 Light is a form of electromagnetic radiation. That's the kind of energy that light is. I think you can say light or electromagnetic radiation. I think you can say them the same and it's weird. It behaves like a particle sometimes and it behaves like a wave sometimes. And I don't understand that and I don't care that I don't understand that. The wavelength of light determines the type of light it is. And I have a visual here to help you make sense of this. For me, the wavelength of light is something that I just sort of have to accept. There's nothing that I can't look at anything and go like, oh yeah, I can visualize that there are waves inside the light from the sun or the light from my little round thing that I have to light up my face for this video. But I accept it, I can go okay, and then I can imagine that the wavelength, which is, let's get, let's slow our roll. What is the wavelength of light? It's the distance between, I don't know, what is this? It's the length of one wave of the light wave. The wave, it's really small. The wavelength of light is in nanometers, which is a really, like what, a billionth of a meter. But you can see that some wavelengths are short and other wavelengths are longer. I mean, is that, can you see that well enough to be like, yes, that's a longer one, and here's a shorter one. In fact, the wavelength length determines qualities of light, including what you perceive. If the wavelength of light that hits your eye is around 400 nanometers long, the wavelength of it, which again, like what does that even mean, you can't see it. But if it has that wavelength, your eyeball will send a message to your brain and your brain will interpret that light as whatever this is, like purple. If, on the other hand, it is 300 billionths of a meter bigger than 400 nanometers, and it is instead 700 nanometers, and that wavelength of light hits your eye, you're going to perceive red. The wavelength that you see is determines the color that you see. Now, in the electromagnetic radiation spectrum, we have way more than just visible light. So visible light is just a small portion from 400 nanometers to 700 nanometers. If you go beyond that, if the wavelength is bigger than 700 nanometers, our eyeballs can't perceive it. We don't have a way of seeing that with our eyes, but it is, there are other things that we can do to perceive those wavelengths. For example, if they're in the meter to what, a kilometer range wavelength? That's a really gigantic wavelength. That's radio waves. Who knew that? I didn't know that. And if they get super small, if the wavelengths go smaller than 400 nanometers, then we get into ultraviolet and X-ray. And I don't know what that is. Is that nuclear radiation? Good graciousness. So we can't actually see any of those other waves. The other thing that I think is important about the part of light that we can see is that we can only see it because the light wave bounces off of a thing and into our eyes. The color that you perceive means that wavelength bounced off the thing you're seeing. So this looks like a black shirt to me in the video, but it's actually like a reddish burgundy shirt. So when you're looking, when I'm looking at my burgundy shirt, I would imagine like that's in this range right here. That means the wavelengths of light, white light is hitting me, but all the other wavelengths of light that are not that color get absorbed into my shirt. The wavelengths that are that color bounce off of my shirt and into your eye right now, like even through video. And you perceive my burgundy colored shirt. The color you perceive is the color that's being reflected off of an object. So think about a leaf. Why would I talk about, oh my gracious, that's a leaf, I promise. Why would I talk about a leaf today? Because we're talking about photosynthesis, which takes place in leaves. This means that white light, which contains all the wavelengths from the sun, all the wavelengths of electromagnetic radiation are in there, but when that white light comes down, here look, here comes the sun's white light, even though it's yellow. The green wavelengths bounce off. The red wavelengths get absorbed. The blue wavelengths get absorbed into the green leaf, but the green wavelengths bounce off and into your eye. Does that make sense to you? If you look at this image of all the possible types of electromagnetic radiation, do you get a sense that, oh yeah, there's energy possible there? Okay, in the next section, we're gonna talk about how photosynthesis captures that energy and stores it in sugar molecules.