Eötvös effect

The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity. When moving eastbound, the object's angular velocity is increased (in addition to the earth's rotation), and thus the centrifugal force also increases, causing a perceived reduction in gravitational force.

So a summary of this is that you weigh less when travelling east and more when travelling west, due to the rotation of the earth. And to my knowledge, flat earthers think the earth isn't spinning.

Explain.

The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity. When moving eastbound, the object's angular velocity is increased (in addition to the earth's rotation), and thus the centrifugal force also increases, causing a perceived reduction in gravitational force.

So a summary of this is that you weigh less when travelling east and more when travelling west, due to the rotation of the earth. And to my knowledge, flat earthers think the earth isn't spinning.

Explain.

OMG, Wikipedia has the same exact text . . . . .

The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity. When moving eastbound, the object's angular velocity is increased (in addition to the earth's rotation), and thus the centrifugal force also increases, causing a perceived reduction in gravitational force.

Why do you think FE'rs think Earth isn't spinning?

OMG, Wikipedia has the same exact text . . . . .

Doesn't make it wrong, or irrelevant; just means the OP found a succinct wording of their point.

Why do you think FE'rs think Earth isn't spinning?

Ambiguous question which can be read one of two ways.

• If you mean "Yes they do.  In your opinion, what makes them think so?" my answer would be: I suppose this could be the result of taking the zetetic approach: "it FEELS like it doesn't move, therefore it REALLY doesn't move"
• If you mean "Maybe they do, maybe they don't.  What makes you think they do?" my answer would be: It's all over the Wiki, with supporting statements regarding the term stationary and opposing statements regarding the term rotating.  It's all over the forums, with derision and sarcasm evident every time a flatty refers to our belief in a spinning ball, and many posts devoted to so-called proofs that it doesn't rotate.  I don't recall ever seeing a flat earth model in which the flat earth rotates; if you have seen one, please share the link.

Why do you think FE'rs think Earth isn't spinning?

Lurk moar.  FE'ers have said countless times that the flat earth doesn't spin.

If you want to do much in the way of convincing, it'd probably be better to give some indication of practical tests. From what I've seen the effect is mostly just a conclusion of maths under RET, but actual testing has been minimal because, well, it's not easy. There seem to have been a couple, but after a brief google I haven't been able to see the precise results. They might be out there, but I can't imagine the effect is particularly significant.
The Eotvos effect is, according to Wiki, calculated by a cosine (attains a maximum at 1), multiplied by 2, the east-west velocity, and then by the rotation rate of the Earth which I think is 0.0000116 per second. Best I can find for a likely speed for a boat at that time (referencing the test Wiki said was performed) is a little over 3m/s, though I'm not a nautical expert so that could be wrong. You might be able to detect something like that, but it's unlikely to be much in the way of confirmation, especially given all the factors that would increase experimental error.
There is an extra term in Wiki, but it's a refinement, and features division by the radius of the Earth so, uh, yep, it'll be small.

If there are good, reliable and clear tests of the effect out there, then this could be an interesting argument, but until then...

And, side note, I don't think it matters whether or not the flat Earth spins. Centrifugal force on a flat world won't have any effect in the same direction as gravity.

The Eotvos effect is, according to Wiki, calculated by a cosine (attains a maximum at 1), multiplied by 2, the east-west velocity, and then by the rotation rate of the Earth which I think is 0.0000116 per second. Best I can find for a likely speed for a boat at that time (referencing the test Wiki said was performed) is a little over 3m/s, though I'm not a nautical expert so that could be wrong. You might be able to detect something like that, but it's unlikely to be much in the way of confirmation, especially given all the factors that would increase experimental error.

the rotation rate of Earth is closer to 0.0000727 per second (it is measured in radians per second, not revolutions per second).
A likely speed for a boat at that time would vary dramatically depending upon what ship, but 10 m/s would be normal.

That would give a variation at the equator of 0.0015 m/s^2.

That isn't all that hard to measure with delicate instruments.

