Moon is a Harsh Mistress - fresh discussion

[Quanders]

I guess if you really want to be specifically fair - what was the Tibet's circumstance at the time of writing - 1966?

Had they regained independence or were they living under Chinese rule day-to-day. Talking trends here, as relates to Heinlein.

I don't know myself, I'm asking.
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Also, anyone know of decent, recent sources on catapult development - Heinlein mentions building on West face of Mountain/higher elevations.

I'm wondering why the mass driver isn't being more seriously pursued right now.
(though I'm aware of 1+ bil development costs)

Whoever did so, it would seem, could potentially monopolize orbit payloads.
Something desperately needed right around the corner.

[Ursa major]

The Chinese "Cultural Revolution" (May 1966 - 1969) affected Tibet badly; perhaps this contributed to Heinlein's thoughts on the matter.

[Moogle]

Isn't a super collidor like the LHC just a particle level mass driver?

I'm not much in the science knowledge department, but let us not forget that in The Sixth Column Heinlein envisioned a world in which the Asiatic peoples of the East had united (I don't remember specifically whether it was through conquest or diplomacy), but they were able to conquer the United States specifically. Perhaps R.A.H. had seen what I'm sure other political scientists of the time had seen as the inevitability of a Chinese Superpower?

As to the OP's last question, remember that in Heinlein's version of the Lunar history, it is first used as a prison colony and work camp. I doubt that even much later in it's history there were many hotels or tourist attractions orbiting or even on the surface.

[ghost8772]

super colliders are particle accelerators. similar function, but designed to move smaller masses.

chrispenycate, the design of the catapult was more rail gun. using electromagnets, computer sequenced on powering up and down, to move a ferrous package. only a few ferrous metals out there, Iron and Nickel are two of the ones I recall. (total of 4?) iron/steel would still be the cheapest to produce, until the raw materials were depleted.

Underground ran several items at once. better insulation from light dark cycles. cheaper construction, since they would be taking away the parts that didn't work like habitation, instead of building all the parts of habitation, and paying carrier fees. Radiation is easiest to discount. considering how many people walked around in p-suits. most radiation can be minimized, or even negated through use of about 1" of metal sheeting. lead would be best of course.

[chrispenycate]

The trouble with the Earth based mass driver is atmosphere. The mountains aren't tall enough that you're not going to get enormous atmospheric friction , energy loss and heating. Look at the height when reentry heating starts to be a consideration for the shuttle; mountains are still tiny wrinkles below.
And the launching velocity would have to be much higher than reentry speed. Still, as a 'first stage' for a laser launcher, or even a chemical rocket or rocketplane, it could be useful.

the design of the catapult was more rail gun. using electromagnets, computer sequenced on powering up and down, to move a ferrous package

Rail gun, mass driver, they're all different names for the Laithwaite linear accellerator. A series of coils at steadily increasing spacing driven by a polyphase electrical current (or contant spacing with steadily increasing frequency if you so desire, but it's wasteful, so I'm sure Heinlein would have use increasing distances betwen coils, even if he used a variable frequency oscillator. The phase difference between ajacent coils produces a magnetic field moving along the axis of the coils. Any electrical conductor will get a current induced in it, which will generate an equal and opposite magnetic field which will tend to keep the conductive object centred in the magnetic peak (which is travelling at a steadily increasing speed along the series of coils.) This will work for any conductor, not just a ferromagnetic, as a number of dents in the IC elec eng building will testify; aluminium, brassm monkey metal (Laithwaite was an inspiring lecturer) Even salt water. I built my own with a lump of plastic drainpipe, and got teaspoons moving faster than sound. Weee!

[j. d. worthington]

Hi, Chris: just wanted to note that the "editing" I did was to change the "i" to an "o" in "quote", so that it showed up as a quote properly....