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'Mathematically perfect' star system being investigated for potential alien tech

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Re: 'Mathematically perfect' star system being investigated for potential alien tech

#261

Post by Petersipoi »

Karrot_Kream wrote: post #253
beambot wrote: post #146

Earlier quoted context omitted.

Why would it be an equally good chance that only one exists?

It depends on what priors you put on things like planetary size and orbital periods. If your prior is uniform, then it is just as likely for this configuration to exist as any other and because the probability mass is uniformly distributed (e.g. every outcome is equally likely) then there's probably only one of it.

> there's probably only one of it.

I fail to see how you arrived at this conclusion give the text that precedes it.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#262

Post by roenxi »

stronglikedan wrote: post #127
NooneAtAll3 wrote: post #121

Reminds me of Titius–Bode law[1], where simple equation correctly gave orbits of all the known planets, while predicting one more in asteroid belt and correct distance to Uranus. Only was considered disproven when Neptune didn't work. I would not trust these relations even existing (other than by pure chance). Even less I'd trust any intelligent design behind it [1] https://en.wikipedia.org/wiki/Titius%E2%80%93Bode_l…

> other than by pure chance Barring intelligent design, there's an extremely good chance that at least one of these systems exist, and an equally good chance that only one exists, and we're just lucky enough to have observed it.

And with mathematically significant orbits, there is also the chance that some process stabilises to them which increases the chance of seeing them significantly. It is like being impressed by fractal designs in plants. The plant isn't intelligent and doesn't know about fractals, it is just that repeating patterns are easier for evolution to stabilise on.

But hey, if the job is staring at planets they may as well stare at these interesting planets.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#263

Post by maweki »

Karrot_Kream wrote: post #253
beambot wrote: post #146

Earlier quoted context omitted.

Why would it be an equally good chance that only one exists?

It depends on what priors you put on things like planetary size and orbital periods. If your prior is uniform, then it is just as likely for this configuration to exist as any other and because the probability mass is uniformly distributed (e.g. every outcome is equally likely) then there's probably only one of it.

Every value being equally likely does not mean we expect every value to appear only once.

Throw a d6 seven times and we expect a configuration to come up twice, even though the distribution is uniform.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#264

Post by gtirloni »

awskinda wrote: post #174
z3phyr wrote: post #123

Earlier quoted context omitted.

Its base64. Its not an encryption.

Sure, but it’s pretty amazing to me that ChatGPT didn’t just hallucinate a response to a generic request to decode a string. It recognized the string as base64, wrote a valid program to decode it, and returned the correct response. Maybe I’m just old and amazed, but that seems pretty cool (terrifying?) to me.

What's terrifying about it? Serious question. Lately people are associating all sorts of doom to LLMs so I'm curious to understand.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#265

Post by lisper »

aylmao wrote: post #211
lisper wrote: post #181

Earlier quoted context omitted.

> My theory is that its darkness is down to the fact that the civilisation there has figured out a way to harness solar energy to near 100% capacity, along the lines of a Dyson sphere [1]. Very unlikely, in light of the fact that "the air of this planet is as hot as lava".

I wonder how temperature is measured for an object this far away. If it's calculated based on the expected energy absorption of a planet with this level of reflectivity, the measurement would be wrong anyway, assuming alien tech. Instead of the energy being absorbed as heat by the planet, it'd instead be stored in some other form or used for interstellar travel, construction etc, right?

> I wonder how temperature is measured for an object this far away.

From the black body radiation spectrum.

[UPDATE] It turns out that the temperature of TrEs-2b is not directly measured, but extrapolated from other measurements (at least according to Wikipedia - https://en.wikipedia.org/wiki/TrES-2b#Temperature ).

> Instead of the energy being absorbed as heat by the planet, it'd instead be stored in some other form or used for interstellar travel, construction etc, right?

Yes, exactly. So the only possible impact of energy harvesting would be to make the planet cooler than it otherwise would be. How much cooler depends on the efficiency of the harvesting. But one way or another, an extremely hot planet is very unlikely to harbor an advanced civilization.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#266

Post by lisper »

mianos wrote: post #222
lisper wrote: post #191

Earlier quoted context omitted.

