4 ms·
Rotations of a point happen in a plane around some point in the plane, not around a line or axis. In two dimensions there is no line perpendicular to the plane
by danbruc 4y ago
Rotations of a point happen in a plane around some point in the plane, not around a line or axis. In two dimensions there is no line perpendicular to the plane to rotate around, in four and higher dimensions there is no unique plane perpendicular to any given line. It is only in three dimensions that rotating in a plane and around a line coincide.
- 411111111111111 4y agoDisclaimer: I'm not a physicist and am must approaching this with a very basic understanding of the matter Isn't it generally said that the earth is rotating around the sun, or is that scientifically inaccurate?
- leephillips 4y agoThe planets all orbit in approximately the same plane, the ecliptic. So it’s fine to say that they rotate around the Sun—except that, really, they orbit in (approximate) ellipses with the Sun at one focus. But these ellipses are pretty circular (low eccentricity), so, again, we can say that we’re orbiting around the Sun without hurting anyone.
- User23 4y agoWe can also say the Sun is orbiting the Earth thanks to being able to choose our frame of reference. GPS makes good practical use of the Earth as the preferred frame.
- Ancapistani 4y ago> really, they orbit in (approximate) ellipses with the Sun at one focus Don't they technically orbit the center of mass, assuming a simplified two-body system? In the case of Sol and a planet, given the massive (pun intended) disparities, the center of mass is very, very close to the center of Sol - but not coincident.