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Mystery of interstellar visitor 'Oumuamua gets trickier

scientificamerican.com

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Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#201

Post by Normille »

mcculley wrote: post #114
Izkata wrote: post #89

Earlier quoted context omitted.

Down in the explanations, a triangle: > Similar regular shapes were created in the laboratory when a circular tank of liquid was rotated at different speeds at its centre and periphery. The most common shape was six sided, but shapes with three to eight sides were also produced.

Natural processes can make lots of structures that look artificial. See Giant's Causeway: https://en.wikipedia.org/wiki/Giant%27s_Causeway

"Worth seeing but not worth going to see" –Charles Dickens

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#202

Post by gus_massa »

teh_klev wrote: post #194
gus_massa wrote: post #137

Earlier quoted context omitted.

The same guy has published the idea of the solar sail in a paper (or preprint?). Solar sails are his research topic. The calculations that a solar sail can survive an interstellar travel are probably ok. The evidence that the solar sail is the most likely explanation is very weak.

Oh sure, and I agree maybe and many theories are likely wrong, but the point of my response was that the post is perfectly valid here on HN because it introduces discussion points such as yours...i.e. it's gratifying our intellectual curiosity (and arguments for and against) despite Loeb's interests...i.e. (sorry) solar sailed interstellar spacecraft. And this is why we're here.

We probably agree.

My guess is that he really knows how much radiation is received by a big block of Hydrogen ice in the middle of space, but I always feel that his opinion about other explanations are biased. I think it's a good submission, but I'd be cautious.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#203

Post by natmaka »

landryraccoon wrote: post #145
throwaway316943 wrote: post #116

Earlier quoted context omitted.

I’m not sure that reasoning holds up. There’s no reason to believe that “mushy human emotional ideas” are not the norm. There’s no data to support that claim since humanity is the only example we have of intelligence. So for the sake of the argument I’m going to define alien intelligence as similar to human intelligence. I’d also inquire what the point of having a Von Neumann probe consume all of a system would be? I…

Consuming all available resources and destroying all competing life doesn’t make sense even for us as the dominant species of a single planet. What’s the evidence that wholesale environmental destruction is a good idea on a galactic scale if it’s already known to be a terrible idea on a planetary scale?

We commonly consume most available resources and try hard to destroy much competing life... in a given part of what we consider as our territory (our planet), for example when establishing then maintaining/growing a city.

Earth may be part of what an alien species consider as their territory.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#204

Post by p1necone »

mcculley wrote: post #114
Izkata wrote: post #89

Earlier quoted context omitted.

Down in the explanations, a triangle: > Similar regular shapes were created in the laboratory when a circular tank of liquid was rotated at different speeds at its centre and periphery. The most common shape was six sided, but shapes with three to eight sides were also produced.

Natural processes can make lots of structures that look artificial. See Giant's Causeway: https://en.wikipedia.org/wiki/Giant%27s_Causeway

And pyrite (fool's gold) crystals: https://en.wikipedia.org/wiki/Pyrite

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#205

Post by hinkley »

kentonv wrote: post #47

My pet theory (which is not intended to be taken too seriously) is that it is indeed a discarded light sail, and that light sail in particular was used to transport a Von Neumann probe which detached at some point after the object entered our solar system but before we first observed it. This detachment, in addition to leaving the sail tumbling, would have changed its trajectory, meaning our estimation of which direc…

Sundiver:

Egg sac for a species of star-dwelling creatures. Hopefully they didn't arrive from Betelgeuse...

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#206

Post by misanthropian00 »

sandworm101 wrote: post #7

If we put half the energy we use up arguing about Oumuamua into detecting more interstellar objects we would have the data to end this debate. I'm a fan of the pragmatic mathematical approach. This was the first thing detected. The chances that the first result is also any sort of outlier are very slim. Detect and track some more of these objects. I'd bet good money that Oumuamua's motion is very explainable once we…

We can just build a ship to chase down Oumuamua and end this debate. If it is no longer where a natural object with a passive trajectory should be well we have our answer. If it is there we can take a close look.

THe fact that another interstellar object was discovered so quickly made me lose hope in the artifact or ship idea though. Part of the appeal was the idea that interstellar meteors were not really a thing, but apparently they are.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#207

Post by nafey »

kentonv wrote: post #175
nafey wrote: post #136

Earlier quoted context omitted.

What you are missing is that technological advancement can accelerate exponentially. Couple this fact nothing can move faster than light. This means if you don't stamp out alien life as soon as you encounter it then the next time you come back they might already have achieved technological parity with you. And they might not be as forgiving as you are. This means you have to hide and you have to exterminate any alien…

> the next time you come back This is imagining that space exploration is done by human-like entities that have discrete physical bodies and slow reproduction rates. They come to a place, check it out, and move on. AI-driven Von Neumann probes would operate very differently. They arrive, and they settle and replicate. Eventually they send out new probes. But they don't leave once they have arrived. There's never any…

Okay the point is you won't wait to mobilize against alien life. Assuming that technology increases exponentially it will be prudent to launch as soon as you detect the alien life even if it takes you a hundred years to reach the destination.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#209

Post by misanthropian00 »

rbanffy wrote: post #87

Can't we build a probe that can reach it? What's the fastest we can launch a ton of equipment in Oumuamua's direction?

A nuclear powered probe could catch it assuming of course that it continues on a passive trajectory and doesn't change course. Obviously the longer we wait the harder it will get though.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#210

Post by misanthropian00 »

craigching wrote: post #22
person_of_color wrote: post #17

I don't get it. Why don't we image this thing directly?

We have! https://en.m.wikipedia.org/wiki/ʻOumuamua But it’s small and moving away from us fast. We couldn’t build anything in time that could catch up to it and image it closer.

A nuclear pulse vehicle could catch it easily even if we waited 50 years to launch. Its slow speed is actually the best argument against it really being an active spacecraft because even we could do better. Much better. It could be part of a swarm of millions of low tech ships assembled from local resources though.
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