Multiverse idea may be testable:

Originally posted by sonhouse
Couldn't you even tell if you were at the north or south pole by the circularity of the swing? Wouldn't the swing be way different on the equator?

The Earth is rotating clockwise at the south pole, and anti-clockwise at the north pole, relative the observer.
"How does it swing at the equator?" As I see it, it retains its swing.
How does it swing at the centre of the Earth?

How about the Earth in a parallel universe? (Just to stay on-topic...)

Originally posted by FabianFnas
The Earth is rotating clockwise at the south pole, and anti-clockwise at the north pole, relative the observer.
"How does it swing at the equator?" As I see it, it retains its swing.
How does it swing at the centre of the Earth?

How about the Earth in a parallel universe? (Just to stay on-topic...)

I guess you heard about the theory that black holes basically start a new universe where the physical constants are close but not exactly the same as those in our universe, G a bit different, c and so forth. And the opposite, the idea our universe is the end journey of what went into a black hole in a parent universe where our physics is slightly different from the parents.

Don't think we will be able to find evidence for that one any time soon though🙂

Originally posted by sonhouse
I guess you heard about the theory that black holes basically start a new universe where the physical constants are close but not exactly the same as those in our universe, G a bit different, c and so forth. And the opposite, the idea our universe is the end journey of what went into a black hole in a parent universe where our physics is slightly different ...[text shortened]... the parents.

Don't think we will be able to find evidence for that one any time soon though🙂

Have you heard about the theory that new universes are created by intelligent beings. Only universes with constans suited for life can evolve life that can create new universes, bad universes cannot. Therefore new universes are evolutionary and darwinian in its very nature.

And there are many more crazy theories too. Like the one that a god once created a universe, and that happened to be ours.

Speculating is fun, but we should know that they are not more than mere speculations.

Originally posted by FabianFnas
Have you heard about the theory that new universes are created by intelligent beings. Only universes with constans suited for life can evolve life that can create new universes, bad universes cannot. Therefore new universes are evolutionary and darwinian in its very nature.

And there are many more crazy theories too. Like the one that a god once create ...[text shortened]... e ours.

Speculating is fun, but we should know that they are not more than mere speculations.

That is a given, not going to run my life as if white holes or multiverses are real. It's just interesting speculation.

Originally posted by sonhouse
I think they proved Earth spins on its axis with a pendulum since they knew a pendulum would swing back and forth in the same path forever unless some outside force was effecting it.

Couldn't you even tell if you were at the north or south pole by the circularity of the swing? Wouldn't the swing be way different on the equator?

This was the answer I was thinking of - Foucault's pendulum, at the equator the pendulum would not rotate - the axis is wrong. It would rotate in the opposite sense in the southern hemisphere compared with the northern hemisphere.

The actual pendulum came quite late, but it would have proved it. The actual reason for the deduction was the common acceptance of heliocentric models for the solar system when it's automatic. Even with the sun orbiting the earth, I think fairly early on they had the earth rotating to give day and night and an annual orbit for the sun which was inclined to give seasons.

The difficulty in the experiment is that one has to know that something continues in a straight line unless an external force is applied, in other words one needs Newton's first law of motion to think of doing the experiment. The actual inference came from the backtracking of the planets (I think).

Originally posted by DeepThought
This was the answer I was thinking of - Foucault's pendulum, at the equator the pendulum would not rotate - the axis is wrong. It would rotate in the opposite sense in the southern hemisphere compared with the northern hemisphere.

The actual pendulum came quite late, but it would have proved it. The actual reason for the deduction was the common acc ...[text shortened]... doing the experiment. The actual inference came from the backtracking of the planets (I think).

I'm curious about this pendulum at the equator thing. Are you saying there would be no circular precession there, would it make a difference if the swing was parallel to the equator Vs parallel to the poles?

Originally posted by sonhouse
I'm curious about this pendulum at the equator thing. Are you saying there would be no circular precession there, would it make a difference if the swing was parallel to the equator Vs parallel to the poles?

You mean in our universe...?

Originally posted by FabianFnas
You mean in our universe...?

Yeah, no other rules of physics please🙂

Originally posted by sonhouse
I'm curious about this pendulum at the equator thing. Are you saying there would be no circular precession there, would it make a difference if the swing was parallel to the equator Vs parallel to the poles?

Imagine a vector pointing up from the equilibrium position of the pendulum weight to its pivot, for the pendulum to apparently precess it has to be aligned with the axis of rotation of the earth. The plane of rotation doesn't make a difference. At 45 degrees latitude there is enough of a component along the axis of rotation for the effect to persist.

Originally posted by DeepThought
Imagine a vector pointing up from the equilibrium position of the pendulum weight to its pivot, for the pendulum to apparently precess it has to be aligned with the axis of rotation of the earth. The plane of rotation doesn't make a difference. At 45 degrees latitude there is enough of a component along the axis of rotation for the effect to persist.

But even at the equator I would think there would be some precession if the direction of swing was north and south, the Earth would be moving underneath it so it would seem maybe the swing would be in a different place each time. Maybe not, I guess the frame of reference would be constant, the pendulum would be moving at the same rate so no precession, eh.

Originally posted by sonhouse
But even at the equator I would think there would be some precession if the direction of swing was north and south, the Earth would be moving underneath it so it would seem maybe the swing would be in a different place each time. Maybe not, I guess the frame of reference would be constant, the pendulum would be moving at the same rate so no precession, eh.

As there is no Coriolis effect at the equator, not even this force would affect a pendulum.

Originally posted by FabianFnas
As there is no Coriolis effect at the equator, not even this force would affect a pendulum.

So the next question, I saw one of the pendulums at a museum and it was huge, like 30 feet long string and a heavy bob, looked like at least 100 Kg.

So how small a pendulum can you make and still see that effect of precession due to being away from the equator?

Originally posted by sonhouse
So the next question, I saw one of the pendulums at a museum and it was huge, like 30 feet long string and a heavy bob, looked like at least 100 Kg.

So how small a pendulum can you make and still see that effect of precession due to being away from the equator?

I don't know but the bigger it is, the better it works. When it is too small other forces takes precedence, like air drag, temerature, humidity, the friction and so on.

So if you plan to construct a pendulum yourself, then do it big.

Originally posted by FabianFnas
I don't know but the bigger it is, the better it works. When it is too small other forces takes precedence, like air drag, temerature, humidity, the friction and so on.

So if you plan to construct a pendulum yourself, then do it big.

Yeah, I noticed that🙂 Wonder if one would work say with only a ten foot string? I also assume they have to give a push to the string to keep the amplitude the same. Wonder if you could do that with air pressure, like a nozzle inside the weight with holes inside to direct air like a little rocket to provide thrust, the string would then be hollow to allow pressurized air to get to the weight. It would have to be able to provide thrust exactly in the next path the pendulum would take on its own. That would probably require a computer and directable thruster. Sounds like it is getting very complicated already🙂

Originally posted by sonhouse
... Sounds like it is getting very complicated already🙂

So don't even try. With all these addendums you propose you end up with no proof at all about the rotation of the earth. It's much eaiser to prove anything with "god did it that way".

This thread have gone off-topic to the extent that the original ideas has gone lost altogether. So I am off here unless we don't return to the subject.

... which really is "Multiverse idea may be testable" which I claim is not with the technology of today. Anyone thinking otherwise I would like to ask: "How do you measure the distance between two universes. And what kind of answer would be appropriate? 'Light years'?"