 We all love our universe. After all, it is our home, and it would be a shame if anything happened to it. But unfortunately, all good things must come to an end, including our universe. But how exactly will our universe end? Well, there are multiple scenarios for how the universe could end, but in this video, let's focus on a few. The first scenario is the big crunch. Now, before I tell you what the big crunch is, let me tell you about a little something called dark energy. Dark energy is an unknown form of energy which hypothetically permeates the entire universe and is believed to be the cause for the expansion of the universe. According to the big crunch theory, the dark energy will not be able to continue expanding the universe in the far future, since the dark energy will either no longer be powerful enough to do so, or there won't be enough dark energy to continue the expansion, all the matter in the universe will collapse into one big monstrous black hole. Isn't that nice? Think the big crunch sounds intense? Let's spice things up a little bit more with the next scenario, the heat death. Our universe is constantly transitioning from a state of order to disorder because of a little thing called entropy. Entropy is a tendency of a system to move from a high state of order to chaos. For example, let's say your room is the universe. You try to keep your room clean and in a state of order. However, as time passes by, you'll notice the room gets more and more messy and chaotic. The same thing can be said about the universe. So what happens once the universe reaches maximum entropy? All the stars would have burned out, all the galaxies would have disintegrated leaving black holes, which will also disintegrate, and after all the black holes disintegrate, the protons themselves begin to deteriorate, and once that's done, the universe will be a mist of electrons that will eventually approach absolute zero. In addition, entropy isn't the only cause of the heat death. The heat death theory also states that dark matter will continue expanding the universe, pushing all the stars, galaxies, and planets far, far away from each other, dispersing the heat throughout space and clusters. Our third and final scenario is the big rip. Remember that dark energy I've continuously mentioned throughout this video? Well, according to the big rip theory, that dark energy is going to be so powerful, it will literally rip apart everything in the future. Solar systems, stars, planets, and even molecules and atoms. So you're probably feeling down about the death of the universe and all that stuff, right? Well, don't. Because you and I have a long time to go before the end of the universe comes, and by the time it does, you and I are going to be dead, so it really won't matter.