Foucault pendulums

I'm wondering who here has heard of these.  This was an important experiment, first conducted in 1851 in Paris, that conclusively showed that the Earth was a rotating sphere.

Many of the conspiracy theories about governents and scientists being part of a large cover-up to dupe the world population into thinking the world is flat really don't hold up for this experiment.  First, Foucault was not a university trained scientist, and many of his contemporaries looked down on him and disparaged his work because of this.

However, the demonstration that a pendulum, without any outside forces working on it, would rotate over the course of a day, showed conclusively that the Earth is a rotating ball.  Any prejudice that the scientists of the day were eventually discarded, due to the conclusiveness of his experiment.

I'm wondering who here has heard of these.  This was an important experiment, first conducted in 1851 in Paris, that conclusively showed that the Earth was a rotating sphere.

I've heard of it.  Are you sure it demonstrated the Earth to be a rotating ball, or just a rotating thing?

My understanding is that it doesn't work the same at every latitude, for reasons and in ways that at this moment are not clear to me.  Would a flat Earth predict the differences at different radii?  Not in any way I can see.

Wikipedia says that the rotations per day is the sine of the latitude.  I find its explanation.... uncompelling, but I've only given it a cursory read.

For those of you attemping to come up with proofs, note that the sine of the latitude is the ratio of the distance to the equatorial plane.  This suggests that on a flat Earth, there should be no difference in rotation rate at different radii, since distance to the equatorial plane is constant.

-Erasmus

I'm sure they will find a way to explain it.

Perhaps the Earth spins clockwise (or anticlockwise) generating a force that moves the pendulum?

There is plenty of evidence for the RE model, but that doesn't stop flat-earthers, oh no.

Perhaps the Earth spins clockwise (or anticlockwise) generating a force that moves the pendulum?

Yeah, they certainly could.  However, any model they could come up with could be examined to see whether it makes different predictions for a round Earth and a flat Earth.  In particular, the rate of rotation as a function of latitude will probably be different.  This is something that could be empirically tested by any individual.  In fact, it could be done simultaneously while they're on that trip to see what the stars look like at different latitudes.

A set of experiments they could perform and understand entirely on their own is the closest approximation of their desires to rationality; this fits nicely into that category.

-Erasmus

The pendulum will seem to rotate 360 degrees in 24 hours at the north pole.  This would suggest that the flat earth spins 360 degrees in 24 hours.  The problem comes when you change latitude.  At the equator, the pendulum doesn't seem to rotate at all.  This would suggest that the flat earth is stationary.  At lattitudes in between the rotation of the pendulum can be described by (360) * sin (phi) where phi is the lattitude.

I personally haven't gone through the math, but I have seen these pendulums in action.

I personally haven't gone through the math, but I have seen these pendulums in action.

I have done neither, I'm afraid, and while I have the same unsupported understanding of pendulum behavior as you, I still feel like I should prove this myself.

-Erasmus

yup, I have seen these pendulums in action. They have one at the Franklin Institute. This would disprove flat Earth theory, because the only explanation would be that the earth is spinning at the north pole, and at the "edge" (in the opposite direction BTW) the rate of raotation decreases as you approach the equator. Either the Earth is round and spinning on it's axis, or else God has magically made the pendulums behave this way to trick the nonbelievers. God is the magic catchall, he's above the physical laws, and can make anything he wants to happen. Most flat earthers (the real ones, not the guys on this site) are bible literalists, so the God catchall is all they need. they don't even need the "conspiracy."

If the earth was flat (and spinning), wouldn't the pendulum stop if it was in the centre? Of course, that would probably be a sea, but it's a theory.

On the flip side, it would also spin more the farther it was from the centre. Since this has never been demonstrated, I guess the whole experiment goes into the big pile of falsity. :roll:

If the earth was flat (and spinning), wouldn't the pendulum stop if it was in the centre?

No.  It would continue swinging through the same fixed plane in space, and the world would rotate around it.

On the flip side, it would also spin more the farther it was from the centre.

Why?

I agree with erasmus here. If the earth were flat and spinning, a pendulum would appear to make make one rotation in one day, regardless of lattitude. This is because the pendulum is actually staying oriented in the same direction in space, and the flat earth would rotate around it. Pendulums want to stay facing the same direction is space, just like a gyroscope (and for the same reasons too). Anywhere on a flat earth you would get one revolution per day. On a round earth, You would get one revolution per day at the north pole, but that would decrease as you got closer to the equator, where it would be zero revolutions. If you continued south, the pendulum would rotate in the opposite direction, very slowly, but getting faster as you approached the south pole. At the south pole the penulum would make one rotation every day, in the opposite direction as it would at the north pole.

OK, a way to prove the flat earth hypothesis is wrong.

The flat earth hypothesis predicts that a foucault pendulum will either make one revolution every day, no matter where you are on earth (if the flat earth is spinning), or that it will not rotate at all (if the flat earth is not spinning).
In fact, a foucault pendulum does not behave this way. It's rate of rotation is equal to the sine of the lattitude.

Because a preiction made by the flat earth hypothesis has been proven wrong, the flat earth hypothesis has been proven wrong. That's how science works.

For info on Foucault pendulums http://en.wikipedia.org/wiki/Foucault_pendulum

I have another proof here, that relies on the earth's magnetic field. you can find it here http://theflatearthsociety.org/forums/viewtopic.php?t=1316

If the earth was flat (and spinning), wouldn't the pendulum stop if it was in the centre? Of course, that would probably be a sea, but it's a theory.

Any pendulum will eventually stop unless something is driving it, but that is not what we are talking about.

I have another proof here, that relies on the earth's magnetic field. you can find it here http://theflatearthsociety.org/forums/viewtopic.php?t=1316

No cross-posting please.