The Flat Earth Society

Other Discussion Boards => Technology, Science & Alt Science => Topic started by: E E K on June 11, 2020, 11:27:44 AM

Title: Question about the Foucault's Pendulum?
Post by: E E K on June 11, 2020, 11:27:44 AM
What is the swing of the Foucault pendulum, has to do with the rotation of the earth?

Foucault demonstrated the earth’s rotation via his famous pendulum. He suspended a 28-kilogram (62 lb) brass-coated lead bob with a 67-meter long (220 ft) wire from the dome of the Pantheon, Paris – Wikipedia

Here is the animation of Foucault's Pendulum.

https://upload.wikimedia.org/wikipedia/commons/8/82/Foucault-rotz.gif
 (https://upload.wikimedia.org/wikipedia/commons/8/82/Foucault-rotz.gif)
Let mark a point “A” on the outer diameter (big enough) of the wire of Foucault's Pendulum, facing exactly west or any other specified direction. 

The wire of Foucault's Pendulum doesn’t spin during swinging in the experiment. It can be observed easily in the above animation – Right. It is the earth, which spins, not the wire of the pendulum. After 24 hours or more

Point “A” is also seen by the north, east, and south of the earth if the green trace in the above animation shows the path of the pendulum bob over the ground (a rotating reference frame).

I may be wrong but I suspect the force that sat the swing of the Foucault pendulum might not be in the perfect direction. The density of bob also affects the direction of the applied force.

Because

If the aforementioned experiment really shows the evidence of rotation of earth then we can also get the same result from the following experiment as well.

– Simply, here we don’t need the swing of the pendulum.
 
Let both the wire and the bob of the aforementioned experiment are at rest and don't rotate. Attached a laser light torch to the bob of the aforesaid pendulum such that it shines a laser light exactly toward the west (in a straight line) perpendicular to the above said 67-meter wire. OR it can be any mark on the wire or bob facing in a specified direction.

Remember: The wire used in the experiment of Foucault's Pendulum doesn't spin during swinging. 

After 24 hours or more

The laser light, in this case, is not seen by the north, east, and south of the earth - I believe.

What do you think?

Your comments, please!!!

Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 11, 2020, 12:28:48 PM
What is the swing of the Foucault pendulum, has to do with the rotation of the earth?

Foucault demonstrated the earth’s rotation via his famous pendulum. He suspended a 28-kilogram (62 lb) brass-coated lead bob with a 67-meter long (220 ft) wire from the dome of the Pantheon, Paris – Wikipedia

Here is the animation of Foucault's Pendulum.

https://upload.wikimedia.org/wikipedia/commons/8/82/Foucault-rotz.gif
 (https://upload.wikimedia.org/wikipedia/commons/8/82/Foucault-rotz.gif)
Let mark a point “A” on the wire of Foucault's Pendulum, facing exactly west or any other specified direction. 

The wire of Foucault's Pendulum doesn’t spin during swinging in the experiment. It can be observed easily in the above animation – Right. It is the earth, which spins, not the wire of the pendulum. After 24 hours or more

Point “A” is also seen by the north, east, and south of the earth if the green trace in the above animation shows the path of the pendulum bob over the ground (a rotating reference frame).

I may be wrong but I suspect the force that sat the swing of the Foucault pendulum might not be in the perfect direction. The density of bob also affects the direction of the applied force.

Because

If the aforementioned experiment really shows the evidence of rotation of earth then we can also get the same result from the following experiment as well.

– Simply, here we don’t need the swing of the pendulum.
 
Let both the wire and the bob of the aforementioned experiment are at rest and don't rotate. Attached a laser light torch to the bob of the aforesaid pendulum such that it shines a laser light exactly toward the west (in a straight line) perpendicular to the above said 67-meter wire. OR it can be any mark on the wire or bob facing in a specified direction.

Remember: The wire used in the experiment of Foucault's Pendulum doesn't spin during swinging. 

After 24 hours or more

The laser light, in this case, is not seen by the north, east, and south of the earth - I believe.

What do you think?

Your comments, please!!!

You won't get any results without it swinging.

The bob and line never rotate during a Foucault's Pendulum experiment either.  The bob always faces in the same direction.

What we are observing is the direction of the swinging changing. Or more accurately, the Earth rotating while the direction of the swing stays the same.

The Foucault's Pendulum experiment has nothing to do with the line twisting, it's that back and forth swing with all that momentum that is staying still while the Earth rotates.

So without the motion, you won't observe anything.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 11, 2020, 03:50:17 PM
What is the swing of the Foucault pendulum, has to do with the rotation of the earth?
Plenty because without the "swing of the Foucault pendulum" there is nothing to define an absolute direction.

Quote from: E E K
If the aforementioned experiment really shows the evidence of rotation of earth then we can also get the same result from the following experiment as well.

– Simply, here we don’t need the swing of the pendulum.
In principle, if you could start with a perfectly suspended massive bob stationary over the North Pole it would stay stationary as the Earth rotated under it.

But there are two problems here:

Quote from: E E K
Let both the wire and the bob of the aforementioned experiment are at rest and don't rotate. Attached a laser light torch to the bob of the aforesaid pendulum such that it shines a laser light exactly toward the west (in a straight line) perpendicular to the above said 67-meter wire. OR it can be any mark on the wire or bob facing in a specified direction.

Remember: The wire used in the experiment of Foucault's Pendulum doesn't spin during swinging. 

After 24 hours or more

The laser light, in this case, is not seen by the north, east, and south of the earth - I believe.

What do you think?

Your comments, please!!!
It is the initial swing of the pendulum that gives the reference direction.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 12, 2020, 02:21:40 AM
Both scenarios should give the same result because both the bob and the wire of the Foucault's Pendulum always face in the same direction and never rotate in each case.

I want to know more about the POINT at which the wire of the pendulum is suspended. Therefore can somebody explain if it is a special suspension - I mean how it possible that the rotation of the earth doesn't have any effect on the suspension of the wire of Foucault's Pendulum if it doesn't rotate or twist during swinging.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 12, 2020, 03:37:56 AM
Both scenarios should give the same result because both the bob and the wire of the Foucault's Pendulum always face in the same direction and never rotate in each case.
These are both much simpler if centred on the North Pole.

There is no way to fix the direction the bob is facing without first assuming that Earth is rotating once in about 23 hours and 56 minutes.

But the initial swing of the pendulum defines an initial direction and if the top support has low enough friction the plane of the pendulum's swing will remain unchanged.

Quote from: E E K
I want to know more about the POINT at which the wire of the pendulum is suspended. Therefore can somebody explain if it is a special suspension
The suspension is very important and should apply no torque (twisting) to the pendulum so various types of universal and point bearings have been used but no bearing is perfect.

Quote from: E E K
I mean how it possible that the rotation of the earth doesn't have any effect on the suspension of the wire of Foucault's Pendulum if it doesn't rotate or twist during swinging.
As above all that can be done is minimise the effect of that "twisting".

So very heavy bobs are used with long wires so that the period is very long.
Another problem is that the without a drive the pendulum will gradually stop swinging.
But the drive must be one that doesn't affect the direction of swing.

This is from a description of the large Foucault Pendulum that used to be at the Smithsonian's National Museum of American History.
Quote
Smithsonian: Foucault Pendulum (https://www.si.edu/spotlight/foucault-pendulum)
Any pendulum consists of a cable or wire or string and a bob. For a pendulum to easily demonstrate the Foucault effect, it should have as long a cable as possible (this one is 52 feet) and a heavy symmetrical bob (this one is hollow brass, weighing about 240 pounds). Like all pendulums this one loses a bit of energy with each swing due to friction from air currents and vibrations in the cable and other factors. Thus, left to itself the pendulum would swing in shorter and shorter arcs until after a few hours it will decrease almost to zero. To keep the Foucault Pendulum going, one must replace the energy lost with each swing. This can be done by giving the pendulum a little "kick" with each swing.

To do this, two iron collars are attached to the cable near the top. There is a doughnut-shaped electromagnet built into the ceiling, and the iron collar swings back and forth inside the hole of the doughnut. When the pendulum cable reaches a particular point in its swing, it is detected by an electronic device and the magnet is turned on at just the right time to give the collar (and thus the cable and the bob) a little "kick" in the exact direction of its natural swing. This restores the energy lost during the swing and keeps the pendulum from stopping. It has no effect on the direction of the swing, and thus does not interfere with the demonstration that the earth is rotating.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 12, 2020, 05:05:25 AM
Quote
But the initial swing of the pendulum defines an initial direction and if the top support has low enough friction the plane of the pendulum's swing will remain unchanged.

