Flat Earth moves upwards?

Please give me a source that states that the Cavendish experiment disproves the equivalence principle.

No one suggested that that's what it did, or should do. Nice straw man.

The equivalence principle is a fairly simple bit of science. I can never understand why you get so excited about it.

What the Cavendish experiment does do is show that there exists a force of attraction between all matter.

If you want to insist that we're accelerating, then you're free to do so, but you need to figure out a way to oppose this force that we know exists.

No, distinguishing between the earth's gravity and the gravity of the test weights has nothing to do with disproving the equivalence between dropping a ball inside an accelerating frame and dropping ball under the influence of the gravitational force.

Apparently it's you who doesn't understand the problem, as no one is contesting the bolded statement.  You also failed to answer my question.

What the experiment demonstrated was that things with mass experience a force that accelerates them towards other things with mass.  You agree that the test weights have their own gravity, however slight, thanks to having mass--so you must then admit that the Earth, having mass, must exhibit its own gravity as well.  THAT'S what's being said here and THAT'S the admission we want you to make.

I'm still waiting on a good explanation on why the wires on the power poles sag.  I mean if an object is simply floating in the air, and the Earth is moving up toward it, would the wire just float in the air?

No one suggested that that's what it did, or should do. Nice straw man.

Then why are you responding to my comments? You know very well that I was talking about the equivalence between gravity and acceleration the whole time.

Apparently it's you who doesn't understand the problem, as no one is contesting the bolded statement.  You also failed to answer my question.

What the experiment demonstrated was that things with mass experience a force that accelerates them towards other things with mass.  You agree that the test weights have their own gravity, however slight, thanks to having mass--so you must then admit that the Earth, having mass, must exhibit its own gravity as well.  THAT'S what's being said here and THAT'S the admission we want you to make.

It is well known within the scientific community that the purpose of the Cavendish experiment was to measure the density of the Earth, and that does not contradict what I said in the very beginning. I said that the UA follows from the equivalence principle, since it merely mimics the effects of gravity in our local frame by accelerating the Earth at 9.8m/s². Thus, since there are no fundamental differences between gravity and acceleration in our local frame, I said that they are governed by the same principle. I did not answer your question because it is completely irrelevant.

I made this claim:

According to GR, gravity and UA are governed by the same principle: there are no experiments that can differentiate gravity from acceleration in our frame of reference.

Lorddave replied with this claim:

Quote from: Jack on May 06, 2010, 04:41:24 PM

According to GR, gravity and UA are governed by the same principle: there are no experiments that can differentiate gravity from acceleration in our frame of reference.

Except the Cavendish Experiment.

The Cavendish experiment does not differentiate gravity from acceleration in our reference frame. In fact, the experiment has nothing to do with it. Lorddave's claim is the claim I am addressing. As I suggested before, pay attention.

"...and that does not contradict what I said in the very beginning."

Again, and this time try to really read it: NO ONE IS TRYING TO CONTRADICT THE EQUIVALENCE PRINCIPLE.  I'm pretty sure the reason you refused twice to respond to my point is because it forces you into a major admission; if you accept that gravity causes acceleration between masses, and that the Earth (and you as an observer) have mass, then you must admit that there is a gravitational force between you and the Earth.

...and I don't think that's something you want to do.  Your avoidance, anyway, indicates as much.

Again, and this time try to really read it: NO ONE IS TRYING TO CONTRADICT THE EQUIVALENCE PRINCIPLE.

This statement

there are no experiments that can differentiate gravity from acceleration in our frame of reference.

is the very definition of the Equivalence Principle. Lorddave responded with the Cavendish experiment, which means he is contesting that statement. Thus, he is trying to contradict the equivalence principle. How can you not understand this?

I'm pretty sure the reason you refused twice to respond to my point is because it forces you into a major admission; if you accept that gravity causes acceleration between masses, and that the Earth (and you as an observer) have mass, then you must admit that there is a gravitational force between you and the Earth.

Non-sequitur. I do not contest the idea that mass distorts space-time. In the other thread, I argued that the Earth must possess something that negates its ability to exert gravitational influence, since its disc shape would eventually collapse on itself if it does. As I said before, I did not address your question because it is completely irrelevant to what I said in this thread.

Quote from: Lorddave on May 07, 2010, 03:11:20 PM

Since the Cavendish experiment shows that gravity exists and can cause objects to accelerate towards each other on a horizontal plane (not just vertical) than mass MUST cause gravity.  And if mass causes gravity than the Earth MUST have gravity.

Non-sequitur. Please show how the Cavendish experiment, which was merely an attempt to measure the Earth's density, can distinguish between a downward pull of gravity and an upward acceleration of 9.8m/s² in our reference frame, thereby contradicting Einstein's equivalence principle.

