[HN Gopher] Rogue Worlds Throw Planetary Ideas Out of Orbit
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       Rogue Worlds Throw Planetary Ideas Out of Orbit
        
       Author : rbanffy
       Score  : 38 points
       Date   : 2024-01-13 15:02 UTC (7 hours ago)
        
 (HTM) web link (www.quantamagazine.org)
 (TXT) w3m dump (www.quantamagazine.org)
        
       | thriftwy wrote:
       | Maybe the actual sentient life in universe lives deep within
       | those rogue worlds. It is also trivial for them to hop worlds -
       | either wait for a flyby or put nuclear reactor on a blob of ices
       | and drive away. They use stars as beacons and can't imagine
       | anyone willing to live directly in the bonfire.
       | 
       | If they are using laser communication, our Sun will likely drown
       | any signals in noise.
        
         | Kalium wrote:
         | It's a neat possibility for a science fiction author. I've seen
         | the idea used a couple of times.
         | 
         | One of the key questions for life is where all the external
         | energy to overcome entropy comes from. Being close to a star
         | without being fried by it is a good way to accomplish this, but
         | there are fewer easy energy sources on a rogue planet.
        
           | pavel_lishin wrote:
           | There's a couple of options; the most obvious one is
           | radiothermal heating from radioactive elements in the core,
           | or even just remnant heat from the core slowly working its
           | way up. And if there are pairs of these, then their orbits
           | might be keeping their cores moving and warm due to tides.
        
         | klyrs wrote:
         | "Deep within" gas giants, physics gets incredibly weird due to
         | the pressures involved. Life arising on a moon seems more
         | likely to me.
        
           | thriftwy wrote:
           | I was thinking more of tectonically active ice giants with
           | large oceans under the ice shield. To explore space, you will
           | have to drill your way out first.
        
         | WJW wrote:
         | > It is also trivial for them to hop worlds - either wait for a
         | flyby
         | 
         | How so? The gravity well of a gas/ice giant would be absolutely
         | massive. Even if you could get away from the planet, waiting
         | for a flyby in interstellar space could well take millions of
         | years between encounters.
        
       | throwaway4aday wrote:
       | If there are that many Jupiter+ sized objects then how many rocky
       | planet sized ones are there? Would they even be detectable via
       | infrared or gravitational lensing?
        
         | api wrote:
         | I had a thought a while back about interstellar flight:
         | 
         | If there are a lot of massive objects out there (rogue planets,
         | maybe primordial black holes) then these could be used to aid
         | acceleration and deceleration through gravity assist and the
         | Oberth effect. (The latter describes how you get more
         | acceleration thrusting near a massive body.)
         | 
         | You could fly along with an ultra sensitive gravity telescope /
         | sensor and hop between massive objects.
         | 
         | You could also perhaps harvest propellant from some of these.
         | 
         | Long duration interstellar flight would be easier if the space
         | between solar systems was not as empty as we think.
        
           | pavel_lishin wrote:
           | I think gravity assists only really make sense when you're
           | talking about orbits - a solitary object floating through the
           | void won't help you accelerate, though it can help you make a
           | cheaper "turn" in space.
        
             | api wrote:
             | Doesn't the Oberth effect still work?
        
         | throw83485 wrote:
         | Not many. Gas giants can form on their own, they have
         | composition similar to interstellar material (mostly hydrogen
         | and helium).
         | 
         | Rocky planets can only form in proto disks around newly forming
         | stars. Heavier materials (carbon and up) are concentrated this
         | way.
        
       | jpm_sd wrote:
       | Haha, I love uncensored quotes from scientists.
       | 
       | > "We know there's a whole bunch of crap between stars," Raymond
       | said
        
       | pavel_lishin wrote:
       | I think I commented this the last time it was posted, but I'm
       | vain enough to post it again:
       | 
       | > _Rather than answering this question, the JWST observation adds
       | to the mystery: The telescope's infrared eye found that dozens of
       | the worlds appear to be in pairs orbiting each other -- a
       | puzzling arrangement that, if confirmed, would defy
       | expectations._
       | 
       | > _"We're missing something," said Nienke van der Marel, a
       | researcher who studies planet formation at Leiden Observatory in
       | the Netherlands, "and we don't know what it is."_
       | 
       | > _These improbable duos cannot be easily explained by any known
       | formation theories of either stars or free-floating planets. But
       | within a week of the JWST announcement, researchers published a
       | daring new idea describing how giant planets might be ejected
       | from their home system in pairs -- an event most researchers had
       | thought all but impossible. Whether or not the proposal can fully
       | account for the entire zoo of dim, starless worlds remains to be
       | seen._
       | 
       | Here's my scifi take on things: these pairworlds are engineered.
       | 
       | The whole "the galaxy should be settled by now" question has an
       | answer: the galaxy is settled, but the people living there don't
       | care to live close to suns - they prefer to live in planetary
       | binaries sailing through the interstellar void, using the
       | gravitational energy of the orbit to keep the cores of the
       | planets in flux, generating internal heat for energy.
       | 
       | My understanding from the article is that these are mostly gas-
       | giant, Jupiter-like pairs - so maybe these creatures live in
       | those types of planets' atmospheres, and have developed the
       | technology to pair up gas giant worlds and go traveling.
       | 
       | Maybe that's how most sentient life does it! Maybe we're half a
       | million years away from our local Gas Giant Natives packing up
       | their shit (Jupiter & Saturn, Neptune & Uranus) and fucking off
       | to join the greater galactic community, leaving us in the dust to
       | be clobbered by asteroids and other orbital disasters.
        
         | thegrim33 wrote:
         | But why? It's much easier and cheaper to just leech off a star
         | for energy. Your theory also doesn't explain why "most
         | intelligent life" would choose that approach rather than only a
         | subset, with the rest staying around stars like normal.
        
         | m4rtink wrote:
         | Single gas giant & moons would easier - see how it keeps Io and
         | possibly other moons warm. :)
        
         | WJW wrote:
         | I personally don't think this is very likely (main question:
         | how do they actually manage to get those planets paired and
         | ejected in the first place??? The energy requirements are quite
         | literally astronomical) but it is a very cool idea.
         | 
         | Would make a great novel.
        
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