August 1st, 2008


Launchpad day 2 - sense of wonder engaged, captain...

The first session of the morning might as well have been titled "Light, the Universe, and Everything". We started out with the basics - the electromagnetic spectrum (everyone who is a sentient being on planet Earth should at least know the wavelengths of visible light, according to prof_brotherton) and what it turns into once it passes out of our range of sight and turns into gamma rays, X-rays, ultraviolet, infrared, microwave, TV and radio frequencies. Much of this was basic high school physics.

But then. Oh, but then.

We went into the theory of Kirchoff's laws, and into the ideas of continuous, absorption, and emission spectra - and the fingerprints that elements leave in the electromagnetic spectrum. I learned that helium was first discovered in an absorption spectrum from our sun - hence helium, from Helios. Should have known that one, dammit, how can it be any other way...? And we went into the intricacies of how telescopes work, where they are best situated, what they can see, how they show us what they can see. Names from legend - Green Bank, Arecibo. We were supposed to be the writers and they were telling US the stories. And from there, to NASA's missions past and current and future, giant telescopes hanging in the heavens staring at galaxies through X-ray eyes,the soon to be launched Herschel Space Observatory, observatory airplanes riding on cushions of air high up in the stratosphere.

A few practical fun things - a chance to stare through military-issue nightsight goggles, through which, we are told, you can actually see Andromeda in the night sky. And seeing the world through the lens of an infrared camera - watching people's footprint heat signatures remain vividly clear on the carpets after they had passed by.

Then they let us catch our breath, and they hit us with dust.

Ladies and gentlemen, the universe is full of dust.

The Solar System appears to have dustbunnies. For some reason that idea makes me smile.

The dust lecture, by department head Danny Dale, was breathtaking. For the first time I got an inkling about how pitifully limited my natural senses are, with picture of distant galaxies as seen in the visible light spectrum and then in the IR range, which sees through the dust that obscures features in the section of the EM spectrum that is visible light and produces false-colour-enhanced spectacular images that are breathtaking,for instance the long narrow white-light galaxy M82, known as the Cigar Galaxy, can be seen spewing huge billows of polycyclic aromatic hydrocarbons or PHAs ten kiloparsecs into space - light from the galaxy's stars picked up by dust and re-emitted by cosmic dust particles in the IR part of the spectrum.

And then we heard about the Stardust probe that went out to gather up dust and information from passing comet Wild 2 - and the heartstopping things it did, and how it came back home with its treasure, and the surprises it returned with them, the much larger and more complex molecules than were expected being found than had ever been expected, including silicate crystals that can only form close to a sun - this, on a comet coming in frozen from cold and inhospitable outer space - Danny Dale called it the "fire and ice" theory, the fiery compounds born from an improbable star lying under the deep ice collected out in the Kuiper Belt - it is a tale fit to tell your grandchildren under starlight, about how comets get born, and live, and die.

You can get more of Stardust at its website, there are pictures there, and video, and you can get lost and spend hours on that site. It's the kind of thing that makes you sit up and breathe, "I believe!" and understand viscerally the tenets that underlie a faith.

More swag - we got a wonderful poster with a bunch of galaxies that had been studied. It's stupendous.

The next thing was a hands-on activity that involved actually seeing those spectra which we had been talking about earlier, through a diffraction grating. We gazed on Hydrogen tubes, Helium tubes, Argon tubes, counted emission lines and drew them with Crayolas on blank template papers, and had more fun than I've had since I don't know when.

Break, and then "back of the envelope" calculations session. My thinnest area, this, the maths. And too many people knew more than I did, made leaps of intuition or guesses more educated than I could muster, and by the time I caught up to figuring out a step they were four steps ahead, and after a while I just gave up trying to follow there and then, took notes for later, and sat back and watched. I did learn that trying to do a scale model of the Solar System within the room we were in was physically impossible to do unless we took the sun, proportionally speaking, to be the size of a mustard seed - in which case even Pluto fit into our long seminar room, and Alpha Centauri would have been located in Cheyenne (another mustard seed). If the sphere used as a model for the sun was any larger, the outermost planets would have to be placed miles away, sometimes MANY miles away. Comes back to that original DOuglas Adams, "The Universe is BIG."

The maths cowed me a little, and I was kind of relieved when at least one other participant wanted to know whom she could call if her novels ever needed such calculations to be done. But we did end with a cool little exercise - watching the "Blue Danube" sequence from "2001" and then calculating the G-force on the space station from the formulae just presented to us. We discovered that the space station had pretty much Moon gravity, and then had to go back and double check whether the denizens of the station "moon-walked" along the corridors (which they didn't) - and then we walked back to the residence hall and relaxed for a short while until they came to pick us up for the party at prof_brotherton's at 7:30 PM. At some point during the evening a couple of us went outside to stare at the perfect, clear night sky... with the Milky Way etched across it in all its glory, the first time I've actually seen it in something like twenty years, and then... and then... we had shooting stars. Streaking across the heavens. Leaving no trace but a memory in the heart.

I stood and stared up at the sky and nearly wept at the beauty of it all, at the pale star shadows of our galaxy's arm hanging across the heavens, at the bright star that might have been Saturn or Jupiter, at the Big Dipper, at the star that must have been Polaris.

And my mind was fed, my heart was full, my soul was overflowing with these glimpses into beauty and power.

Good night, wherever you are. I am happy.