wheel physics

[jb]

The last point i can answer with certainty , we are not moving as a result of universal expansion, the space between galaxies is getting bigger, the galaxies them self are not moving , as counter intuitive as that sounds that things are simultaneously staying still and receding, but that relativity for you

The first bit I'm perplexed about, if I'm stood next to a mountain, I'm accelerating with respect to the sun, but the mountain is not ! Is that correct ?

No, you and the mountain are jiving together - along with everything else on the planet.

Your point about the universe expansion and relativity I don't disagree with but it's not that relevant to local space.

But the mountain is part of the planet you you said the planet wasnt accelerating just things on it, that's me, not the mountain

5he mountain will be counter balanced by a similar mountain on the other side that is decelerating

Ever been on a fairground on that thing that spins as it rotates, you get the feeling of slowing down and then being catapulted forward, because it spins at a rate that actually sends you backwards whilst traveling forwards, the effect is many times milder on the planet but it's there.

[Pinkie]

No, you and the mountain are jiving together - along with everything else on the planet.

Your point about the universe expansion and relativity I don't disagree with but it's not that relevant to local space.

But the mountain is part of the planet you you said the planet wasnt accelerating just things on it, that's me, not the mountain

5he mountain will be counter balanced by a similar mountain on the other side that is decelerating

Ever been on a fairground on that thing that spins as it rotates, you get the feeling of slowing down and then being catapulted forward, because it spins at a rate that actually sends you backwards whilst traveling forwards, the effect is many times milder on the planet but it's there.

I'd be more intrested in an explination of mountains and people

I'm still not clear if the mountain accelerates or not and if it does why the other side of the planet doesnt slow it down

[KM2]

The earth is accelerating towards the sun. Changing velocity. Any other rotation/acceration must surely be superimposed on that.
If we weren’t rotating, we’d still be accelerating towards the sun.

[Pinkie]

The earth is accelerating towards the sun. Changing velocity. Any other rotation/acceration must surely be superimposed on that.
If we weren’t rotating, we’d still be accelerating towards the sun.

I'm pretty sure it's not. It does speed up and slow down due to the eccentricity of its orbit. But at no time is it accelerating towards the sun as it not travelling towards the sun at all.Its travelling in a straight line in curved space time not towards the sun

The sun is slowly expanding and thus getting nearer

[fausto99]

[moderator note: this topic was split off from viewtopic.php?f=5&t=148727

An explanation - with images - of the movement of a rolling wheel

https://peltiertech.com/rolling-wheel-animation/

This is why, if the earth were rotating and orbiting, we'd know about it - there would be a speeding and slowing effect with the extremes at 12AM (fastest) and 12PM (slowest). If this seems conspiratorial then I apologize, but it's just physics as the above link demonstrates. What happens when you apply this to the earth...

Is this for real or are you looking for the Month Python £5 argument? You've certainly achieved it.
Shouldn't this all be moved to a flat earth forum?

[KM2]

Any object in orbit is falling towards the central mass. We are no different. We happen to be travelling at a speed which allows us never to get to the sun, in our case.
Velocity is a vector, if the direction of movement changes, it has accelerated, and must have had a force applied in our case, the sun’s gravity.
The gravity acts directly towards the sun and is pulling the earth towards it. The earth falls towards the sun at a curvature (approximately) equal to the sun’s curvature so it never gets there. I do understand elliptical orbits.
All other movements/forces will have to be superimposed upon the main force(s)
Isn’t that how they find ‘new’ bodies in space by looking for the variation from the expected orbit

[Pinkie]

Any object in orbit is falling towards the central mass. We are no different. We happen to be travelling at a speed which allows us never to get to the sun, in our case.
Velocity is a vector, if the direction of movement changes, it has accelerated, and must have had a force applied in our case, the sun’s gravity.
The gravity acts directly towards the sun and is pulling the earth towards it. The earth falls towards the sun at a curvature (approximately) equal to the sun’s curvature so it never gets there. I do understand elliptical orbits.
All other movements/forces will have to be superimposed upon the main force(s)
Isn’t that how they find ‘new’ bodies in space by looking for the variation from the expected orbit

Gravity isnt a force exerted by the sun. Its caused by the sun warping time and space. It may or may not be a particle

If its accelerated it must have got faster. As it hasnt its fair to conclude it hasnt accelerated

The earth is not changing direction its travelling in a straight line with in a geodesic .Not towards the sun. If its momentum decreases it will travel towards the sun. But so far it hasnt

An orbit could be summarised as an object trying to fall to the central mass. But missing. The reason it misses is because it's going in the wrong direction. Ie not towards the sun

[KM2]

The earth is in orbit, therefore cannot be travelling in a straight line.
If you remove the gravity it would continue to travel in a straight line, tangential to it’s orbit.

