited to single cells.