00:02Oh, hey, hi. I'm Chris and Chris and welcome to So Cool Science. Science you can do right at home.
00:11I'm just looking at the very first calendar and going over today's science file. In today's science file, it says.
00:21How did ancient people track the year? Well, that's an awesome question. Try this. You'll need some rocks, a railing,
00:40and a sunny day. Today, I am going to show you how to make your very own calendar right at
00:47home.
00:48No, no, no, no. I'm not talking about, you know, one of those days of the week out, you know,
00:52with the boxes and numbers and the month at the top. I'm talking about a solar calendar because I am
00:59going to show you how to make your very own solar calendar right at home.
01:03So the first thing you need is the sun because you can't make a solar calendar without it.
01:11And the next thing you're going to want to get is, yeah, that's right, a railing. You thought I was
01:16going to say a rock, right? That's the third item.
01:20Okay, here's what you're going to do. You're going to take your rock and you're going to line your rock
01:24up with the sun in the horizon. A lot like this.
01:28Okay, so now you've got to wait an entire month before we can do the next step. But it's way,
01:33way, way cool. So, you know, you're going to want to wait it.
01:36Whoa!
01:46Whoa, now check this out. Each of the months that I did this, you can see that the sun moves
01:51across the horizon.
01:53Now that's so wicked cool. So, why does the sun move across the horizon? And how is this like a
02:00calendar?
02:01Well, don't look at me. Take a closer look at this.
02:06The reason the sun moves across the horizon is due to a phenomenon known as parallax.
02:11Parallax simply means appearance of objects due to motion.
02:15Parallax is one of the major reasons we know the earth goes around the sun.
02:19If we record the sun in the horizon at one spot, the earth will move from that current position.
02:24As the earth moves, we'll see the sun at a slightly different angle from what we previously recorded.
02:30If we continue to track the sun for a whole year, we'll get six rocks, and the sun will continue
02:36to bounce back and forth through those rocks.
02:38Ancient cultures figured this out about 8,000 B.C. and used this to mark important events throughout the year,
02:45such as the spring and autumn equinoxes.
02:47This was important because ancient people needed to know when to plant crops as well as when to harvest those
02:53crops.
02:54In fact, many of our modern day winter solstice celebrations are based upon the sun.
02:59On December 21st, in the northern hemisphere, the sun stops rising above the horizon for three days.
03:06On December 25th, the sun would rise up one degree in the horizon.
03:10Ancient people celebrated this because to them it meant this fictional supernatural being would return them to the warmer, sunny
03:17days of life.
03:19So now you know how ancient people track the year.
03:22You know, making your own solar calendar right at home is why science is so cool.
03:32You know, in the middle of the world, it's a little bit of a little bit of a little bit
03:34of a little bit of a little bit of a little bit of a little bit of a little bit
03:34of a little bit of a little bit of a little bit of a little bit of a little bit
03:35of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit about a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a little bit
03:36of a little bit of a little bit of a little bit of a little bit of a
Comments