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"At its best, SF is the medium in which our miserable certainty that tomorrow will be different from today in ways we can't predict, can be transmuted to a sense of excitement and anticipation, occasionally evolving into awe."
- John Brunner
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| Liquid Mirror Telescope on Mars | ||
| A large telescope using a spinning bowl of mercury as the mirror. |
Although Gallun did not invent the LMT, he makes good use of it as alien technology. Number 774, the Martian mentioned in the story, made great use of different exoskeletons to perform different tasks.
See if you can spot what appears to be an error in his use of the liquid mirror telescope in the quote below.
| Enigmatic forms of weird apparatus crowded in bewildering complexity against the walls. Tipped at a steep angle at the center of the floor was a vast cylinder of webby girders. Piercing the dome, opposite the upper end of the cylinder, was a circular opening through which a portion of the starlit sky was visible; and at the base of the cylinder a great bowl rotated rapidly, like a huge wheel.
The bowl contained mercury. As the container spun on its perfectly balanced axis, centrifugal force caused the mercury to spread in a thin, precisely distributed layer over the inside of the bowl, forming a concave surface that acted admirably as a mirror for Number 774's gigantic reflecting telescope. It's area, and its consequent light-gathering capacity, was many times greater than any rigid mirror that could have been constructed without flaws. |
| From Old Faithful,
by Raymond Z. Gallun. Published by Astounding in 1934 Additional resources -
|
He states that the cylinder was tipped at a steep angle; a real liquid mirror telescope has to remain fixed with the "bowl" perpendicular to gravity's pull.
In the story, Number 774 discovers people of the Earth using the telescope; he positions it to look at a particular part of the Earth during each observation session. Since an actual LMT cannot be "steered" (it can only look at the patch of sky directly above the instrument), the user cannot choose to focus directly on any object in the visible sky, as you can with a regular telescope.
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Additional
resources:
More Ideas
and Technology from Old Faithful
More Ideas
and Technology by Raymond Z. Gallun
Tech news articles related to Old Faithful
Tech news articles related to works by Raymond Z. Gallun
Liquid Mirror Telescope on Mars-related
news articles:
- Liquid Mirror Telescope For Moon Studied By NASA
- Telescopes With Liquid Mirrors Go Mainstream
| Elon Musk Tweets Versions Of Clarke's Operation Cleanup |
| Espresso Telescope Searches For Exoplanets |
| Manned Maneuvering Unit From 1984 |
| Astronaut Gets Younger In Space |
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Looks like the City Fathers are starting to take over China's education system.
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'The smoky globe, hung in the vault, was shot with colored light...'
