From what I can tell there are 2 main forces operating on a rotating circular spacecraft in zero gravity. One force is the centrifugal force, which pushes an object to the outer wall of the spacecraft. The other main force is the forward force as that object attempts to move forward in a straight line, but is forced to move in a curve. These 2 forces are at 90 degrees to each other. I believe this causes the coriolis effect. I propose that aligning the floors of the wheel to 45 degrees, with respect to the axis,(see illustration) will create a balance between these two forces, which should render the floor as having almost uniform artificial gravity across the entire floor, with almost no coriolis effect.
The blue circle represents the outer wall of the spacecraft. The green lines represent the centrifugal and forward forces. The yellow lines represent the two forces balanced by the the angled floor (Purple plane). This would of course mean that the spacecraft would require multiple 45 degree floors connected by ladders and passageways. Am I missing anything?
- 3$\begingroup$ Your "forward force" is only present if the spacecraft's rotation is accelerating. $\endgroup$A McKelvy– A McKelvy2025-07-31 18:57:42 +00:00Commented Jul 31 at 18:57
- 1$\begingroup$ "I believe this causes the coriolis effect." You've missed looking up what the Coriolis Force actually is. $\endgroup$Erin Anne– Erin Anne ♦2025-07-31 19:01:06 +00:00Commented Jul 31 at 19:01
- $\begingroup$ You're right, I'm using the wrong term, it's the Coriolis force, which is created by angular acceleration. $\endgroup$Robert LeMar– Robert LeMar2025-07-31 19:27:30 +00:00Commented Jul 31 at 19:27
- 1$\begingroup$ @RobertLeMar you're not just using the wrong term. See the answer I've posted. $\endgroup$Erin Anne– Erin Anne ♦2025-07-31 19:33:08 +00:00Commented Jul 31 at 19:33
- 1$\begingroup$ The answer to the only question in your post is "yes". $\endgroup$Organic Marble– Organic Marble2025-07-31 19:41:18 +00:00Commented Jul 31 at 19:41
1 Answer
Coriolis force isn't present for objects stationary in the rotating reference frame. It arises from motion inside of the rotating frame; i.e. motion inside the proposed space habitat. Coriolis force doesn't arise perpendicular to the centrifugal force; it arises perpendicular to both the rotation axis of the rotating frame and the velocity of the object relative to the rotating frame:
$$F_\text{Coriolis} = -2m(\vec{\omega}\times\vec{v})$$
Stationary objects are going to find the floors at 45 degrees to the centrifugal acceleration vector frustratingly steep. So will most moving objects, honestly. Objects moving "linearly" along a circumference of the rotating reference frame, i.e. clockwise or counterclockwise around a ring, will feel coriolis acceleration purely as an increase (moving with the rotation) or decrease (moving against the rotation) of apparent gravity. Objects moving radially inward will feel a forward (with the rotation) coriolis acceleration, and objects moving radially outward will feel a backward (against the rotation) acceleration. Again, those are in proportion to the velocity in the frame, so your fixed 45 degree floors are only suitable for very specific (and likely inconvenient) motions.
This all makes quite a lot of sense even without the vector math if you're already comfortable with centrifugal accelerations. If you take something rotating at a certain rate a certain radius from an axis, i.e. in "artificial gravity", and give it some velocity, it's easy to tell what will happen: giving it with-rotation or anti-rotation velocity changes its rate of rotation around the axis, which changes the centrifugal acceleration, and that difference is Coriolis Force (and goes away again if you stop its motion relative to the rotating frame). Giving it toward-axis or away-from-axis velocity changes the radius, but you already had circumferential velocity. If it moved toward-axis, it now have excess circumferential velocity for its new radius and it'll move faster than the frame is rotating around the circumference, a forward/with-rotation force. If it moved away-from-axis, it doesn't have sufficient circumferential velocity to stay with the frame, and it'll move backward/anti-rotation in the rotating frame, apparently accelerating in that direction. Those are also Coriolis forces.
Start your designs with the physics, not guesswork.
artificial-gravity.com collects a wealth of resources, including an interactive simulation of an object in a rotating frame with an impulsive force applied and an AIAA poster for "Envisioning Artificial Gravity" that may be of service.
- 3$\begingroup$ The maker of the interactive simulation also made Centrifuge Volleyball; the link to it from the interactive simulation in the answer is broken, but it's still on the site at a truncated URL. It switches perspectives between with-the-rotating-frame and with-inertial-space, which is quite confusing and good fun. $\endgroup$2025-07-31 19:35:25 +00:00Commented Jul 31 at 19:35