Insignificance on a Cosmic Scale

Our sun is just one of a couple of hundred billion stars in the Milky Way. Think of it this way–if you took a soccer field, built a four-foot retaining wall around it and filled it with birdseed–THAT's approximately how many stars there are in just our own galaxy. It's estimated that there are 125 billion galaxies in the observable universe; they span a distance of about 80 billion trillion miles. I'm the self-proclaimed "king of all adjectives" and I'm stumped to think of any words that can do those numbers justice.

Take a look at the attached poster. It's a photograph of a typical spiral galaxy and probably similar to how our own Milky Way galaxy appears from "above." Within one of the galaxy's spiraling arms, the black box marks the area of the Milky Way in which it's thought our sun and entire solar system are located. Zoom in on the enlargement of that area in the poster's lower right hand corner, and within the blow-up you can see a tiny turquoise circle. That circle represents mankind's shout-out to the universe. 

Let's round off man's achievement of broadcast radio transmissions to 100 years ago. Beginning back in the early 20th century, radio waves beamed outward from transmission towers and reached out in all directions. Radio antennae across the broadcast area of those pioneering stations started picking up that signal within the tiniest fraction of a second after transmission since those waves traveled at close to the speed of light. However, those radio waves also traveled beyond the intended cities and towns in their broadcast area–they continued out into the atmosphere and beyond. In fact, every radio and television broadcast and every cell phone call and instant message throughout the history of mankind has been racing out in all directions from Earth into space at 186,000 miles a second.

The turquoise circle below, then, at 200 light years across, represents the distance the very first radio transmissions have traveled since they were first broadcast in the early 1900s. Our news broadcasts, classical concerts and political talk shows have not even come close to leaving our own galaxy; imagine how long it will take for radio waves to reach the hand-full of our neighboring galaxies, let alone the billions of galaxies in the known universe. The folks at SETI (Search for Extra-Terrestrial Intelligence) shouldn't hold their collective breath for a timely reply to their "Anybody Out There???" inquiries.

I had the pleasure of grandnephews Harrison and Zachary's company in Manhattan last winter. Along with their lovely, doting mom, we toured the American Museum of Natural History's exhibit on "Beyond Planet Earth - The Future of Space Exploration" which celebrates 50 years of human exploration of space. Toward the end of the exhibit was a crystal ball view into future plans for space travel and exploration: sprawling moon bases, Martian communities, and permanent space-based cities–all relatively close to Earth. Beyond that, there's little NASA budget for manned missions far into the cosmos. With hope there will continue to be e-gazzillionaires and i-tycoons who will see the potential for huge profits and bankroll our future forays into deep space.

The AMNH has put together a video which provides a yardstick with which to get a better handle on cosmic proportions. Enjoy this round trip from Earth to the edge of the known universe and back. http://vimeo.com/19568852

Safe travels,

Frank Drake