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Rotation of the Earth reduces acceleration or deceleration effect?


alpha2cen

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When Earth is moving around the sun, our movement is pro or con against the Galaxy rotation or it's movement. But we do not feel anything about it. Does the rotation of the Earth cancel the effects out?

Edited by alpha2cen
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When Earth is moving around the sun, our movement is pro or con against the Galaxy rotation. But we do not feel anything about it. Does the rotation of the Earth eliminate the effects?

 

I see what you're getting at, but you have the wrong idea. In the same way you wouldn't 'feel' the earth spinning, you can't detect the spin of the galaxy relative to our movement around the sun. I think you are imagining a theme park ride, that we are all sat on where there is strong G force and momentum (mass and velocity) affecting our persons. It doesn't work in that way for whole planets... for many reasons.

Edited by Iota93
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I see what you're getting at, but you have the wrong idea. In the same way you wouldn't 'feel' the earth spinning, you can't detect the spin of the galaxy relative to our movement around the sun. I think you are imagining a theme park ride, that we are all sat on where there is strong G force and momentum (mass and velocity) affecting our persons. It doesn't work in that way for whole planets... for many reasons.

 

Earth rotation speed is constant. But Earth moving speed against the Galaxy rotation is not constant. It's speed is increased or decreased with it's position in the solar system.

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When Earth is moving around the sun, our movement is pro or con against the Galaxy rotation or it's movement. But we do not feel anything about it. Does the rotation of the Earth cancel the effects out?

 

Acceleration/deceleration effect isn't official terminology that I've heard of. There was a programme on the Discovery Channel not too long ago, where these two scientists drove their car approximately in the direction of the earth's spin. They calculated that, relative to the Earth, they were travelling much faster than what they were relative to themselves. If you get what I mean. If the Earth's vector is travelling around the Sun in the same direction as our galaxy is spinning, the speed of the Earth relative to objects outside of our galaxy is moving faster than what the Earth is moving relative to our Sun, which is also inside the same galaxy/environment.

 

Look into vector calculation methodology to understand this better.

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The speed of Galaxy rotation is much higher than the speed of the Earth revolution around the Sun. And, acceleration is not too high we feel it. And then, the Earth rotates.

Edited by alpha2cen
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About 8.3 times higher than the revolving speed around the sun.

http://en.wikipedia.org/wiki/Milky_Way

http://en.wikipedia.org/wiki/Earth

 

No, I think you're referring to the linear speed. The rotation period of the sun around the galactic center is 200 MY, while for the earth around the sun, it's 1 year. So, it's a factor of 200 Million smaller. And the motion around the sun is 365 times smaller than the daily rotation, which we don't feel.

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Earth energy fraction(assuming self rotation is 1)

 

self rotation----------------------------------- 1

 

revolution around the Sun------------- 9000

 

revolution around the Galaxy------- 625000

 

revolution around the local group--- 900000

 

Direction component is ignored.

Edited by alpha2cen
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You appear to be confused, alpha2cen, confused about the difference between rotation and revolution, confused about the difference between angular velocity and translational velocity, confused about superposition, and confused about what we do and don't "feel". I'll go over these one at a time.

 

Rotation verus revolution

Suppose you have a friend stand stationary, say facing north. You stand in front of your friend and spin in place. From your friend's perspective, you are rotating but you are not revolving. Next suppose you walk in a circle around your friend, but you always face north during this walk. Now your friend sees you as revolving but not rotating. Finally, imagine combining the two motions, spinning while walking around your friend. Now your friend will see you as both rotating and revolving.

 

You are using the word "rotation" when you should be using "revolution" or "orbit". Rotation and revolution are very distinct concepts.

 

 

Angular versus translational velocity

The Earth's rotation rate is one 360 degree revolution per sidereal day. This rotational rate, 360 degrees per day, has units of angle divided by time. The Earth revolves about the Sun, completing an orbit (360 degrees) in one year. The solar system revolves about the Milky Way galaxy, completing an orbit in about 230 million years. These orbital rates, like planetary rotation, have units of angle divided by time. Angle divided by time is angular velocity.

 

You answered swansont's question about angular velocity with translational velocity. The angular velocity of the solar system as it orbits the Milky Way is very, very small.

 

 

Superposition of force

NASA has occasionally placed satellites in orbit about the Moon. A pair of such satellites are orbiting the Moon right now. That these satellites are orbiting the Moon does not mean that the gravitational influences of the Earth, Sun, Milky Way don't influence the orbits of these satellites about the Moon, nor does it mean that they aren't also orbiting the Earth, the Sun, or the Milky Way. Those other bodies do perturb the orbits of those satellites about the Moon, and those satellites are in a sense orbiting the Moon, and the Earth, and the Sun, and the Milky Way. Forces are subject to the superposition principle in Newtonian mechanics, which means that forces add as vectors.

