Re: Interesting Web Site

Jerry W. Decker ( (no email) )
Sun, 04 Jul 1999 20:19:55 -0500

Hi Darren et al!

Thanks for that interesting website about the PERMANENT project (
http://www.permanent.com ) to promote use of asteroids and other space
bodies for raw material. We still have to figure out a cheaper, more
efficient and faster way to easily achieve bidirectional space flight,
but it is really great to see people are working on WHAT DO WE DO when
we get there...<g>...

There was an interesting comment about using these rotating space
stations to produce centrifugal force to simulate gravity;
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Consider the advantages of a habitat based in orbit:

A habitat based in orbit can be wheel-shaped and rotated to produce
artificial gravity by the centrifugal (centripetal) force. Choose the
healthiest gravity you want. Earth-normal gravity may be needed for good
health for longterm stays.

A habitat based in orbit has access to sunshine 24 hours/day. No nights.
Crops can grow faster by varying sun (not sunlit 24 hours/day since
plants need nights, but opening/closing sunshades or mirrors for optimal
sunlit periods), for more economical output per unit of habitat and
time. Year-round growing season. Orbit-based habitats will be very
green, glassy structures with some very exciting architectural and
recreational features, including areas for human flight.

Products and services for selling to Earth economies will be
manufactured and assembled in orbital space, and operated there. So, the
suburbs in space will be located where the demand is, namely, next to
the factories, like it or not. (Why the manufacturing facilities will be
located in orbital space instead of on the Moon is discussed elsewhere
on the PERMANENT site.)

There will eventually be settlements on other planets' bodies as well,
as there will be all kinds of people with diverse preferences, but
settlements on other planets and moons will be feasible only after we
have settlements in orbital space and the economic support and physical
infrastructure to support them.
--------
I always envisioned factories in space and people flying back and forth
to work for something like 4 days and be off 3 days...or maybe even
weeks or months, like offshore oil drilling platforms, it really depends
on how easy and cheap it is to get to and from the factory.

That way, the earth could once again become a garden with minimal
pollution from industrial processes.

He also has interesting comments over use of the terms centrifugal as
opposed to centrifugal...here is the relevant comment;
--------
Over the years, I have received many comments that I should be using the
word "centripetal" rather than "centrifugal" in my general public
presentations. Technically, "centripetal" is correct, of course.

However, the word centripetal is understood by only a small percent of
the population, whereas the word centrifugal is understood by many times
more people. That is why I decided to use the word centrifugal for this
level of presentation - to the general public on the World Wide Web from
the highest financial executives to the most general of laymen).

In the physics classroom, centripetal is more appropriate.

....For those who don't know, when you are in a rotating space colony,
your feet exert a centrifugal force on the floor, whereas the floor
exerts a centripetal force on your feet.

Hence, artificial gravity as regards a force on your body is a
centripetal force. They're equal and opposite forces of the same
phenomenon.
--------
Isn't that an interesting 'take'? That the inside floor on the outer
ring would push against the body standing on it, to resist the
centrifugal thrust....hmmm, sounds like semantics to me as it is the
centrifugal force that is doing the throwing and without the floor, it
would simply keep going until it eventually hit something else in space.

I don't agree with that argument at all, the floor ISN'T moving
centripetally otherwise it would be drawn to the inside shaft.

The earth spins producing a centrifugal force that should throw us off
except for the 'suction' of gravity or the push of aether/zpe, take your
pick.

Of course, WHEN we learn to control gravity, we will be able to produce
it at will at any intensity we so desire, so such large rotating bodies
won't be the ONLY way to create artificial gravity and might be cheaper,
requiring less hardware and electronics, but we have to crawl before we
fly...<g>...thanks Darren...

--            Jerry Wayne Decker  /   jdecker@keelynet.com         http://keelynet.com   /  "From an Art to a Science"      Voice : (214) 324-8741   /   FAX :  (214) 324-3501   KeelyNet - PO BOX 870716 - Mesquite - Republic of Texas - 75187