Korpella's work has appeared in a variety of publications. He holds a bachelor's degree from the University of Arkansas. TL;DR Too Long; Didn't Read The earth rotates around the sun because of the sun's gravitational pull -- earth keeps moving forward, and the gravitational pull means it rotates around the sun.
What is Inertia? How to Calculate Pendulum Force. How to Find the Inertia of an Object. What Is Gravitational Pull?
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Stage and screen. Birds and the bees. Could its rotation ever slow down? It is always spinning and causes the earth to spin with it. When it does, the entire eco-system could be wiped out if it's a big enough shift. Mega tsunamis, total change of weather systems, etc. Antartica could end up in the tropics. Johnathan Wilkinson, Surabaya, Indonesia No force is needed because there is no resistive force trying to slow the earth down, so in a sense it rotates now because it rotated before: angular momentum.
To a good approximation, the planets and sun exert zero rotational as opposed to linear gravitational forces on each other. However, there are subtle couplings related to deformations of the planets, which is why for example the moon rotates so that one hemisphere is always visible from earth.
By a similar mechanism the earth's rate of rotation could also change. Tom Boddington, Leeds, UK Another factor is the earth's "moment of inertia", a concept like mass but related to rotations rather than linear motion. Try this: spin round on a swivel chair, then spread out your arms and you will notice that your rotation slows. Bring your arms in and the rotation will speed up again.
With your arms outspread, you have more mass at a distance from your axis of rotation, so your moment of intertia increases. If the earth became more oblique or if geological events redistributed its dense iron core to shallower depths, then the earth would rotate more slowly. Tom Boddington, Leeds, UK Because the earth is rotating it will continue to do so unless a force is applied to either speed it up, or slow it down. Then the powerful radiation and solar winds from the young Sun cleared out everything that was left over.
Without any unbalanced forces acting on them, the inertia of the Sun and the planets have kept them spinning for billions of years. The Earth spins because it formed in the accretion disk of a cloud of hydrogen that collapsed down from mutual gravity and needed to conserve its angular momentum.
It continues to spin because of inertia. Podcast audio : Download Duration: — 3. Podcast video : Download In the case of Uranus, scientists have suggested that collisions — one huge crash with a big rock or maybe a one-two punch with two different objects — knocked it off kilter, Scientific American reported.
Despite these kinds of disturbances, everything in space rotates in one direction or another. Asteroids rotate. Stars rotate. Galaxies rotate it takes million years for the solar system to complete one circuit around the Milky Way, according to NASA.
Some of the fastest things in the universe are dense, whirling objects called pulsars, which are the corpses of massive stars.
Some pulsars, which have a diameter about the size of a city, can spin hundreds of times per second. The fastest one, announced in Science in and dubbed Terzan 5ad , rotates times per second. Black holes can be even faster. But things slow down, too.
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