The Universe Is Mean. I'm Telling The Teacher >:(If you think about it, you'll realize just how "meaningless" you are in the grand scheme of things. Now, what I mean by that is that we're just one little teeny weenie planet in this indescribably huge universe.
The universe is not a nice place, it is in fact a very DANGEROUS place. The earth could be wiped from existence in an instant if we were to be unlucky enough to have one of the universe's many hazards come our way.
Let me give you an example of one way the earth can go poof. So there is a star, very very far from earth, and it has a pretty name to classify it's destructive potential. This star is called a Wolf-Rayet. Wolf-Rayets like to produce gamma ray bursts when they die, which is basically an unbelievably powerful stream of energy that emits from the axis of rotation. This stream is full of nasty things that don't play nice with living things, such as intense radiation. So lets introduce Wolf-Rayet 104 to the stage. This pretty star (it does look pretty) has it's top axis pointed (what seems to be from observation) directly at earth. Now, it can't be said for sure if it is aiming DIRECTLY pinpoint 100% at us, but if you look up pictures of this star, you'll see that we are looking pretty much directly at the top of the star, which well... means its top axis is pointing in our direction. So if wolf-rayet 104 decides it's going to produce a gamma ray burst, it will turn the earth into a piece of burnt toast if it comes near us. NO amount of scraping will remove the black either. Let this be an example of how RIDICULOUSLY powerful a gamma ray burst is. This star is thousands of light years away from us, and it would STILL reach earth. There's no doubt that the gamma ray burst would reach earth, because it definitely would. The question is whether it would hit earth or not. This will not happen in your life time though, or the life times of generations and generations to come, because the star still has a few hundred thousand years to live. On a cosmic scale, this is actually a very short amount of time however. You have to realize things in the universe can take up to a few billion years before they happen. How long does our star have left to live? about 4 billion years or so? So yeah, that's a pretty uh... long time lol. Compare those 4 billion years to wolf-rayet's hundred thousand years left to live however, and it suddenly seems much closer than before.
This next one is actually a personal favorite of mine. So there are two galaxies, yeah? Both have a super massive black hole at their center, however the larger galaxy's black hole is emanating an unbelievably large stream of energy. This jerk galaxy, appropriately named a death galaxy, is blasting its neighbor galaxy with all sorts of life eradicating energy. You can actually find a picture that shows the "death galaxy" blasting the other galaxy. The picture is small and you can barely make out what's happening, but you have to realize this is... ******* far as HELL from us, and despite how small it appears, remember that it's a freaking galaxy. Galaxies tend to be pretty large you know, so take that into account when you see that this death galaxy is pretty much coating the entire neighbor galaxy with its "love." :)
Good thing that thing isn't near us hmm?
I think the "creepiest" way for the earth to go goodbye though is through "strange matter." What is strange matter? Strange matter is a theoretical type of matter which is hypothesized to occur in a high density environment, such as the core of a neutron star. Strange matter has the frightening ability to catalyze the conversion of "normal matter" into strange matter. Taking this into account, if a single tiny strangelet were to impact earth, it would instantly catalyze the conversion of whatever it hit, and turn that into strange matter. This conversion releases energy, which sends the newly formed strange matter in more directions converting more matter. Eventually earth would be reduced to nothing more than a giant ball of strange matter. This is one we don't have much to fear from naturally happening though, as it's said that strange matter should occur so far from us, that if it did ever reach earth it would have decayed to its ground state, which is positively charged. It would be repelled by our negatively charged atoms, and rarely merge with anything. Now we look at Brookhaven and see they have an ion collider. This collider is said to produce the conditions necessary for strange matter to form. It's okay though because the scientists operating the collider have said the world hasn't ended yet, so it's okay D:.
More common ways for the earth go goodbye is a simple asteroid ******* us up. Our moon has taken shots for us, I mean look at the damn thing. Even Jupiter has stopped asteroids on a potential collision course with earth. So be sure to bake a cake for our moon and Jupiter whenever you get a chance, just to show your appreciation that they've stopped a big *** rock from splitting the earth in two :).
So try to appreciate life a little more because well... it could be worse. Our galaxy could be getting blasted by a death galaxy, or earth could be getting converted into a giant ball of strange matter :).