Just need some help for a story. While I am not aiming for hard-science fiction, I would like to get some plausibility for a backstory I am developing. So let's cut to the chase. Mars is terraformed. It would be earth-like but still different. There's only one thing I can't seem to figure out. Is it possible to make the lower gravity on Mars earth-like? If so, how? If not, is there any visual examples (such as a video) I could look at to see how Martian gravity is simulated?
The answer to your gravity question is no, not without some heavy Star Trek waving of the hand magic science. Mars has no electromagnetic shield, which on earth is created by the spinning core of iron at the planet's center. This is what keeps us from being blasted by radiation from the sun. Your biggest problem with Mars terraforming is not gravity, but insane doses of cosmic and solar radiation.
do you need it to be raised out in the open, or would establishing an earth-like gravity under a dome or below ground do?
Well I already came up with an idea to combat solar radiation as some form of global anti-radiation shield to built to repel any radiation from coming at all. I haven't came up on how it works and what it's made of but the radiation is already taken care of. Like you said about the electromagnetic shield being created by the spinning core, I guess a man-made one would have no relation with Mars's core at all. Or could it? Any plausible way on tampering with the core at all?
Kim Stanley Robinson wrote a whole series about a terraformed Mars. I can't remember now if he had some sort of dome on any kind of temporary basis, but I think mostly he had gasses pumped into the atmosphere to make it so you could walk outside. I don't remember how he handled the gravity issue. It might be worth perusing his books to see how he dealt with the gravity issue.
Why not use some sort of gravity boots? This would be easier than to have some force fields surrounding the entire planet to make an earth like gravity. Unless, of course you also want your people to walk and breath in the open without the aid of equipment. Than you would need some sort of technology that could surround the planet, or a part of it in a shield, providing a livable atmosphere. For your gravity problem, I've seen a few books in which they use black wholes to provide an artificial gravity field. In most case, the size of the black whole dictates the force of the gravity. If it's not hard-science than you don't need to explain much on how this work. Everybody knows black wholes suck so use that
With a global anti-radiation shield, you're already well into Star Trek Science territory, which is fine. Where would sci-fi be without magic science? A power source for a thing like that is utterly beyond current real science. You would need to wave some kind of magic energy wand to make that happen. Dark energy, Planck Energy, Controlled Singularity, etc. Something like that. If you're already there, you may as well buy some anti-gravity / heavy-gravity plates or run a system of cables under the ground where the colonists live in order to control gravity in those areas or you could drill to the center of Mars and house a semi-controlled singularity in the center, sufficiently controlled as not to consume the planet, but just wild enough to exert gravitational pull.
This also leaves room for an interesting plot device later. What would happen if the singularity slowly began becoming unstable? How would the inhabitants deal with the possibility of their entire planet potentially imploding?
What about an artificial moon of sorts? it could over time increase the gravitational pull on mars a produce a more substantial electromagnetic field. Could be done by man made means or moving asteroids into mars orbit. The spin would also in theory produce centrifugal force and artificial gravity?
So i've been thinking, let's say Mars has a breathable atmosphere, anti-radiation protection from a global sheild but the gravity is still the same. Which means the low gravity could affect human lives living on the red planet. Gravity boots sounds interesting actually but I really want the entire world to react to the same level of gravity. So, despite not using pressure-suits and being able to breathe, Mars will still feel different and can affect the bone density in humans. So in order to fix that, people would have to get some bone recovery augumentation. It's like people have to become transhuman to live on Mars. And speaking of radiation, even if any more solar radiation is prevented, Mars still has high levels of it. I guess I could write a plot device where most of the radiation on the surface is cleaned up but then I was thinking of anti-radiation medicine people could take. So many ideas I can come up with. I just don't want them to sound too silly.
Nope. Firstly, you would need a HUGE body to effect enough tidal force on the interior of Mars to heat it back up. Mars is stone cold. No interior heat. The tidal pull of Jupiter on its moons is just enough to possibly create liquid water on Europa. Jupiter is the largest thing in the solar system other than the sun. And no, having things in orbit around Mars would not increase any gravity on Mars because the mass of Mars is not increased.
So because of the Mass of Mars, no matter what, the planet will never have the same gravity akin to Earth?
That is correct. It is the mass of an object that determines its gravitational pull. The more massive it is, the higher the gravity. In real life, that's the one and only determining factor.
Okay. That would make sense how large planets such as the gas giants have the biggest gravitional pull in the solar system. So really by real science, there isn't a way to change the gravitational pull of a planet such as Mars I guess figuring out a more logical way to solve the radiation problem is the way to do it. (I think I might stick to the shields, by creating some fictional resource that powers it that was mined from Alpha Centauri. Sometimes sci-fi does need to take an entirely fictional approach.) So without rambling, I'm trying make a story with realistic and fictional science at the same time. Some new technology is born because of newly discovered ores, minerals and resources found in other star systems.
I did think of that initially, i understand the mass problem hence the idea of the centrifugal force creating the artificial gravity, i know they are thinking about it for space stations etc i just up scaled the idea to a planet. Also you mentioned earlier about the effect on the core, i did think of that too but decided to omit it from my comment to keep it simple. I remember reading about the em fields on mars and how they thought that maybe passing asteroids had given mars a sort of fly by kick start by pulling at its liquid core. It might be an option to say that giving the core a boost at the right time might help, a bomb of somesort to help fuel the jump. Far fetched i know
The only way that centripetal force (it's centripetal, not centrifugal) can create "gravity" is if you live on the inner surface of the thing that's spinning. Like the spinning environment in the movie Elysium. Having something spinning around Mars won't create gravity on the planet.
I probably wouldn't choose the artificial moon idea because I doubt one could be created within the time frame of my backstory. The story takes place in 2500's. No way we could build anything like a death star at least.
But would this "something" create it's own gravity if it spun around Mars? You made a comparison about the space staiton in Elysium (it's called a torus by the way) spinning so it could have gravity on the surface of the station. If the torus did the same thing in deep space, would it not work?
ah my mistake, also didnt think of the inner surface part. Was just taking a stab in dark at it terraforming mars wouldn't fit in that time frame either to be honest. came across this just now, might be an interesting read for you. http://www.science20.com/robert_inventor/trouble_terraforming_mars-126407
No, because what is happening on the inner surface of a torus (yes, I'm aware of the name ) is not truly gravity. There is no spatial distortion creating the force. You are simply falling at a rate with the spin of the station that keeps you on an even keel and mimics gravity. You're not actually making the same phenomenon. As to your second question, yes, it doesn't matter where such a thing spins, the effect is the same. A torus like Elysium or the Ringworld of Larry Niven's books, which is in effect a modified Dyson Sphere. It spins around a sun, with the sun at the center. Where the torus is in space is not relevant to the effect of spinning it.
You've been really helping me out more than ever. I appreciate that. I like your lectures regarding the subject as well. Best way to learn!
Well then. I guess I choose optimisim. and Mars in my story doesn't have high vegetation. It's pretty much a desert world with breathable atmosphere. I could make up a fictional planet but Mars means a lot to the story.