The Cavendish experiment does not differentiate gravity from acceleration in our reference frame. In fact, the experiment has nothing to do with it. Lorddave's claim is the claim I am addressing. As I suggested before, pay attention.

It doesn't.  Why would it?  
There is no way, from our frame of reference, to distinguish an upwards acceleration or a downwards gravitational pull.
So, what we need to do is figure out if Gravity exists or not.

With me so far?

It doesn't.  Why would it? 
There is no way, from our frame of reference, to distinguish an upwards acceleration or a downwards gravitational pull.
So the only thing we can do is figure out if gravity exists or not.

With me so far?

Then why did you make this claim?

Quote from: Jack on May 06, 2010, 04:41:24 PM

According to GR, gravity and UA are governed by the same principle: there are no experiments that can differentiate gravity from acceleration in our frame of reference.

Except the Cavendish Experiment.

I argued that the Earth must possess something that negates its ability to exert gravitational influence, since its disc shape would eventually collapse on itself if it does.

Find that something and you've just won the Nobel prize.

Quote from: Lorddave on May 07, 2010, 09:15:19 PM

It doesn't.  Why would it?  
There is no way, from our frame of reference, to distinguish an upwards acceleration or a downwards gravitational pull.
So the only thing we can do is figure out if gravity exists or not.

With me so far?

Then why did you make this claim?

Quote from: Lorddave on May 06, 2010, 04:54:52 PM

Quote from: Jack on May 06, 2010, 04:41:24 PM

According to GR, gravity and UA are governed by the same principle: there are no experiments that can differentiate gravity from acceleration in our frame of reference.

Except the Cavendish Experiment.

Sorry, edited my previous post a bit:

Well, I made that claim because gravity accelerates two masses together regardless of direction.  Your UA is direction specific.  Thus, the UA and Gravity are not the same thing and don't govern based on the same principal (one moves the Earth in a constant direction the other attracts masses together).
See?  Very different principals.


Oh and one more thing...

In the other thread, I argued that the Earth must possess something that negates its ability to exert gravitational influence, since its disc shape would eventually collapse on itself if it does.

If the Earth negates it's gravity, the Cavendish experiment shouldn't work.

Quote

there are no experiments that can differentiate gravity from acceleration in our frame of reference.

is the very definition of the Equivalence Principle. Lorddave responded with the Cavendish experiment, which means he is contesting that statement. Thus, he is trying to contradict the equivalence principle. How can you not understand this?

Ah, I see your mix-up.

By our frame of reference (as a point on the Earth), we can't tell if the Earth is accelerating or if we're feeling a gravitational force.  By the other frame of reference (a point on the weight in the experiment) we can't tell if we're being turned by gravity or if the mechanism itself is turning us.  What you're missing is that both of these phenomena are observed to be happening at the same time and in perpendicular directions.  From one reference frame, we can view the other.  The equivalence principle relies only on a single reference frame.  You're overextending the idea.

Sorry, edited my previous post a bit:

Well, I made that claim because gravity accelerates two masses together regardless of direction.  Your UA is direction specific.  Thus, the UA and Gravity are not the same thing and don't govern based on the same principal (one moves the Earth in a constant direction the other attracts masses together).
See?  Very different principals.

Therefore, my statement that "there are no experiments that can differentiate gravity from acceleration in our frame of reference" stands correct. I honestly do not understand why you used the Cavendish experiment as a response to that statement.

Ah, I see your mix-up.

By our frame of reference (as a point on the Earth), we can't tell if the Earth is accelerating or if we're feeling a gravitational force.  By the other frame of reference (a point on the weight in the experiment) we can't tell if we're being turned by gravity or if the mechanism itself is turning us.  What you're missing is that both of these phenomena are observed to be happening at the same time and in perpendicular directions.  From one reference frame, we can view the other.  The equivalence principle relies only on a single reference frame.  You're overextending the idea.

That is why I wrote "in our frame of reference" in my statement.

If I'm reading that and the previous posts correctly, gravity does exist between all masses in the universe...except Earth's.  Well, aren't we special?     When you get some data to back these claims up, I'll be mighty impressed!  Godspeed, sir.

Oh and one more thing...

Quote

In the other thread, I argued that the Earth must possess something that negates its ability to exert gravitational influence, since its disc shape would eventually collapse on itself if it does.

If the Earth negates it's gravity, the Cavendish experiment shouldn't work.

I said something is negating the Earth's ability to exert gravitational influence, not that the Earth is negating its own ability to do so.

Quote from: Lorddave on May 07, 2010, 09:19:30 PM

Sorry, edited my previous post a bit:

Well, I made that claim because gravity accelerates two masses together regardless of direction.  Your UA is direction specific.  Thus, the UA and Gravity are not the same thing and don't govern based on the same principal (one moves the Earth in a constant direction the other attracts masses together).
See?  Very different principals.