If you want to do much in the way of convincing, it'd probably be better to give some indication of practical tests. From what I've seen the effect is mostly just a conclusion of maths under RET, but actual testing has been minimal because, well, it's not easy. There seem to have been a couple, but after a brief google I haven't been able to see the precise results. They might be out there, but I can't imagine the effect is particularly significant.
The Eotvos effect is, according to Wiki, calculated by a cosine (attains a maximum at 1), multiplied by 2, the east-west velocity, and then by the rotation rate of the Earth which I think is 0.0000116 per second. Best I can find for a likely speed for a boat at that time (referencing the test Wiki said was performed) is a little over 3m/s, though I'm not a nautical expert so that could be wrong. You might be able to detect something like that, but it's unlikely to be much in the way of confirmation, especially given all the factors that would increase experimental error.
There is an extra term in Wiki, but it's a refinement, and features division by the radius of the Earth so, uh, yep, it'll be small.

If there are good, reliable and clear tests of the effect out there, then this could be an interesting argument, but until then...

And, side note, I don't think it matters whether or not the flat Earth spins. Centrifugal force on a flat world won't have any effect in the same direction as gravity.

I believe that the Eötvös effect was first found experimentally on a gravimetric survey, when different results were observed for West to East and East to West runs.

The Eötvös effect

In the early 1900s a German team from the Institute of Geodesy in Potsdam carried out gravity measurements on moving ships in the Atlantic, Indian and Pacific Oceans. While studying their results the Hungarian nobleman and physicist Lorand Eötvös noticed that the readings were lower when the boat moved eastwards, higher when it moved westward. He identified this as primarily a consequence of the rotation of the Earth. In 1908 new measurements were made in the Black Sea on two ships, one moving eastward and one westward. The results substantiated Eötvös' claim. Since then geodesists use the following formula to correct for velocity relative to the Earth during a measurement run.

         
          a_r     correction when moving relative to the Earth
          Ω     rotation rate of the Earth
          u     velocity in latitudinal direction (east-west)
          φ     latitude where the measurements are taken.
          v     velocity in longitudinal direction (north-south)
          R     radius of the Earth
See: Cleonis Physics, The Eötvös effect

Of course, the Eötvös effect won't help in the FE ~ Globe debate. FEers only take note of physical evidence that they, themselves can see with their unaided eyes.
Unless of course, it's in their SacredTexts "Earth Not a Globe", by the patron saint of flat earthers: Saint Samuel of Rowbotham published in 1881!

It is slight, but it first showed up in show up in gravity surveys and it is much more pronounced in an aircraft flying at around 1000 kph.

If the earth was indeed spinning, I could get some awesome world record distances in a long jump. I just jump up in the air and the earth would travel under my feet at over 1675km/h 

Please don't ruin this fantasy for me with your sciency talk. It's not fair 

If the earth was indeed spinning, I could get some awesome world record distances in a long jump. I just jump up in the air and the earth would travel under my feet at over 1675km/h 

Please don't ruin this fantasy for me with your sciency talk. It's not fair 

It's such a pity that little things like the Eötvös effect seem to crop up all the time.

the rotation rate of Earth is closer to 0.0000727 per second (it is measured in radians per second, not revolutions per second).
A likely speed for a boat at that time would vary dramatically depending upon what ship, but 10 m/s would be normal.

That would give a variation at the equator of 0.0015 m/s^2.

That isn't all that hard to measure with delicate instruments.

I'll take your word for it as far as radians go, I was just going from a skim-read of the page. Yep, delicate instruments might be able to read that, if you had access to a pair of boats and were near the equator. The only reference to an experiment I can find however was a couple of ships in 1908 in the Black Sea (latitude 43.4 degrees, which would approximately halve the variation) and I'm not sure how good the significant figures of 1908-era instruments would be, especially on a boat.
It's certainly testable, but I haven't seen any especially reliable instances of the test, and it's hardly easy to confirm or replicate.

I believe that the Eötvös effect was first found experimentally on a gravimetric survey, when different results were observed for West to East and East to West runs.

I read that; but note that the gravimetric survey just made Eotvos curious, it wasn't proof by any means. Ships at multiple latitudes, etc, it's the kind of thing that'd make him interested in testing it, but it'd take ships at similar latitudes, such as the Black Sea experiment, to actually provide any particularly meaningful evidence.

