I’m a pretty optimistic guy. Okay, I’m a really optimistic guy. But even my optimism has its limits when bashing up against the cold hard reality of what experiments plus our understanding of the laws of physics tells us about the universe. Here are my top three most depressing facts about the universe coming from the field of physics and astronomy.
- The speed of light. The speed of light is a real bummer, dude. I mean sure, 299792458 meters per second may sound fast, but in comparison to the nearly 40 trillion kilometers to the nearest star, it’s not very fast. And considering the fact that it takes light around 100000 years to cross the galaxy, which is not even to mention the 20 to 40 times longer it takes light to travel between the galaxies, well, if there is something that the speed of light is shouting it must be “You might as well cancel your travel plans!” Because the speed of light limits how fast we can travel, this means any plans for galactic empire (which of course we all dream about) face a stiff barrier in how long such a trip will take. Of course, time dilation helps out the actual travel time, but any star traveler moving at relativistic speeds is doomed to abandon the society he or she originated from. Gone is the idea of space traveler, replaced, by a spacetime traveler, whose travels must abandon not just his society’s place but also his society’s time. Exploration has always been a lonesome endeavor, but on an astronomical scale, the speed of light makes any such trip a major downer.
- Heat death Personally, I love thermodynamics. If you’ve ever seen a thermodynamic argument applied outside its natural domain, well it’s a thing of beauty. But the second law of thermodynamics. Well it’s a bummer. The entropy of a system, well, like a hippie in Amstradam, it just seems to be getting higher. Disorder, disorder, disorder. Ultimately will we reach a point of maximum entropy, with the universe in complete equilibrium? Some people worry about communism, me I worry about things all going to equilibrium. Of course one can take solace in estimates that the time it will take to reach heat death is something like 10100 years, but not me. At night I wake up worrying that in the end, not only will we all be alone, but we will be nothing but the remains of blackhole Hawking radiation. Oh, right, I’ll be dead well before then. Which I guess is to say “entropy sucks.”
- Dark Energy The bad news used to be that the universe was expanding. As far as things go, this isn’t too bad of news, because it was possible that while the universe was currently expanding, with everyone running away from you like you’ve got swine flu, it was possible that soon the universe might stop expanding and start contracting (of course the big crunch at the end of all of this might be a problem.) All the better to spread the swine flu, don’t you know? But now we are learning that not only is the universe expanding, but that the rate of expansion is actually accelerating! The villain here is the apply named “dark energy.” Dark is right, it seems that not only are we getting more cosmically lonely, but that we must have made a faux pas of epic proportions and everyone is leaving the party with the pedal to the metal. At night the ice weasels may come, but someday they won’t come any more, damn you dark energy.