
Space Suit: 1949 - bootload
http://www.wired.com/wiredscience/2012/09/space-suit-1949/
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lloeki
> Ross and Smith ended their paper by estimating their suit’s weight. It
> would, they calculated, have an Earth weight of 150 pounds. On the moon,
> however, where gravity pulls with about 15% as much force as on Earth, their
> suit would weigh only about 25 pounds.

This kind of audience-confusing shortcut always makes me jump. It would still
weight 150 pounds on the moon, but it would exert 15% of the force as
generated on Earth. The distinction is important, even for the uneducated,
because it means that although you _appear_ to weight less statically, you
have exactly the same inertia.

~~~
nemetroid
Isn't _pound_ the name of both the mass and force units? In that case it would
have the mass 150 pounds, but weigh 25 pounds.

~~~
chris_j
When I studied physics in highschool, we were taught to measure mass in
kilograms and to measure weight in newtons. While this seemed a little strange
at the time, it had the effect of forcing you to be clear which one you were
talking about and it avoided this kind of confusion.

~~~
ghaff
As I recall, the mass term "slug" is often used rather than pound-mass to
remove this ambiguity. A slug = 32.174049 lbm (i.e. multiplied by the earth's
gravitational acceleration constant without any units).

But, yes, the terminology among other things can introduce ambiguity and the
potential for error when using Imperial units for these types of calculations.
(In fact, I seem to remember it sometimes was easier to convert into metric
and back again at the end.)

The general point here though is that the local gravitational constant changes
the weight (downward force on the object) but not its inertia (a property of
mass and other physical properties).

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jarel
<http://www.gutenberg.org/files/19141/19141-h/19141-h.htm> Edison's Conquest
of Mars

aka "Space Suit: 1898"

Ctrl+F "the air-tight suit".

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justincormack
The British Interplanetary Society is still around and active...
<http://www.bis-space.com/>

