ballistics, etc.

[Brian D. McCary]

> Could someone comment on a) if this is correct and b) if so,
> why would Pynchon have thought it was (or presented it as) a parabola?
> 
> Derek Davis                           3311 Baring St., Phila., PA 19104

	Yup, you're right, as already covered by others.  The distinction
between controlled & ballistic flight pointed out by Andrew Dinn is 
particularly important.  However, I offer the following defense:

1	A parabola is a degenerate form of ellipse, with one focus at
infinity.  This could be a very obscure joke on analytical geometry, 
given the degenerate nature of most of the population of the book...

2	This was his way of trying not to confuse the readers too much.
At least some portion of the population is familiar with the word parabola,
from parabolic mikes, radar dishes, ect.  Mention ellipses and eyes glaze.
Since any description of the path is going to be an approximation, you 
might as well use one people are familiar with

3	Hey, it's not even that bad an approximation, on the first order.
It's better than a circular arc (another degenerate ellipse, along with
the line) and a field artillery man in space could use it to get accurate
hits within two or three shots.  With the distance between the ballistic 
object and one of the focal points of the ellipse at around 4000 miles, and
the total arc height less than 100 (I'm guessing) the change in gravatational
attraction is going to be around 5%.  In addition, the actual arc chord is 
going to be somewhat less than the distance from the launch site to London, 
due to the rotation of the earth, so one has to consider whether the point of
referance is on the earth (where distortion will occur) or in space, (where
it will be reduced to the change due to the orbital position change for the
earth) when trying to describe the observed shape.

	See how everyone fell asleep during 3?  That's why he used the
parabola.  

Brian McCary
rotation of the earth