Therefore, my statement that "there are no experiments that can differentiate gravity from acceleration in our frame of reference" stands correct. I honestly do not understand why you used the Cavendish experiment as a response to that statement.

Actually I was responding to your claim that both UA and Gravity operate on the same principal, which was poorly worded on my part, but this works too.

See, while you can't show that there is a difference between gravity and acceleration (because gravity causes acceleration) you CAN show that there is a constant acceleration (or attempted acceleration) between mass.  Because the UA is a single vector acceleration, any acceleration between mass that is not in the vertical position MUST be caused by something other than the UA.

Quote from: Lorddave on May 07, 2010, 09:19:30 PM

Oh and one more thing...

Quote

In the other thread, I argued that the Earth must possess something that negates its ability to exert gravitational influence, since its disc shape would eventually collapse on itself if it does.

If the Earth negates it's gravity, the Cavendish experiment shouldn't work.

I said something is negating the Earth's ability to exert gravitational influence, not that the Earth is negating its own ability to do so.

Which shouldn't make a bit of difference should it?  If I'm ON the Earth and I take PART of the Earth out, should that be negated too by whatever force is negating the gravity of the mass below my feet?
Or is this "force" negating only the gravity of the ground and not anything above said ground?

Actually I was responding to your claim that both UA and Gravity operate on the same principal, which was poorly worded on my part, but this works too.

The principle I was referring to is quite obviously the Principle of Equivalence.

See, while you can't show that there is a difference between gravity and acceleration (because gravity causes acceleration) you CAN show that there is a constant acceleration (or attempted acceleration) between mass.  Because the UA is a single vector acceleration, any acceleration between mass that is not in the vertical position MUST be caused by something other than the UA.

Local masses that are independent of the Earth should still be able to exert gravitational influence on each other.

Which shouldn't make a bit of difference should it?  If I'm ON the Earth and I take PART of the Earth out, should that be negated too by whatever force is negating the gravity of the mass below my feet?
Or is this "force" negating only the gravity of the ground and not anything above said ground?

The negator should only negate the gravitation of the Earth's surface and below just so that the Earth does not collapse on itself.

So gravity affects all mass in the universe except for just below the Earth's surface, where it must be negated somehow, because--as you say--otherwise the disc of the Earth would collapse.  Alright, let's play this out in our heads.  I'll give you three guesses what shape the planet would collapse to, but you'll only need one.

Side note: this is exactly the kind of FE stuff I mention in other threads.  A bunch of superfluous ideas and unknown negating forces have to be made up that inexplicably affect only certain things at certain times to explain phenomena that, in RET, make perfect sense with a handful of simple laws.

It is not a matter of what I say. If the disc is massive enough and is generating a gravitational field, it would eventually collapse so that it reaches hydrostatic equilibrium and its gravitational strength is distributed as evenly as possible across its surface. It would eventually become more or less spherical in shape.

If you are in a train and you jump, wouldn't the UA cause you to move slightly to the back of the train?

What if the Cavendish experiment were to be performed in an underground cave? Would gravity still somehow stop at the cave walls but somehow leave everything that is "above the surface" affected by gravity?

Which leads me to another question: We can measure a reduction in gravitational acceleration if we go deep underground. This is explained perfectly well in RE by the matter above you pulling up and slightly reducing the pull downwards. How is this explained in FE?

Quote from: Crustinator on May 07, 2010, 07:14:40 PM

No one suggested that that's what it did, or should do. Nice straw man.

Then why are you responding to my comments?

Because you're either very confused or are deliberately confusing two issues.

The Cavendish experiment does not disprove the equivalence principle. It never intended to, nor should it. It does however establish by experimentation that a force of attraction exists between all matter.

From this fact we can deduce that there is a force of attraction between the earth and ourselves.

While we might not be able to measurably distinguish the forces, we must recognise that a proportion (if not all) of any force felt is attributable to gravity. (This raises interesting holes in FET that I've noticed you're deftly sidestepping)

If you want to insist that you're confused and can't make this distinction, then that's OK.

What if the Cavendish experiment were to be performed in an underground cave? Would gravity still somehow stop at the cave walls but somehow leave everything that is "above the surface" affected by gravity?

Which leads me to another question: We can measure a reduction in gravitational acceleration if we go deep underground. This is explained perfectly well in RE by the matter above you pulling up and slightly reducing the pull downwards. How is this explained in FE?

Since the deepest human excavations, even based on the claims of globularists, barely exceed seven kilometers, how do you know this exactly?

You could just dismiss any evidence I posted as being "part of the conspiracy" so why bother?

