Questions from a grade 3
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For a long time, people though the sun was just a big ball of fire in the sky. And it true that the sun is very hot; hot enough to burn almost anything. But actually, the sun doesn shine because it on fire. If it did, it would have gone out already, because even the sun isn big enough to burn for that long. Instead, the sun shines for the same reason that nuclear bombs explode.
What happens in the sun and in nuclear bombs (some of them, anyway) is that it squeezes atoms together. In the sun, the squeezing is from gravity; in nuclear bombs the squeezing is from normal bombs that go off in a circle around the nuclear bomb. Anyway, it squeezes the atoms together enough that they get smashed into a single atom, like if you push two balls of play dough together. Now, it takes energy to hold something together: like if you had two dogs on leashes it would be hard to keep them from running away from each other, right? Well, it turns out that for some type of atoms (like hydrogen getting smashed into helium) it takes less energy to keep the new big atom together than it did to hold the two old atoms together. So the extra energy comes out of the smashed atom, and one of the ways it comes out is by light. And the light shines out into space and that why the sun shines. In nuclear bombs the extra energy comes out as an explosion (and also light). Just like a nuclear bomb is bigger than a campfire, there a lot more energy Pandora Silver Gold Yellow Charm 284 made from smashing atoms than if the sun was just a big fire, so the sun will keep shining for a very long time.
To start off, remember that black is just what you see when there Pandora Silver Gold Yellow Charm 284 is no light. So if you don see anything, it will look black. So the real question is, why don we see anything in most places we look?
OK, so there has been a paradox for hundreds of years that says that if the universe is full of stars and has no edges, then every direction we look, there should eventually be a star. So if the universe has existed forever, then the whole sky should be as bright as the sun, because the light from each of those stars has had forever to reach us. Since that obviously not true, people decided that one of several things had to be true: either the universe had edges or wasn filled with stars, or it hadn lasted forever. That was one of the reasons that eventually the Big Bang theory won over the Steady State theory, because people decided it was more likely that the universe had a beginning than that it had an edge.
But the Big Bang theory had its own problems. Although it did say that the universe had a beginning (about 14 billion years ago), it also said the universe all started out compressed into a tiny space, and was very hot and bright, and since it was the entire universe in every direction we should see that even if we weren looking at a star. And actually, that true: we do see the Big Bang everywhere. But it still looks black, and here why. The Big Bang says that the universe is getting bigger all the time. It doesn get bigger the way an explosion gets bigger, where things fly apart. Instead, it gets bigger the way a balloon inflates: the universe is stretching out like a giant balloon. When light from far away places travels through space, it gets stretched out along with the universe. And when light gets stretched out, its color changes. First it turns red, and then if you keep stretching it goes dark. It not actually dark, it tiffany necklace cheap just a color that our eyes can see (called "infrared" because it below red). Well, light from the Big Bang has traveled so far, and been stretched so much, that its color is far past what our eyes can see. But we can make special cameras that can pick up that color, and that another reason we think the Big Bang is true.
So it turns out that the universe is not actually black, it just that we can see the color it is.
When a normal ("main sequence") star forms, it first starts fusing hydrogen into helium in the center, or core, because that where the pressure is highest. Over time, as hydrogen is Pandora Silver Gold Yellow Charm 284 used up, a ball of helium grows at the core. Since helium is Pandora Silver Gold Yellow Charm 284 denser than hydrogen, it forms a smaller ball than the original hydrogen, but with nearly the same total mass. That means that gravity is stronger at the surface (of the helium core, not the star), and so more hydrogen can be fused. So the helium core Pandora Murano Glass Bead 088 keeps growing, with more and more hydrogen fusing at its surface.
As the core grows and hydrogen fuses, this creates more and more outward pressure, pushing the rest of the star that outside the core farther and farther away. As it gets farther from the hydrogen fusion, it cools down and turns "red". This is a gradual process that continues throughout the normal lifetime of the star. It only stops when the temperature and pressure are high enough to start burning helium.
Metal is dug from the earth, Pandora Murano Glass Bead 261 but when it comes out of the ground it is in a rock called an ore. Factories do various things like heating the ore up super hot, or dissolving it in chemicals to get the metal out.
Why do we need food and water?
Food contains energy, which is the stuff that lets your body run and jump and move around. As you do that, you lose energy so you must replace it by eating. When you run and jump and move around, you sweat, and you lose water. You also lose water by going to the bathroom. This must be replaced as well. One thing water is used for in your bodies is blood, which is mostly water. (Maybe over simplified)
How do your eyes and body move?
Your muscles are attached to your bones, and your muscles can pull like rubber bands, which allows you to move.
Languages in Canada came from a few different places. Long before europeans (white people, if you will), came to Canada, the First Nations inhabited it, and so their languages are a part of Canada. Once the europeans found out about Canada, they sent explorers to claim chunks of it as soon as they could. The English and the French both got large chunks of Canada, and they brought their languages with them. England and France fought some wars over Canada, but ultimately the French gave their territory to England. The French settlers still lived there, so they kept their language, and thus French is still an official language of Canada.
Why did the dinosaurs come before people?
Earth was different back when the dinosaurs lived. For one thing, it was warmer, and more humid. Dinosaurs are great at living in that kind of environment, but people weren (Again, maybe an oversimplification but I tried).
The universe is black because black is what we call it when there is no light. Most of the universe is empty, with only the occasional star to put out light. Black crayons are black because they do not reflect very much light.
The more people you have, the harder it is to keep order amongst them. Historically this was an even bigger problem, because there were no phones and no internet, so if something was happening far away, you could not react to it quickly. Over time people settled in groups and formed governments at sizes that made sense to them, based on how many people they had and how Pandora Silver Gold Yellow Charm 284 spread out they were. Nowadays that is not such a big deal, but countries have persisted because it is a convenient way to order things.