Sorry but the initial to and fro motion of the pendulum has nothing to do with changing the facing direction of point "A" marked on the outer diameter (big enough) of the wire  – quite clear in words and in animation. Unless I'm conceiving it wrong.

Point A on the outer surface of the wire always faces in the same direction whether the pendulum is at rest or swinging.


Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 12, 2020, 11:09:42 AM
How about the idea of using a drone instead of suspending the Foucault's Pendulum from the dome which is in question!

Would we be able to get the same result for the evidence of earth’s rotation if suspend a modified version of Foucault's Pendulum from the bottom of drone which can hover for a couple of hours at one fixed point in a closed environment?

Source: internet: "Given that your average drone can hover for around half an hour, the four hours, 40 minute record claimed by Spanish drone manufacturer Quaternium is pretty darn impressive"
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 12, 2020, 11:31:09 AM
How about the idea of using a drone instead of suspending the Foucault's Pendulum from the dome which is in question!

Would we be able to get the same result for the evidence of earth’s rotation if suspend a modified version of Foucault's Pendulum from the bottom of drone which can hover for a couple of hours at one fixed point in a closed environment?

Source: internet: "Given that your average drone can hover for around half an hour, the four hours, 40 minute record claimed by Spanish drone manufacturer Quaternium is pretty darn impressive"

Drones can't carry much weight at all, and the constant corrections and drifting would overwhelm any subtle forces from the earths rotation.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 12, 2020, 11:41:30 AM
Quote
Drones can't carry much weight at all, and the constant corrections and drifting would overwhelm any subtle forces from the earths rotation.

I mentioned a modified version so it can be a simple plumb bob with a long wire either stationary or swinging at the dome of the Pantheon, Paris, or ideally at north pole.
addendum:
Using Foucault's concept, we don't need any pendulum in case of using a drone because the four or multiple sides/ faces of the drone are enough for the evidence of earth's rotation if it hovers at one fixed point for a couple of hours. 
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 12, 2020, 12:34:17 PM
Quote
Drones can't carry much weight at all, and the constant corrections and drifting would overwhelm any subtle forces from the earths rotation.

I mentioned a modified version so it can be a simple plumb bob with a long wire either stationary or swinging at the dome of the Pantheon, Paris, or ideally at north pole.
addendum:
Using Foucault's concept, we don't need any pendulum in case of using a drone because the four or multiple sides/ faces of the drone are enough for the evidence of earth's rotation if it hovers at one fixed point for a couple of hours.

Except the drone uses active sensors to keep itself positioned.  Cameras, gyros, GPS.  That's going to overwhelm any small rotation you might detect over 40 minutes.  If it was turning due to the Earths motion, it would simply correct itself and turn with it.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 12, 2020, 01:30:23 PM
Quote
Except the drone uses active sensors to keep itself positioned.  Cameras, gyros, GPS.  That's going to overwhelm any small rotation you might detect over 40 minutes.  If it was turning due to the Earths motion, it would simply correct itself and turn with it.

I meant if the drone is under the influence of noncontact gravity force only just like a bob in the case of Foucault's pendulum experiment.

The bob of Foucault's pendulum (either stationary or swinging) is constantly under the influence of the non-contact gravity force of the earth. No idea how does the said bob if swinging transfers its weight "mg" during the rotation of the earth due to such noncontact gravitational force on the surface of the earth if it shows the evidence of earth's rotation.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 12, 2020, 02:02:54 PM
How about the idea of using a drone instead of suspending the Foucault's Pendulum from the dome which is in question!

Would we be able to get the same result for the evidence of earth’s rotation if suspend a modified version of Foucault's Pendulum from the bottom of drone which can hover for a couple of hours at one fixed point in a closed environment?
Not at all.
Drones fly in the air and either they are controlled by GPS or will simply move with the air and wherever their propellers direct them.

Quote from: E E K
Source: internet: "Given that your average drone can hover for around half an hour, the four hours, 40 minute record claimed by Spanish drone manufacturer Quaternium is pretty darn impressive"
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 13, 2020, 12:14:25 AM
Quote
Not at all.
Drones fly in the air and either they are controlled by GPS or will simply move with the air and wherever their propellers direct them.
- Similar control happens in Foucault's pendulum as well. This means

You didn't comment on the weight transfer of the wire and bob = mg (combined) of Foucault's pendulum which is controlled by the NONCONTACT GRAVITY FORCE OF EARTH from blue traced to the green traced.

"The bob of Foucault's pendulum (either stationary or swinging) is constantly under the influence of the non-contact gravity force of the earth. No idea how does the said bob if swinging transfers its weight "mg" during the rotation of the earth due to such noncontact gravitational force on the surface of the earth if it shows the evidence of earth's rotation".
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 13, 2020, 03:47:16 AM
Quote
But the initial swing of the pendulum defines an initial direction and if the top support has low enough friction the plane of the pendulum's swing will remain unchanged.

Sorry but the initial to and fro motion of the pendulum has nothing to do with changing the facing direction of point "A" marked on the outer diameter (big enough) of the wire  – quite clear in words and in animation. Unless I'm conceiving it wrong.

Point A on the outer surface of the wire always faces in the same direction whether the pendulum is at rest or swinging.

Imagine you suspend something on a wire with completely frictionless bearing at the North Pole.  It’s completely free to rotate (or stay still while the earth rotates).

How do set a zero reference to measure the earth’s rotation against?  It might be motionless wrt the earth, or you might have given it a slight spin while setting it up (which could be at any speed).  You could get any result out of it.  You need a way to know that rotation you measure isn’t just some initial rotation you’ve given it.

You can’t align it to anything on earth, because then you’ll measure no rotation.  You could align it to a point in space like a star, but that kind of defeats the whole point of the experiment and it’s easier just to look at the stars.

Swinging the pendulum is what gives you that reference.  Because you’d need to apply another force to change the direction of its momentum.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 13, 2020, 05:48:36 AM
As you said "You can’t align it to anything on earth" Therefore, the question is

How do you separate (de-align) that to and fro swing of the pendulum from the rotation of the earth.

Can you show me the point at which that to and fro swing motionless (remain still) w.r.t rotation of the earth.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 13, 2020, 05:52:06 AM
As you said "You can’t align it to anything on earth" Therefore, the question is

How do you separate (de-align) that to and fro swing of the pendulum from the rotation of the earth.

Can you show me the point at which that to and fro swing motionless (remain still) w.r.t rotation of the earth.
From the first swing.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 13, 2020, 06:02:42 AM
As you said "You can’t align it to anything on earth" Therefore, the question is

How do you separate (de-align) that to and fro swing of the pendulum from the rotation of the earth.

Can you show me the point at which that to and fro swing motionless (remain still) w.r.t rotation of the earth.
From the first swing.
- in simple words

I mean the gravitational field of the earth shouldn't have any effect on the pendulum (bob and wire) at all if it is stationary w,r.t to the rotation of the earth. Hope this help 
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 13, 2020, 07:06:09 PM
As you said "You can’t align it to anything on earth" Therefore, the question is

How do you separate (de-align) that to and fro swing of the pendulum from the rotation of the earth.

Can you show me the point at which that to and fro swing motionless (remain still) w.r.t rotation of the earth.
From the first swing.
- in simple words

I mean the gravitational field of the earth shouldn't have any effect on the pendulum (bob and wire) at all if it is stationary w,r.t to the rotation of the earth. Hope this help
No it doesn't help. Just what do you mean?
The only place the Earth's gravity comes into it is in providing the restoring force to make the pendulum swing
A spring pulling down could provide that.

An ideal large gyroscope could also demonstrate the rotation and, in fact does, in the old mechanical versions of a marine gyrocompass (https://en.wikipedia.org/wiki/Gyrocompass) or a gyro-theodolite (https://www.slideshare.net/PrashantTiwari150/gyrotheodolite-114086305).
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 14, 2020, 01:24:45 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 14, 2020, 02:31:31 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.
Why? How would you know when the pendulum is fixed in space?
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 14, 2020, 03:36:22 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.

