Comment on What if?
hihi24522@lemm.ee 1 month agoGravitational capture occurs when one object enters a stable orbit around another (typically referring to natural orbits rather than orbit insertion of a spacecraft with an orbital maneuvers).
So saying it “is not possible” is verifiably wrong. The perceived rarity of gravitational capture is most likely just due to how empty space is, not the unlikelihood of stability.
On that note, I think you might want to do some math yourself. You seem to be laboring under the impression that there are limited or maybe only a single exact state of stability for systems like this. “You have to perfectly set the velocities and magnetic moments” I’m not sure about magnets but I am sure about gravitation, and you don’t need to be very precise at all.
If you know how to code I’d suggest you try simulating two bodies with random masses traveling at random velocities. You’ll see that many times they do swing apart and a few times they will directly collide but there is a wide range of stable orbits. Sure, if you wanted to get perfectly circular orbits, you’d need to be more precise, but circular orbits are not necessary at all. Most orbits are at least a little eccentric, and eccentric orbits are still stable orbits. Importantly, they can be created without precision.
Next, while binary systems are assumed to form during star formation as you assert, the quote I listed from Wikipedia says it is possible for binary systems to form via gravitational capture.
Anyway, since that wasn’t enough evidence for you I decided to find an example of a combination system. Fortunately I didn’t have to look very far.
Alpha Centauri (our nearest stellar neighbor and triple star system) is a specific example of stable combination. Rigil and Toliman are main sequence stars that likely formed the way you listed since they are very close together and roughly the same size with slightly more massive than the other.
However, Proxima Centauri is a red dwarf that orbits the two circumbinarily. It is .2 light years from the other two which means it is roughly 5% of the distance to us from the barycenter of Toliman and Rigil.
However, despite the distance, it is “gravitationally bound” to them and its orbit has a 30deg inclination relative to them. This out of plane motion, the large distance, and the eccentricity of its orbit, imply that Proxima Centauri did not form from in the ways you listed. It may have formed in the same nebula as the other two, but it also very possibly could have travelled before getting gravitationally captured. In either case, it was gravitationally captured by some means and has formed a stable system despite having an out of plane velocity.
Proxima Centauri even has circumstellar planets, and its small mass and large distance from the binary pair mean it very easily could be stolen from the system if another main sequence star passed closely by. So it’s a great example of this “bonding” I’ve described.
Now magnets. Your magnet analogy is not similar to these scenarios because electromagnetism is highly directional. I don’t think you’d be able to combine systems of spinning magnets in any stable configuration other than a straight (spinning) line of them. However—as shown by the Alpha Centauri system—it is very possible to form stable multistellar systems from the combination of two stable systems.
Lastly you are correct that there are many many differences between atoms and gravitational systems. I mean shit, we don’t even know how atoms really work. String theory and particle physics don’t play nice and there are many more theories for unifying relativity and quantum physics that would impact what the “true” internal structure of an atom is like.
However, as mentioned in my last comment, that is not the point! My point was simply that there are some similarities and that you could do certain things with them that would have chemistry analogues. Does that make sense? I’m not saying “these are the same” I’m saying “it might be possible to use these in some similar ways to atoms.” And I’ve now found proof it is possible because of this debate, but the point of my original comment was curiosity/discovery not debate.
mexicancartel@lemmy.dbzer0.com 1 month ago
I wasnt saying it was not possible for gravitational captured system, but bringing your two atoms together and they bond is not possible(because it keeps falling into each other). It’s the (outward)momentum that keeps such a system stable. It would not have form a stable system when you keep it near without any velocity to spin around each other, it will not form a stable system–another dissimiliarity from atoms.
Its hard to make a stable system with magnets so i said perfectly setting velocities. As you mentioned, a straight line spinning was what I imagined when writing. But i’m asking if you set it and made it work, would you count that also as some kind of atomic model?
If you are just saying there are some similiarities with atoms, sure! But then many things has some similiarity to atomic model. Your examples sure could be regarded as such atomic bonds philosophically. I couldn’t imagine stealing proxima centauri as bonding, since its already so far away from “nucleus”. Or in your analogy it could be atom held by van der Walls force being removed… man… I gave you another point
And I don’t know If there would be a magnetic bonding scenario but I think it might be possible with complicated calculations and perfect initial conditions. Also what about some ferromagnetic metal moving around a magnet?
What I am trying to point out is that any-force system could be then regarded like capable of being like an atomic model with chemical-like properties.
hihi24522@lemm.ee 1 month ago
See I agree with your last statement. I mean “any” is a stretch but yeah there probably are other systems involving distance based forces that we could draw similarities to chemistry from.
I guess the issue here is that my argument is there are similarities and your argument is that one shouldn’t point out similarities unless there are enough of them…?
Your first paragraph implies you thought I meant just setting these systems statically next to each other would create a stable orbit. You’re right, that would be wrong. But I don’t think I ever mentioned stationary combination. Furthermore, while regular chemistry could work like that, in the real world every atom is moving. The bonds form when atoms get close enough. This is why temperature increases chemical reactions. More motion means more “collisions” that aren’t really collisions but you get the picture.
Objects in space are also constantly in motion. If you want to bring two stellar systems together, you need to give them velocities relative to each other. Or as you put it, momentum. This could be enough to ensure a stable system but it requires that the velocities at least a roughly specific which is what I meant when I said system chemistry would be highly directional in my original comment.
As for magnets. You could say both atoms and magnets run on similar forces. You could make the argument that they, like atoms, have components which are constantly in motion and that if perturbed enough one could overcome those forces and break the system into its individual components.
However the behavior of the system as a whole is not similar to atoms because it cannot form any bonds of any kind with other similar systems.
If you were able to find magnetic monopoles which may or may not exist, you could probably build a system that is much more atom like than a gravitational system. But with magnets that have dipoles, even a ferromagnetic material would be drawn to one pole or the other. I suppose you could get up to two ferromagnetic bodies to orbit a rotating bar magnet if the velocities and distances were right, but you wouldn’t be able to combine them because moving any magnet closer would disrupt the conditions needed for stability.
Magnets are much more sensitive than gravitational systems because the objects have to be large relative to the system and close together whereas gravitational systems can be ginormous like Alpha Centauri.
Anyway it’s fun to think about what exactly I would count as chemical like properties.
I’d say they are mostly just the following:
I think that covers it. So if you can find a system that fits those then I’d say there are similarities between them and atoms/chemistry. I will honestly be pretty excited if you do because it will be interesting.
mexicancartel@lemmy.dbzer0.com 1 month ago
I’d say, kind of… Yeah jackfruits are like apples but yellow. And also big. And also tastes different. Also have spikes. But they are still like apples.
Sure you can imagine it like that, and one more note, the components of the units are very different on stellar system, unlike indifferentiable subatomic particles. This means you can’t have any named atom since all of them are different. It also emmits energy from star. Still yes you could imagine it like an atom, and fit the crieterias you mentioned(which I think must include a bit more which would disqualify stellar systems from being atom, but that’s your classification).
For another system which may fit your atomic desciption, we could also try scaling up the normal atom! That is, make electrically charged macroscopic bodies as nucleus and electrons. This I think in principle will work much better than gravitational atom. We can have repulsion as well as attraction which would be enough to balance out for stability. We would still get a planetary model(Rutherford model) of such an atom.
Also unfortunately, there aren’t many forces in physics, so i’m afraid i can’t find more analogous systems. Anyway thank you for the curious exploration<3