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The Coriolis Effect The Coriolis Effect

08-25-2020 , 01:33 PM
I'm not going to comment in this thread except to clarify the question if needs be.

What I am interested in, is how would you define the Coriolis effect. What is it, why it happens, examples of situations in which it would happen, the mathematics involved and so on. The more detail the better.
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08-25-2020 , 04:03 PM
You are not the first who wonders

https://www.thoughtco.com/what-is-th...effect-1435315
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08-26-2020 , 10:29 AM
Yeah it is defined as the apparent deflection of a body when viewed by an observer who is on a non inertial rotating frame. By definition 2 reference frames are required, defined either explicitly as a non-inertial rotating frame and an inertial frame, or implied by the fact we need the motion of a body, AND a rotating reference frame. I have not seen a defintion at any level that gets away from the 2 frames.
However, I am told that 2 reference frames are not required, only one. Mathematically this may be the case, but not physically - with only a rotating frame a Coriolis force does not become apparent, you just rotate. But with motion with respect to this frame, a Coriolis effect becomes apparent as the body is viewed from the perspective of the rotating frame. So physically there are 2 frames, one in which the body is moving (inertial) and one from which the body is viewed (non inertial rotating).
According to the definition of the guy who developed the framework, I do not think the inertial frame need be inertial, there could be 2 non inertial frames, ie "motion either linear or otherwise" with respect to a non inertial rotating frame. But usually it is defined as motion in a straight line in an inertial frame as viewed by an observer on a rotating frame, eg throw a ball from a moving roundabout. This is clearer, easier to understand and gets the physical principles across without obfuscating the point with stuff about there only being one frame - which I think is wrong anyway.
Did say I wasn't going to comment (ie debate) but I guess the context is required
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08-26-2020 , 08:12 PM
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Originally Posted by 1&onlybillyshears

Did say I wasn't going to comment (ie debate) but I guess the context is required
That was a good guess, but it was incorrect
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08-28-2020 , 09:35 AM
Well anyway that is the context - establishing various ways to consider the Coriolis effect
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08-28-2020 , 01:30 PM
{Bad links Can Mod delete previous version pls.}

Quote:
Originally Posted by 1&onlybillyshears
.
However, I am told that 2 reference frames are not required, only one. Mathematically this may be the case, but not physically - with only a rotating frame a Coriolis force does not become apparent, you just rotate. But with motion with respect to this frame, a Coriolis effect becomes apparent as the body is viewed from the perspective of the rotating frame. So physically there are 2 frames, one in which the body is moving (inertial) and one from which the body is viewed (non inertial rotating)
This has been debated for 300+ years. Newton held the view that rotation was absolute and not simply relative to some inertial frame. The Einstein/modern view is that the universe supplies a chosen reference frame in which distant galaxies are not rotating and that defines 0 rotation. But that brings up the obvious question. We know that centrifugal forces cause rotating planets to bulge at the sides, so are we really going to say that if the entire universe was just one planet in empty space centrifugal forces would cease to exist and it wouldn’t be meaningful to talk about whether it was rotating or not? I think most people have some issues with that but experiment obviously doesn’t allow us to test it either way[/quote]
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08-29-2020 , 02:42 PM
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Originally Posted by ecriture d'adulte
{Bad links Can Mod delete previous version pls.}

This has been debated for 300+ years. Newton held the view that rotation was absolute and not simply relative to some inertial frame. The Einstein/modern view is that the universe supplies a chosen reference frame in which distant galaxies are not rotating and that defines 0 rotation. But that brings up the obvious question. We know that centrifugal forces cause rotating planets to bulge at the sides, so are we really going to say that if the entire universe was just one planet in empty space centrifugal forces would cease to exist and it wouldn’t be meaningful to talk about whether it was rotating or not? I think most people have some issues with that but experiment obviously doesn’t allow us to test it either way
Would it not be more fair to say that the distant galaxies simply reveal the non-rotating frame, and do not actually supply it? (or is supply to be meant in exactly this sense - perhaps a problem of language or translation)? Mach's statements are stronger, but in the end Mach had to be abandoned by Einstein.

https://www.sciencedirect.com/scienc...05722316300111

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The gravitational field due to a rotating body was first attempted by Thirring who used Einstein field equations in the linear approximation and showed that a rotating thin spherical shell produces near its centre forces analogous to the Coriolis and centrifugal forces of classical machines.
This paper goes further and shows the same effects with exact solutions of Einstein's equations.

A universe consisting of just one rotating planet would presumably have some gravitational and electromagnetic fields. And if the planet had varying density or surface imperfections (mountains, etc) it would produce gravitational waves as it rotated, and would not produce these when it did not rotate. So it would seem that empty space is something that can be "rotated relative to" (and we know that empty space is far from empty, quantum mechanically speaking).

Last edited by TimM; 08-29-2020 at 03:05 PM.
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08-29-2020 , 07:00 PM
Quote:
Originally Posted by TimM
Would it not be more fair to say that the distant galaxies simply reveal the non-rotating frame, and do not actually supply it? (or is supply to be meant in exactly this sense - perhaps a problem of language or translation)? Mach's statements are stronger, but in the end Mach had to be abandoned by Einstein.
That might be a better way to say it, I’m not an expert on the history but I thought Mach’s statements were not quantifiable mathematically so aren’t “in” general relativity the same way the equivalence principle is. Maybe your formulation is more accurate though.

