eli5: How can a laser burn of rust without melting?

Question

I just saw a YouTube video by someone with 2000 W laser and now I wonder how can the laser not melt itself when compared to a lense bundeling sunlight its always said cannot get hotter than the sun itself?

In: Physics

Answer 1

The laser isn’t transmitting heat. You are correct that you can’t transmit heat to get something hotter than the original source.

It transmits pure light, which the rust then converts into heat.

The sun transmits heat, through blackbody radiation like /u/Lithuim said.