When the sun becomes a white dwarf why will it take SO long to cool off?

Jonathan Thornburg -- remove -animal to reply wrote:

Sorry to nitpick but ...

* The sun-as-white-dwarf will be a *lot* smaller in diameter than
sun-now, maybe by a factor of 50 or so. That means 50^4 times less
surface area to radiate energy away!

Area depends on the square of the radius, shouldn't
that be 50^2 times less?

This means

tau_wd
------- = (m_wd/m_now) * (C_wd/C_now) * (T_wd/T_now)^-3 * (r_wd/r_now)^-3
tau_now
= 1 * 1 * 3^-3 * (1/50)^-3

Again shouldn't the last term be (1/50)^-2

George