Four galaxies interacting and merging together (N-body simulation)

The simulation shows four identical galaxies interacting gravitationally, exchanging stars and finally merging into a single elliptical galaxy.
Each galaxy initially contains 500k particles.
Computed with OpenSPH
pavelsevecek.g...
Join the Discord server: / discord
Simulation file: www.dropbox.co...
Original video: www.dropbox.co...

[@Pluspython]

Now I’ve seen galaxies collide, asteroids collide, planets collide, even black holes collide, but I am yet to see stars collide.

[@keterpatrol7527]

I'm not an astrophysicist, but that usually results in a supernova iirc

[@shebahammy]

@@keterpatrol7527universe sandbox logic

[@ortherner]

@@keterpatrol7527That only happens if both stars are really massive i think (10 Solar Masses or higher). Usually they just combine to be a more massive star.

[@keterpatrol7527]

@@ortherner ah ok, thank you. I am by no means an astrophysicist. My expertise is limited to random facts I learned on the subject via autistic obsession and Universe Sandbox logic, neither of which are degree level expertise

[@Agn-zh3yd]

Same!

[@T3ss3R]

If was possible to slow down your brain functions so much that you'd see these kind of stuff in real time, I would spend my whole life floating around looking these as everything in the universe turns into iron stars and black holes

[@Malkovith2]

Trillions years later in an empty dying universe: - Uh... now what?

[@mastermenthe]

What else? LET THERE BE LIGHT And begun again.

[@Ing_Failure]

Poetic

[@FisTheDucc]

@@Malkovith2 wait for the next one:D

[@physics_hacker]

@@mastermenthe A fellow The Last Question enjoyer, perhaps?

[@Sebi076]

Nice how the leftover clumps become dwarf galaxies themselves

[@bazpearce9993]

I noticed that too. :)

[@code-cave]

I'd love to learn how you created the renderings of the simulation snapshots; it looks great!

[@robbiefronda9991]

I’ve always wanted to see 4 galaxies colliding and merging

[@MarshalRando]

Gets me in the feels.

[@Darkness_Black_hole_355]

Milky way Andromeda Milkdromeda Sombrero Galaxy

[@Jaydenkieltrances54867]

Ic 1101 galaxy largest?

[@pukulu]

It's not hard to see how giant ellipticals form from the collisions of galaxies of other types.

[@histiest1628]

why do galaxy mergers always end up as elliptical? is there any case in which it takes up a spiral shape again?

I think, that there is simply too much chaotic movement. Spiral arms need some sort of order don't they?

[@KyouzukaTakahashi]

To get the spiral-y vortex is very dependent since its birth, a scaled up version of how our solar system works which follows the same set of rule and order. Now the merge between these two straight up ruins this billion years old achievement by throwing objects *everywhere* , thus their orbit will no longer be the same and all over the place orbiting at every degrees possible. - By the rule it could somehow reach that order again through the same process (collision), the thing is- the stars would be gone many time faster than the galaxy could ever reorganize itself as it once before, this added by the more massive distance between objects just reduces the possibility of collision *drastically* . - The likely scenario is that the spiral/order would only exist very close to the center where the star density is at it highest allowing collision to happen but we will never be able to observe it because of the old giant stars packed together is blinding.

[@physics_hacker]

As others have stated, the disk shape is an ordered state, or moreso a slightly disrdered state which causes spiral arms to form. But when galaxies collide it's necessarily such a messy process the chances of ever getting a disk shape after are practically nonexistent. The galaxies would more or less have to be perfectly aligned and heading directly toward each other but not so directly as to cause them both to dissipate completely when they collide, which is a difficult enough ask even if the rare angle alignment were a given. It's not impossible, so it's likely it's happened somewhere at some point, but such a find would be very strange and unlikely indeed. There would be headlines "Everything we know about galaxies: WRONG!?" even if scientists realized it were just an example of an unlikely case.

[@Earth_Luna]

2 million particles!!

[@spaceexplorer2304]

it really bugs me that there is a galaxy background instead of just black

[@pavelsevecek]

I was wondering if anyone would point it out :)

[@poolman6898]

Thumbs up!

[@alacer8878]

Is this in 3D space?

[@pavelsevecek]

yes it is

[@Seliotka]

Hi I downloaded sim file and it's not working why

[@pavelsevecek]

I don't know, what exactly is the problem? Does it fail to open the simulation? I tried it and it works as expected.

[@Seliotka]

@@pavelsevecek hi im fixed it but simulation goes very slow

[@pavelsevecek]

@@Seliotka It does, it will take a few hours even with a powerful CPU. You can lower the number of particles to speed it up.

[@danielfernandes8641]

How can I open the .sph file ?

[@pavelsevecek]

Download and install OpenSPH, then you should be able to just double-click .sph files to open them.

[@danielfernandes8641]

@@pavelsevecek Thanks!

