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Why the hack do you assume it's abandoned? It can be full of lifeforms even and we are just not able to see them, talk to them, etc. Imo at this point any assum

by erikb 9y ago

Why the hack do you assume it's abandoned? It can be full of lifeforms even and we are just not able to see them, talk to them, etc. Imo at this point any assumption is closing in too much. We don't have a definiton of "life" that for sure would include extraterrestrial lifeforms that are not actors with masks in star trek, right?

paulmd 9y ago
Well, it's tumbling end-over-end which suggests that if it's a spaceship, it's no longer in control. The discussion around the possibility of it being a spaceship rests on the idea that long thin cigar-shaped objects are the most efficient way to travel in space because it minimizes your need for ablative protection from interstellar dust/etc. But if you're tumbling end-over-end you've thrown that advantage away, so presumably that's not a thing you would intentionally do. And if you are assuming that this spaceship has shields or whatever, then there is no reason they would be restricted to a cylindrical shape. It could be a discarded booster stage or fuel tank, of course. Maybe they were trying to drop it into the sun and missed. Or a a mass-driver shot (maybe they finally took care of that pesky Russell's Teapot for us...) The presumptive conclusion is of course that it's a natural phenomenon, but it sure is a weird object, and unless we can find a way to catch it (or any future objects) we will never know. Maybe a starshot probe could catch it?
- deleted 9y ago
  [deleted]
- lawlessone 9y ago
  How is it tumbling? Could that provide a force to simulate gravity?
- tfha 9y ago
  Wouldn't tumbling a spaceship give you some basic gravity? Isn't that a desired outcome?
  - valuearb 9y ago
    It appears to be tumbling end over end. It's possible that it's spinning end over end in order to generate artificial gravity at the ends, but this contradicts one basic design star-ship design principle. You build a long narrow ship so you can have heaviest particle shielding only at the narrow front to reduce shielding mass required. But maybe since it's traveling so slow, they didn't need any excessive shielding. Maybe they have super light super strong shielding technologies. That itself would seem to be contradictory, given you'd think they'd have access to far more energy than would produce only 40 km/sec velocity.
- semi-extrinsic 9y ago
  The really interesting prospect raised in that Reddit thread is that while the velocity is likely wrong for an interstellar spaceship, it could be just right for the spent and discarded deceleration stage of an interstellar spaceship. In which case the spaceship would be arriving some time later...
  - cjsuk 9y ago
    I like this explanation best, as long as they're friendly.
  - api 9y ago
    Watch some rocket separations. Usually they end up tumbling.
  - valuearb 9y ago
    It's already passed pedigree with the sun. It is traveling slowly enough that if it's a discarded stage the spaceship should already be here.
    - semi-extrinsic 9y ago
      How do you know that, without knowing the non-booster-assisted deceleration rate of the spaceship? (Presumably the hypothetical ship separated from the booster when that was out of fuel, and then the ship continued decelerating on its own to get to a velocity congruent with a stable orbit in our system).
      - valuearb 9y ago
        The object is traveling at 26Km/sec, earth is orbiting at 30 Km/sec. To generate a "stable orbit" is a matter of maneuvering at that velocity. So it's really unlikely that the parent ship is traveling much slower than the discarded booster, and so it's arrival is unlikely to be much later.
    - xelxebar 9y ago
      I'm assuming autocorrect helpfully fixed "perigee" to "pedigree" for you. It's a nice little malapropism though. Anyway, minor point but "perigee" usually means closest approach to Earth; "-gee" is from the Greek for Earth (as is "geo-"). In the case of the sun, we have the word "perihelion", and for generic orbits around an object, you generally hear "periapsis". And just for completeness, I'll mention that the counterpoint to periapsis is apoapsis, with apogee and aphelion being the obvious specializations. There are more words in this pattern for various different objects; Wikipædia has all the gory details: https://en.m.wikipedia.org/wiki/Apsis https://en.m.wikipedia.org/wiki/Apsis
- clort 9y ago
  I can counter this concept about the tumbling meaning it cannot be an active vessel thus: The vessel proceeds in a length aligned manner during its long interstellar traverse under the supervision of an AI which does not care about the time taken and when it nears a star system, its occupants are woken (or created) and a small bit of reaction mass is emitted in order to rotate and provide gravity for them. As it leaves the system, the occupants can go back to sleep and the rotation is halted while it proceeds to the next system. I'm not saying that its a vessel, just saying that if it is one, then it presumably has some level of active ability, which could include the above. Thats not so far from Rama, actually.
  - deleted 9y ago
    [deleted]
  - Santosh83 9y ago
    But it could rotate about its long axis for artificial gravity no? Seems more "natural"...
    - clort 9y ago
      Coriolis effects would be more pronounced with a smaller radius? Also, the rotational speed would need to be a lot higher to get the same gravitational effect, so the effects might end up many times greater. Its difficult to suggest what conditions these hypothetical aliens would need, of course..
    - valuearb 9y ago
      The reddit thread has the following calculation. "At a spin rate of 1 rotation every 7.3 hours and a radius of 200 metres, an object on the inner surface of the very end of the "spaceship" would experience gravity at 0.000001g" That's really far to small to simulate any type of artificial gravity.
      - AdamJacobMuller 9y ago
        0.000001g doesn't even seem like its enough to make liquids pourable.
zodPod 9y ago
This has always been my argument too! I understand that scientists want to start with what they know to narrow stuff down but is it not entirely possible that there's life on a planet that just doesn't work like ours? Obviously the organic structures that we're familiar with need a certain series of parameters to survive but that doesn't mean that any other kind of object couldn't end up being a sentient being.

