# "State the effects produced by rotation and revolution of the earth".

Discussion in 'After Hours Lounge (Off Topic)' started by John Pine, Mar 8, 2005.

1. ### John Pine Supporting Actor

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Need help with this question. Here's all I've come up with.

rotation: gravity, atmosphere and magnetic field/ozone layer

revolution: seasonal changes?.... or is that caused by the 23-degree tilt of the axis?

Any feedback?

2. ### Rob Gardiner Cinematographer

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Who taught you this? Gravity is the attraction between two masses. Rotation has nothing to do with it.

3. ### Jeff Gatie Lead Actor

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The seasonal changes are due to the revolution around the sun, taking into account the tilt in the earth's axis. As the earth revolves around the sun, at some times of the year the tilt (as seen at the North Pole) is more towards the sun (summer in the Northern hemisphere) and other times it is away from the sun (summer in the Southern Hemisphere). Tides are also influenced by the revolution, i.e. since the path is an ellipse, the earth is closer to the sun at some points of the year than others, so the sun's gravity is stronger, thus influencing the height and/or lowness of tides (but not the time of them, that's rotation).

4. ### MikeSerrano Second Unit

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You're 0 for 4 on rotation. Gravity is related to mass, the magnetic field is due to a liquid ferrous core, the atmosphere (of which the ozone layer is a component) hangs around and doesn't evaporate into space thanks to gravity and protection by the magnetic field.

For rotation, you may look into what's called "frame dragging".

Seasons are caused by both the solar orbit and the tilt of the axis.

[EDIT: yeah, what they said...]

-Mike

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Damn .

Perhaps you should provide the context of the question i.e., what kind of exam? I mean, day and night is a pretty obvious answer, but may be too simplistic for your case.

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H

6. ### Andrew Pratt Producer

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7. ### Jeff Gatie Lead Actor

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Holadem is right. Could you tell us what grade level and difficulty we are talking about? We could be talking about the effect of linear acceleration on the measurement of gravity, taking into account Einstein's theory of relativity of a high velocity object as opposed to a stationary one affecting the time element of the gravitational constant... or we could be talking night and day.

My bet is on the latter, any takers?

8. ### John Pine Supporting Actor

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"Perhaps you should provide the context of the question i.e., what kind of exam? I mean, day and night is a pretty obvious answer, but may be too simplistic for your case."

Ok, point taken, here's the context. This is a possible essay question that will be given for a county-wide Science Olympiad on the Intermediate School grade level (4th-6th). Ok...so...

Rotation: Day/Night, Tides

Revolution: Seasonal changes

9. ### Jeff Gatie Lead Actor

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Yeah, I think we can rule out the effect of relativity on the gravitational constant. The coriolis effect might be an interesting tidbit to add to rotation.

Edit, note also that the tides are further influenced by the orbit of the moon around the earth and the orbit of the earth around the sun. This relationship is more complex than just the rotation of the earth, but the earth's rotation is an important component.

10. ### Ken Chan Producer

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More on day/night: if the planet did not rotate as often as it does, one side would get hotter and the other side would get colder. Imagine if it took a week or a month for the sun to "cross the sky". If we were spectacularly unlucky, and a day took exactly one year, one side of the planet would always face the sun. I suppose people would have to live in a ring, right on the edge between day and night; I think I saw that in a movie or TV show So overall, it would affect the weather (short-term) and the climate (long-term).

11. ### Bryan X Producer

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I always thought gravity was the result of the Earth's core being made up primarily of Silica while all other matter was made up primarly of water.

12. ### Eric_L Screenwriter

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Rotation - day/night - shorter trips when flying east, partially responsible for weather patterns and ocean currents, moderating temperatures, love..

no wait, I got the last one backwards...

13. ### Al.Anderson Cinematographer

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To be more precise, the seasonal changes are due to the angle of the earth vs the sun - not the distance between the earth and the sun.

14. ### Sean Bryan Sean Bryan

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The "spin" of tropical storms.

Water spiraling down the drain.

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16. ### Adil M Supporting Actor

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Rotation is used to simulate gravity in outerspace where gravity's effects are lesser. It's cool how if there is a missing force you just redirect other forces.

17. ### Grant B Producer

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Kids these days...when we were young we use to cheat by copying out of an encyclopedia but noooooooooo
Now we ask physicists who hang out on home theater forums

I think copying was easier now that I look at the thread

18. ### Jeff Gatie Lead Actor

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But that is just centrifugal force (actually it's centripetal force, cetrifugal force is a "ghost" force) where the outside of the ship is "pushing in" due to centripetal acceleration towards the center of the spin. This has nothing to do with gravity, it is just kinematics. Besides, outside of theory and Kubrick's 2001, it has never been used (at least to my knowledge).

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And we're talking about Earth's rotation anyway.

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H

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