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‘Oumuamua: A Hydrogen Iceberg?
- The_rationalist 6y agoBetteridge law strike again
- happytoexplain 6y agoDoes it? The article seems to bear out the headline: That the matter is an active question.
- The_rationalist 6y agoAccording to 2020 in science (the Wikipedia article) Astronomers report that the interstellar object ʻOumuamua (1I/2017 U1) is not likely to have been composed of frozen hydrogen which had been proposed earlier; the compositional nature of the object continues to be unknown.[127][128] So?
- joe_the_user 6y agoThere are so many questions and so little data. Oumuamua as the space junk of an extra-terrestial society naturally appeals to me even if it's not a legitimate guess (I understand that technological artifact is only a legitimate guess if all other options are exhausted, Ok). One question would be whether the "axiom of mediocrity" implies that Oumuamua's flyby of the sun was not the object's first flyby. Logically, if objects that can survive a million encounter with stars exist, they would seem a million times more common than objects that could survive one. Which would also be why you'd be more likely to find space junk than a working space craft.
- perl4ever 6y ago>Logically, if objects that can survive a million encounter with stars exist, they would seem a million times more common than objects that could survive one That doesn't seem quite right. Wouldn't they be a million times more common relative to their overall proportion in the universe? Durable objects could be, say, one in a million, cancelling out the probability.
- joe_the_user 6y agoI mean "all else being equal", of course all else might not be equal. The thing is that I don't think objects need to be that durable to survive for a long time in space.
- beamatronic 6y agoWould an advanced star-faring society make a spacecraft out of anything other than objects that are already moving? Asteroids and such. This way you don’t have to lift any mass out of a gravity well.
- CarbyAu 6y agoI absolutely don't know much, so question here: Why is it assumed that a "star faring society" must originate from a place of significant gravity? I can understand heat and some way to gather the required chemicals (primordial ooze) together is required. But does it require much gravity really?
- zdragnar 6y agoWell, life as we know it relies on carbon (energy storage), oxygen (energy activation) and liquid water (oxygen and chemical transfer). Setting aside the quandary of sufficient mass to support life evolution and development from 0 => faster-than-light (or some other interstellar) travel, there's the problem of liquid water. The lower the pressure it is under, the more quickly it will evaporate or even boil. Not only that, but dissolved gasses within the water will also boil out. So, we're left with either imagining some means of having a large quantity and volume of mass configured in a way that maintains pressure without gravity, OR identifying an alternative set of chemicals for the properties that carbon, oxygen and water currently fulfill. Water is especially useful due to being a dipole, and there are several other known compounds that are as well, but they are significantly more complex. I'm definitely not super informed in this area, but my understanding is there really aren't other options that are readily found in nature in regular quantities.
- CarbyAu 6y agoOh! Thank you so much for that, my mind figuratively went Ding! While I mentioned "primordial ooze" I was thinking of ooze as a random assortment of elements we may or may not know much about as my "keep your mind open to possibilities" attitude left it vague. But by defining the Ooze(especially with probabilities of elements in the universe) you define the requirements - mainly liquid water. And then conditions by which you have to keep a blob of water together and liquid in the harshness of space are more apparent. As you say, in theory you could come up with weird physical structures to keep water liquid and together; or some other chemistry to fulfill the same roles. But in practice, probability says "Liquid Water + Gravity".
- garmaine 6y ago> Logically, if objects that can survive a million encounter with stars exist, they would seem a million times more common than objects that could survive one. That’s not how the statistics work.
- mellosouls 6y agoWorth noting co-author Avi Loeb produced the headline-making Alien-origin hypothesis paper of a couple of years ago. i.e. context: the paper summarised in the OP is his counter to a "hydrogen iceberg" challenge/alternative to his original "alien" paper. https://www.wikipedia.org/wiki/Avi_Loeb#%CA%BBOumuamua https://www.wikipedia.org/wiki/Avi_Loeb#%CA%BBOumuamua
- s1artibartfast 6y agoPaper: https://iopscience.iop.org/article/10.3847/2041-8213/abab0c/pdf https://iopscience.iop.org/article/10.3847/2041-8213/abab0c/...
- withinboredom 6y agoIn a short story I'm writing, things like this are sent every few hundred years to stars with life. Your species is invited to the galactic community once you can spot it, catch it, and utilize the tech without killing yourself.
- ChuckMcM 6y agolove it! Send me a link to my email (it's in my profile) when you finish it.
- pokoleo 6y agoThis sounds suspiciously like some concepts involved in the three body problem. I'd love to read it.
- Erik816 6y agoYou may want to read Rendezvous with Rama by Arthur C. Clarke. That's basically the plot.
- walrus01 6y agoAs I recall the first two books are pretty good, after that the novel series kind of goes off the rails.
- interfixus 6y agoAs I recall, the original novel is vintage Clarke of the better kind, and then the rest are [co-]authored by some entity named Gentry Lee and basically unreadable.
- walrus01 6y agoYou are right... In this case I think it might be a good example of how serious scientists are not always the best fiction writers. https://en.wikipedia.org/wiki/Gentry_Lee https://en.wikipedia.org/wiki/Gentry_Lee
- credit_guy 6y agoThe main question here is not whether Oumuamua was a hydrogen iceberg, but rather whether hydrogen icebergs are possible. Solid hydrogen is terribly difficult to study [1]. Solid hydrogen does not exist at pressures below 100 GPa (i.e. 1 million times higher than the atmospheric pressure). These pressures occur deep inside Jupiter, for example, but how do you get the "hydrogen iceberg" free? [1] https://en.wikipedia.org/wiki/Solid_hydrogen https://en.wikipedia.org/wiki/Solid_hydrogen