Of course, the Eötvös effect won't help in the FE ~ Globe debate. FEers only take note of physical evidence that they, themselves can see with their unaided eyes.
Unless of course, it's in their SacredTexts "Earth Not a Globe", by the patron saint of flat earthers: Saint Samuel of Rowbotham published in 1881!

Do you have any idea how tedious it is for grudge match-esque shenanigans like that to pop up constantly? We get it. You don't like FEers. You don't like the cliche personal-observation-only mentality. Put it in your sig or something, it's not really important here.

It is slight, but it first showed up in show up in gravity surveys and it is much more pronounced in an aircraft flying at around 1000 kph.

Flat Earth vs Globe - The Eötvös effect observed in aircraft - how does it affect Gravity?

Thanks, definitely a better experiment with the higher speed of aircraft etc, from a skimmed watch, but even so it's not the hardest thing to dismiss with how the movement of the plane is constantly impacting the scale's measurements, to say nothing of the source. It's a nice idea, but there's a reason youtube creators rarely revolutionise science.

If the earth was indeed spinning, I could get some awesome world record distances in a long jump. I just jump up in the air and the earth would travel under my feet at over 1675km/h 

Please don't ruin this fantasy for me with your sciency talk. It's not fair 

But imagine the high jump you could achieve with universal acceleration 

If the earth was indeed spinning, I could get some awesome world record distances in a long jump. I just jump up in the air and the earth would travel under my feet at over 1675km/h 

Please don't ruin this fantasy for me with your sciency talk. It's not fair 

Except that's not how things work.

Our velocity is the same as that on earth. So when you jump straight up, you land in the same spot. Easy fucking science you downy.

Quote from: Shifter on June 04, 2017, 03:19:11 PM

If the earth was indeed spinning, I could get some awesome world record distances in a long jump. I just jump up in the air and the earth would travel under my feet at over 1675km/h 

Please don't ruin this fantasy for me with your sciency talk. It's not fair 

Except that's not how things work.

Our velocity is the same as that on earth. So when you jump straight up, you land in the same spot. Easy fucking science you downy.

So I've been told

If you want to do much in the way of convincing, it'd probably be better to give some indication of practical tests. From what I've seen the effect is mostly just a conclusion of maths under RET, but actual testing has been minimal because, well, it's not easy. There seem to have been a couple, but after a brief google I haven't been able to see the precise results. They might be out there, but I can't imagine the effect is particularly significant....If there are good, reliable and clear tests of the effect out there, then this could be an interesting argument, but until then...

Something like this, for example?


Photo and the following description come from this website.  The device is basically a balance with horizontal axis, where instead of pans, weights are attached to the end of the arms. The balance stands on a tripod, which rotates evenly. When the balance is rotated the weight moving towards the west will become heavier, the one moving towards the east lighter. The balance will, therefore, deflect from its state of equilibrium. If the balance is rotated at such a speed that the rotation period equals the period of its oscillation the impulses occurring during the rotations will cause the arms to make ever greater oscillations.

Quote from: Jane on June 04, 2017, 11:22:07 AM

If you want to do much in the way of convincing, it'd probably be better to give some indication of practical tests. From what I've seen the effect is mostly just a conclusion of maths under RET, but actual testing has been minimal because, well, it's not easy. There seem to have been a couple, but after a brief google I haven't been able to see the precise results. They might be out there, but I can't imagine the effect is particularly significant....If there are good, reliable and clear tests of the effect out there, then this could be an interesting argument, but until then...

Something like this, for example?


Photo and the following description come from this website.  The device is basically a balance with horizontal axis, where instead of pans, weights are attached to the end of the arms. The balance stands on a tripod, which rotates evenly. When the balance is rotated the weight moving towards the west will become heavier, the one moving towards the east lighter. The balance will, therefore, deflect from its state of equilibrium. If the balance is rotated at such a speed that the rotation period equals the period of its oscillation the impulses occurring during the rotations will cause the arms to make ever greater oscillations.

I saw that, but I haven't been able to find any actual instances of it, or anything like it's, use. At best we have a picture of something and a claim, with no indication as to whether that claim is feasible to test (matching rotation period to oscillation is hardly easy) and no idea how noticeable the result would be (how greater would the oscillations become?).