# What's a good gravity substitute?

1. Sep 14, 2016

### Noisy Rhysling

The "constant acceleration" (CS) vs. "spin the wheel" (SW) options have advantages and disadvantages. As I understand it the "wheel" for a spin gravity-substitute would have to be about a kilometer across? But would use less fuel. The CS doesn't need a big wheel but you'd need a Bussard ramjet to provide fuel?

So, anything better? I'd like to limit the serious suggestions to things that can actually be done within the laws of physics. The non-serious suggestions should at least be funny.

2. Sep 14, 2016

### phinds

That sounds unnecessarily large to me. Where did you hear that? I think that must have included some other constraints.

3. Sep 14, 2016

### Noisy Rhysling

Just heard it in passing, no provenance. I come here to double check what I hear elsewhere.

4. Sep 14, 2016

### phinds

Kind of hard to "double check" something that is unsourced. As I said, that likely included constraints that you have not mentioned. That's one reason that sources are important when you ask for an opinion on a statement.

5. Sep 14, 2016

### Noisy Rhysling

Yeah, tossed it out to see if there was blood in the water. ;)

6. Sep 14, 2016

### Bystander

Coriolis effects less than some "acceptable" maximum?

7. Sep 14, 2016

### Bandersnatch

Depends on how fast it's spinning. A 20m diameter wheel would have to spin once every 6 seconds to maintain 1 g. That ain't so bad, is it?

8. Sep 14, 2016

### phinds

I get dizzy just thinking about it

9. Sep 14, 2016

### Noisy Rhysling

But with a small wheel would there be issues of vertigo?

10. Sep 14, 2016

### Bystander

Depends ... if you're used to things moving "freely" on highly curved trajectories, "No;" if not, "Yes."

11. Sep 14, 2016

### Noisy Rhysling

Would there be any serious problem acclimating to that sort of thing? Is it something some people can do and others can't despite their best efforts, or is it like learning to like broccoli?

12. Sep 14, 2016

### Bystander

I get seasick watching a washing machine, so I'd say it's "despite their best efforts."

13. Sep 15, 2016

### GTOM

Spinning is IMHO the best, the living quarters can be sent far away from the ships torso with telescopic arms.
I dont think 1km radius is needed, far less is enough, especially if people aboard are accustomed to it.

https://en.wikipedia.org/wiki/Artificial_gravity

14. Sep 15, 2016

### Noisy Rhysling

:console:

I'm a retired CPO, and the first time I went out I got sick. Wore off after what seemed like a century.