This is easy to understand.

Imagine taking one of those huge pendulums and putting it on a giant turntable.  Now, slowly turn it, taking an entire day to do so.  What will happen? Will the weight at the bottom move with the table?  Of course it will.

It's the exact same process as if you took that pendulum and twisted it 360 degrees and then let go. It wouldn't just stay there, it would turn back to it's starting position. It's not on a fishing line, it's heavy metal cable, and that's not going to twist without a force applied.

Now if that weight were suspended in a vacuum on a friction-less bearing, then it would turn.  But that cable is not going to twist with the force of a slow, 24 hour rotation. 
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 14, 2020, 05:49:14 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.
Why? How would you know when the pendulum is fixed in space?
Have the pendulum affixed to the ceiling with no rotary movement and have the table on a fine bearing.
Mark the pendulum ball weight or attach a laser light to it to point down to the table.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 14, 2020, 09:36:42 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.
Why? How would you know when the pendulum is fixed in space?
Have the pendulum affixed to the ceiling with no rotary movement and have the table on a fine bearing.
Mark the pendulum ball weight or attach a laser light to it to point down to the table.

No rotary movement relative to what?  The room? 

You’ll read zero rotation, just because you set it up to have zero rotation.  It doesn’t tell you anything.
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 14, 2020, 10:01:10 AM
Why does the pendulum have to swing in the first place?

Surely the same pendulum just hanging above the table, floor should see the table/floor move around it.
Why? How would you know when the pendulum is fixed in space?
Have the pendulum affixed to the ceiling with no rotary movement and have the table on a fine bearing.
Mark the pendulum ball weight or attach a laser light to it to point down to the table.

No rotary movement relative to what?  The room? 

You’ll read zero rotation, just because you set it up to have zero rotation.  It doesn’t tell you anything.
I set up the table to account for rotation.
If the room moves the ball moves and the table resists movement, meaning the ball should show a change as that building supposedly rotates with the supposed globe.

Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 14, 2020, 10:29:09 AM
I set up the table to account for rotation.
If the room moves the ball moves and the table resists movement, meaning the ball should show a change as that building supposedly rotates with the supposed globe.

Then you’ve set up the table with some amount of rotation relative to the room, which could be anything.
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 14, 2020, 10:45:29 AM
I set up the table to account for rotation.
If the room moves the ball moves and the table resists movement, meaning the ball should show a change as that building supposedly rotates with the supposed globe.

Then you’ve set up the table with some amount of rotation relative to the room, which could be anything.
All I've done is nullified the swing on the pendulum and also nullified the bearing the pendulum is swinging under.
I've instead transferred the bearing to the table so the table can resist the supposed motion of the supposed turning building,

A laser pointer on the ball and aimed at the table should show whether the pendulum rotates and the table stays still.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 14, 2020, 10:51:09 AM
I set up the table to account for rotation.
If the room moves the ball moves and the table resists movement, meaning the ball should show a change as that building supposedly rotates with the supposed globe.

Then you’ve set up the table with some amount of rotation relative to the room, which could be anything.
All I've done is nullified the swing on the pendulum and also nullified the bearing the pendulum is swinging under.
I've instead transferred the bearing to the table so the table can resist the supposed motion of the supposed turning building,

A laser pointer on the ball and aimed at the table should show whether the pendulum rotates and the table stays still.

Nothing is going to move unless the force can overcome friction and torsion.  One rotation every hour is so slow you need a frictionless mount for your weight or it will just move with whatever is spinning, be it the Earth or a big turntable. Even air will provide some resistance and likely you need a vacuum chamber too.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 14, 2020, 11:17:48 AM

All I've done is nullified the swing on the pendulum and also nullified the bearing the pendulum is swinging under.
I've instead transferred the bearing to the table so the table can resist the supposed motion of the supposed turning building,

A laser pointer on the ball and aimed at the table should show whether the pendulum rotates and the table stays still.

Except the table doesn’t resist anything.  You’ve put it on a bearing to spin freely or not at all.  You have no way to know if the table is spinning or not in absolute terms.  It has as much rotation  as you give it when setting it up.
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 14, 2020, 11:09:43 PM
Why swing a pendulum at all. It stinks of pretence.

Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 14, 2020, 11:46:03 PM
Why swing a pendulum at all. It stinks of pretence.
It doesn't.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 15, 2020, 04:40:11 AM
Why swing a pendulum at all. It stinks of pretence.

How else do you impart a large amount of inertia?  Ever see the bicycle wheel on a rope demonstration? Or play with a gyroscope?  How would those things work if they didn't move?
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 15, 2020, 10:11:05 AM
Quote
No it doesn't help. Just what do you mean?
The only place the Earth's gravity comes into it is in providing the restoring force to make the pendulum swing
A spring pulling down could provide that.

I would suggest watching the following. Please!
https://english.alarabiya.net/en/variety/2015/02/16/Saudi-cleric-Sun-revolves-around-stationary-Earth

Foucault and his believers are thinking just like the aforementioned Saudi cleric - Right
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 15, 2020, 11:14:46 AM
Quote
This is easy to understand.

Imagine taking one of those huge pendulums and putting it on a giant turntable.  Now, slowly turn it, taking an entire day to do so.  What will happen? Will the weight at the bottom move with the table?  Of course it will.

Turntable acts like a cantilever beam. The major parts of interest of the turntable are the central column and top. The weight of the bob is transferred to the top surface of the table. The combined weight of the bob and the top surface of the table  is transferred to the central column. The combined weight of the central column, the top surface, and the bob are then transferred to the ground.

let placed a bob on top of the table but near the edge. it doesn't matter whether the table is stationary or revolving; the weight of the bob doesn't transfer directly to the ground but via aforesaid techniques. 

Addendum: its quite clear but still for those who have not yet applied above-said weight transfer techniques [ or simply weight transfer in frame structure] to Foucault's Pendulum.

The weight of bob of Foucault's Pendulum = mg where m = mass of the bob. Tention in wire = T=mg this T (=mg) is taken by the dome. The combined weight of the T=mg and the dome is transferred to the slab. 

I don't know about the bones/ structure of the building where Foucault's Pendulum is suspended but the weight of the slab and the weight taken by the slab is transferred to girders or beams. Usually, columns take the load from beams instead of the walls, and then finally the total weight of the building and Foucault's Pendulum are transferred to the ground via foundation either shallow or deep. 

Conclusion: the swing of the bob of Foucault's Pendulum has nothing to do with the rotation of the earth.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 15, 2020, 11:35:00 AM
Why swing a pendulum at all. It stinks of pretence.

How else do you impart a large amount of inertia?  Ever see the bicycle wheel on a rope demonstration? Or play with a gyroscope?  How would those things work if they didn't move?

Normally I’d say the best way to think about it is to compare to a spacecraft away from any gravitational fields.

Fire the main engine then shut it off.  The spacecraft just moves under its own linear momentum.  Now apply a rotation with RCS thrusters or whatever.  You’ve introduced a spin, but it doesn’t change the linear momentum of the craft. They are independent.

Normally that is. 
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 15, 2020, 01:51:45 PM
Addendum: its quite clear but still for those who have not yet applied above-said weight transfer techniques [ or simply weight transfer in frame structure] to Foucault's Pendulum.

The weight of bob of Foucault's Pendulum = mg where m = mass of the bob. Tention in wire = T=mg this T (=mg) is taken by the dome. The combined weight of the T=mg and the dome is transferred to the slab.

I don't know about the bones/ structure of the building where Foucault's Pendulum is suspended but the weight of the slab and the weight taken by the slab is transferred to girders or beams. Usually, columns take the load from beams instead of the walls, and then finally the total weight of the building and Foucault's Pendulum are transferred to the ground via foundation either shallow or deep.

Conclusion: the swing of the bob of Foucault's Pendulum has nothing to do with the rotation of the earth.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 15, 2020, 02:15:06 PM
None of that matters.  It’s all about the motion.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 15, 2020, 02:54:40 PM
Addendum: its quite clear but still for those who have not yet applied above-said weight transfer techniques [ or simply weight transfer in frame structure] to Foucault's Pendulum.

