# Alternatives to centripetal force and constant acceleration to simulate Earth-like gravity

This is follow-up to @Erik's answer to the question Is artificial gravity feasible in manned long-term space exploration? I'm curious, whether there's any alternative methods to simulating effects of gravitational acceleration as felt on Earth (9.78 - 9.82 m/s2), if there's any ongoing research, or proposed methods of achieving this? Could, for example, dynamic principles of a gyroscope (i.e. powerball) be used to create equally distributed centripetal force on the whole inner spherical body of a space station? Could such rotation on all three axis be sustained with inertia?

I don't want to limit my question to only, but would also like to know of possible ways to actually create long-term sustainable gravitational fields, be it directly by producing gravitons, or by other ways of producing gravitational effects of a large mass body with small mass bodies, if this is at all feasible (quantum mechanical black holes maybe?), and how far are we from seeing any of such systems demonstrated either on paper and/or actual model-scale systems?

I am not interested in infeasible far-out / fictional ideas, but actual scientific research in this area and pragmatics of proposed (if any?) alternative methods.

• The problem with a space station rotating around every dimension to produce gravity would be the issue with trying to dock with it – user106 Jul 19 '13 at 18:54
• I've asked on physics SE if artificail gravity as seen in many movies cen be proven to be impossible - so far without success: physics.stackexchange.com/questions/68957/… – mart Jul 19 '13 at 20:12

Wikipedia has a good page on the subject of artificial gravity, highlighting many (very interesting) possibilities.

Rotation is exactly what you would expect. The spacecraft is a big rotating cylinder, just like in physics textbooks.

Linear acceleration, however, is a very interesting idea:

Any spacecraft could, in theory, continuously accelerate in a straight line, forcing objects inside the spacecraft in the opposite direction of the direction of acceleration.

Note, however, that you need to keep accelerating. As soon as you need to slow down, your gravity goes away. Therefore, this would probably be best for very long-range voyages.

The idea of using Mass for gravity basically involves installing an ultra-high density mass in the spacecraft to attract objects toward it, simulating gravity.

Magnetism is another interesting one:

A similar effect to gravity has been created through diamagnetism. It requires magnets with extremely powerful magnetic fields. Such devices have been made that were able to levitate at most a small mouse and thus produced a 1 g field to cancel the Earth's; yet it required a magnet and system that weighed thousands of kilograms, was kept superconductive with expensive cryogenics, and required 6 megawatts of power.

Using this technique to levitate a frog.

Gravity generator/gravitomagnetism is highly theoretical, and probably won't work anytime soon:

In science fiction, artificial gravity (or cancellation of gravity) or "paragravity" is sometimes present in spacecraft that are neither rotating nor accelerating. At present, there is no confirmed technique that can simulate gravity other than actual mass or acceleration.

• A craft with acceleration-based gravity could shift to rotation-based gravity. Imagine an elongated craft with one side habitable, and the other containing instruments, fuel etc. If it needs to stop, it can start spinning and the habitable part retains gravity (while on the "engineering" part the gravity vector is reversed). – SF. Jul 19 '13 at 20:07
• A high density mass would not simulate gravity, it would generate real gravity. It would also be very weak, or the ship would be an dwarf planet with drives.... – aramis Jul 21 '13 at 0:16