I don't agree that "the energy is not being emitted"; the Sun is roughly in thermal equilibrium, and the energy emitted equals the energy produced by fusion. Th

I don't agree that "the energy is not being emitted"; the Sun is roughly in thermal equilibrium, and the energy emitted equals the energy produced by fusion. The same would happen to a "bright light inside a box" - the box would emit the same amount of power once it's in thermal equilibrium, only it would presumably emit in infrared. The power produced by nuclear fusion inside the Sun turns out to be very small compared to the mass of the Sun. I don't claim that this is some kind of a discovery, and I am sure that this is obvious and intuitive to astrophysicists, but it's not intuitive to laymen, who think that the Sun emits a lot of power relative to its mass. That's not misleading, it's only unintuitive. In their immediate experience, anything this bright is indeed producing tens of thousands of watts per kilogram at least. And I never doubted that you would get a whole lot of power if the energy contained in the Sun was released on a human time scale; this is something where intuition serves us well.