Do you see that pic over there on the right? You can click it to make it bigger for a better look. It’s a look backward in time at just a small sampling of the number of galaxies floating around since the beginnings of the universe. It’s estimated that some of those galaxies shown therein existed back when the universe was only about 2 billion years old. Practically still an infant when you’re talking about the universe.
This particular pic is only 1/10th of the field surveyed by Hubble during a search for young galaxies. The full field is estimated to contain over 25,000 galaxies and that was one of two spots in the sky surveyed. The total produced over 50,000 galaxies of which Nasa thinks there’s at least a good 2,000 or so that qualify as infant galaxies from back when the universe itself was still very young. There’s a great article about this survey up over at RedNova News which is where I got the image from.
Think about that for a moment: Two relatively small patches of night sky and we have images of thousands of galaxies out there. Consider that our galaxy, the Milky Way, is thought to contain around 400 billion stars (give or take 200 billion depending on who you ask). Assuming that the Milky Way is an average galaxy and multiplying all of this together and you realize that there’s a shitload of stars out there floating around with a good chance that there are billions upon billions of planets floating around out there as well.
It’s a hard thing to wrap your head around. The probability for other life to exist on other worlds goes up with each star that could potentially have one or more planets around it and with the number of stars in our own galaxy alone, let alone the galaxies we’ve been able to photograph, it becomes hard to accept the idea that this single planet is the only one on which it developed.
Not that I’m going to start buying into the claims of the UFO Nuts anytime soon, though. The presence of life doesn’t necessarily mean that life is intelligent on a scale similar to, or even beyond that, of mankind. The majority of life on Earth, after all, is driven by instinct and not intelligence. People often conclude that the rise of self-aware intelligent beings is an inevitable part of evolution, but many evolutionary biologists are still debating whether intelligence has any real value for long-term survival of a species. If we end up wiping ourselves out with the products of our intelligence (weapons, cars, engineered super germs, what have you) then the development of intelligence could be said to have been a bad thing for us as a species. Even if we manage to wipe out a good chunk of life on this planet, the simplest organisms that have been here all along will continue to thrive until the sun burns itself out. The development of intelligence may just be a fluke of evolution instead of a common result of it.
Even assuming for the moment that intelligent life is relatively common, the distances involved between stars are mind boggling. Our closest neighbor, Proxima Centauri, is at least 4.2 light years away. The speed of light is 299,792,458 meters a second or roughly 983,571,056 feet a second or even more roughly 186,283 miles per second which means that in a year’s time light travels somewhere around 9,454,254,955,488,000 meters or roughly 5,874,601,673,407 miles. Now multiply that by 4.2 and you get 39,707,870,813,049,600 meters or roughly 24,673,327,028,311 miles to Proxima Centauri. In my 2000 Pontiac Grand Prix with an average of 350 miles to a tank of gas it would take 70,495,220,080.885,714,285,714,285,714,286 tanks of gas to get there. Assuming, of course, my car and I could operate in a vacuum and were capable of “driving” to the nearest star. At today’s gas prices this clearly becomes an impractical vacation destination. Keeping in mind that these distances are all calculated based on how the photon flies and even at the ridiculous speed of photons it still takes 4 years and 2 months or so for light to get there and given what we know about light speed travel not only would it be difficult to reach that speed, but it would have some unpleasant side effects on our social lives.
OK, so does your brain hurt yet? If not then try this: All of the distances crap I list up above was for just the nearest star to us in our own galaxy. The next nearest spiral galaxy similar to the Milky Way is the galaxy Andromeda which is a mere 2.2 million light-years away and is headed in our direction at a healthy speed of roughly 670,000 miles per hour on a possible collision course in about another 5 billion years. We’d better start drawing up evacuation plans now. You can never be too early in your planning for upcoming disasters.
So what was the point of all of this babbling? Not much, I just got wrapped up in my awe and wonder at a really cool picture from the Hubble and wanted to try and wrap my brain around some of the numbers. Figured I’d take the rest of you along for the ride.