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1º ESO/ROTATION AND REVOLUTION - Contenido educativo
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You've seen the sunset, right?
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And if you get up early enough, maybe you've seen it rise, too.
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But have you ever wondered, if the sun rises every day and sets every night, where does
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it go when we can't see it?
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Well, nowhere.
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It's actually us that goes somewhere, because we're on the Earth and our planet is always
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turning or spinning on its axis.
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Imagine a line passing through the center of the Earth that goes both through the North
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pole and the South Pole. We call that invisible line the axis. Earth spins around on this
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axis like a top. This spinning movement is called the Earth's rotation, and the Earth's
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rotation is what gives us day and night. Every day, all year. If you're on the side of the
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Earth that's facing away from the Sun, as the Earth is spinning, it's night. If you're
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on the side facing the Sun, it's, you guessed it, day. Now hold on tight, because the Earth
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is actually moving in more ways than one. At the same time that the Earth spins on its
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axis it also orbits or revolves around the Sun this movement is called its
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revolution one full orbit all the way around the Sun is one revolution and the
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earth takes 365 days or one year to complete a revolution so have you got
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all of this so far the earth is rotating on its axis creating day and night and
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the same time it's revolving all the way around the Sun now here's the thing as
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the earth is both rotating and revolving it's not sitting straight up and down
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Its axis is actually tilted just a little.
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It's not all that much, but this tilt causes one part of the Earth to lean towards the Sun,
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while another part of it is leaning away.
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This means that different parts of our planet's surface gets different amounts of sunlight and heat.
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So, why am I telling you all of this?
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Well, as the Earth travels around the Sun, it creates a pattern throughout the year.
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This pattern happens over and over again, and I'm sure you've noticed it.
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At certain times of the year, you see the Northern Hemisphere leans towards the Sun,
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and the Southern Hemisphere leans away.
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And at other times, the southern hemisphere leans towards the sun, and the northern hemisphere leans away.
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That pattern, my friend, is what makes seasons.
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When the part of the world that you're living in is leaning towards the sun, it's warm and the days are long.
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Summer. When you're on the part that's leaning away from the sun, it's cold and the days are short.
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Winter. In between, it's spring or autumn.
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If the Earth weren't tilted, we would have the same season all year long.
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So, revolution, rotation, orbit. Is your head spinning?
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Let's do a demonstration to shed a little light on these concepts.
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Okay, you're going to need a globe and a table lamp without a shade,
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plus a table to put them both on.
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Put the lamp in the center of the table and turn it on.
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Put the globe on one side of the table.
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Now hit the lights.
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The globe is Earth.
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Makes sense, right?
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The lamp at the center of the table is the sun at the center of the solar system.
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Now slowly spin the globe.
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As the Earth rotates, the sun lights up one side of the planet better than the other.
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It's day where the light is shining more brightly on the globe and night where it's not.
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Now let's see what the Earth's revolution around the Sun looks like.
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Give the globe a few spins with one hand while slowly pushing the globe in a circle around
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the Sun, or the lamp with your other hand.
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So do you notice how the Earth keeps rotating as it revolves around the Sun?
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If this were the real Sun and Earth, by the time you get back to where you started, the
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globe would have completed 365 rotations, or days.
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And that's another year gone by.
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So what does all this show us?
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It shows that what looks to us to be the motion of the Sun in the sky is really caused by
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the motion of the Earth.
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So now you know.
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When you look up and see the Sun setting or rising, it's not going around us.
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It's sitting pretty much at the center of the solar system while we and the seven other
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planets go around it.
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That Sun always got to be the center of attention.
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- Subido por:
- Alicia M.
- Licencia:
- Dominio público
- Visualizaciones:
- 131
- Fecha:
- 24 de febrero de 2021 - 19:25
- Visibilidad:
- Público
- Centro:
- IES LA SENDA
- Duración:
- 04′
- Relación de aspecto:
- 1.78:1
- Resolución:
- 1920x1080 píxeles
- Tamaño:
- 106.98 MBytes