Thread: Game Developer Needs YOUR HELP!

Hello everyone.

I am doing research for an online game that is currently being developed and I need the science community to help me with some problems we are running into.

Without releasing too much information about the game, we are researching gravity, mass, and orbits etc for a game that is based on an alien world. I was hoping I could get some good information from this forum.

(WE KNOWN NOTHING ABOUT THIS SUBJECT SO PLEASE TREAT US AS LAYMANS)

We are creating a solar system in our game and in that solar system there are 4 planets. 3 of the planets will be superficial, the "MAIN" planet is the one that is farthest from our solar system's star. What we want to know is the dynamics of our "Planet".

The planet is going to have 7 "moons", We would like the planet to be bigger than Earth but have Intelligent Life. We want to know how this would be possible, We need to know the gravity, mass and all that good stuff.

Help us out here if you can. I know this message doesn't seem to make much sense I was kinda hoping to get a discussion going here and gather a little bit of data. I will post back VERY often. Thanks.

For a planet to have 7 moons it would have to be pretty big I would think, otherwise the moons would not have formed to number 7. They would probably have encountered each other in the past to form fewer. For the planet to be that big, it would have to be a gas giant. So no life as we know it could live on this planet. If such a system existed, life could only be possible on one of the moons. That would require that the gas giant not be too far from its sun, which would incidentally have to be of the same type as ours to have existed long enough for intelligent life to develop. It depends really on what type of aliens you had in mind?

We really want intelligent life in the same form as human beings.. HUMANOID type life. Okay, so let's say it is a "GAS" giant. Could a gas giant that is as far away as our Sun have an "Earth sized" moon? If it could I would think not enough light would get to it. Would there be enough heat from the Planet to sustain life on our planet size moon? Keep in mind you are talking to someone who has hardly no knowledge of "Space" I'm only a programmer. So it's perfectly fine to baby talk me.

I know about Europa and that it could possibly sustain life so I could entertain modeling something along those lines. We would like to make this project VERY realistic. We want someone to look at the game and say, well... YES that could be true. etc.

Thanks for the feedback.

Since most stars exist as part of a binary system, yours could too. That should help some with the required temperature for life. I don't think there is any reason why a satellite can't be as big as or bigger than the earth, when you take into consideration the size of our moon relative to the earth. A possible problem I can think of is that a moon of the size of the earth would suffer badly from tidal effects from the gravity of the gas giant, if the moon was rotating. So if the moon always presented the same face to the gas giant, complicated day and night cycles would result, especially in a binary system. I am sure that simple programs exist where you could basically design your own star system and observe the effects. I am not sure however where you would be able to find such a program. I am not a scientist either , only an enthusiast, so maybe some of our other members could add some less vague parameters for such a system. :wink:

Edit: I remembered about THIS one somebody here suggested. It should do the trick.

Let me ask you this. What would be the requirements for a moon the size of earth, give or take, to be life sustainable? And when you say Binary you mean a twin star system?

Originally Posted by hedolgames

Let me ask you this. What would be the requirements for a moon the size of earth, give or take, to be life sustainable? And when you say Binary you mean a twin star system?

Yes, a binary is a twin system. Well I guess you can look at what the earth has, i.e. water, mild temperatures, an atmosphere, etc. The link I provided, Celestia, could be very useful for working out the day and night cycles and such. The two stars in the binary would also have to be in their main sequence (still fusing hydrogen) and they should also be more or less the same type of star as our sun. A much more massive star would burn brighter, but it would burn out much more quickly. A much smaller star would be much colder and would last very long, but it might not be bright enough to add much usable solar energy to your planet. With 6 moons available during night times with them rising and setting at different times, your humanoids could have a complicated and interesting calendar worked out or each moon could represent a god. Like I said, for the moon to be viable, I think it would have to present the same face to the gas giant at all times, or tidal forces would either break it up, or keep the crust permanently molten (no life). The moon would also have to have a strong magnetosphere, otherwise the charged particles in the magnetosphere of the gas giant would be hazardous to life on the moon. Anything specific you want to know? Hopefully some of my fellow forum members could jump in and correct any mistakes I could have made and provide some additional information for you. Will your game be an online community type thing?

Originally Posted by hedolgames

We really want intelligent life in the same form as human beings.. HUMANOID type life. Okay, so let's say it is a "GAS" giant. Could a gas giant that is as far away as our Sun have an "Earth sized" moon? If it could I would think not enough light would get to it. Would there be enough heat from the Planet to sustain life on our planet size moon? Keep in mind you are talking to someone who has hardly no knowledge of "Space" I'm only a programmer. So it's perfectly fine to baby talk me.

I know about Europa and that it could possibly sustain life so I could entertain modeling something along those lines. We would like to make this project VERY realistic. We want someone to look at the game and say, well... YES that could be true. etc.

Thanks for the feedback.

Gas can orbit closer to their star then ours do. We have detected some of these "hot Jupiter" type planets. You can assume that your gas giant is one of these.

Assuming that the gas giant is of Jupiter size and orbiting around a star like our own at a like distance as the Earth, you could have your habitable moon orbit as far away as 10,000,000 km from the planet.

At this distance, the tidal effect of the gas giant would be just about the same that our moon has on the Earth. Your habitable moon could spin and not be tidally locked to the planet.

From the moon, the planet would look about 1.6 times the size of our Moon as seen from Earth. If the moon's orbit is inclined to the plane of the planet's orbit around its star, you would only have occasional total eclipses of the Sun by the planet. (though interesting enough, because of the orbital speed of the moon around the planet and the slightly larger angular size of the planet, the eclipse would take about 12 hrs. )

Originally Posted by KALSTER

Will your game be an online community type thing?