The weight of bob of Foucault's Pendulum = mg where m = mass of the bob. Tention in wire = T=mg this T (=mg) is taken by the dome. The combined weight of the T=mg and the dome is transferred to the slab.

I don't know about the bones/ structure of the building where Foucault's Pendulum is suspended but the weight of the slab and the weight taken by the slab is transferred to girders or beams. Usually, columns take the load from beams instead of the walls, and then finally the total weight of the building and Foucault's Pendulum are transferred to the ground via foundation either shallow or deep.

Conclusion: the swing of the bob of Foucault's Pendulum has nothing to do with the rotation of the earth.

You are discussing loads and weight and tension when the pendulum is all about kinetic energy in the swing. They have nothing at all to do with each other.

Conclusion: You are not understanding physics.
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 15, 2020, 11:25:12 PM
Why swing a pendulum at all. It stinks of pretence.

How else do you impart a large amount of inertia?  Ever see the bicycle wheel on a rope demonstration? Or play with a gyroscope?  How would those things work if they didn't move?
They work by resisting atmospheric pressure and crating pressure variations, just like the swinging pendulum does.
Because we live in a atmospheric cyclone ranging in super strength to the centre to mild (to us) from our existing point, a swinging weighted pendulum would definitely alter in movement.
The pendulum would actually be more of a proof of a stationary Earth with moving pressure. created by the displacement of atmosphere by the dense movement of the ball, through it....and compressing it each time, which is compressed back onto.


Foucault's pendulum proves opposite to what's told, in my opinion.

This is why having it stood still and having a table on a bearing instead is argued against, because the table would obviously not move and neither would the pendulum.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 16, 2020, 05:20:51 AM
Quote
You are discussing loads and weight and tension when the pendulum is all about kinetic energy in the swing. They have nothing at all to do with each other.

Can the pendulum of the subject gain motion without its weight (mg)?

Doesn’t the weight of the pendulum transfer to the ground at one POINT if it is attached to the L-shaped pole / or the same points in case of the building as explained above?

Doesn’t the said POINT, which is attached firmly to the earth, rotate along with the rotation of the earth and ultimately the pendulum with or w/o swinging or the vertical plane in which it lies?

As asked earlier I want to know more about the mechanism at a point where the wire is attached to the dome of the building. No idea how does dome rotate in the animation while the wire and bob don’t get along with revolving of the earth? TY

The pendulum must be detached from the gravitational field while observing the rotation of the earth. 

The weight of the rotating platform in the following along with anything on it is transferred to one point as explained. There two types of gravitational force



1-   b/t the ball in air and turntable  AND
2-   b/t  earth and ball in the air
Since 1 <<<<<< 2, therefore, ball in the air follow the g of the earth not the g of the turntable. The ball in the air makes a curve on the turntable but actually it rotates along with the rotation of the earth.  The moving plane in the air is similar to a ball in the air in the above video.

Why would a sniper adjust for the Coriolis effect in the absence of a rotating platform @ 2:44 in the following when he/she and the target are spinning along with earth?
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 16, 2020, 08:06:40 AM
Why would a sniper adjust for the Coriolis effect in the absence of a rotating platform @ 2:44 in the following when he/she and the target are spinning along with earth?


Well this one is super easy to explain, barely an inconvenience.

The sniper and target are attached to the Earth and moving with it.

The bullet is NOT attached to the Earth, and is affected by the Coriolis effect.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 16, 2020, 08:30:26 AM

Well this one is super easy to explain, hardly an inconvenience.

Do you mean barely an inconvenience?

Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 16, 2020, 08:35:20 AM

Well this one is super easy to explain, hardly an inconvenience.

Do you mean barely an inconvenience?

I did mean that.  I am a terrible person, and feel quite stupid now for misquoting. I'll fix it right away, nobody will ever know.

At least I got the Coriolis effect question right. Although I didn't mention that the bullet is still somewhat attached to the Earths rotation via atmospheric drag, but that's minimal in this case.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 16, 2020, 08:44:03 AM

Well this one is super easy to explain, hardly an inconvenience.

Do you mean barely an inconvenience?

I did mean that.  I am a terrible person, and feel quite stupid now for misquoting. I'll fix it right away, nobody will ever know.

At least I got the Coriolis effect question right. Although I didn't mention that the bullet is still somewhat attached to the Earths rotation via atmospheric drag, but that's minimal in this case.

I’m just happy I’m not the only one who finds it vastly amusing.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 16, 2020, 09:25:10 AM
Quote
You are discussing loads and weight and tension when the pendulum is all about kinetic energy in the swing. They have nothing at all to do with each other.

Can the pendulum of the subject gain motion without its weight (mg)?

No.  But the direction of that motion comes entirely from the angle of the weight relative to the fixing when you first release it (if you were careful enough).

Once it starts swinging it should  just oscillate in that line without changing direction.  Gravity just pulls down, so as the weight passes the center it will slow down and then swing back along the same path.

Quote
Doesn’t the weight of the pendulum transfer to the ground at one POINT if it is attached to the L-shaped pole / or the same points in case of the building as explained above?

Of course.

Quote
Doesn’t the said POINT, which is attached firmly to the earth, rotate along with the rotation of the earth and ultimately the pendulum with or w/o swinging or the vertical plane in which it lies?

Yes.  The fixing point rotates with the earth, therefore the wire rotates with the earth, therefore the body of the pendulum rotates with the earth. 

But the direction of the swing doesn’t.

If something has linear momentum and you give it a spin, the direction of its momentum doesn’t change.  See my spaceship example above.

Quote
As asked earlier I want to know more about the mechanism at a point where the wire is attached to the dome of the building. No idea how does dome rotate in the animation while the wire and bob don’t get along with revolving of the earth? TY

Then you are looking in the wrong place.

If you want you know how it works, we’re trying to tell you.

Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 16, 2020, 10:20:46 AM
Quote
But the direction of the swing doesn’t.
-How?
Quote
If you want you know how it works, we’re trying to tell you
- Yes, please!

Quote
If something has linear momentum and you give it a spin, the direction of its momentum doesn’t change.  See my spaceship example above.
- Understood but how does it work in the experiment of Foucault's pendulum?
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 16, 2020, 11:21:00 AM
Quote
The sniper and target are attached to the Earth and moving with it.

The bullet is NOT attached to the Earth, and is affected by the Coriolis effect.
Do airplanes also affect by the Coriolis effect?
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 16, 2020, 11:27:36 AM
Quote
But the direction of the swing doesn’t.
-How?
Quote
If you want you know how it works, we’re trying to tell you
- Yes, please!

Quote
If something has linear momentum and you give it a spin, the direction of its momentum doesn’t change.  See my spaceship example above.
- Understood but how does it work in the experiment of Foucault's pendulum?

The exact same way.  It takes a force to change an objects momentum.  A pendulum swinging back and forth has momentum in the direction of the swing.

Imagine you want to make the 950 pound weight swing in a different direction?  First you have to catch it, which is going to take an enormous amount of work, imagine just standing in front of that thing and trying to stop it!  It would send you flying.  Then you have to pull it in a new direction and set it in motion, again a lot of work.

So all that work to change it's direction is what keeps it swinging back and forth as the Earth rotates under it. It takes a massive amount of force applied to it to change it's direction, so it stays swinging in place as the Earth moves.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 17, 2020, 03:20:50 AM
Quote
Fire the main engine then shut it off.  The spacecraft just moves under its own linear momentum.  Now apply a rotation with RCS thrusters or whatever.  You’ve introduced a spin, but it doesn’t change the linear momentum of the craft. They are independent.
what if the said craft orbits the celestial body? like the earth orbits around the sun
Quote
The exact same way.  It takes a force to change an objects momentum.  A pendulum swinging back and forth has momentum in the direction of the swing.

Pendulum rotates along with the rotation of the earth. It also revolves around the sun as it attached to the earth. its about the rotating frame. Would the said pendulum work if tried in merry go round?

According to you, the vertical plane remains fixed relative to the rotation of earth but changes its side relative to the sun when the earth moves to on the opposite side in its orbit around the sun. i.e bob changes its faces from west to east if faces west initially. 
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 17, 2020, 03:39:14 AM
Quote from: JJA
The exact same way.  It takes a force to change an objects momentum.  A pendulum swinging back and forth has momentum in the direction of the swing.