[[XAP]Bob]

But the acceleration and deceleration aren't felt because they are negligible.
Of course we are also speeding outwards as the universe expands which adds a little to the mix, but not noticeably.

No - the acceleration isn't felt because it is constant and in a constant direction relative to the surface of the earth.

The only acceleration which isn't constant in terms of direction relative to the earth is the solar gravity, which is rather weak... </sarcasm>

[Pinkie]

The earth is in orbit, therefore cannot be travelling in a straight line.
If you remove the gravity it would continue to travel in a straight line, tangential to it’s orbit.

A straight line is... the shortest distance between two points. With in a geodesic ( a curve) the shortest distance between two points is also a curve. Ergo its travelling in a straight line

An orbit could be summarised as an object trying to fall to the central mass. But missing. The reason it misses is because it's going in the wrong direction

[[XAP]Bob]

But the mountain is part of the planet you you said the planet wasnt accelerating just things on it, that's me, not the mountain

5he mountain will be counter balanced by a similar mountain on the other side that is decelerating

Ever been on a fairground on that thing that spins as it rotates, you get the feeling of slowing down and then being catapulted forward, because it spins at a rate that actually sends you backwards whilst traveling forwards, the effect is many times milder on the planet but it's there.

I'd be more intrested in an explination of mountains and people

I'm still not clear if the mountain accelerates or not and if it does why the other side of the planet doesnt slow it down

The acceleration is always perpendicular to the direction of travel, and the centre of the rotation is the centre of mass of the planet system... so yes there is always a "mountain" on the other side of the planet, though it may not be a mountain, just slightly heavier rocks... or a wide area of slightly raised terrain.

[Pinkie]

But the acceleration and deceleration aren't felt because they are negligible.
Of course we are also speeding outwards as the universe expands which adds a little to the mix, but not noticeably.

No - the acceleration isn't felt because it is constant and in a constant direction relative to the surface of the earth.

The only acceleration which isn't constant in terms of direction relative to the earth is the solar gravity, which is rather weak... </sarcasm>

I didnt say it could be felt/ perceived. I said any object that accelerated must be travelling faster than it was before hand. It's rather what acceleration is

I said it could be measured. By virtue of it now going faster than before

[Pinkie]

Ever been on a fairground on that thing that spins as it rotates, you get the feeling of slowing down and then being catapulted forward, because it spins at a rate that actually sends you backwards whilst traveling forwards, the effect is many times milder on the planet but it's there.

I'd be more intrested in an explination of mountains and people

I'm still not clear if the mountain accelerates or not and if it does why the other side of the planet doesnt slow it down

The acceleration is always perpendicular to the direction of travel, and the centre of the rotation is the centre of mass of the planet system... so yes there is always a "mountain" on the other side of the planet, though it may not be a mountain, just slightly heavier rocks... or a wide area of slightly raised terrain.

Thanks but that hasnt help. Is the mountain accelerating or not ?

[[XAP]Bob]

I'd argue that on the surface of the planet the only natural measurement is relative to the surface.
In the same way that planes naturally measure their airspeed, and ground speed indicators are relatively recent.

Yes from the (approximately) inertial frame of sol the bits of the earth are moving faster and slower throughout a 24 hour period... but it's not something that can be measured on the earth, since there is nothing to measure it against.

[Pinkie]

I'd argue that on the surface of the planet the only natural measurement is relative to the surface.
In the same way that planes naturally measure their airspeed, and ground speed indicators are relatively recent.

Yes from the (approximately) inertial frame of sol the bits of the earth are moving faster and slower throughout a 24 hour period... but it's not something that can be measured on the earth, since there is nothing to measure it against.

I get mixed up which person I'm talking to some times

If one side of the earth is accelerating and the other decelerating. I'm at a loss to see why that doesnt cancel out