Re: escape velocity question

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

On Mon, 15 Mar 1999, John Mallinckrodt wrote:

> No relativity required here.  Escape velocity is given classically by
>
>   v_esc = (2 g R)^(1/2)
>
> For an escape velocity equal to the speed of light with g = 37,000 g_earth
> we would find R = 120 million km (the size of a red giant) and
> M = 42 million solar masses.  A white dwarf has (I think) a radius closer
> to that of Earth so the escape velocity would be "only"
> 37000^(1/2) x 11.2 km/s = 2.2 x 10^6 m/s, less than 1/100 the speed of
> light.

Hmm...  I just noticed that this is the speed of the electron in the first
Bohr orbit--i.e., the speed of light divided by the fine structure
constant.

      do                do
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do                do            ...

John
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