[ExI] Discontent with the path physics is taking

spike spike66 at att.net
Wed Aug 17 18:47:01 UTC 2011


>... On Behalf Of Kelly Anderson
Subject: Re: [ExI] Discontent with the path physics is taking

2011/8/17 spike <spike66 at att.net>:
>> Dan...I am interested in theoretical physics myself.  I worry they may
have taken a long and fruitless path.  But I don’t lose any sleep over it.

...

>...I am with Spike here that I'm more interested in physics that at least
has the possibility of some kind of application eventually. Now, we all know
that we can't tell in advance what is going to have application and what
isn't... look at the math that led to CAT scanners, it sat dusty on the
shelf for more than 50 years... -Kelly


Two fun examples.  In the early 90s I took graduate class up at Stanford in
orbit mechanics.  The text kept referring to a book from way back, so I
looked up the reference.  It had all the necessary equations for rocketry,
orbit maneuvers, specific thrust, pretty much everything in a modern orbit
mechanics text, originally published in... 1865.  While Johnny Reb and Billy
Yank were popping Minnie balls at each other with smooth bore percussion cap
muskets, someone somewhere was working out the equations that were used in
the Gemini program to do on-orbit docking a century later.  The original had
nothing about fuels, no LOX, no hydrogen, none of the mechanical parts, but
he had started with Newton and worked out the propulsion requirements, what
we would now call top level systems engineering, way back in the middle of
the 1800s.  Cool!

A young Stanford doctoral candidate worked out the critical details in a
doctoral thesis in 1968 a system which would later become the THAAD missile.
THAAD is an anti-missile missile with no explosive aboard, which destroys an
incoming missile by colliding with it, waaaay up in the upper atmosphere.
This in itself constitutes an aaaawesome flight feedback controls
accomplishment.  He had early and midcourse guidance using information from
ground based radar and everything.  The only significant departure of his
original thesis from the system coming on line today is that his paper had a
control moment gyro stabilization, whereas the current THAAD is mid-body
thrust stabilized.  I heard from a colleague that there is a theoretical
next generation THAAD which is control moment gyro stabilized.  {8^D  His
thesis sat collecting dust for over two decades, then (according to company
urban legend) they retrieved it from the archives at Stanford and attempted
to make parts of it classified!  {8^D  Haaaahahahaaa!

spike





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