Pendulum rotates along with the rotation of the earth. It also revolves around the sun as it attached to the earth. its about the rotating frame. Would the said pendulum work if tried in merry go round?

According to you, the vertical plane remains fixed relative to the rotation of earth but changes its side relative to the sun when the earth moves to on the opposite side in its orbit around the sun. i.e bob changes its faces from west to east if faces west initially.

I'm not sure who you are replying to about the Sun, I never mentioned the Sun and it has nothing to do with the Foucault's Pendulum.

Would the said pendulum work if tried in merry go round?

Yes, it would absolutely work the same on a merry go round.

Lets assume we are on a flat, non rotating Earth.

Not take a merry go round, clear off all the horses and set up a large pendulum on it.  Start the pendulum swinging.  Now start up the merry go round, but remember it is going to be going slowly, it's only going to go around once every 24 hours.

The pendulum is not going to follow the merry go round, it will continue to swing in the same direction.
Title: Re: Question about the Foucault's Pendulum?
Post by: Unconvinced on June 17, 2020, 08:05:45 AM

Not take a merry go round, clear off all the horses and set up a large pendulum on it.  Start the pendulum swinging.  Now start up the merry go round, but remember it is going to be going slowly, it's only going to go around once every 24 hours.

The pendulum is not going to follow the merry go round, it will continue to swing in the same direction.

No need to go that slowly.  Should be much easier to demonstrate if not.

Take a weight and a piece of string, go to local children’s playground (although they may currently be shut).  Give the thing a spin, sit in the middle and swing the pendulum.

Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 01:11:28 AM
Quote
Yes, it would absolutely work the same on a merry go round.

Lets assume we are on a flat, non rotating Earth. 

Not take a merry go round, clear off all the horses and set up a large pendulum on it.  Start the pendulum swinging.  Now start up the merry go round, but remember it is going to be going slowly, it's only going to go around once every 24 hours.

The weight of the pendulum and its to and fro motion is not going to follow the merry go round, it will continue to swing in the same direction.
But again the bob is connected to the earth gravitationally, not merry go round as compared o earth as explained in reply #38.

Question: Earth rotates from East to West. If the Coriolis effect is true then would the whole mass of water/liquid in a container (including water bodies) on the equator either at a small or large scale push to the east side if yes any reference. It means the shores are not leveled. Reasons if no? TY, please!
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 18, 2020, 04:27:03 AM
Quote
Yes, it would absolutely work the same on a merry go round.

Lets assume we are on a flat, non rotating Earth. 

Not take a merry go round, clear off all the horses and set up a large pendulum on it.  Start the pendulum swinging.  Now start up the merry go round, but remember it is going to be going slowly, it's only going to go around once every 24 hours.

The weight of the pendulum and its to and fro motion is not going to follow the merry go round, it will continue to swing in the same direction.
But again the bob is connected to the earth gravitationally, not merry go round as compared o earth as explained in reply #38.

The bob is attracted to the earth but isn't connected.  This isn't hard to understand.

Take something heavy, tie a rope to it and swing it, then turn the support.  The direction of the swing oesn't change.

I just tried this myself with a 2 liter soda bottle.

These are things you can do yourself.  Find a playground as another said and do an actual, real experiment to show it. Showing that a pendulum will keep swinging int he same direction unless forced to change is an extremely simple, and basic experiment, and should be very easy to understand. It's basic momentum.

Question: Earth rotates from East to West. If the Coriolis effect is true then would the whole mass of water/liquid in a container (including water bodies) on the equator either at a small or large scale push to the east side if yes any reference. It means the shores are not leveled. Reasons if no? TY, please!

The spinning Earth does cause water to be higher at the equator, and makes the seas not all at the same level.

Earth Ocean Bulge (https://en.wikipedia.org/wiki/Equatorial_bulge#:~:text=But%20since%20the%20ocean%20also,sea%20level%20as%20Everest%20is.)
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 18, 2020, 04:31:44 AM
Quote
Yes, it would absolutely work the same on a merry go round.

Lets assume we are on a flat, non rotating Earth. 

Not take a merry go round, clear off all the horses and set up a large pendulum on it.  Start the pendulum swinging.  Now start up the merry go round, but remember it is going to be going slowly, it's only going to go around once every 24 hours.

The weight of the pendulum and its to and fro motion is not going to follow the merry go round, it will continue to swing in the same direction.
But again the bob is connected to the earth gravitationally, not merry go round as compared o earth as explained in reply #38.

Question: Earth rotates from East to West. If the Coriolis effect is true
The Coriolis force is certainly true but also very small!
Just consider that anyone can observe the four distinct situations observed for High and Low-Pressure Weather systems in the Northern and Southern Hemispheres.

These include the intense low pressure systems,  Hurricanes, Typhoons and Cyclones. These four distinct situations observed are:
     
Northern Hemisphere
     
Southern Hemisphere
Rotation direction of Highs
     
Clockwise
     
Anti-clockwise
Rotation direction of Lows
     
Anti-clockwise
     
Clockwise
Just look at weather maps that show highs, lows and wind directions to verify this for yourself.

Explain that without the Coriolis effect!

Quote from: E E K
then would the whole mass of water/liquid in a container (including water bodies) on the equator either at a small or large scale push to the east side if yes any reference. It means the shores are not leveled. Reasons if no? TY, please!
Why should the shores be levelled? The Coriolis force on moving air or water is very slight,
Have you ever calculated the actual Coriolis force on moving water?

I don't know it this will help or hinder: The Coriolis Effect by Dave Van Domelen (https://stratus.ssec.wisc.edu/courses/gg101/coriolis/coriolis.html).
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 05:13:26 AM
Quote
I just tried this myself with a 2 liter soda bottle.
I understand what you say but I have a disagreement over the rotating frame, which is attached to another rotating frame (earth). 

Similarly, a container could be a cup of tea or a big ocean. Fill a small circular container (big enough for the observation) with water till it spills over the brim.  Place it on a level surface on the equator line of earth before filling.

The water level must disturb in the container after 24 hours or more if Coriolis effect is true but I believe it will be the same. No spill at all on the east brim.

Moreover, earth has an angular momentum in its orbit around the sun besides spinning about its own axis. Doesn’t gravity of moon bulge the oceans during tides and the speed of earth changes in its orbit?
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 18, 2020, 05:21:56 AM
Quote
I just tried this myself with a 2 liter soda bottle.
I understand what you say but I have a disagreement over the rotating frame, which is attached to another rotating frame (earth). 

Similarly, a container could be a cup of tea or a big ocean. Fill a small circular container (big enough for the observation) with water till it spills over the brim.  Place it on a level surface on the equator line of earth before filling.

The water level must disturb in the container after 24 hours or more if Coriolis effect is true but I believe it will be the same. No spill at all on the east brim.

This is a question of scale.  Remember, the Earth only spins once every 24 hours.  That is a very, very, very small effect.  You are not going to see water in a cup spin.

Again, think of a merry go round that turns once every 24 hours.  Are you going to see a cup of water swirling around or sloshing out? No. The motion is far to slow to cause that. You could hardly even perceive the motion, let alone see water spilling from the cup.

The Earth is HUGE.  8,000 miles across. Turning once a day. At this scale, puny humans don't have the ability to see immediately and directly any of these effects.

But we can see them over time, like with Foucault's Pendulum.

Moreover, earth has an angular momentum in its orbit around the sun besides spinning about its own axis. Doesn’t gravity of moon bulge the oceans during tides and the speed of earth changes in its orbit?

Yes, the Moon causes the oceans to bulge and causes tides.

No, changes in the Earth's orbital speed don't affect us. Earth is in free-fall in relation to the Sun and isn't affected in any measurable way by changes in seasonal orbital speeds.

Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 07:11:17 AM
Quote
This is a question of scale.  Remember, the Earth only spins once every 24 hours.  That is a very, very, very small effect.  You are not going to see water in a cup spin.
We are observing the motion of the mass of water as a whole from west to east, not spin. Water/ liquid has no definite shape and takes a shape set down by its container and the rotation of the earth from west to east. This means shifting of the water will be more in the upper portion as compared to the lower portion in a container and ultimately spill over east brim.   

