Earth's Rotational Speed
I can understand that the poles arent moving as far as
the equator is but it is still moving. Since the earth is one mass how
can a different space move faster than another? So what do you mean the
equator is moving faster than another part?
The problem with analyzing motion is the need for a point of reference - a
place we assume is standing still. I am standing still compared to the chair
I am sitting on, yet I am moving rather fast compared to the center of the
earth. What might help with your question is if you think of looking straight
down on the north pole and considering the north pole as your frame of
reference. The equator would appear to move a much greater distance than the
north pole (which seems appears to be standing still).
Which person on the merry-go-round moves faster? If you assume the earth is
standing still, the person on the outside is moving faster. But, it is all
relative. Hope that helps.
Assuming that the Earth makes one turn every twenty four hours, and the
Earth if wider at the equator, you have to cover more distance to spin
past a point. Thus to cover that distance, you have to move faster at
the equator than at the pole.
Once per day, the earth rotates about its axis. In each rotation, a point
on the equator will move farther than a point on the axis. Since it moves
farther in the same amount of time, it MUST be moving faster.
As I understand it, your objection is that we're claiming that two points
can move at different speeds and still stay the same distance from each
other. Clearly, this can't happen if both points are constrained to be in a
line. However, when one object revolves around another (for example), the
distance does not have to change. Just because the two objects move at
different speeds, they aren't necessarily moving away from each other.
Richard E. Barrans Jr., Ph.D.
Assistant Director, PG Research Foundation
Darien, IL USA
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Update: June 2012