Stellar evolution - timelapse

[Wehr Wulf]

Hey everyone <3

Has there been any talk about implementing stellar evolution mechanics? Itd be awesome to watch how different stars get larger, smaller, turn into black holes, change temperature and luminosity, become white dwarfs and red giants etcetera....
For example, our Sun will continue to get larger, brighter and hotter everyday, its core will shrink but the outer layers will continue to expand and one day will become a Red Giant engulfing our planet.
In the game when I speed time up I see the Sun does grow in size a little bit (nowhere near enough) and some eventually supernova, so it looks like stellar evolution was at least started...

I guess itd be kinda complex to implement...
Itd have to calculate the different rates at which hydrogen fuses into helium, helium -> carbon, oxygen, silicon and so on until iron. And itd need to make sure heavier elements only fuse when the temp/pressure gets high enough. The rate of fusion changes depends on temp/pressure so itd be changing constantly. And itd need to keep track of how much there are of each element. Then itd take that calculation and use it to change the stars size color and temp. Which would then be taken and used to determine the rate at which elements were fusing :P

So I can see that being a challenge, but I see updates tackling atmosphere and water distribution on planet surfaces... thats pretty complex, and thats a relatively micro feature to implement in a macro "Universe" simulator if you ask me. So clearly theyre not afraid of a challenge :P

It also takes millions-billions of years for these changes to occur, and most people arent playing the simulator in a 50 million years/second time scale. In fact, one of the only times a person would use that kind of time would be to watch stellar evolution :P So I can see why its not their top priority to implement. That being said, stellar evolution is a fundamental phenomenon in the universe - having a universe sandbox without it would be like going to work naked. So I hope its at least on the to-do list......

XOxoXO

[76561198025051992]

There are 2 basic problem with the time lapse of stars, one that could probably be fixed by the devs, and the other that we could probably live with.

First, if you look at the life cycle of a 10 solar mass star, it burns though its hydrogen in about 20 million years and it burns through its silicon in about a day. That means if you set the simulation speed to where the silicon burning would last a tenth of a second, you'd have to wait decades to get to to point when silicon burning happens. This could be fixed by the devs by adding a way to pause the simulation when the star reaches a certain point, or by basing the simulation speed on the rate of stellar evolution.

The second problem is accuracy. Magnetic fields, rotation rate, metallicity, binary partners, and more all effect stellar evolution. Simulating stellar evolution is so hard that the best simulators yet developed by scientists don't well describe all the stars we see in the night sky. We could probably live with this, though at the limits the stars may act entirely wrong. A 0.08 solar mass star might not ever start burning hydrogen. A 200 solar mass star might supernova instantly.

Some of this is already in the game, but not enough to see when fusion of each new material starts.

[Thundercracker]

Originally posted by Aledore:

There are 2 basic problem with the time lapse of stars, one that could probably be fixed by the devs, and the other that we could probably live with.

First, if you look at the life cycle of a 10 solar mass star, it burns though its hydrogen in about 20 million years and it burns through its silicon in about a day. That means if you set the simulation speed to where the silicon burning would last a tenth of a second, you'd have to wait decades to get to to point when silicon burning happens. This could be fixed by the devs by adding a way to pause the simulation when the star reaches a certain point, or by basing the simulation speed on the rate of stellar evolution.

The second problem is accuracy. Magnetic fields, rotation rate, metallicity, binary partners, and more all effect stellar evolution. Simulating stellar evolution is so hard that the best simulators yet developed by scientists don't well describe all the stars we see in the night sky. We could probably live with this, though at the limits the stars may act entirely wrong. A 0.08 solar mass star might not ever start burning hydrogen. A 200 solar mass star might supernova instantly.

Some of this is already in the game, but not enough to see when fusion of each new material starts.

i think this is going a bit into more detail than is desired. changing temperature and radius over time is not complex. i'd personally like at least the bare basics of stellar evolution, as our current eternally static stars are less realistic than even that simple implementation of evolution.

[MrNegotiator]

the older it is, the bigger it gets. the old system for aging stars was they got big.

[bshapiroalbert]

Thanks for your feedback and suggestions. We know that there are some issues with our current star simulation and that we currently don't include stellar evolution. We want to fix these issues, and we would like to add in stellar evolution sometime in the future.

We have had some internal discussions about implementing these fixes. The short version is that adding stellar evolution and fixing these issues within our current star simulation system is very difficult. To implement stellar evolution in a physically accurate way would more or less mean re-writing our entire stellar simulation code right now.

We want to do this in the future, and it is on our roadmap. However, given the scope of this task, we currently do not have a timeline for implementing it. We really appreciate feedback like this, though, as it helps us figure out what features we want to work on next.