Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: scientizscht on 26/06/2020 11:50:26
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Hello
I am confused by Coriolis force.
Is it real? Does it really act on objects?
I read that it is not a real force however how can it then be a result of earth's movement onto objects and not be a real force?
The earth's movement exerts force on the objects on the planet and it supposedly creates and maintains their kinetic energy in respect to the earth's rotation.
Thanks!
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Like centrifugal force, it is real in a rotating reference frame, and not real in an inertial frame.
So say I'm on a space station in deep space with artificial gravity from rotation.
A dropped stationary ball will accelerate to the floor despite no gravity. That's centrifugal force.
It will follow a curved path instead of a straight one. That's Coriolis force.
In an inertial reference frame, the same ball does not accelerate at all and follows a straight path with constant speed until a force is applied to it (by the accelerating floor). Neither centrifugal nor Coriolis forces are real in that frame.
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Like centrifugal force, it is real in a rotating reference frame, and not real in an inertial frame.
So say I'm on a space station in deep space with artificial gravity from rotation.
A dropped stationary ball will accelerate to the floor despite no gravity. That's centrifugal force.
It will follow a curved path instead of a straight one. That's Coriolis force.
In an inertial reference frame, the same ball does not accelerate at all and follows a straight path with constant speed until a force is applied to it (by the accelerating floor). Neither centrifugal nor Coriolis forces are real in that frame.
OK but does Coriolis force change the total kinetic energy of the object in any way?
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OK but does Coriolis force change the total kinetic energy of the object in any way?
It seems so. Take my dropped object. Let's remove the space station 'floor' and just let the thing go. Over time it will pick up speed, without bound, most of that being due to Coriolis force, so its kinetic energy is going up continuously in our rotating frame of reference. In an inertial frame where the Coriolis force doesn't exist, the ball does not gain KE over time. This is one way to show that KE is quite frame dependent.
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If you fly on a great circle track from the north pole, you have exert a force to keep turning left, because the Coriolis effect makes the apparent wind blow from the east.
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https://www.ametsoc.org/ams/index.cfm/education-careers/education-program/k-12-teachers/project-atmosphere/training-opportunities/project-atmosphere-peer-led-training/project-atmosphere-peer-training-resources/coriolis-effect-module/
This is worth a look,
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Gawdamighty! If that's what they teach in schools, no wonder nobody understands it! The meteorology courses for pilots and mariners are a lot simpler.
Difference between a teacher and an educationalist. A teacher takes a subject he understands and phrases it so a child can understand it. An educationalist takes a subject he doesn't understand and phrases it so nobody else can.
Please, Sir, if the Coriolis force is responsible for the jet stream, why does it go the other way?
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Could be I should have read more than the intro before posting.
Maybe I won't waste the time now.
Thanks Alan.
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Hello
I am confused by Coriolis force.
Is it real? Does it really act on objects?
I read that it is not a real force however how can it then be a result of earth's movement onto objects and not be a real force?
The earth's movement exerts force on the objects on the planet and it supposedly creates and maintains their kinetic energy in respect to the earth's rotation.
Thanks!
It's among a class of forces called inertial forces[/b]. Before Einstein they were referred to as pseudo forces. After Einstein created general relativity they were called inertial forces and looked at as real forces. At least it was looked at byh Einstein that way. Some modern relativists look at it that way, such as D'Inverno.
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Please, Sir, if the Coriolis force is responsible for the jet stream, why does it go the other way?
I know (I think) that the Coriolis effect is involved, but are there not other factors that have greater responsibility for the actual development of jet streams?
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I'm just quoting from your reference!
The only atmospheric drivers are heat, water and spin.
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If you are on a moving train, you see the train not moving however an engine consumes energy to maintain the train's movement.
Is coriolis like that? If yes, then it creates/maintains kinetic energy in respect to a static point in the universe.
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If you are on a moving train, you see the train not moving however an engine consumes energy to maintain the train's movement.
Is coriolis like that? If yes, then it creates/maintains kinetic energy in respect to a static point in the universe.
The energy the engine consumes is just to overcome friction. You can also claim that the train is motionless, and it's engine is consuming just so keep it from being drag along with the moving Earth.
There is no "static point" for the universe.