>Brad said:
>
>> Where did the 10% number come from?
>
>Consider dropping an object onto the neutron star from infinity. The
>amount of gravitational potential energy converted to kinetic energy and
>hence thermalised in the impact is
>
>E_g = G M m / r
>
>where M is the mass of the neutron star, r its radius and m the mass of
>the object. The object's rest mass energy is
>
>E_m = m c^2
>
>and so the ratio is
>
>E_g G M
>--- = -----
>E_m r c^2
>
>A solar mass neutron star has a mass of 2x10^30 kg and a radius of about
>10^4 m, G is 6x10^-11 m^3 kg^-1 s^-2 and c is 3x10^8 m s^-1, so the
>ratio is about 0.1. (All very approximate.)
>
>> And how much does a single marshmallow weigh?
>
>I've no idea. That's why I said "1g of marshmallows".
>
Aha! I don't know the solar mass in kg or the radius of a neutron
star, but I *do* know that there are approximately 150 marshmallows
in a one pound bag. That works out to be 3 grams per marshmallow, or
60 kilotons of released energy per marshmallow.
I will treat opponents armed with marshmallows with renewed respect.
ROU The Word "Thermalize"... Sounds So Clean