Yes it will be, so the non-varibles of the game must be worked out COMPLETELY before proceeding any further. We must have definitive details ironed out of the logistics of the planet, it's history etc before we can move any further. I referenced the link you provided and it wasn't that much help however I tried a program out called Planet 10 which seems to give me some good information however it was locked in on the solar system only having 4 planets. I noticed that there is a certain "Habitable" range a planet must be from the star in order for it to have life on it.

There are two things I'd be interested in you explaining to me. 1 = What is AU? I've noticed that it requires this variable and indicates that Earth is 1. 2 = What would be a "livable" gravity range? Earth =ing 1. 3 = What is a proper elemental balance for intelligent life to be sustainable, i.e % on Nitrogren, Oxygen and Carbon Dioxide etc?

Again, my research is progressing thanks to all of your help but there is still quite a bit that needs to be discovered.

Ideally it would be great to have the habital "Planet" be a moon of a gas giant. Would it be possible to have the Moon get all of it's heat from the gas giant? Do gas giants produce enough heat? Would the gas giant produce enough light in order to maintain a definate "Night" & "day"? Thansk again for all the info.

Originally Posted by hedolgames

Originally Posted by KALSTER

Will your game be an online community type thing?

Yes it will be, so the non-varibles of the game must be worked out COMPLETELY before proceeding any further. We must have definitive details ironed out of the logistics of the planet, it's history etc before we can move any further. I referenced the link you provided and it wasn't that much help however I tried a program out called Planet 10 which seems to give me some good information however it was locked in on the solar system only having 4 planets. I noticed that there is a certain "Habitable" range a planet must be from the star in order for it to have life on it.

There are two things I'd be interested in you explaining to me.
1 = What is AU? I've noticed that it requires this variable and indicates that Earth is 1.

1 AU (Astronomical Unit) is 149,598,000 km. It is based on the average distance of the Earth from the Sun.

2 = What would be a "livable" gravity range? Earth =ing 1.

If I remember right, humans can tolerate up to about 1.5 g (Earth Surface gravity being 1 g) for extended periods of time

3 = What is a proper elemental balance for intelligent life to be sustainable, i.e % on Nitrogren, Oxygen and Carbon Dioxide etc?

Nitrogen content has no effect on breathability of air.
Oxygen would need to fall between 400 and 50mm of mercury partial pressure. Above 400 and oxygen becomes toxic, below 50 and anoxia sets in.

Carbon dioxide content must be below 5mm partial pressure, after which it becomes toxic.

Partial pressure is what the pressure would be if all the other gases were removed from the mixture. Sea level pressure is 760mm of mercury. Earth normal partial pressure for oxygen is 160mm and for carbon dioxide 0.21mm

So for example, at standard sea-level air pressure oxygen could make up from 7% to 53% oxygen and still be breathable over long periods. (though at 7% I wouldn't be doing any wind-sprints)

At the same pressure carbon dioxide would have to be below .06 percent.

At higher pressures these percentages go down and for lower percentages they go up.

You could breath pure oxygen if the total air pressure is kept below 400 mm (7.73 lb/in²) and above 50mm (1 lb/in²). In fact, the early space capsules used pure oxygen at 3-4 lb/in² for their cabin atmosphere.

Again, my research is progressing thanks to all of your help but there is still quite a bit that needs to be discovered.

Ideally it would be great to have the habital "Planet" be a moon of a gas giant. Would it be possible to have the Moon get all of it's heat from the gas giant? Do gas giants produce enough heat? Would the gas giant produce enough light in order to maintain a definate "Night" & "day"? Thansk again for all the info.

No, a gas giant wouldn't produce nearly enough heat or light. It would be better to assume that your gas giant is itself orbiting close enough to its star that the star would supply the light and heat, as I mentioned in my previous post.

Thank you very much for that detailed post Janus, somehow I completely missed your first post and I don't know how so I apologize for that as it also answered some questions for me. I think this will help out a lot, I'll be keeping in touch if I have any other questions thank you very much guys.

The point of a video game is to make everything more interesting! Why stick with normal physics? Make up your own.

Originally Posted by Cold Fusion

The point of a video game is to make everything more interesting! Why stick with normal physics? Make up your own.

Because it can be more interesting (and satisfying) to be creative within the confines of real physics. Besides, making up your own physics won't always make things more interesting. Flight sims, for instance, become more interesting as their flight models become more realistic.

An example of making things interesting while sticking to real physics can be taken from the proposed habital world orbiting a gas giant. Every so often (say every century or so. The exact timing depends on some variables) The gas giant will eclipse the Sun as seen from the habital world. Due to the length of the orbit of this world, this eclipse could last over 24 hrs. Assuming a day on this world is comparable to an Earth day, this means that every hundred years or so, the Sun would not rise in the morning, and you will have an entire day of night. Considering the effect the sun disappearing for just a few moments had on our forebearers, what consequences would the Sun disappearing for a whole day at a time have for this culture?

I know, I put the physics at maximum on all of my games at the detriment of anti-aliasing and textures...


I'm only saying that on a small level you should be creative. Take half life 2 for example (The best game ever made, hands down). All of the motion and astronomical physics are correct, but to allow for cool things like zero point energy guns, the physics were twisted a little bit.

If modifying physics will yield things like more interesting weapons or vehicles, then I would do it. Pseudoscience also works.

Half life, if you listened or looked carefully enough, gave relatively elaborate explanations for all of their un-realistic physics....in fact many of them were based on current scientific hypothesis.