[net.physics] pressures at planetary centers

lew (04/12/83)

I once calculated the pressures at the centers of the planets.
Assuming a constant density, the pressure is given by:

p0 = 1/2 * rho * g * R

where rho, g, and R are the density, g-value at the surface, and radius
Giving the results in bars and in earth units we get:

earth	1.7e6	1.0
mercury	2.5e5	.145
venus	1.4e6	.82
mars	2.5e5	.144
jupiter	1.2e7	7.0
saturn	2.3e6	1.34
uranus	2.1e6	1.23
neptune	2.5e6	1.46
pluto	3.8e5	.221
sun	1.3e9	778

Except for the sun, a surprisingly small range of variation. The formula
is quite questionable for the sun, but it gives a pretty good answer
anyway. The radiation pressure alone (due to photons) at the center of the
sun is 1e8 bars, more than enough to explode the earth like a cherry bomb.

	Lew Mammel, Jr. ihuxr!lew