In simple words: SWAY in the mass of water as a whole from west to east.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 18, 2020, 09:00:55 AM
Quote
This is a question of scale.  Remember, the Earth only spins once every 24 hours.  That is a very, very, very small effect.  You are not going to see water in a cup spin.
We are observing the motion of the mass of water as a whole from west to east, not spin. Water/ liquid has no definite shape and takes a shape set down by its container and the rotation of the earth from west to east. This means shifting of the water will be more in the upper portion as compared to the lower portion in a container and ultimately spill over east brim.   

In simple words: SWAY in the mass of water as a whole from west to east.

You have some good ideas for tests here but are missing a few details.

The Earth does rotate west to east, but the water isn't going to shift to the east. If you are on the equator where the rotation is strongest, the rotation will cause it to shift UP.

Think of a merry go round again.  If you put a glass of water on it, which way is a full glass of water going to start to flow over?  It's going to flow out, away from the merry go round.

Now if you suddenly sped up or slowed down the Earth then yes, water would flow to the east or west. But the Earth rotates at a steady rate, so any movement of the water will be thrown away from the planet.

But again, remember that the rotation is only once every 24 hours.  That glass of water on a merry go round that only turns once a day isn't going to have any noticeable spilling at that slow of a rate.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 09:31:14 AM
Quote
only once every 24 hours
rotation is non-stop therefore time is not a factor. It can be observed for many many years if possible. It will show a noticeable rise/ spill at the east of container one day
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 18, 2020, 11:11:48 AM
Quote
only once every 24 hours
rotation is non-stop therefore time is not a factor. It can be observed for many many years if possible. It will show a noticeable rise/ spill at the east of container one day

"Once every 24 hours" is a unit of speed, not time.  I was pointing out how SLOW the rotation was.  If a rotation is slow, the effect is small, and rotating at 0.0007 RPM is very very very very slow.

A glass of water on a platform rotating at 0.0007 RPM simply isn't going to show a visible effect. 

You can try this at home.  Here is something that runs at 1 RPM, a thousand times faster than the Earth, you can put a cup of water on there and see if you can spot any spilling of the water. Then remember the Earth is a thousand times slower.

https://www.amazon.com/dp/B0756ZQX42/
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 11:59:17 AM
Quote
only once every 24 hours
rotation is non-stop therefore time is not a factor. It can be observed for many many years if possible. It will show a noticeable rise/ spill at the east of container one day

"Once every 24 hours" is a unit of speed, not time.  I was pointing out how SLOW the rotation was.  If a rotation is slow, the effect is small, and rotating at 0.0007 RPM is very very very very slow.

A glass of water on a platform rotating at 0.0007 RPM simply isn't going to show a visible effect. 

You can try this at home.  Here is something that runs at 1 RPM, a thousand times faster than the Earth, you can put a cup of water on there and see if you can spot any spilling of the water. Then remember the Earth is a thousand times slower.

https://www.amazon.com/dp/B0756ZQX42/
460 meters per second or roughly 1,000 miles per hour is not enough to show leaning in the aforementioned water or any water bodies.
Title: Re: Question about the Foucault's Pendulum?
Post by: sokarul on June 18, 2020, 01:23:58 PM
Those are velocities. Objects don’t feel velocity.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 18, 2020, 02:44:33 PM
Quote
only once every 24 hours
rotation is non-stop therefore time is not a factor. It can be observed for many many years if possible. It will show a noticeable rise/ spill at the east of container one day

"Once every 24 hours" is a unit of speed, not time.  I was pointing out how SLOW the rotation was.  If a rotation is slow, the effect is small, and rotating at 0.0007 RPM is very very very very slow.

A glass of water on a platform rotating at 0.0007 RPM simply isn't going to show a visible effect. 

You can try this at home.  Here is something that runs at 1 RPM, a thousand times faster than the Earth, you can put a cup of water on there and see if you can spot any spilling of the water. Then remember the Earth is a thousand times slower.

https://www.amazon.com/dp/B0756ZQX42/
460 meters per second or roughly 1,000 miles per hour is not enough to show leaning in the aforementioned water or any water bodies.

1000 miles an hour going around a 30 foot merry go round would probably kill you.

1000 miles an hour going around a planet 8,000 miles in diameter means you hardly feel it.

It's all about scale.

So no, 1000 miles an hour when it's 24,000 miles to make one rotation means it's rotating VERY SLOWLY.

Too slow to show any lean.  And remember that lean will be UP, not to the east.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 18, 2020, 07:25:56 PM
Quote
only once every 24 hours
rotation is non-stop therefore time is not a factor. It can be observed for many many years if possible. It will show a noticeable rise/ spill at the east of container one day
The Coriolis force has nothing to do with the velocity of the Earth's surface but only the angular velocity of the Earth's rotation and the velocity of the "particle" - air , water etc.

The strongest Coriolis force would be near either pole where the velocity is near zero.

The following expression is from: Coriolis force (https://en.wikipedia.org/wiki/Coriolis_force)
The Coriolis force on a particle depends on  the angular velocity times the velocity of the particle towards the centre of rotation as in (https://wikimedia.org/api/rest_v1/media/math/render/svg/e4eb6b9a1018b1ffbdf7bdf9883a8b4e8bd7f8fb),
where: m is the mass of the particle, Ω and v' is the particle velocity in the rotating frame - ie on Earth. The × is the vector cross product and means we use the component of v' at right angles to the axis of rotation

On Earth, the rate of rotation is close to 360°/24 hours or about 7.29 × 10−5/sec.
So for air or water at 45° latitude moving at 10 m/s (36 km/hr) acceleration would only be about 0.001 m/s2 (the same as a force of 0.001 N/kg) - it is minute (unless I've made a mistake ;D).

The Coriolis effect isn't going to "pile anything up" see Coriolis Acceleration and Scales of Circulation (http://tornado.sfsu.edu/Geosciences/classes/m201/Coriolis_rdg/Coriolis.html).
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 18, 2020, 11:28:42 PM
How about a balanced pencil on its pointed end. it could be similar anything of greater height. Would it fall east (day time) or west (night time)? - I know the answer will be NO from your side.

similarly, there is a Coriolis effect on the surface water and wind but the velocity (30 km/sec) of the earth in its orbit around the sun has no effect on wind, atmosphere or water - no idea 
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 19, 2020, 04:00:07 AM
How about a balanced pencil on its pointed end. it could be similar anything of greater height. Would it fall east (day time) or west (night time)? - I know the answer will be NO from your side.

You are correct, we would say no, it would not fall over, because that's not how forces like that work.

Think of the classic experiment where you put a bucket of water on a rope and swing it around you as fast as you can.

Where does the water go?  It goes to the bottom of the bucket.  It goes away from you.  The same with the spinning Earth, the force will try and send things away from it, not sideways.

Here is a diagram to illustrate.  The force is AWAY from the man spinning the weight.  That's why when you swing something around the rope goes away from you, not sideways.

(https://4.bp.blogspot.com/-sjeIgYiEVm0/WpFitSAfuCI/AAAAAAAAAC0/p5ZIpZ9499si2QKAkPC7vNNWaDGcI8IIQCLcBGAs/s1600/centifugal%252C%2Bpetal%2Bforce.jpg)

similarly, there is a Coriolis effect on the surface water and wind but the velocity (30 km/sec) of the earth in its orbit around the sun has no effect on wind, atmosphere or water - no idea

The Earth doesn't feel a force from it's orbit around the Sun, it's in free-fall around the Sun.  It's the same as astronauts aboard the ISS. They aren't being thrown around because they are in orbit, they are weightless. The Earth is not locked physically to the Sun like you are the surface of the Earth when standing on it.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 19, 2020, 05:31:46 AM
How about a balanced pencil on its pointed end. it could be similar anything of greater height. Would it fall east (day time) or west (night time)? - I know the answer will be NO from your side.

You are correct, we would say no, it would not fall over, because that's not how forces like that work.

Think of the classic experiment where you put a bucket of water on a rope and swing it around you as fast as you can.

Where does the water go?  It goes to the bottom of the bucket.  It goes away from you.  The same with the spinning Earth, the force will try and send things away from it, not sideways.

Here is a diagram to illustrate.  The force is AWAY from the man spinning the weight.  That's why when you swing something around the rope goes away from you, not sideways.

