The power in a gravitationally self-focussing light beam is c^5/G = 10^52 Watt (no hbar because it's just classical wave physics). Now consider a white dwarf at the Chandrasekhar limit, and how it depends on fundamental constants: M = (hc/G)^3/2 m_p^-2 R = (h^3/Gc)^1/2 (m_e m_p)^-1 Both the mass and radius depend on hbar, no surprise. But let's work out the power in a supernova, using GM^2/R for the energy released and R/c for the characteristic time: P = cG(M/R)^2 = (c^5/G) (m_e/m_p)^2 The hbars have cancelled, giving us the Planck power times the square of the electron/proton mass ratio. Since the latter is roughly 10^-7 (Joule -> erg), we get 10^52 erg/sec for the supernova power. -Veit
On Aug 23, 2015, at 9:17 PM, Warren D Smith <warren.wds@gmail.com> wrote:
c^5 / G = 3.6 * 10^52 watts.
A black hole, in the final stage of its evaporation, lasting order one Planck time, would emit about this amount of power.
Is it just an odd coincidence... that this amount of power, is roughly equal to the total luminosity of everything in the observable universe?
(Actually, I think the universe currently is perhaps 10^5 times less powerful than the Planck power, but the universe was more powerful in the past.)
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