 Now, let's take a look at how our energy gets into our system. And hopefully, this doesn't hurt your head to think about this. All the energy on our planet, all of it. Everything that is fueling you comes from the sun. And I think it's relevant. Energy from the sun comes to us in the form of light. And that's actually, light energy is what is fueling the whole shebang. You, right now, are functioning because of light energy from the sun. When the sun goes out in, I can't remember, like eight billion years or something like that, done, game over. So, we figured out a way to manufacture our own light energy that doesn't come ultimately from the sun's light energy. We're out of luck. We're screwed. Okay. How does light come out of the sun? Well, it's a process called fusion. And this is insane. Fusion is combining atoms. So, it actually takes, for example, a hydrogen atom. Okay, I'm going to eliminate the ion part of it. Two hydrogen atoms. And instead of producing what you would expect, which would be like hydrogen gas, no. It actually produces helium. What? Seriously? Yeah. Fusion reactions make new molecules. And it is not messing around. If you did this in your body, you'd be looking like the sun, which you would not be very happy about. We can't really do this in our bodies, so we rely on the sun to do it for us. So, the process of fusion happening in the sun is how we end up with light energy. Light energy comes down and it enters the Earth's atmosphere. So, this is the atmosphere. And I have some facts on here, just how much energy actually does, check about, check, seriously? Two billionths of all the light energy that the sun is producing in any moment. Two billionths of that actually makes it through into our atmosphere. The rest of it, guess what happens to it? It comes down and bounces off. It's like, oh, I'd like in, no. The rest of the, whatever, two billionth minus 100% percent of the sunlight energy gets bounced off, it goes back out. The atmosphere rejects it. Sorry, man, no. And thank your atmosphere right now, because we're actually glad that only two billionths of the light of the sun makes it in. Okay, so this sunlight actually made it in. What happens to it? Well, do you agree? Let's draw ourselves a little apple tree, because the sunlight is used by that apple tree. This is my apple. That's an apple. Totally looks like an apple. Let's make an apple. The tree captures the light from the sun and makes sugar. Seriously, how awesome is that? What's that process, clowns? Photosynthesis. Photosynthesis takes the light energy, and then with some other stuff, and we're spending an entire day on photosynthesis, produces sugar. Thank you, holy thank you very much, because then, guess what happens? We're going to eat the sugar. I'm going to stop here, and we're going to talk about what do we do? What is the process that we do in our bodies to get the energy out of the apple that the tree produced for us?