RDFRS US:
The mission of the Richard Dawkins Foundation for Reason and Science is to support scientific education, critical thinking and evidence-based understanding of the natural world in the quest to overcome religious fundamentalism, superstition, intolerance and suffering.
The Magic of Reality
for the iPad
Sean Faircloth:
Attack of the Theocrats!
I'm not sure this is the right calculation. As the planet gets bigger people on the surface are further away from the centre.
I think the correct calculation goes as follows. The gravitational force on a person of mass m on the surface of a planet of mass M is the same as if you make the planet into a point mass as its centre. As the person is relatively small compared to the planet you can make them a point mass as well. If the density of the planet is d and assumed constant and radius is r then the mass of the planet is
M = d [ (4/3) pi (r cubed) ]
the force is
F = C (m M ) / ( r squared)
where C is some constant. So ignoring all the constants the force is proportional to the radius. Hence gravity should be 2.4 g on the surface of this planet of gravity if g on the surface of earth.. Uncomfortable for us but evolution could have adapted I think.
Michael
EDIT: See also wikipedia.
Permalink Wed, 07 Dec 2011 04:43:10 UTC | #896365