There are stars, called Wolf-Rayet stars, which have momentum numbers greater than unity!
How can this be?
Well, once a photon scatters in the wind and gives up its momentum, is it gone? No, it’s just changed its direction. It can transfer its momentum again, and again, and again...
The problem (for theoretical astrophysicists) then becomes: How to provide enough opacity in the wind to keep the photons trapped so that multiple scattering can occur?
Note: the atoms that absorb the light’s momentum also absorb some of its energy…there isn’t an infinite supply from a given photon (what do you suppose the ratio of momentum to energy lost in each scattering is?)
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