No. The temperature of the atmosphere has nothing to do with whether or not aliens are harvesting the energy. At equilibrium, all of the incoming energy has to get radiated back out into space eventually whether there are aliens harvesting that energy or not. The problem with an atmosphere hotter than lava is that very few materials are solid at those temperatures, and it's hard to imagine how a civilization could bu…

Those liquid green aliens are probably looking at us and going "how can life exist with so much matter in solid form and so cold”.

Well, they have a point. This is why the presence of liquid water on earth is a big deal.

But when the rocks start to melt you have problems.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#267

Post by gtirloni »

awskinda wrote: post #98
pavel_lishin wrote: post #74

Earlier quoted context omitted.

Good idea! Um9iZXJ0IEogU2F3eWVyIC0gU3RhcnBsZXgK

Holy cow. ChatGPT 4 actually decoded this. It went into analysis mode, wrote some python, ran it, and gave the correct answer.

Did you ask it to create code for this?

Me: Um9iZXJ0IEogU2F3eWVyIC0gU3RhcnBsZXgK ChatGPT: "xxxx" is a science fiction novel by Robert x xxxx. It explores themes of discovery, the nature of the universe, and the potential for cooperation among diverse life forms. The story revolves around a space station, xxxxxx, and its crew as they encounter mysterious wormholes, alien species, and cosmic phenomena, challenging their understanding of the universe and their place within it.

ps. I don't know what is there to spoil by sharing a book title but whatever :)

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#268

Post by thaumasiotes »

maweki wrote: post #263
Karrot_Kream wrote: post #253

Earlier quoted context omitted.

It depends on what priors you put on things like planetary size and orbital periods. If your prior is uniform, then it is just as likely for this configuration to exist as any other and because the probability mass is uniformly distributed (e.g. every outcome is equally likely) then there's probably only one of it.

Every value being equally likely does not mean we expect every value to appear only once. Throw a d6 seven times and we expect a configuration to come up twice, even though the distribution is uniform.

Throw a d6 seven times and the pigeonhole principle requires that a configuration will come up twice. The example is weakening your argument; it's still true that if you throw a d6 five times, you expect a configuration to come up twice.

A better example wouldn't involve a probability that can achieve 1; maybe ask about the probability of rolling a 3, or of rolling another 3 given you've already observed one 3.

None of those will match the comment above; it isn't well posed.

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#269

Post by wolverine876 »

wolverine876 wrote: post #218
onetimeuse92304 wrote: post #101

I think the authors do not understand how planetary resonances work and how precise (or imprecise) the orbits need to be for the resonance to hold. Resonances are very common. We have lots of resonances in our Solar system in all different places between bodies. For the resonance to be stable, two bodies do not need to have mathematically precise orbits in relation to each other. There is quite a wide margin for erro…

> I think the authors do not understand ... The authors are scientists from SETI, Berkeley, Oxford, and NASA. Probably they understand anything you (or I) understand about the topic, and quite a bit more. (A funny phenomenon is that if they posted here, starting their comment with 'SETI researcher here ...', we would all listen to them and ask questions. If they 'post' a paper to a journal, a paper they spent years r…

And here is the apparent answer to the mystery:

https://news.ycombinator.com/item?id=39543532

Re: 'Mathematically perfect' star system being investigated for potential alien tech

#270

Post by lisper »

11101010001100 wrote: post #208
lisper wrote: post #191

Earlier quoted context omitted.

No. The temperature of the atmosphere has nothing to do with whether or not aliens are harvesting the energy. At equilibrium, all of the incoming energy has to get radiated back out into space eventually whether there are aliens harvesting that energy or not. The problem with an atmosphere hotter than lava is that very few materials are solid at those temperatures, and it's hard to imagine how a civilization could bu…

Sure, energy in equals energy out at equilibrium, but another option is to have a steady state solution where energy is generated leading to potentially large temperature gradients.

Yes, that's possible. It could be that what we're looking at on the planet surface is the output of a huge planet-sized radiator, with a civilization living in air-conditioned comfort underneath. But the problem with that theory is that you can't actually use the whole planet as a radiator. You can only use the space-facing side. You have to use the sun-facing side for energy harvesting. That temperature gradient would show up in the spectrum, and AFAIK it's not there.

[UPDATE] I don't actually know if current exoplanet observing technology is capable of detecting such a temperature gradient, but given what I know we can observe I'd be a little surprised if it couldn't. A planet-sized energy harvester would make a pretty big dent in the passive thermodynamics, and detecting that should not be too hard. And it would be Really Big News.

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