Tuesday, June 08, 2010


A recent APOD, a cloud of cosmic gas shaped vaguely like a winged Norse helmet, called Thor's Helmet. The nebula is 30 light-years wide and 15,000 light years away, among he stars of our own Milky Way Galaxy. A hot, massive central star is blowing off a wind of matter and energy that heats and excites the surrounding molecular medium. The pink is the glow of hydrogen. The blue-green emission is the signature of oxygen. No doubt the cloud also contains carbon and nitrogen, and smatterings of other elements. Stars are forges of the elements, fusing the nuclei of primeval hydrogen into the stuff of Earthlike planets and life.

It is worth pondering that every atom in our bodies -- yes, the very atoms -- had a cosmic origin. Here again is a schematic of the twenty amino acids that constitutes the building blocks of proteins, with atoms represented by their chemical symbols and by colored "balls," black for carbon, red for oxygen, white for hydrogen, gray for nitrogen (click to enlarge). This is the stuff we are made of. Proteins are hundreds or thousands of amino acid units long, assembled into chains by RNA with information in DNA. Wiggle your finger. You are wiggling stuff that was made in the big bang (hydrogen) and in the cores of stars that lived long before the Sun was born and died in convulsions like the one above.

Think about what makes a successful child's building set, Tinkertoy, say, or Lego, or K'NEX. You'll want a set of basic units in standardized sizes, enough sizes to be versatile but not so many as to be unwieldy. The units should snap or lock together smartly, and hold securely. Lincoln Log constructions fall apart too easily. Erector or Meccano constructions may be fun to build but are a pain to dismantle. A good construction toy should be easy to put together, rigid once assembled, and not too hard to take apart.

And guess what? That's just the way the world is made.

Look out the window at this marvelous world. A gigantic Tinkertoy construction, rigid enough to be satisfyingly permanent, but easily enough disassembled and rearranged to allow for the universe to have a history. My own body -- my own self -- is a temporary accretion in an unceasing cosmic flow of "sticks" and "knobs".

Of course, there is one crucial difference between nature's construction set and Tinkertoy, Lego or K'NEX. Nature's set is self-assembling and self-disassembling. The physics and chemistry of how it happens are pretty well known. But the grand trajectory of cosmic evolution? That, my friends, is a mystery too deep for this poor tinkerer's brain to illuminate.