[@Darkness_Black_hole_355]

Guy

[@IrinaMiklashevskaya]

If u mess this planet up i have 4 u can see that we can end up in i can talk about it so u understand and stop 😂 and then we have universe and so on 😉

[@AstroCatz]

Impressive!

[@leezarahman2934]

Ayee

[@Betis91]

That's the possible scenario between the LMC, The Milky Way, Andromeda, and the Triangulum galaxies 😂😂😂

[@michaeldreemurrandhisaus2165]

What about the SMC

[@Betis91]

@@michaeldreemurrandhisaus2165 Also too

[@Flesh_Wizard]

​@@michaeldreemurrandhisaus2165sorry I was hungry 🥺

[@michaeldreemurrandhisaus2165]

@@Flesh_Wizardnah it’s fine, I ate the majority of it 🗿

[@bazpearce9993]

Cool sim. I suppose this shows why there are still so many dwarf elliptical galaxies knocking about.

[@Dativ2]

I like how spiral galaxies when they collide or interact they form 2 big spiral arms

[@ThomasKundera]

Where does the energy before collision (kinetic+potential) goes, so that the systems merge? Is it in the few faster ejected stars?

[@pavelsevecek]

yes, exactly

[@ThomasKundera]

@@pavelsevecek : Thanks.

[@Agn-zh3yd]

Milky Way vs andromeda (Edit: here is the part 1:03 )

Tyhle simulace jsou fenomenální. Rád bych udělal díl našeho pořadu o tom, jak vznikají...

[@pavelsevecek]

To budu rád, napište mi na Discord nebo na mail (kontakty v About tohoto kanálu).

[@cricket-lt8nc]

Music name?

[@arishemthejudge6780]

Name of the piano song?

[@TheLukas135]

Imagine the nightsky from one of the habitable planets there

[@sirlight-ljij]

Sadly, it won't look like much. The galaxy merger takes millions of years to complete, so from a viewpoint over a single lifetime nobody will notice any of the dynamics above. The "milky way" line might look distorted, but that is about it, no actual changes will be noticeable

[@TheLukas135]

@@sirlight-ljij just the fact to See 3 other galaxies that close without the "dynamic" would be amazing i guess :)

[@AstroCatz]

How do I get a color like this? I always get weird colors for galaxies

[@pavelsevecek]

You can download the simulation file and see how I did that, it's in the video description.

[@jackrobinson1073]

What’s the song in the background?

[@samfletcher8338]

imagine being on a planet in one of those galaxies, the night sky would be fucking awesome

[@ronjon7942]

How many billions of years were compressed into this 90 second simulation?

[@kjj8776]

gas particles or star particles or dark matter particles? I had been assuming gas because of the triggered spiral structures, but the motion is pretty dissipationless so stars or DM would make more sense

[@matejsteinhauser3974]

Can you please do next simulation steady, without rotation of the camera? I wanna see physics go by

[@RobertDorschel]

will this be in a higher resolution than 720p? It's fantastic but I with it had higher resolution. Or mayb youtube hasn't prepared it yet?

[@pavelsevecek]

it's rendered in 1600x900, so that's the best I can provide.

[@pavelsevecek]

I added the original video to video description.

[@RobertDorschel]

@@pavelsevecek thank you! I love your work, by the way.

[@cuidadocomaferaverde]

why mine open sph dont make that realistic the planets for me is just a white ball

[@PatrickSmith]

It’s been often said that most stars don’t collide in a Galactic collision and merge. However, nearly every star is disrupted in some way. Any planets, orbiting any of these stars would be subject to a rain of asteroids and other debris from near misses and possible planetary ejections. My guess is very few advanced civilizations, or even advanced life forms would survive in any of those galaxies unless their star was ejected early.

[@xXFluffers]

Galactic merges take millions of years, there's more than enough time to see things coming literally millions of years in advance and prepare for it

[@양익서-g8j]

저 속에 있는 고등문명은 태양계 주기가 깨지고 얼어버리고 다시 우주로 가면서 되살아날 기회를 만나겠죠.

[@jimmywrangles]

Outstanding.

[@poolman6898]

Where does my lifetime fit in all of this...

[@bazpearce9993]

It's a mere speck. This would take billions of years to occur naturally.

[@FPEFUNDEM55]

But I did a 8 Galaxy collision

[@dearbanyai]

😮The same thing, put together in the same thing. Do you think like me?

[@Mr_Bruh656]

if i die and are able to wonder around the cosmos, im taking it.

[@IrinaMiklashevskaya]

They done tho ❤🫂

[@tonym31whisnantjr95]

Galaxy murder and cannibalism

[@bazpearce9993]

There's always a bigger fish.

[@HARBINGER8752]

I wonder what the timescale is here

[@pavelsevecek]

from hundred million to a few billion years