Re: a surprising escape speed problem

[John Mallinckrodt <ajm@CSUPOMONA.EDU>]

At 8:39 AM -0500 10/26/02, Brian Whatcott wrote:

> I am probably missing the whole point of this puzzle which I thought was to
> posit the replacement of the Sun's gravitational attraction with a string.
>
> I visualize a string distributed to act on every Earth particle, and
> realise that
>   this is a gravity force by another name. So the question turns out to be:
> what is the effect on space launches if Earth's diurnal rotation is stopped?
>   I take it that one loses the advantage of equatorial launches.
>   And that's about it.
>
> Isn't it?

No, it isn't at least for the following reason:  With the Sun in the
picture, a launch speed that allows the object to escape from the
Earth is far too small to allow it to "escape to infinity."  On the
other hand I think it *is* true that replacing the Sun with a string
does not appreciably change the required launch speed for escape from
the Earth.

--
John Mallinckrodt        mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.