 

 

What we "feel"

Whether we feel gravitation depends on what you mean by "feel". If by "feel" you mean "subject to the force of", then the answer is yes. It's the superposition principle. If by "feel" you mean "sense", the answer is no. We don't "feel" gravitational force. We feel everything but gravity. The astronauts and cosmonauts aboard the International Space Station feel weightlessness even though the Earth's gravitational force on those astronauts and cosmonauts is about 90% of that on the surface of the Earth. What you are feeling as weight is the normal force of the Earth's surface pushing up on you. Take away this upward force such as by taking one of those zero-g rides at an amusement park and you too will feel weightless.

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What we "feel"

Whether we feel gravitation depends on what you mean by "feel". If by "feel" you mean "subject to the force of", then the answer is yes. It's the superposition principle. If by "feel" you mean "sense", the answer is no. We don't "feel" gravitational force. We feel everything but gravity. The astronauts and cosmonauts aboard the International Space Station feel weightlessness even though the Earth's gravitational force on those astronauts and cosmonauts is about 90% of that on the surface of the Earth. What you are feeling as weight is the normal force of the Earth's surface pushing up on you. Take away this upward force such as by taking one of those zero-g rides at an amusement park and you too will feel weightless.

 

So, no gravity in the space comes from the force balance. Actually, there is no place which has not gravity in the Galaxy.

Edited by alpha2cen
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So, no gravity in the space comes from the force balance. Actually, there is no place which has not gravity in the Galaxy.

Try again. The first sentence does not make sense, and the latter is false if you mean zero gravitational acceleration.

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No gravity state in the International Space Station comes from the interrelationship between the centrifugal force and the Earth gravity.

 

Earth energy fraction(assuming self rotation is 1)

 

self rotation----------------------------------- 1

 

revolution around the Sun------------- 9000

 

revolution around the Galaxy------- 625000

 

revolution around the local group--- 900000

 

Direction component is ignored.

 

A particle energy in the Earth is very high than one of the stationary state in the Local Group.

Edited by alpha2cen
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No gravity state in the International Space Station comes from the interrelationship between the centrifugal force and the Earth gravity.

Nonsense. There is no centrifugal force in an inertial frame. The centrifugal force is a kind of fictitious force. Fictitious forces exists solely in the mind of a non-inertial observer. Fictitious forces cannot be sensed. Looking at orbits as a balance between centrifugal force and gravity is an absolutely lousy way to explain orbits. It doesn't work.

 

The correct Newtonian explanation of why a uniform gravitational field cannot be sensed is that the gravitational acceleration of a test mass is independent of mass. A uniform gravitational field exerts zero measurable stress or strain on an object. A non uniform gravitational field such as the near-spherical field exerted by a planet on an object can be sensed, but only when the object is large enough / sensors are sensitive enough so as to make tidal gravitational effects observable.

 

Newtonian mechanics is not the ultimate explanation of gravitation. General relativity is much closer to that ultimate explanation. The general relativistic explanation of why a uniform gravitational field cannot be sensed is very simple: Gravitation is a fictitious force in general relativity. Fictitious forces cannot be sensed.

 

 

A particle energy in the Earth is very high than one of the stationary state in the Local Group.

This isn't even nonsense. It isn't even a sentence.

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Nonsense. There is no centrifugal force in an inertial frame. The centrifugal force is a kind of fictitious force. Fictitious forces exists solely in the mind of a non-inertial observer. Fictitious forces cannot be sensed. Looking at orbits as a balance between centrifugal force and gravity is an absolutely lousy way to explain orbits. It doesn't work.

 

The correct Newtonian explanation of why a uniform gravitational field cannot be sensed is that the gravitational acceleration of a test mass is independent of mass. A uniform gravitational field exerts zero measurable stress or strain on an object. A non uniform gravitational field such as the near-spherical field exerted by a planet on an object can be sensed, but only when the object is large enough / sensors are sensitive enough so as to make tidal gravitational effects observable.

 

Newtonian mechanics is not the ultimate explanation of gravitation. General relativity is much closer to that ultimate explanation. The general relativistic explanation of why a uniform gravitational field cannot be sensed is very simple: Gravitation is a fictitious force in general relativity. Fictitious forces cannot be sensed.

 

 

The objects in the Space Station

Fg=(G ms mE)/r2

Fc= - ms r (omega)2

 

Fg+Fc=0

 

ms; mass of the object in the Station

mE; mass of the Earth

r; distance from the center of the Earth

 

Any object is on this force equilibrium state.

This isn't even nonsense. It isn't even a sentence.

 

Ep_earth= Ep_stationary local basis + Ep_local translation + Ep_galaxy revolution in local group + Ep_galaxyrotation + Ep_earth revolution + Ep_earth rotation

About 0.000005 Ep energy might be increased.

The translational speed of the Local Group is not precise, yet. The more reference is needed.

Edited by alpha2cen
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As D H has already stated, there is no centrifugal force if analyzed in an inertial reference frame. The force can't be zero. The object is moving in a circle, thus it must be accelerating.

 

Energy is frame-dependent. The energy of the earth is high in a frame moving quickly with respect to us. The energy is small in a frame that is close to being at rest with respect to us.

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