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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

#161

Post by microtherion »

doytch wrote: post #144
edgyquant wrote: post #125

Earlier quoted context omitted.

Why would this not be a good domain for image recognition?

If you’re trying to classify images as whether or not they contain something, you need a bunch of images that you already know don’t contain the thing (got it), and a bunch of images that you already know /do/ contain the thing. We lack the latter, so there’s nothing for the algorithm to learn based on.

But this is not the only way you can deploy machine learning techniques. You could deploy unsupervised learning to first learn what visual features are common in such images, and then successively refine until you end up with a set of images containing very rare phenomena. That could give human evaluators then a considerable head start.

In fact, this idea seems so obvious that it must have been tried already…

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#163

Post by jrussino »

monkeypizza wrote: post #123
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…

Excellent page discussing the physics of colonizing mercury: https://einstein-schrodinger.com/mercury_colony.html "Colonization of Mercury appears to be a very real and practical possibility, whereas colonization of Mars or the other planets, moons or asteroids is really more in the realm of fantasy." A big advantage of Mercury over mars is higher light intensity: "One very important advantage is the high solar light…

Cool! Personally, I like the idea of building a Dyson swarm out of it (sorry Mercury!) https://www.youtube.com/watch?v=pP44EPBMb8A

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#164

Post by wffurr »

KozmoNau7 wrote: post #124
kentonv wrote: post #106

Earlier quoted context omitted.

While it's entirely possible they'd have a good reason to be stealthy, I don't think it's likely to be anything we've thought of. The Prime Directive is a mushy human emotional idea, not something that makes any logical sense for a space-faring civilization to follow. If there's any competition out there among space-faring civilizations, none of them are going to tie their hands behind their backs by refusing to touc…

No, they're currently terraforming Earth¹ to have a CO2 level that is better for their metabolisms. ¹ through influencing politicians and the rich and powerful to keep poisoning the Earth with extreme pollution.

The politicians and rich and powerful are the aliens.

https://www.google.com/amp/s/www.indiewire.com/2014/10/john-...

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#165

Post by Nicksil »

coolspot wrote: post #122
themgt wrote: post #10

Earlier quoted context omitted.

> 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 This HN comment was just the motivation I needed to get off my computer and rededicate myself to polishing eighteen 1.32m gold-plated beryllium hexagonal mirror segments.

I know you are joking, but a second interstellar object after the Oumuamua was discovered using a 0.65m DIY telescope built by Gennadiy Borisov. https://en.m.wikipedia.org/wiki/2I/Borisov

https://en.wikipedia.org/wiki/2I/Borisov

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#166

Post by Ancalagon »

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…

I thought one of the main issues arising with the "alien tech" theory is that this object was moving too slowly to ever make it to our solar system in any timely manner? Thats not to say it couldn't have slowed down prior to us finding it, but if its a detached light sail why wouldn't the alien probe have detached it at higher speeds to have less mass to slow down?

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#167

Post by jonathankoren »

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…

I thought you were going to say that’s the the discarded lightsail from a probe that’s thousands of years old, and all we were never the target of it. It’s just space trash now.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#168

Post by Nicksil »

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.

https://en.wikipedia.org/wiki/ʻOumuamua

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#169

Post by petascale »

kristianp wrote: post #162

Why does it have to be a hydrogen snowball? Because no tail was detected that would have indicated a dirty methane-etc snowball? What about an stony asteroid-like object?

Quoting the article:

"While a few other substances (like solid neon) could potentially explain the coma-free acceleration, hydrogen was the best match for the data."

It doesn't have to be hydrogen. But to explain acceleration from solar heating it does need outgassing, and the outgassing has to be in a form that we can't detect (no comet tail). Stone won't have much (or any) of that.

Re: Mystery of interstellar visitor 'Oumuamua gets trickier

#170

Post by edgyquant »

microtherion wrote: post #161
doytch wrote: post #144

Earlier quoted context omitted.

If you’re trying to classify images as whether or not they contain something, you need a bunch of images that you already know don’t contain the thing (got it), and a bunch of images that you already know /do/ contain the thing. We lack the latter, so there’s nothing for the algorithm to learn based on.

But this is not the only way you can deploy machine learning techniques. You could deploy unsupervised learning to first learn what visual features are common in such images, and then successively refine until you end up with a set of images containing very rare phenomena. That could give human evaluators then a considerable head start. In fact, this idea seems so obvious that it must have been tried already…

Has it? I'm very interested in using data science for astronomy as it was my childhood passion and I'd love to read anything you can provide.
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