Coriolis Effect Seems Contradictory to Relativity?

Question

Einstein showed that all frames of reference are equally valid, so the earth can be considered as a frame of reference independent of the rest of the universe. Given that the earth is merely rotating and NOT accelerating, why are winds or missiles or anything above the earth's surface affected by the earth's rotation?

Does it have to do with conservation of angular momentum, as a body travels from large spinning circles toward smaller spinning circles (lines of latitude)? Even then, it still seems contradictory to relativity theory in that the earth doesn't "know" that it is rotating, nor does anything on it.

I guess my question is Why is a rotating frame of reference discernable from a non-rotating one? It's only rotating relative to the rest of the universe; does the universe's inertia matter? Is this related to gyroscopic precession?

I've read the Wikipedia entry and seen the movies of balls on merry-go-rounds. What am I not getting?

This has been bugging me for 15 years

Answer 1

Einstein’s special theory of relativity considers only inertial frames of reference.

EARTH IS ALSO A FRAME OF REFERENCE; BUT IT IS NOT AN INERTIAL FRAME OF REFERENCE.


The difference between inertial and non-inertial frame of reference is as follows.

In non-inertial system of coordinates, a body executes accelerated motion even when it is not interacting with other bodies Hence non-inertial systems possess, in addition to forces due to interaction, forces of different origin, i.e., forces resulting from the non-inertial character of the system. These additional forces do not satisfy Newton’s third law of motion.

Let us select a system of coordinates moving with an acceleration a, having a constant magnitude and direction. All bodies at rest or moving uniformly with respect inertial systems will move with acceleration - a in relation to the non inertial system selected. The acceleration -a is produced by a force
-ma.

But it is not the result of the interaction of the bodies, but is due to the accelerated motion of the reference system.

The fundamental law of mechanics in non- inertial systems of coordinates is written in the form
ma = F + forces due to the non-inertial character.

F is the resultant force due to the interaction of the bodies.

Forces due to the non-inertial character will vary in accordance with the nature of the motion of the non-inertial reference system (rectilinear, circular, circular with accelerated speed etc.)

Earth is a non-inertial frame of reference.

Answer 2

The earth is accelerating by the way!
The point is that the general theory of relativity states it is impossibile to discern if one is in a rotating frame or not!!! This is the general principle of relativity (extension of the special principle of relativity which excluded gravity and said that all the laws are the same in all inertial frames, i.e. non accelerating frames and moving in a straight line. The special principle is in turn an extension of the galileian principle which again took into account only inertial frames but ONLY mechanical phenomena). It states that ALL the laws of physics (mechanical, electromagnetic, optical, etc) are the same (have the same mathematical formulation) in all the possible frames of reference. After all how could nature be affected by our choice on how to describe it? To do this was a really hard task and he had to completely revise Newtonian gavitation. In a few words: how could you tell (I mean perform an experiment) whether your at rest on the earth or in space in a rotating frame which generates a centrifugal force yielding an acceleration perfectly equal to the one due to gravity? No experiment exists to choose which is the case.

Answer 3

Einstein's special relativity theory does not apply to rotating or accelerating masses. The Coriolis effect applies to moving objects on rotating bodies and it can be described by the general relativity theory, because it completely includes Newton's classical theories, wherein the Coriolis effect is understood.

My question: Take ALL mass away from the universe but be the only mass in it. How can we know whether we rest, move uniformly, accelerate or even rotate? Send out and follow a lightbeam and you will know the difference.
We have the total mass in the universe as reference, from which we can also deduct our movements, more or less.

Answer 4

First off who said the earth isnt accelerating :) Secondly no island is and island unto itself cept for an island. In other words nothing in the universe is its own frame of reference without the other frames of reference also being there. So in short Everything effects everything else in some way shape or form. Light coming off a star a billion miles away right now has an effect on the earth we just dont notice it because we cant or dont want to think that big. Its like an ant realizing its an ant what ant would really want to realize its not king of the world? Id love to talk over IMs with you about this subject if you wanted just IM me my contact info is in my profile.

Answer 5

Rotation IS acceleration. Acceleration is a change in *velocity* and velocity is a measurement of speed AND direction. By moving with angular momentum (ie spinning) you are accelerating because you are constantly changing direction.

Therefore a rotating path is not an inertial reference frame.

Answer 6

Hi there.

While I can't answer your question confidently myself, I've posted it on a Science forum that I frequent to see if they can help:

http://www.sciencefile.org/cgi-bin/yabb2/YaBB.pl?num=1166702904/0