The Universe Made Simple/The Earth

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The Universe Made Simple - The Earth

The Solar System →

The Earth is the planet that we live on. All lands, all countries, the oceans, every city, and every human and animal, are all on the Earth. But what is the Earth?

What is the Earth?

The Earth looks flat from where you are, because it's such a big sphere.

The Earth as it looks like from space.

The Earth is shaped like a huge sphere. People used to think it was flat because no matter where you stand, it looks that way. But that's only because the Earth is so large that you can't tell it's a sphere in shape.

Why is there a horizon? Imagine looking out at sea - there's a point in the distance at which it just cuts off and you can't see anymore. Why is this? It's because the Earth is a sphere, and you're looking off its edge!

Life As We Know It

The Earth is the only known planet that sustains life. We are very fortunate to be just the right distance from the Sun, having a perfectly and unusually large moon to keep us poised in harmony, and having a perfect axis to rotate on. More than this, we have land to live on and water to sustain a perfectly functioning atmosphere; without these few things, or if even one of them were missing or out of balance, no life could exist to see the world and the universe in all it's beauty!

Other unique characteristics of the Earth include the magnetic field, which protects us from the Sun's dangerous radiation, our ozone layer, which keeps our atmosphere working at the correct temperatures, and the atmosphere itself; the atmosphere is what allows us to breathe and continue living. Most of the "air" is Nitrogen, about 75% of it! The oxygen we breathe is very important, we couldn't even live without it; it makes up about 21% of the air, while the rest of the air has small percentages of other gases.

We have a lot of ocean water covering the face of the Earth, so the ratio between land and water, especially fresh water, is very important. The "carrying capacity" or limit for carrying life is just right in order for our human and animal populations to continue growing and sustaining each other for a certain amount of time. This is known as the Ecosystem, where all life and aspects of the environment work together in harmony, uniquely, to sustain and carry life. However, we all contribute to making the world a better place, yet not everyone understands that we can also harm things such as the air, the water supply, and the food supply, making life harder to sustain.

Again, all the inhabitants of the Earth - the fish of the sea, the beasts of the field, and the birds of the air - and don't forget mankind; we are all very fortunate to have the perfect planet that keeps us alive. Therefore, many call Earth, "Mother Earth" because she acts as a nurturer of life being born.

All this makes us wonder, with our intelligence and ability to wonder -- how is all this possible?