# Does the worldline of light depend on the frequency?

My Question is: If 2 rays of light are emitted with different frequencies from the same spacetime point, does an observer see them in the same worldline?

I know that the worldline of light behaves as ligtht-like curves in spacetime (i.e. $$g(v_{\gamma},v_{\gamma})=0$$ and $$u^{\nu}u_{\nu}$$=0). But where exactly is the dependence of the emitted frequency?

• Are these light rays travelling in a perfect vacuum? – PM 2Ring Jan 22 at 19:54
• No dependence in vacuum. In most real media, the speed of light is dependent on the wavelength, this is called dispersion and it depends on the medium. – Bobak Hashemi Jan 22 at 19:54
• I am mostly trying to understand how worldlines work, and especially the wordline of light – HELP Jan 23 at 6:21