But If distant stars reveal the non-rotating frame, what happens if the universe is rotating around a central point and you place a stationary planet there?

Last edited by ecriture d'adulte; 08-29-2020 at 07:25 PM.
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08-29-2020 , 11:14 PM
If the universe were rotating about a central point, all the bodies in it would have to be gravitationally bound to that point, so it would represent the center of an enormous mass. So I imagine there would be some effect, as in the paper above. But I'm not sure it would be the same effect as the planet itself rotating in a non-rotating universe. If it would, such that the two situations were indistinguishable, it seems you'd have a new kind of equivalence principle between the two situations.
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08-30-2020 , 01:11 AM
Incidentally I see one citation that part of Godel’s motivation for finding a roatating universe solution in general relativity was to convince Einstein that Mach’s principe doesn’t make sense. No idea if that is true but it seems reasonable.
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09-05-2020 , 08:36 AM
The Coriolis Effect is bs

If there was any effect bc of the earths rotation then riddle me this...

If a plane traveling from LA to New York is traveling 600mph and the earth rotates west to East at around 1000mph then how does the plane ever get to New York?

The answer is simple: the earth is flat and motionless; fixed and immovable

The plane gets there exactly the minute you expect it to get there using rate x time = distance ... thus there’s no such thing as Coriolis effect

The circular effect that appears to take place could be explained by having a circular disk like plane that we live on with north as the true center point and south being in every direction outwards from due north.
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09-09-2020 , 11:16 AM
Quote:
Originally Posted by ecriture d'adulte
Incidentally I see one citation that part of Godel’s motivation for finding a roatating universe solution in general relativity was to convince Einstein that Mach’s principe doesn’t make sense. No idea if that is true but it seems reasonable.
Now we know that empty space is not empty, but filled with quantum effects. I have not looked into how hard this would be, but it should be possible to detect rotation with respect to these effects. So it's not just the distant masses that would have to revolve around the planet, but space itself. That definitely makes no sense (if the entire universe is rotating, what is it rotating relative to?).
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09-10-2020 , 04:01 PM
Since we are only talking about general relativity, we are completely ignoring the quantum mechanical nature of matter and the vacuum. The Godel Rotating universe is filled with an idealized type of dust, which causes the the rotation.
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09-11-2020 , 11:33 AM
Practically, a rotating frame must rotate with respect to an inertial frame.
Mathematically, representing absolute rotation is difficult if not impossible.
Fair summary?
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09-17-2020 , 03:02 PM
Quote:
Originally Posted by rjr777
The Coriolis Effect is bs

If there was any effect bc of the earths rotation then riddle me this...

If a plane traveling from LA to New York is traveling 600mph and the earth rotates west to East at around 1000mph then how does the plane ever get to New York?

The answer is simple: the earth is flat and motionless; fixed and immovable

The plane gets there exactly the minute you expect it to get there using rate x time = distance ... thus there’s no such thing as Coriolis effect

The circular effect that appears to take place could be explained by having a circular disk like plane that we live on with north as the true center point and south being in every direction outwards from due north.
This one’s easy. There’s no such thing as absolute velocity, only velocity relative to some reference frame. The 1000 mph velocity of the earth’s rotating surface is relative to a reference frame attached to a (non-rotating) point at the center of the earth. The plane’s 600 mph velocity is relative to a point (such as LA or NYC) on the surface of the earth. The plane as it sits on the tarmac in LA awaiting clearance to takeoff has a velocity of zero relative to the surface, but 1000 mph relative to the center point — it’s rotating right along with the rest of the surface. When it taxis down the runway, it doesn’t lose that velocity due to earth’s rotation; the plane’s velocity adds to the rotational velocity. As a result, while cruising, the plane is moving 1600 mph relative to the center point, while NYC is only moving 1,000 mph away from the plane. Thus the plane “catches up” to NYC and lands as expected.
The Coriolis Effect Quote
09-25-2020 , 01:43 PM
Quote:
Originally Posted by rjr777
The Coriolis Effect is bs

If there was any effect bc of the earths rotation then riddle me this...

If a plane traveling from LA to New York is traveling 600mph and the earth rotates west to East at around 1000mph then how does the plane ever get to New York?

The answer is simple: the earth is flat and motionless; fixed and immovable

The plane gets there exactly the minute you expect it to get there using rate x time = distance ... thus there’s no such thing as Coriolis effect

The circular effect that appears to take place could be explained by having a circular disk like plane that we live on with north as the true center point and south being in every direction outwards from due north.
Lol christ, is this really the level flat earthers think at? An argument like this passes through the group with no one giving it a minutes thought and pointing out that it's very obviously wrong and they should maybe stop using it? The susceptibility of fringe subcultures to terrible arguments is one of the scariest things to emerge from the internet.
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09-25-2020 , 03:56 PM
I was just going to ignore it. Answer found in any middle school science text.
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