by erikb 9y ago

paulmd 9y ago

Well, it's tumbling end-over-end which suggests that if it's a spaceship, it's no longer in control. The discussion around the possibility of it being a spaceship rests on the idea that long thin cigar-shaped objects are the most efficient way to travel in space because it minimizes your need for ablative protection from interstellar dust/etc. But if you're tumbling end-over-end you've thrown that advantage away, so presumably that's not a thing you would intentionally do. And if you are assuming that this spaceship has shields or whatever, then there is no reason they would be restricted to a cylindrical shape. It could be a discarded booster stage or fuel tank, of course. Maybe they were trying to drop it into the sun and missed. Or a a mass-driver shot (maybe they finally took care of that pesky Russell's Teapot for us...) The presumptive conclusion is of course that it's a natural phenomenon, but it sure is a weird object, and unless we can find a way to catch it (or any future objects) we will never know. Maybe a starshot probe could catch it?

deleted 9y ago
[deleted]
lawlessone 9y ago
How is it tumbling? Could that provide a force to simulate gravity?
tfha 9y ago
Wouldn't tumbling a spaceship give you some basic gravity? Isn't that a desired outcome?
- valuearb 9y ago
  It appears to be tumbling end over end. It's possible that it's spinning end over end in order to generate artificial gravity at the ends, but this contradicts one basic design star-ship design principle. You build a long narrow ship so you can have heaviest particle shielding only at the narrow front to reduce shielding mass required. But maybe since it's traveling so slow, they didn't need any excessive shielding. Maybe they have super light super strong shielding technologies. That itself would seem to be contradictory, given you'd think they'd have access to far more energy than would produce only 40 km/sec velocity.
semi-extrinsic 9y ago
The really interesting prospect raised in that Reddit thread is that while the velocity is likely wrong for an interstellar spaceship, it could be just right for the spent and discarded deceleration stage of an interstellar spaceship. In which case the spaceship would be arriving some time later...
- cjsuk 9y ago
  I like this explanation best, as long as they're friendly.
- api 9y ago
  Watch some rocket separations. Usually they end up tumbling.
- valuearb 9y ago
  It's already passed pedigree with the sun. It is traveling slowly enough that if it's a discarded stage the spaceship should already be here.
  - semi-extrinsic 9y ago
    How do you know that, without knowing the non-booster-assisted deceleration rate of the spaceship? (Presumably the hypothetical ship separated from the booster when that was out of fuel, and then the ship continued decelerating on its own to get to a velocity congruent with a stable orbit in our system).
    - valuearb 9y ago
      The object is traveling at 26Km/sec, earth is orbiting at 30 Km/sec. To generate a "stable orbit" is a matter of maneuvering at that velocity. So it's really unlikely that the parent ship is traveling much slower than the discarded booster, and so it's arrival is unlikely to be much later.
  - xelxebar 9y ago
    I'm assuming autocorrect helpfully fixed "perigee" to "pedigree" for you. It's a nice little malapropism though. Anyway, minor point but "perigee" usually means closest approach to Earth; "-gee" is from the Greek for Earth (as is "geo-"). In the case of the sun, we have the word "perihelion", and for generic orbits around an object, you generally hear "periapsis". And just for completeness, I'll mention that the counterpoint to periapsis is apoapsis, with apogee and aphelion being the obvious specializations. There are more words in this pattern for various different objects; Wikipædia has all the gory details: https://en.m.wikipedia.org/wiki/Apsis https://en.m.wikipedia.org/wiki/Apsis
clort 9y ago
I can counter this concept about the tumbling meaning it cannot be an active vessel thus: The vessel proceeds in a length aligned manner during its long interstellar traverse under the supervision of an AI which does not care about the time taken and when it nears a star system, its occupants are woken (or created) and a small bit of reaction mass is emitted in order to rotate and provide gravity for them. As it leaves the system, the occupants can go back to sleep and the rotation is halted while it proceeds to the next system. I'm not saying that its a vessel, just saying that if it is one, then it presumably has some level of active ability, which could include the above. Thats not so far from Rama, actually.
- deleted 9y ago
  [deleted]
- Santosh83 9y ago
  But it could rotate about its long axis for artificial gravity no? Seems more "natural"...
  - clort 9y ago
    Coriolis effects would be more pronounced with a smaller radius? Also, the rotational speed would need to be a lot higher to get the same gravitational effect, so the effects might end up many times greater. Its difficult to suggest what conditions these hypothetical aliens would need, of course..
  - valuearb 9y ago
    The reddit thread has the following calculation. "At a spin rate of 1 rotation every 7.3 hours and a radius of 200 metres, an object on the inner surface of the very end of the "spaceship" would experience gravity at 0.000001g" That's really far to small to simulate any type of artificial gravity.
    - AdamJacobMuller 9y ago
      0.000001g doesn't even seem like its enough to make liquids pourable.

zodPod 9y ago

This has always been my argument too! I understand that scientists want to start with what they know to narrow stuff down but is it not entirely possible that there's life on a planet that just doesn't work like ours? Obviously the organic structures that we're familiar with need a certain series of parameters to survive but that doesn't mean that any other kind of object couldn't end up being a sentient being.