(https://4.bp.blogspot.com/-sjeIgYiEVm0/WpFitSAfuCI/AAAAAAAAAC0/p5ZIpZ9499si2QKAkPC7vNNWaDGcI8IIQCLcBGAs/s1600/centifugal%252C%2Bpetal%2Bforce.jpg)

similarly, there is a Coriolis effect on the surface water and wind but the velocity (30 km/sec) of the earth in its orbit around the sun has no effect on wind, atmosphere or water - no idea

The Earth doesn't feel a force from it's orbit around the Sun, it's in free-fall around the Sun.  It's the same as astronauts aboard the ISS. They aren't being thrown around because they are in orbit, they are weightless. The Earth is not locked physically to the Sun like you are the surface of the Earth when standing on it.
That’s what I was explaining to you. Do you remember the example of Saudi Clerik, contact, and non-contact gravitational forces that I had mentioned earlier? 
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 19, 2020, 05:43:45 AM
How about a balanced pencil on its pointed end. it could be similar anything of greater height. Would it fall east (day time) or west (night time)? - I know the answer will be NO from your side.

You are correct, we would say no, it would not fall over, because that's not how forces like that work.

Think of the classic experiment where you put a bucket of water on a rope and swing it around you as fast as you can.

Where does the water go?  It goes to the bottom of the bucket.  It goes away from you.  The same with the spinning Earth, the force will try and send things away from it, not sideways.

Here is a diagram to illustrate.  The force is AWAY from the man spinning the weight.  That's why when you swing something around the rope goes away from you, not sideways.

(https://4.bp.blogspot.com/-sjeIgYiEVm0/WpFitSAfuCI/AAAAAAAAAC0/p5ZIpZ9499si2QKAkPC7vNNWaDGcI8IIQCLcBGAs/s1600/centifugal%252C%2Bpetal%2Bforce.jpg)

similarly, there is a Coriolis effect on the surface water and wind but the velocity (30 km/sec) of the earth in its orbit around the sun has no effect on wind, atmosphere or water - no idea

The Earth doesn't feel a force from it's orbit around the Sun, it's in free-fall around the Sun.  It's the same as astronauts aboard the ISS. They aren't being thrown around because they are in orbit, they are weightless. The Earth is not locked physically to the Sun like you are the surface of the Earth when standing on it.
That’s what I was explaining to you. Do you remember the example of Saudi Clerik, contact, and non-contact gravitational forces that I had mentioned earlier?
But that has nothing to do with the Coriolis effect and Fouclault pendulums!
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 19, 2020, 08:03:35 AM
How about a balanced pencil on its pointed end. it could be similar anything of greater height. Would it fall east (day time) or west (night time)? - I know the answer will be NO from your side.

You are correct, we would say no, it would not fall over, because that's not how forces like that work.

Think of the classic experiment where you put a bucket of water on a rope and swing it around you as fast as you can.

Where does the water go?  It goes to the bottom of the bucket.  It goes away from you.  The same with the spinning Earth, the force will try and send things away from it, not sideways.

Here is a diagram to illustrate.  The force is AWAY from the man spinning the weight.  That's why when you swing something around the rope goes away from you, not sideways.

(https://4.bp.blogspot.com/-sjeIgYiEVm0/WpFitSAfuCI/AAAAAAAAAC0/p5ZIpZ9499si2QKAkPC7vNNWaDGcI8IIQCLcBGAs/s1600/centifugal%252C%2Bpetal%2Bforce.jpg)

similarly, there is a Coriolis effect on the surface water and wind but the velocity (30 km/sec) of the earth in its orbit around the sun has no effect on wind, atmosphere or water - no idea

The Earth doesn't feel a force from it's orbit around the Sun, it's in free-fall around the Sun.  It's the same as astronauts aboard the ISS. They aren't being thrown around because they are in orbit, they are weightless. The Earth is not locked physically to the Sun like you are the surface of the Earth when standing on it.
That’s what I was explaining to you. Do you remember the example of Saudi Clerik, contact, and non-contact gravitational forces that I had mentioned earlier?
But that has nothing to do with the Coriolis effect and Fouclault pendulums!
Earth doesn’t rotate below the airplanes or suspended pendulum either stationary or swinging in the air. They including the atmosphere move along with the Earth's rotation. Earth's spinning has no effect on the landing or taking off of planes, birds sitting on trees or elsewhere, etc because their motion is inertial to earth. It’s all relative to the Earth.



00:17 - 1:48 "All free-moving objects including masses of air on earth are subjected to Coriolis effect". 

Why? when there is no rotating frame (like merry go round) in between the earth and masses of the air?
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 19, 2020, 04:11:32 PM
But that has nothing to do with the Coriolis effect and Fouclault pendulums!
Earth doesn’t rotate below the airplanes
Because, as has been explained numerous times, the airplanes are flying in the air and are navigated to their destination.
You might notice that are designed to be controlled by the air-flow. They have both vertical and horizontal control surfaces for exactly that purpose.

Quote from: E E K
or suspended pendulum either stationary or swinging in the air. They including the atmosphere move along with the Earth's rotation.
Because Foucault pendulums are purposely made very heavy so that the air will have virtually no effect on them.

Quote from: E E K
Earth's spinning has no effect on the landing or taking off of planes, birds sitting on trees or elsewhere, etc because their motion is inertial to earth. It’s all relative to the Earth.
Why should it? The planes are taking of from the Earth in air that (apart from local winds) that is all moving together.

Quote from: E E K


00:17 - 1:48 "All free-moving objects including masses of air on earth are subjected to Coriolis effect". 

Why? when there is no rotating frame (like merry go round) in between the earth and masses of the air?
Air (or anything else) moving from a part of the Earth moving at one velocity to another moving at a different velocity will be subject "subjected to Coriolis effect".
It is a very slight effect and is quite negligible on planes or cars that are directed but other means.
But the effect can be seen on the movement or air, water or projectiles (artillery) move South to North or North to South and this must be taken into account when shooting at long range - tens of kilometers.

But, if you want big Coriolis, here's big Coriolis and long-range artillery, and the Coriolis Effect, try the "Paris Gun" used by Germany in WW I. It's at ranges like thus where the Coriolis and Eötvös effects become essential.

Have a look at:
Quote from: G. Trifkovic

In June 2002 issue of Military Heritage there is an article on Paris gun and a good part of it is about calculations that needed to be done in order to ensure accuracy. So,the Germans digged out the works of one Gustave Gaspard Coriolis (1792-1843),who in 1835 published his Sur les Equations du Mouvement Relatif des Systemes de Corps ("On the equations of Relative Motion of System of Bodies"),in which he stated that ,due to spherical nature of the Earth and it's rotation, a moving object on a north-south vector would be affected by the relative rotational speeds of launch and impact points. Earlier German use of long-range guns (firing from Lugenboom on Dunkirk), didn't have to take into account Coriolis Effect, because the firing site and target were on an east-west axis. Obscure mathematician von Eberhardt, at the time working for Krupp, understood the problems of firing on the north-south axis, so he based his research on Coriolis' works and made calculations accordingly.
Being advised on the site of the gun (Crepy-an-Laonnois), he estimated rotational speed of Paris at 567 mph on the 49th parallel and that of Laon at 555.55mph on the 48th parallel.So, an adjustment of 11.58 mph had to be provided for the laying of the gun. Also, he calculated the estimated flight time at 176 seconds and this called for easterly correction of 0.566 miles to compensate for differing rotational speeds of gun and target.
I am not too keen on math  ::) but this article really captured me, showing how much hard work (apart from technical aspects) was needed just to fire this gun. And all this was done without computer...  :o

Cheers,

GAius

From: Axis History Forum, The Paris Gun (https://forum.axishistory.com//viewtopic.php?t=45404)
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 20, 2020, 12:08:52 AM
I may be wrong but there are no such free moving objects like masses of air on earth. Free means Earth’s gravity has no effect on them at all. It’s only possible if moving with escape velocity. Temperature and pressure play an important role in their moving but it doesn’t mean that they move freely w/o the effect of gravity on them.

We know the air is a mixture of different gasses at different temperatures and pressure therefore the center of gravity of the whole mass of air might change its place wrt the earth which may be the reason for changing the direction of movement of air.
Title: Re: Question about the Foucault's Pendulum?
Post by: rabinoz on June 20, 2020, 01:23:01 AM
I may be wrong but there are no such free moving objects like masses of air on earth. Free means Earth’s gravity has no effect on them at all. It’s only possible if moving with escape velocity. Temperature and pressure play an important role in their moving but it doesn’t mean that they move freely w/o the effect of gravity on them.