I learned that when calculating the gravitational force on an object, you only include the mass out from the center of the planet to a radius of where the object is. In fact one of the more painful problems I had on a final exam in advanced mechanics was to calculate the path of an object dropped through a chord drilled straight through a planet. You had to include differential gravitation and everything, it was tough.

So would I be correct in saying that FE'ers deny that your acceleration goes down as you descend into the earth?

It is not a matter of what I say. If the disc is massive enough and is generating a gravitational field, it would eventually collapse so that it reaches hydrostatic equilibrium and its gravitational strength is distributed as evenly as possible across its surface. It would eventually become more or less spherical in shape.

This is what's wrong with FET.
You always start with the assumption that the Earth is flat then build around it. Just to disprove me you had to say that there is something, though you don't know what, can't prove it exists, and have no model for it, tha negates gavity only below the surface enough to be undetectable but do exactly what you need it to in order to keep the Earth a disk AND allow for gravity to exist above the surface.

This isn't science, it's religion.  

Since the deepest human excavations, even based on the claims of globularists, barely exceed seven kilometers, how do you know this exactly?

Know what?!

That gravity doesn't stop underground? Take a tube ride and find out.

 

Since the deepest human excavations, even based on the claims of globularists, barely exceed seven kilometers, how do you know this exactly?

If you're going to throw out facts, at least keep up to date.

Barely seven kilometers? In 1989 we reached depths beyond 12km !
http://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
Came complete with loads of new geophysical and geochemical data!

Science progresses every day, often with modern discoveries confirming old predictions...

You could just dismiss any evidence I posted as being "part of the conspiracy" so why bother?

I learned that when calculating the gravitational force on an object, you only include the mass out from the center of the planet to a radius of where the object is. In fact one of the more painful problems I had on a final exam in advanced mechanics was to calculate the path of an object dropped through a chord drilled straight through a planet. You had to include differential gravitation and everything, it was tough.

So would I be correct in saying that FE'ers deny that your acceleration goes down as you descend into the earth?

So the sum total of your evidence for the previous claim is that you were told so by globularist academics? What's more, what you were told was openly presented as the result of a purely hypothetical thought-experiment which presupposes the existence of gravity? Why do you expect anybody to find this convincing?

Because you're either very confused or are deliberately confusing two issues.

There was confusion on both sides. When I first stated that UA and gravity follow the same principle in that there are no experiments capable of differentiating gravity from acceleration in our reference frame, Lorddave responded with the Cavendish experiment. Either he was confused with my statement or he tried to argue that there is an experiment that can distinguish between gravity and acceleration. Anyone who has seen General Relativity would notice that there is no falsehood in my statement, so I thought he was confused. However, when I made the statement "in no way does the Cavendish experiment differentiate gravity from acceleration in our frame of reference," he and Ellipsis replied against it.

Fine. I asked him how does the experiment distinguish between the two, and you came with [this post] as a response. Thus, I asked you too, and you replied with your interpretation of the experiment. There could be three reasons for this: you were confused with what I was saying, you knew what I was saying but you intended to contest my claim just to be a nuisance, or you simply failed to clarify that you were not contesting my claim but merely trying to make a distinction between the Equivalence Principle and the Cavendish experiment.

There was confusion on both sides.

Not really. The Cavendish experiment establishes that a force due to gravitational attraction between masses exists.

It also enables the density of the earth to be calculated.

Therefore any force experienced while falling is in part or wholly (depending on the level of fanatical adherance to FET) due to this attraction.

Given this fact, the "accelerating earth" in FET becomes largely irrelevant. What FET now needs to do is counter the gravitational force with some kind of anti-gravity in order to maintain the hovering position of the moon, sun, stars etc.

PS. There are experiments which can distinguish gravity and acceleration, as you know.

Quote from: General Disarray on May 08, 2010, 08:00:01 AM

You could just dismiss any evidence I posted as being "part of the conspiracy" so why bother?

I learned that when calculating the gravitational force on an object, you only include the mass out from the center of the planet to a radius of where the object is. In fact one of the more painful problems I had on a final exam in advanced mechanics was to calculate the path of an object dropped through a chord drilled straight through a planet. You had to include differential gravitation and everything, it was tough.

So would I be correct in saying that FE'ers deny that your acceleration goes down as you descend into the earth?

So the sum total of your evidence for the previous claim is that you were told so by globularist academics? What's more, what you were told was openly presented as the result of a purely hypothetical thought-experiment which presupposes the existence of gravity? Why do you expect anybody to find this convincing?

Wasn't trying to be convincing. I haven't performed any underground gravity measurements myself, so I doubt you would believe anything I said anyway.

In fact, I was kind of hoping that Deceiver who seems to be the guru of all things underground could help me out in that area.

So just for the record, do you deny that there would be any changes in acceleration (gravity or UA) measured deep underground?