All the talk about the “supermoon” last weekend got me thinking about celestial events. It’s cool that the moon was sort of close to the Earth for a few days, and that those few days happened to have coincided with a full moon, but there are a lot more exciting things going on in the universe! So I’ll share a few with you.
As we speak, the Sun is performing a great feat of alchemy. Ok, so it’s not turning lesser metals into gold, but in a way it’s trying. The Sun, along with most stars in the universe, is converting hydrogen to helium. What’s helium useful for? Why do we care? Well eventually it will run mostly out of hydrogen, and start making that helium into carbon. Again: who cares? We want gold here, why should we care about carbon? Well, if our sun were much bigger, then after a little longer it would turn start turning that carbon into bigger elements. The bigger the star, the bigger the elements it can form, but there is an upper limit. A really huge star will eventually supernova, which basically means that it explodes, spraying all the stuff inside it all over the place. This creates a nebula, but what it also does, is creates enough pressure and heat to form much larger elements like Uranium and, yes, GOLD! So all you have to do is throw your worthless metals onto a gigantic star, wait a few billion years for it to go nova, and then fly around collecting all the little particles of gold. Have fun.
The word “collision” brings to mind images of car crashes, things smashing into each other, and general wreckage. But what do you think about the concept of galaxies colliding? Yes, it happens. The thing about the universe as we think we know it is, that once you reach the order of magnitude of galactic distances, things really aren’t all that far away. The edge of our galaxy is about 6 orders of magnitude away (around 10^6 light years,) whereas galaxies might be less than an order of magnitude away from each other. That doesn’t mean that it’s easier to travel to a distant galaxy than a nearby star, but rather that, for their size, galaxies are relatively close together. Galaxies are also freaking massive (pardon the physics pun,) and where there’s a lot of stuff, there’s a lot of gravity. Gravity attracts, and things that attract collide. Of course, a galactic collision isn’t quiet as terrifying as it sounds. Since galaxies are so sparse, the objects within them rarely actually collide with each other. They affect each others orbits, but there aren’t planets hurtling around smashing into one another while the aliens in their super fast space ships dodge the debris.
Do you believe in aliens? Do you believe in space travel? Maybe you should. To the best of my knowledge (this is where my education drops off and my curiosity kicks in,) there is no physical proof that there are any more than 3 dimensions. While it would be small-minded to assume that ours is the highest dimension, we haven’t yet been able to hop through the 4th dimension like they do on Gene Roddenberry’s Andromeda. It’s a shame too, because a quick trip through the fourth dimension would make space travel a lot easier. Let’s say that, on the next piece of paper that you encounter, there lives a race of two dimensional people. They don’t really look like people, exactly, but more like amoebas, since any lines that crossed their bodies would actually divide them in half, but let’s say, for the sake of argument, that they’re there. You see one tired little 2D amoeba who has to cross the entire paper to get home, and crawling as a 2D amoeba does, he’ll never make it home in time for dinner. So, being the 3D being that you are, you fold the paper in half, and allow the amoeba to transit through your dimension to reach the paper on the other side. The amoeba crosses the whole piece of paper – at least an hour’s journey – in a matter of seconds, and you’ve saved the day.
Now, let’s say there’s a 4D creature looking down on us Earthlings. He/she/it sees us with our eyes peeled looking for new life and new civilizations, trying to go boldly where no one has gone before (classic slogan edited for grammatical correctness and gender neutrality.) The 4D creature takes pity on us, folds our space, and let’s us transit through the 4th dimension to a new region of space. A journey that would have taken us several lifetimes takes a few minutes. That’s fantastic, but wouldn’t it be better if we could fold space ourselves? This is one of the ideas behind much of the interstellar travel in science fiction. Apparently scientists aren’t convinced that it’s possible, mostly because we don’t know enough about it, but I choose to say that they’re a bunch of pessimistic old fools, because I want to believe that reasonably fast interstellar travel is possible. (If you want to play with the idea of multiple dimentions, try the open source game Adanaxis, or (yet to be released) Miegakure.)
Finally: The Biggest Explosion in the History of Anything
The biggest explosion in the history of anything, depending on who you talk to, happened about 13 billion years ago. They don’t call it the “Big Bang” for nothing. In fact, “Big Bang” doesn’t really do it justice. It was such a big explosion that it didn’t destroy anything, it created everything. From five minutes after the Big Bang to 380,000 years after it, the entire universe was more than three thousand degrees Kelvin, made up mostly of hydrogen and helium, and existed as a big ball of rapidly expanding plasma. Plasma, if you didn’t know, is what happens to gas when it gets so hot that it can’t remain a gas anymore, and the electrons begin to float freely between adjacent nuclei. Yes, it’s that dramatic. But what about before that? You ask? Before that, the universe was so hot (from 10^29 to 10^15 degrees kelvin) that photons (particles of light) could spontaneously turn into other subatomic particles. 0.001 seconds afterward, those particles weren’t hot enough to change their type anymore, and began to annihilate each other. The creation of the Universe, at least according to the Big Bang theory, was very violent, and quite AWESOME. The creation of the universe is one of the only instances in human speech where you can use as extreme language as you like and barely scrape the boundaries of hyperbole.
I hope you enjoyed these galactic facts. Remember that, while space seems to be it’s own little niche field that only super nerdy smart people go into (note: not referring to myself here; I would be honored to work at NASA or CSA, but I’m not sure that’s ever going to happen,) you’re technically in space right now; it’s not nearly as far away as we might think. If you’re curious about our knowledge of the universe, Wikipedia is probably your best source. Just find a page about which you’re curious and click around. Ok, maybe it’s not the most “accurate” source of information, but it’s more accurate than other online encyclopedias, it’s updated more frequently, it’s totally free, and has awesome pictures so it’s excellent for exploration, if not for term papers. The book I used in my Astrophysics course in CEGEP, which I’m now realizing is quite good is called Stars, Galaxies, and Cosmology by Bennett, Donahue, Schneider, and Voit. Since it’s a textbook it’s probably more expensive than a typical “quench my thirst for knowledge” book, but it’s quite thorough, has great pictures and diagrams, and if you buy the “Media Update” it’s relatively cheap for a textbook. The online examples are also pretty sweet.