We know the air is a mixture of different gasses at different temperatures and pressure therefore the center of gravity of the whole mass of air might change its place wrt the earth which may be the reason for changing the direction of movement of air.
How is any of that relevant to the Coriolis effect and the related action the Foucault Pendulum?

Gravity accelerates a projectile down towards the Earth but the Coriolis acceleration is at right angles to that.
And the Coriolis effect is certainly observed and must be allowed for in the aiming of long-range artillery.

Likewise gravity makes the Foucault Pendulum swing but, at least at either pole, has no effect on the direction of the swing.
Title: Re: Question about the Foucault's Pendulum?
Post by: sceptimatic on June 20, 2020, 03:18:19 AM
Those are velocities. Objects don’t feel velocity.
Objects do feel velocity.
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 20, 2020, 04:17:12 AM
Those are velocities. Objects don’t feel velocity.
Objects do feel velocity.

No objects do not feel velocity.  When you are sitting in an airplane flying at cruising altitude at 500mph, you don't "feel" hat 500mph, do you?  It feels like you are sitting still. There is no way for you to know without looking out the window or using a GPS if you are going 50mph or 500mph.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 20, 2020, 08:08:08 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 20, 2020, 09:22:28 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 20, 2020, 09:59:15 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 20, 2020, 10:57:13 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)

If you dropped it the plumb would deviate as the earth rotated under it, but that short a distance it would be hard to measure with much accuracy due to wind and other environmental effects. If you built a vacuum chamber that big it would be easy to measure if you dropped a smaller object.

Bullets and artillery shells are better demonstrations of the Coriolis effect.

Details and math - https://www.dpmms.cam.ac.uk/~stcs/courses/dynamics/handouts/handout5a.pdf
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 20, 2020, 11:23:54 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)

If you dropped it the plumb would deviate as the earth rotated under it, but that short a distance it would be hard to measure with much accuracy due to wind and other environmental effects. If you built a vacuum chamber that big it would be easy to measure if you dropped a smaller object.

Bullets and artillery shells are better demonstrations of the Coriolis effect.

Details and math - https://www.dpmms.cam.ac.uk/~stcs/courses/dynamics/handouts/handout5a.pdf
since all masses fall at the same rate, therefore, how about the idea of trying with the bob of Foucault's pendulum on a day determined by mereological conditions instead of building a vacuum chamber. 
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 20, 2020, 11:37:16 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)

If you dropped it the plumb would deviate as the earth rotated under it, but that short a distance it would be hard to measure with much accuracy due to wind and other environmental effects. If you built a vacuum chamber that big it would be easy to measure if you dropped a smaller object.

Bullets and artillery shells are better demonstrations of the Coriolis effect.

Details and math - https://www.dpmms.cam.ac.uk/~stcs/courses/dynamics/handouts/handout5a.pdf
since all masses fall at the same rate, therefore, how about the idea of trying with the bob of Foucault's pendulum on a day determined by mereological conditions instead of building a vacuum chamber.

Wind is always random and erratic, but the idea is sound.  If you drop a weight far enough, it will drift due to the Coriolis effect, yes.
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 20, 2020, 01:53:20 PM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)

If you dropped it the plumb would deviate as the earth rotated under it, but that short a distance it would be hard to measure with much accuracy due to wind and other environmental effects. If you built a vacuum chamber that big it would be easy to measure if you dropped a smaller object.

Bullets and artillery shells are better demonstrations of the Coriolis effect.

Details and math - https://www.dpmms.cam.ac.uk/~stcs/courses/dynamics/handouts/handout5a.pdf
since all masses fall at the same rate, therefore, how about the idea of trying with the bob of Foucault's pendulum on a day determined by mereological conditions instead of building a vacuum chamber.

Wind is always random and erratic, but the idea is sound.  If you drop a weight far enough, it will drift due to the Coriolis effect, yes.
True, wind may interrupt but at least we can test the idea if a controlled environment is not possible. Similarly, we can monitor the whole experiment by installing

1-   Laser light inside the pointed end of the bob (hollow cone-type nozzle).
2-   At least two video cameras; one totally focusing at the target on the ground and the other at the tip of a nozzle for observing the deviation of laser light from its target all the way from the start point to the target and the spinning of the earth.
3-   The latest available technology of the time.

It was nice chatting with all -TY- Have a good one!
Title: Re: Question about the Foucault's Pendulum?
Post by: JJA on June 21, 2020, 04:04:22 AM
Rotation of earth does change the direction of the vertical plane in which the Foucault's pendulum swings due to the weight of the bob when it comes to rest at its two extreme ends during swinging. 

Apropos the direction of swing in between the two ends:

Earth rotates about its axis at a rate of 460 meters per second. I believe a plumb bob of considerable size hits exactly at its plumb target on the ground if it drops from the top of Burj Khalifa which is 830 m high under the control environment, which doesn’t affect falling of bob.

According to Foucault believers, it should deviate its plumb target on the ground due to the rotation of the earth – Right?

The Earth rotates once every 24 hours, or 0.0007 RPM.  You are moving 460 m/s on the surface.

If you hang a pendulum from the Burj Khalifa and swing it long enough then yes, it will rotate.

This is because a pendulum, a gyroscope, a flywheel or a mass supported on a frictionless surface will want to keep it's orientation unless an external force acts upon it.
I said if dropped (the only bob, not along with its wire)

If you dropped it the plumb would deviate as the earth rotated under it, but that short a distance it would be hard to measure with much accuracy due to wind and other environmental effects. If you built a vacuum chamber that big it would be easy to measure if you dropped a smaller object.

Bullets and artillery shells are better demonstrations of the Coriolis effect.

Details and math - https://www.dpmms.cam.ac.uk/~stcs/courses/dynamics/handouts/handout5a.pdf
since all masses fall at the same rate, therefore, how about the idea of trying with the bob of Foucault's pendulum on a day determined by mereological conditions instead of building a vacuum chamber.

Wind is always random and erratic, but the idea is sound.  If you drop a weight far enough, it will drift due to the Coriolis effect, yes.
True, wind may interrupt but at least we can test the idea if a controlled environment is not possible. Similarly, we can monitor the whole experiment by installing

1-   Laser light inside the pointed end of the bob (hollow cone-type nozzle).
2-   At least two video cameras; one totally focusing at the target on the ground and the other at the tip of a nozzle for observing the deviation of laser light from its target all the way from the start point to the target and the spinning of the earth.
3-   The latest available technology of the time.

It was nice chatting with all -TY- Have a good one!

This experiment would show the effects of a rotating Earth.  When the weight is dropped, it would retain the momentum it had, but the ground below it would continue to rotate.  This would cause a very slight deviation, and to an Earth observer it would appear to rotate very very slightly as it fell, if you could measure it accurately.

There are lots of easier ways to demonstrate it, the pendulum and a gyro are two of them. And lots of other evidence. Bullets in flight, artillery shells, laser ring gyroscopes.

Would this one extra experiment prove to you the fact of the Earths spin? 
Title: Re: Question about the Foucault's Pendulum?
Post by: E E K on June 21, 2020, 09:33:45 AM
Quote
There are lots of easier ways to demonstrate it, the pendulum and a gyro are two of them. And lots of other evidence. Bullets in flight, artillery shells, laser ring gyroscopes.

Would this one extra experiment prove to you the fact of the Earths spin?

True but just to clear (my) doubt about the direction of the swing which doesn’t change.
Title: Re: Question about the Foucault's Pendulum?
Post by: Heiwa on June 22, 2020, 07:13:41 AM
When I lived on the Equator a little north of Mombasa, it was not necessary to use a pendulum to see that Earth is rotating. End March and October the Sun was always rising straight East at 06am out of the Indian Ocean to set a little south behind Kilmanjaro at 06pm. End December and June the Sun rose at 06am little South or North of straight East as the equatorial plane is not lined up with the Sun. We had a grandmother clock with a pendulum lined up North/South so the bob crossed the Equator at regular intervals. When I turned the clock 90° the bob never crossed the Equator. Imagine that.