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Author Topic: Some More Physics  (Read 3956 times)

Koningkrush

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Some More Physics
« on: August 26, 2015, 10:51:29 PM »
There are a few things that I was wondering whether or not they will be eventually in the simulation engine.
1. Will black holes eventually be more realistic?
By more realistic, I mean will planets and stars that get too close be shown to be ripped apart rather than suddenly exploding? Planets would have their atmosphere stripped and start breaking apart form such high gravity, and stars would just be sucked up like a vacuum cleaner. There could be different settings for this though based on how powerful your computer is. The lowest could just show the body being stretched into it, while the highest setting actually rips pieces of the planet off to be sucked into the black hole.
2. Aren't supernovas explosions?
I might just be wrong on this, but I figured that supernovas were intense enough to just disintegrate planets, not just super heat them.
3. Nebula Clouds.
Will Nebula clouds formed from supernovas eventually be affected by gravity? I think it would be cool to watch the birth of a star, not just its death. It might be very intensive on hardware to simulate a nebula condensing to form little fragments that eventually form into a star with planets though.
4. Pulsars and Solar Flares.
Do solar flares really do anything? I see them come off the sun, but do they really go out into space and hit planets? I can't tell if it's just for visual effect or not. Also, do pulsars actually emit pulses that affect anything sometimes? It seems like if a planet gets hit by a pulse, it would suddenly become pretty hot.
5. Incredibly strong magnetic fields, and magnetism in general.
Will magnetars ever be a thing? They have magnetic fields so strong that it practically turns electrons in atoms alone from circular orbits to lines. I also wonder if increasing the magnetic field on any body to high levels affects anything, like the pull it has on other objects or heating.
6. Strange Mass Increase Effects.
Why does increasing mass turn a rocky planet into a gas giant, then a star, then a black hole? If I had a lump of iron and I increased its mass continuously, I wouldn't expect it to suddenly explode into a ball of gas. When I first played, I tried to increase the density of Earth until it turned into a black hole, but it wouldn't let me so I just increased mass instead until the core collapsed upon itself into one which, if realistic black hole physics were in place, would be awesome to watch in real time. Instead, Earth just explodes into a gas giant and turns into a star. It seems like material make up should decide what a body turns into at different masses, not just mass itself.
7. Sun evolution.
I've seen a lot of documentaries talking about how the sun will turn into a red giant, but in the sandbox it just spontaneously turns into a super nova remnant instead of expanding greatly. Is this accurate? A lot of times with realism turned on, nothing seems as realistic.
« Last Edit: August 26, 2015, 11:29:46 PM by Koningkrush »

Greenleaf

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Re: Some More Physics
« Reply #1 on: September 03, 2015, 11:15:59 PM »
There are a few things that I was wondering whether or not they will be eventually in the simulation engine.
1. Will black holes eventually be more realistic?
By more realistic, I mean will planets and stars that get too close be shown to be ripped apart rather than suddenly exploding? Planets would have their atmosphere stripped and start breaking apart form such high gravity, and stars would just be sucked up like a vacuum cleaner. There could be different settings for this though based on how powerful your computer is. The lowest could just show the body being stretched into it, while the highest setting actually rips pieces of the planet off to be sucked into the black hole.
2. Aren't supernovas explosions?
I might just be wrong on this, but I figured that supernovas were intense enough to just disintegrate planets, not just super heat them.
3. Nebula Clouds.
Will Nebula clouds formed from supernovas eventually be affected by gravity? I think it would be cool to watch the birth of a star, not just its death. It might be very intensive on hardware to simulate a nebula condensing to form little fragments that eventually form into a star with planets though.
4. Pulsars and Solar Flares.
Do solar flares really do anything? I see them come off the sun, but do they really go out into space and hit planets? I can't tell if it's just for visual effect or not. Also, do pulsars actually emit pulses that affect anything sometimes? It seems like if a planet gets hit by a pulse, it would suddenly become pretty hot.
5. Incredibly strong magnetic fields, and magnetism in general.
Will magnetars ever be a thing? They have magnetic fields so strong that it practically turns electrons in atoms alone from circular orbits to lines. I also wonder if increasing the magnetic field on any body to high levels affects anything, like the pull it has on other objects or heating.
6. Strange Mass Increase Effects.
Why does increasing mass turn a rocky planet into a gas giant, then a star, then a black hole? If I had a lump of iron and I increased its mass continuously, I wouldn't expect it to suddenly explode into a ball of gas. When I first played, I tried to increase the density of Earth until it turned into a black hole, but it wouldn't let me so I just increased mass instead until the core collapsed upon itself into one which, if realistic black hole physics were in place, would be awesome to watch in real time. Instead, Earth just explodes into a gas giant and turns into a star. It seems like material make up should decide what a body turns into at different masses, not just mass itself.
7. Sun evolution.
I've seen a lot of documentaries talking about how the sun will turn into a red giant, but in the sandbox it just spontaneously turns into a super nova remnant instead of expanding greatly. Is this accurate? A lot of times with realism turned on, nothing seems as realistic.


These are all very god questions. Let me see if I can answer some of them.


Any strong gravity gradient will (potentially - depending on composition)make bodies fragment eventually. We are working on what we call "total body fragmentation" which would support this. A body is torn apart from tidal effects and those fragments will stretch out due to a continued high gravity gradient.
Looks like this old video I made https://www.youtube.com/watch?v=PaH7tf22hx0
Go to my channel to see some more relevant videos https://www.youtube.com/c/GreenleafDk


Supernovas are indeed explosions and we will model them as such. Far enough away you will mostly get the radiation, but closer in, a planet would be blasted. That is something we are working on.


Currently the nova cloud is a visual effect only. When the long awaited fluid dynamics, using SPH, gets into the simulation, we fully intend to model collapsing clouds on both small and large scale. Meaning, both forming clusters of stars as well as planetary systems.


Radiation from pulsars and flares are currently visual only.


If you make earth into iron and the mass it up, it says iron. The visuals, however, change. This is due to the way we classify planets based on their mass. In reality, a planet of a certain mass is generally a certain type of planet with a certain type of look. You do have a valid point that it doesn't really make sense in the case where you have created a very unnatural planet, such as a jupiter sized chunk of metal, and that it would be nice to have a more generalized system for picking the looks.


The issue with sun is not something I was aware of before. I will have to come back to you on that one, because you are right; the sun should not go nova.




Evil_Tom

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Re: Some More Physics
« Reply #2 on: September 08, 2015, 05:05:10 AM »
On the issue of increasing the mass of an iron body...

I did this and it was counter intuitive to what I expected. The results were once it reaches certain masses it _instantly_ changes from a rock planet to a gas planet to a star.
I guess at the point a body is 0.1 solar masses it becomes a star in this simulation. However there are some issues with all iron bodies.

Now I would ask something like this. At what point will an all iron body turn its core to liquid due to gravitational pressure? I guess the outer layers will still be solid so I'd expect some strange or extreme magnetic qualities at this point. Next would be at what point will the mass of an iron body be so large that fusion of iron occurs? I believe fusion of iron _requires_ energy to take place (see https://en.wikipedia.org/wiki/Iron_peak) so fusion of iron could actually cool the body.

This is a very interesting mental exercise and would be even better to see in simulation.