Time Troubles

I just calculated something out and the result, well, rather depressing... This is a photo of a portion of the Milky Way galaxy. Each dot in the photo is a star. More than 50% of all stars have planetary systems such as our Solar system. The nearest star to Earth, is Proxima Centauri, one of three stars in the Alpha Centauri system. Proxima is 4.2 light-years away. There are 5.8 trillion miles in one light-year (or 5.8 thousand billion, or, if you prefer, 5,800,000,000,000), so, we're dealing with about 25 trillion miles.

A view of the Milky Way toward the  constellation 
Sagittarius.  Source: Wikipedia.

OK, That's bad enough. But, let's say we decide to send an astronaut to Proxima Centauri, in the fastest rocket, at the fastest manned flight speed we've been able to attain (that would be the Saturn V, a 3-stage booster used for the Apollo program - a top speed of 26,000mph). Now, even if we could send that astronaut at the speed of light (exactly 186,282.3976 miles per second, in vacuo), it would take her (or him), 4.2 years to complete the trip as measured by an observer on Earth (because of the relativistic effects of time dilation, only a few days will have passed, as judged by the astronaut - but we're not going there! - not here - that's another story, for another time). But, now for the sad part...

At 26,000mph 0.000037% the speed of light, the trip would take 116,000 years. That's one-way. Our astronaut would be, long ago, fossilized. Time dilation is negligible here, so we don't need to factor it in at such low velocities. One of the nearest stars with a known planetary system is around 15 light-years. So, if we have cosmic relatives somewhere out there within that range, the chances of meeting up with them, are about, absolutely, nil. These distances and times involved are the reason most astronomers don't believe in UFOs, or, that we're being visited by extraterrestrials. YES, WE DO BELIEVE they exist but, not that we're being visited by them on any regular basis. The situation isn't much better with radio communications. Even though radio waves travel at the speed of light, transmission to any hypothetical beings in, say, the Fomalhaut planetary system, will take 15 years. That's one-way. Telepathy, should it prove to be viable, would be much more economical, assuming it to be instantaneous. Another plausible answer might be, to travel through wormholes, to beat the clock, but, for now, they're hypothetical. Other than that, due to the restrictions on speed, we may never meet anyone else; we might always be alone - surrounded, perhaps, by a myriad of Celestial Peoples - and yet alone, regardless.

Dale Alan Bryant
Senior Contributing Science Writer