Why are the leaves FALLING?

        Ha ha, get it? Falling in the fall. You have to love corny jokes. They're just awesome. Oh, dang, where are my manners? Hi there. What's up? Today we're going to learn about the leaves changing. Oh, man, it's so cool. I mean, just the different colors and shapes, and then when they fall, sometimes they get crunchy, and then you step on them...ah, memories.

        And don't forget making leaf piles and jumping in 'em! Of course, SuperSara hasn't done this, so what we're gonna do is make on for her! Okay, so have you ever wondered why your pretty tree in your backyard that has your tire swing is looking like it's sick because its poor leaves are falling off?

        And if you think how much that tree helps you, you could get really worried. But there's no need! The tree isn't dying. The leaves are...which is better, but not by much. The leaves are dying, not because the earth is moving away from the sun, like some people think, or because the weather gets colder, like other people think, but because there's less sunlight. And, no, that still has nothing to do with the earth moving away from the sun or the cold. Stop interrupting me! It has to do with season, which we'll get into later, all right? Good.

        So why would leaves need sunlight, you ask? Well, it has something to do with a thing called photosynthesis. Plants can't go into McDonald's and ask for a double cheese burger with large fries. It doesn't happen that way with them. Plants have to make their own food, which is where photosynthesis comes in. The plants, which obviously includes leaves, take in the sunlight and, well, create food. It's a longer process than that, but that's not what we're learning about. I kind of feel bad for the plants, because they get no variety, just the same old boring food every day.
        Anyway, I think you can see where I'm going with this. If leaves need sunlight for food, and there's less sunlight during the fall and winter, can't you guess why the leaves die? They can't get enough food, in case you can't guess. It's actually pretty sad when you think about it: leaves only live for two seasons.

         

        Okay, so now you know why leaves fall off the trees. Now you have to know why leaves change colors. What some people don't know is that leaves already started out with the red, orange, and yellow that you see during the fall. But chlorophyll, which helps get energy from the sun for photosynthesis and gets rid of waste that the tree can't use, is green, and that green overpowers the other colors. And when the days get shorter, the chlorophyll sort of dies, and the other colors start to show through.

        Now it is time for the season changes! Whoop whoop! I love spring, fall, winter, and summer. But I like the cold more than the summer, and I'd like the cold to stay a bit longer! Maybe, if I find out what makes it like that, I can persuade the earth to stay a bit longer in winter, and a bit shorter during the summer. Of course, everybody's probably gonna kill me, because there's no school during summer. 

        Okay, so like I told you before, seasons don't depend on the earth moving away from the sun. While that would be easier to explain, it is not possible. You see, the the earth moving from....and I'm getting off topic. Sorry about that. So you know how a globe is never strait? How it's always tilted? Have you ever wondered why that is? Just in case you don't know, it's because that real earth is tilted. It's tilted on its axis. The axis is tilted at about 23.5 degrees. 

 

        The earth rotates on its axis, and that causes the days and nights.

        But the earth spinning on the path around the sun, the path that takes a year, or 365 earth days, to complete, is what causes the seasons. Without the tilt, however, the seasons wouldn't change, and it would probably be the same temperature all year where you live. Can you imagine that? Anyway, when the sun hits the northern hemisphere directly, the days get longer and hotter. That's summer.

        While that's happening, the sunlight is hitting the southern hemisphere at an angle, which make the days shorter and colder. That's winter.

        When the earth is on the other side of the sun, the northern hemisphere has winter, and the southern hemisphere has summer. But the tropical place are on the equator, which is the border between the northern and southern hemisphere. The poor tropics are hit by the sun for the whole year, so their seasons don't change much. Poor them. The north and south poles are different. It's winter, then summer, and there's no fall or spring. Summer there means it's always light, even during the night. Winter there means it's always dark, even during the afternoon and morning. 

       

        Here's when the seasons are supposed to start in the northern hemisphere: spring starts with the vernal equinox on March 20th, or 21st.

        Summer starts at the summer solstice, which begins on June 21st.

        Fall falls on the autumnal equinox, on September 22nd, or 23rd.

        Winter starts on the winter solstice, on December 22nd or 23rd.

        Together, of course, these create the seasons!

        Of course, the southern hemisphere would start spring when the northern hemisphere stars fall, vice versa. The southern hemisphere would start winter when the northen hemisphere starts summer, and vice versa again.


        And that's basically it for this! Yeah, I know there was a lot of pictures, and I'm sorry for that, but you can't blame me. Seasons are beautiful. Okay, so if you want to learn more, I'll put some links below, and as always, my classmates' blogs are going to be there, too. I hope you guys have a great day. I have to leaf now...haha, get it? Peace out!
Fountain of Seasons Animation: Really Cool but Not Very Informative
Science Made Simple: Why Are The Leaves Changing?
Why Leaves Change Color
How Stuff Works: Changing Seasons
When Do The Seasons Change?
SuperSara's Blog
Katie's Blog
Logan's Blog