Monday, July 11, 2011

Launch Pad Diary July 11

The mission of Launch Pad is "to get the science right in sf," increase the signal to noise ratio and reduce misconceptions - Hollywood moguls are next, so movies can get it right, too. Participants include emerging and established writers, fantasy as well as sf. Will know they've done their job when a werewolf novel describes the phases of the moon correctly.

Stan Schmidt says: Everything is outgrowth of astronomy, carried to extremes. Fictitious science is presented within constraints of real science.

Astronomical objects vast range sizes, speeds, times, most of the beyond our ordinary experience; we and our solar system are tiny on cosmic scales. How to convey scale to readers? Earth is about the largest size we can understand experientially.
Earth 12,756 km diam. (Use metrics for science!)
384,000 km (about 1 light-second) to Moon.
c = 300,000 km/sec
1 AU = 150,000,000 km (about 8 light-minutes) (orbit is actually elliptical, as most orbits, so this is average orbital distance) Use AU for solar system, use light years for beyond
solar system 100 AU diam.
closest stars 17 light years; typical interstellar distances, galactic disk not as dense as center but denser than non-disc areas.
63,000 AU = 1 light year
3 1/4 light years = 1 parsec = 206,000 AU (from parallax triangulation, earth baseline 2 AU, compare observations different times of year, 1 arc-second, measurable by telescope)
Milky Way 75,000 ly diam. (Large spirals typically about 100,000 ly diam.) Can measure stuff beyond that, like molecular or atomic hydrogen gas or dark matter. Not such a big gap between galaxies as between stars; hence, galaxies collide but stars rarely do. Only a few galactic radii, galaxies cluster (our local group about 20, Milky Way one of 3 large spirals, Andromeda is another) Distances, millions of light years.
Superclusters form filaments and walls around voids (like sponge structure) voids not empty but fewer galaxies

"Observable universe" only what emits light: 14 billion ly; but actual universe may be much larger.
Relate to reader's everyday experience; how long to walk to moon? Movies: Powers of Ten, Cosmic Voyages, opening of Contact, popular mass-consumption version.

Stan: Sun & planets are impossible to see all in same system, may not even be obvious that you are in a solar system; you must watch for very small objects moving, need instruments to record position with high precision.

In this solar system, planets more or less in plane (ecliptic); there is good reason to think this is true for other systems as well. Solar nebula forms from collapsing clouds of dust, spins faster with collapse; then forms disc. Planetary systems are very common; we see gassy dust discs around young and proto-stars that we think are forming planetary systems.

Jim Verley on Misconceptions. "Larger" size of Moon on horizon is optical illusion, not lensing effect of atmosphere. Authority of print gives power to written misconceptions.
Kids have private ideas, formed very early and very resistant to alteration: examples include what makes season, phases of moon, that air has no weight, and oxygen is the only component of air. Embarrassment is a common response to confrontation. Many readers harbor these misconceptions; as a writer, put on a teacher's hat. Repeating a misconception cements it; bad information tends to be self-reinforcing. Conceptual change theory requires identification/confrontation of misinformation. Other examples: the age of universe, mastodons and dinosaurs coinciding with humans; astrology = astronomy; greenhouse/global warming deniers. Pedagogy is never at its best when declaratory; in fiction, you can address misconceptions in many ways; a character who is wrong or who has questions. General misunderstanding about science as belief system or information handed down by authority, don't understand scientific thinking. Legal argument vs. scientific thinking: "let me convince you about my position." Science is not like a jury verdict based on how two sides of case are presented. Majority opinion is not necessarily the right answer. On the internet, anyone can claim to be an authority. Conceptual change involves people making predictions based on their theory.

Jerry Oltion: Amateur astronomy: amateurs look through telescopes; professionals attach cameras to telescopes and then analyze the data. Refracting telescope gives larger field of view - harder to build because of precision of lenses. Also reflector (uses mirrors). Both turn images upside down. Binoculars - brain designed to use both eyes - 2 sets of prisms result in right-side up images. A lot of cool stuff is too dim to see with naked eyes or binoculars. The bigger the light-collecting ability the more you can see (i.e., size of mirror). What's important is how much light, not magnification. This is diameter, not length of telescope. Can change focal length with eyepiece lenses. 50x power per inch diameter. (3" refractor; 4" reflector is minimum). Benefit of low power is field of view, but crispness important. 1/2 hour to dark adapt eyes for chemical changes to occur in retina, so use dim red light. Tricks to use (rods) on periphery of vision, which is much more sensitive to dim light. This is called averted vision. Don't see much color, but will see what colors your retina is most sensitive to, telescope camera pictures show other colors. Telescope lenses can compensate for myopia but not astigmatism; get "eye relief" to accommodate corrective lenses.
What to see? Planets readily accessible, including details on Moon and Mars, rings of Saturn, even moons of Jupiter. Stars are so far away, magnification doesn't change appearance. About half are double-stars, so can see split. Clusters of stars, born in batches; light blows residual dust away, leaving cluster. Globular clusters 1/4 million stars so densely packed you cannot see through them - 200 in our galaxy, can see about half. Messier studied comets; found 110 fuzzy non-comets; list has beautiful and important objects.
Amateurs do make discoveries, pick up work that's too much for professionals, such as monitoring variable stars. Automated sky surveys find most comets, but amateurs still find some.

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