Home Alone

I’ve always been fascinated by astronomy. I followed the progress of the new Mars explorer, Curiosity, as it made the journey to Mars and then safely descended to its surface earlier this year. Now Curiosity is sending back photographs of dried up river beds giving evidence that a large amount of water existed on Mars in the past. Where did this water go?

Recently other planets have been found orbiting other distant stars and many of these planets have been shown to have water as well. It all gives a sense that if we really do screw up our planet Earth that we can always move. I carried out a little thought experiment when thinking of all this stuff. The nearest star to us is Proxima Centauri. This star is not even visible with the naked eye. Proxima is a red dwarf star and doesn’t sound very inviting. It is what they call a flare star; flare stars’ output vary dramatically from time to time. Searches for planets around Proxima have found nothing. But… let’s imagine going to visit this star if there was something interesting there. After all, it is in our vicinity.

Proxima is just over 4.2 light years away. A light year is the distance that light travels in one year. Light travels very fast and a light year is a very big number. For comparison Polaris, the North Star, is 430 light years away. The fastest speed that a manned space vehicle has travelled was Apollo 10 when it was returning from the moon. Apollo 10 achieved a speed of almost 40,000 km per hour. Pause for a moment and imagine how long a voyage it would be to our nearest neighbor at this speed. Human devices have travelled faster. The Helios unmanned mission to the sun achieved a higher speed by using the sun’s gravity. Its highest speed was roughly 245,000 km/hour. How long do you think it would take at this speed?

A spacecraft travelling at Apollo’s speed would take 113,692 years! A craft travelling at Helio’s speed would take 18,500 years! Eighteen thousand years is an impossibly long voyage. Eighteen thousand years ago the area we live in was covered with ice–our last ice age. Most of our land was covered with thousands of meters of ice. This ice melted. North America grew its vast forests. The first Native Americans travelled into the area and multiplied. Rich civilizations developed in Egypt and our history began. (This all occurred probably in a 12,000 year period).

The point of all of these calculations is that we are alone. I do believe in extra-terrestrial life but the distances are so great that we may never find other beings. We’re certainly not going to move any time soon. This precious Earth is all we have and we should each strive as much as we can to protect it.

Imagine if this sense of aloneness was the central framework used in making all of our decisions. Would we be ripping tar out of the land, processing it at great environmental costs and shipping it across plains and mountains ? Would we be creating chemicals that persist for thousands of years? Would we be fishing out the oceans? Would we be polluting our oceans, destroying the plankton and causing mass extinctions? Think about it. We are home alone.

Larry Hill still cares for his patients part-time at his dental practice. At home he is cared for by his three chickens and raises ideas at his small farm in Nanaimo.

Published by Dr. Larry Hill

Dr. Larry Hill traveled to Nepal as a volunteer dentist in September 2008.