Mathematics of life bearing worlds

[WKFO]

https://github.com/WKFO/pioneer/tree/WKFO-lifesupport ---> Current progress to compare
Aside from creating an ugly code, this is only so much I can do with a single integer value.
I suggest discussing and creating a mathematical function to calculate which forms of life can exist on a planet and make it into a code. We will use (add whatever necessary):

-Surface temperature
-Type/chemistry of planet, (bonus points for liquids and ice?) (+ Habitable zone calculations for different types of stars)
-Atmospherical composition
-Atmospheric density
-Orbit of planet (i.e. Difference of distance to star between apoapsis and periapsis
? Gravity ?
? Planetary rotation, (minus points for tidal lock?) ?

[bszlrd]

Some things I think are contributing to this: (assuming we are talking about terrestial like life, carbon based). Wikipdeia has a quite long article we could springboard form. Atomic rockets also have stuff on it.

• Orbit of planet: Every star has a habitable zone based on it's energy output. That't the zone where water can remain liquid. I could imagine that some variation between Apoapsis and Periapsis could be tolerable. If you have liquid water for half a year, then life could still evolve maybe. Might even be a good evolutionary pressure too.
• Planet gravity: low enough, and gases will slowly leak out to space. It directly influences the atmosphere. Lighter gases leak out sooner.
• Tidal locking might rule out life because the planet has to be close enough to the star for that to happen that it's atmosphere would be blown away by solar winds. I think they talked about this for TRAPPIST-1 (I have to finish that system).
• Axial tilt. Because then you have seasons, which is good for the evolution I think.
• Having a Moon is a big bonus, because tides are important for evolution, they say. Also it can protect against asteroids.
• On the same line of thinking, they say that having some gas giants in the system is an important thing for the protection against asteroids.
• Magnetosphere is important to shield from cosmic radiation, and it also prevents strong solar wind to strip the atmosphere.
• Activity of the star. Solar winds, flares, etc.
• Metal and heavy element amount in the star. Since without them, you don't have the lego blocks of life.

[WKFO]

https://en.wikipedia.org/wiki/2017_bloc ... _in_Turkey
I want to curse so badly.

If we want to consider everything then we have some stuff to add to the generation part of the things. Types and ages of stars give us valuable information about their composition but I don't think the game generates compositions for stars or planets.
I don't know how we could implement the solar activities to the game but that would be cool.
Magnetosphere will involve mass of the planet so I will put that to the list.

[bszlrd]

Sorry, I didn't realized that there's a ban. Would it get you in trouble if I sent you those articles as pdf?

[WKFO]

If someone wanted to cause trouble to me bc of this, then I would already have about 4 star wanted level by now :)
Of course it is better to have the pdf files since accessing local files on my PC doesn't reveal my... You know what I'm talking about...

*ahem*
About the main topic, there's a m_life value in StarSystem.h and .cpp but I didn't get where we assign a value to m_life, later to be compared by a fixed(value, value). Perhaps, instead of creating new integers and booleans out of nowhere I could use this value for tweaks.

Also we can use this: http://www.planetarybiology.com/calcula ... _zone.html We will need to read these values from generated stars (meaning we need to generate these values first) and use a mathematical function to return the radius_max and radius_min values for that system's habitable zones. Then a planet will only be able to contain liquid water on a planet in that area (given that the planet has the correct pressure to keep the water liquid).

Binary and more star-populated systems (which, I think, makes more then %50 of the star systems) are going to give me headaches if I calculate HZ for a planet using data of more than one star, let alone orbit eccentricities. We may need to make more than one calculation about the habitable zone, or we can just limit the calculation for the planet to it's host star, which will decrease realism but significantly improve performance. How much realism about life do we currently have anyway?

[Marcel]

Tidal locking might rule out life because the planet has to be close enough to the star for that to happen that it's atmosphere would be blown away by solar winds.

Venus is an exception that probes the rule. It's very nearly tidally locked and may have had conditions suitable for life for 2 billion years. The side facing Sol would have been covered with clouds and subject to continual rain. The Swamps of Venus may have actually been there! The lack of plate tectonics is what caused the CO2 buildup as I understand it.

[bszlrd]

I thought Venus isn't tidally locked, but almost resonant, and rotates the other way compared to the other planets.

I also read an article about scientist thinking about ways to remove that hellish atmosphere to get a nice Earth-like planet which could be easier to terraform.