# Can an electron moving with constant velocity but is spinning on its axis radiate?

If we can consider electron as a small sphere then the question arises that if its spinning, it must radiate but its centre of mass is moving with a constant velocity, but an electron moving with constant velocity do not radiate. So will it radiate?

• But an electron isn't a small sphere. – Rob Jeffries Sep 25 '17 at 8:49

I'd like to add some things about spin in order to complete the good answer of Luc J Bourhis. It is pretty tricky to consider an electron as a spinning small sphere as you do. Spinning around what? You cannot properly define an axis of rotation in quantum mechanics. If you want a visual representation of a spin, it is a quantity that describes how the particle is when you turn around it. Imagine an arrow $\uparrow$ , if you look at it from the top and you turn around it, you need to make a 360°-turn to see exactly the same pattern again, which would correspond to a spin-1 particle. You need 720° in the case of an electron (spin one half).