Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

First I would like to be clear: this is a noob question, I need a simple answer if such an answer exists.

In a three-dimentional space, how can I name this rotation?

See an animation

Let's assume X is red, Y is blue, Z is green. I need to know the direction of the rotation (+ or - 90°) and how can I name it: is it name depending on the Z axis which is the "static" axis of my box, or depending on the Y axis? I need to name this rotation for a physical sculpture documentation project.
I am sorry if I am a bit confused! Thanks for your help.

share|cite|improve this question
up vote 1 down vote accepted

Use the right hand rule.

With the fingers of you right hand, follow the rotating object. Your thumb will be pointing in the direction of the axis you are revolving about. If it is pointing in the positive direction, your angle is positive. If it is pointing in the opposite direction, the angle is negative.

share|cite|improve this answer
Thank you but how can I name it? "Z along rotation: 90°" ? – rooofl Nov 3 '12 at 15:10
I would say: "Rotation by 90 degrees about the positive z-axis" – Bernhard Nov 4 '12 at 8:58

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.