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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

#61

Post by thfuran »

hef19898 wrote: post #48
TeMPOraL wrote: post #43

Earlier quoted context omitted.

That sounds like aliasing issue in signals; we should be able to distinguish between them as long as we sample more often than half the actual orbital period (i.e. with a sampling frequency larger than the Nyquist frequency). https://en.wikipedia.org/wiki/Nyquist_frequency

Another question, is there something like a max. rotation speed for a planet in a certain distance to a sun of a certain size? Edit as a general response: Question answered, multiple times, thank you! Also, there my basic physics knowledge resurfaces, thank you for that as well!

For a given stellar mass and orbital radius (assuming a circular orbit), there's not really any wiggle room on how long the planet's orbital period is. Speeding up or slowing down the planet requires it to orbit at a different distance. If you meant the speed of a planet's rotation about its own axis, I guess the limit would basically be the point at which it tears itself apart by spinning so fast that its gravity no longer holds it together.

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

#62

Post by justusthane »

pavel_lishin wrote: post #7

Reminds me of a bit from a novel I read (won't be naming the title to avoid spoilers) where one of the minor twists is that the gigastructure of galaxies that we observe in the universe - the thing that's conducive to things like "star formation" and "life" - is an art project by intelligent species who've been alive since around the time of the Big Bang. (No, it's not part of the Xeelee Sequence :P)

If you would recommend it, could you email the title to j@justus.ws? I’m on a sci-fi kick lately and always looking for good recs.

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

#63

Post by zeroonetwothree »

hinkley wrote: post #38
marcosdumay wrote: post #13

Earlier quoted context omitted.

Well, perfectly spaced is the only way 3 planets can share the same orbit. And if we go for a gas giant and two small planets, there are probably many of those out there. We almost got one such trio.

Perfectly spaced is not a stable orbit. https://en.wikipedia.org/wiki/Lagrange_point You want L4 and L5 for that.

That applies to a small body with two large ones, not three similarly sized planets.

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

#64

Post by pavel_lishin »

hef19898 wrote: post #48
TeMPOraL wrote: post #43

Earlier quoted context omitted.

That sounds like aliasing issue in signals; we should be able to distinguish between them as long as we sample more often than half the actual orbital period (i.e. with a sampling frequency larger than the Nyquist frequency). https://en.wikipedia.org/wiki/Nyquist_frequency

Another question, is there something like a max. rotation speed for a planet in a certain distance to a sun of a certain size? Edit as a general response: Question answered, multiple times, thank you! Also, there my basic physics knowledge resurfaces, thank you for that as well!

There is only one stable speed at which a planet can orbit in a circle; any slower, and it'll start falling in toward the star, and any faster and it'll start to move away from the star.

The only way to vary the speed is a powered orbit, and that's not likely to happen with a planet.

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

#65

Post by hef19898 »

NoMoreNicksLeft wrote: post #58
rob74 wrote: post #26

Earlier quoted context omitted.

Not convinced until they find a Dyson sphere...

Dyson spheres are probably really rare. It's just bad strategy, everyone within your galaxy knows you're there pretty much immediately when a star just up and disappears one day. Granted, the non-K2s just stare in awe maybe, but the other K2s will fuck your shit up. Can't exactly pack it up and run either, not with a medium-sized star in your suitcase.

Temporal displacement fields: Wrap you star system in one of those and remove from the normal universe with a time shift of a couple of seconds! Let those pesky K2 Dyson Sphere civilisation figure that out!

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

#66

Post by NoMoreNicksLeft »

tromp wrote: post #47
jb1991 wrote: post #17

What is the "mathematically perfect" aspect of this system? I don't see it in the article.

As detailed in the companion article [1], for every 54 orbits of planet 1, planets 2..6 orbit 36, 24, 16, 12, and 8 times respectively, giving successive ratios of 2/3, 2/3, 2/3, 3/4 and 3/4. After those 54 planet 1 orbits, all planets are in the same relative position. [1] https://www.space.com/six-sub-neptunes-found-100-light-years...

If a K1.5 wanted to do that just for shits and giggles, is there a viable way to slow down or speed up orbits of rocky planets? Like, wouldn't they be shooting a bunch of mass out of their system to even attempt this? If one could build a Dyson sphere, is that more difficult or less difficult than engineering a system like this? The sphere/swarm has some absurd amount of mass all in a very uniform orbit around the sun, and most of that mass didn't start there... so it sort of seems like it's equivalent (but if so, they're much closer to K2 than K1).

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

#67

Post by Retric »

hinkley wrote: post #38
marcosdumay wrote: post #13

Earlier quoted context omitted.

Well, perfectly spaced is the only way 3 planets can share the same orbit. And if we go for a gas giant and two small planets, there are probably many of those out there. We almost got one such trio.

Perfectly spaced is not a stable orbit. https://en.wikipedia.org/wiki/Lagrange_point You want L4 and L5 for that.

L4 and L5 are unstable unless there is an extreme, as in many orders of magnitude, difference in the masses involved.

At equal mass the separation increases until they are all equidistant from each other assuming a completely circular orbit.

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

#68

Post by TeMPOraL »

hef19898 wrote: post #55
TeMPOraL wrote: post #52

Earlier quoted context omitted.

Yes, but that would be dictated by how fast can it spin before shattering into pieces. So mostly gravity/composition thing, I'd imagine. Many things in solar systems are (postulated to) derive from the rotation of the protoplanetary disk, via conservation of angular momentum - however, planets can also get spun up or down after forming by e.g. collisions with other objects, including extra-system objects.

Just realized, I meant orbit speed and not rotation aeound the planets axis. Shouldn't write in parallel to meetings... Your answer was very interesting so, thank you!

I see! In the other case, the answer is: velocity vector determines the orbit. For any given point at any given orbit, there's only one valid velocity vector relative to the star (direction and magnitude) - tweaking it tweaks the shape of the orbit.

One of the best way to get an intuition for orbits is to play Kerbal Space Program for a few hours :).

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

#69

Post by NoMoreNicksLeft »

PaulHoule wrote: post #25
riskable wrote: post #23

Earlier quoted context omitted.

They might not be planets but planet-sized, artificially-created cities/machinery/engineered objects. Think about it: If you were tasked with creating a planet-sized thing why would you give it anything less than a perfect orbit? You'd also put it in orbit around a super stable dwarf star to maximize the useful life of the project. Even if they are planets, imperfect orbits lead to problems in the looooooong term. An…

Makes me think of how the Puppeteers in Niven's Known Space escaped the explosion at the center of the galaxy by moving 5 planets in this configuration https://en.wikipedia.org/wiki/Klemperer_rosette with an inertialess drive that (I think) they bought from the Outsiders.

I thought they mortgaged the drive, and were more than a little upset at how onerous the terms were.

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

#70

Post by dkarl »

spacecadet wrote: post #39
sirsinsalot wrote: post #31

Earlier quoted context omitted.

Flexbox will be seen by aliens as alien technology, our peak, our absolute pinnacle before collapse.

LOL, better then them finding the industry 10 years ago.

I would love to see a movie where aliens show up to help us with the looming crisis that is about to destroy our civilization, and it's CSS.
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