My Zero Gravity Challenge

[SelfSim]

And you can't deny that they might be there. So the very best that you can say is that we can't measure them. But they theoretically exist. End of story.

What do you mean by 'theoretically exist but we can't measure them'?

 

[sjastro]

And you can't deny that they might be there. So the very best that you can say is that we can't measure them. But they theoretically exist. End of story.

By definition it must then be testable, but you have also stated there is no meaningful way it can be done hence the argument they theoretically exist is invalid.

 

[durangodawood]

Zero is a numerical value which can be based on a measurement.
The temperature can be 0⁰ C but it doesn’t make sense to refer to the temperature as "none" as it implies temperature is a countable physical object.

Is there a scale like that for gravity, with a "zero" point contrived for convenience amidst non-negligible positive values? The probability that the OP (or anyone) was inquiring about gravity in terms of that sense of zero is.... zero. We can dispense with it.

Mathematicians and scientists use the term "negligible" to exclude values which are too small or insignificant in their models in which case they take on the value of zero.

Do they also use zero to refer to actually none?

 

[SelfSim]

Is there a scale like that for gravity, with a "zero" point contrived for convenience amidst non-negligible positive values? The probability that the OP (or anyone) was inquiring about gravity in terms of that sense of zero is.... zero. We can dispense with it.

If such a scale was conceived in some model under study, including 'zero' would automatically contradict the purpose of creating such a scale ... which is to make measurements .. (and not: 'no measurements').

 

[sjastro]

Is there a scale like that for gravity, with a "zero" point contrived for convenience amidst non-negligible positive values? The probability that the OP (or anyone) was inquiring about gravity in terms of that sense of zero is.... zero. We can dispense with it.

Mathematically there is no zero point for gravity as the inverse square law for the gravitational force
F = Gm₁m₂/r² can never reach a zero value as shown in the graph.

Let’s apply this law to a physical scenario, the gravitational force between the Earth and Moon which equals F = 1.97 x 10²⁰ N.
Suppose we increase this distance to the size of the observable universe which is around 92 billion light years.
The gravitational force is now F = 3.84 x 10⁻¹⁷ N = 0.0000000000000000384 N.
There is nothing on Earth which can even remotely measure such a small value so as a valid approximation 0.0000000000000000384 N ≈ 0 N.
This is not to say there is no gravitational force or “none” but the gravitational force is extremely weak at this distance and is assigned a value of 0.

Do they also use zero to refer to actually none?

As a mathematician zero is a value, I'm not aware if zero is equated with "none" occurs in physics so the question is for the physicists in the forum.
In the early 20th century physicists found aether was not necessary as a medium for the propagation of light as the Michelson-Morely experiment showed a null result.
An experimental physicist will tell you the null result does not mean the aether did not exist or “none” but the result did not support the theory for its existence which is an important distinction.
I suspect this is the type of answer a physicist will give.

 

[Bradskii]

What do you mean by 'theoretically exist but we can't measure them'?

Anything with mass will have a gravitational effect. That effect will still be there even if it's too weak to measure. You seem to be saying that if it's too small to measure then therefore it doesn't exist. When I think that what you are saying is that it's too negligible to be of any consequence.

'The gravitational force acts between all objects that have mass. This force always attracts objects together, and although it is the weakest of the four fundamental forces, gravity has an infinite range.' Gravity - Energy Education.

 

[sjastro]

Here is a humorous introductory video of how gravity is treated in general relativity.

 

[SelfSim]

Anything with mass will have a gravitational effect. That effect will still be there even if it's too weak to measure.

That is a valid theoretical prediction, which also happens to be untestable in theory because the measurement, (aka: science's test for existence), will fall below the uncertainty inherent in the measurement. It will thus not be possible to infer 'that effect will still be there', from such a test.

We don't know whether the theory which makes the prediction, is valid for the context we're discussing. Theories are contextually dependent.

You seem to be saying that if it's too small to measure then therefore it doesn't exist. When I think that what you are saying is that it's too negligible to be of any consequence.

I'm saying the measurement for distinguishing existence, can also be predicted to fail in achieving its goal, in principle.
The consequence of treating it as 'too negligible' is just a declaration of considered irrelevancy to the particular model under test.

 

[Bradskii]

That is a valid theoretical prediction, which also happens to be untestable in theory because the measurement, (aka: science's test for existence), will fall below the uncertainty inherent in the measurement. It will thus not be possible to infer 'that effect will still be there', from such a test.

We don't know whether the theory which makes the prediction, is valid for the context we're discussing. Theories are contextually dependent.
I'm saying the measurement for distinguishing existence, can also be predicted to fail in achieving its goal, in principle.
The consequence of treating it as 'too negligible' is just a declaration of considered irrelevancy to the particular model under test.

Then can I suggest that we say that the effects are considered to be negligible...according to theory...until shown to be otherwise.

 

[durangodawood]

That is a valid theoretical prediction, which also happens to be untestable in theory because the measurement, (aka: science's test for existence), will fall below the uncertainty inherent in the measurement. It will thus not be possible to infer 'that effect will still be there', from such a test....

Sure, untestable.
But what do the models we have predict?
Well heres the Newtonian one, which predicts some positive effect of gravity at any distance:

Mathematically there is no zero point for gravity as the inverse square law for the gravitational force
F = Gm₁m₂/r² can never reach a zero value as shown in the graph.....

And if I understood the presentation of the general realitivity model earlier, theres also some positive effect predicted at any distance, though negligible at some point.

So, the question is empirically indeterminate - too small to test, beyond a point.
(no points for either option)
But, as I understand, no model we currently use predicts absolutely no positive effect at any distance. All models predict some effect.
(+1 point for some gravity everywhere)

Some gravity everywhere wins 1 to nil!

 

[durangodawood]

Does zero gravity exist?

So what do you make of all this, Mr Challenge Initiator ?

 

[AV1611VET]

So what do you make of all this, Mr Challenge Initiator ?

My take is that zero gravity does not exist, unless God himself suspends it.

Until He does, one electron at the edge of the universe exerts a pull on an electron at the the opposite edge.

 

[sjastro]

Sure, untestable.
But what do the models we have predict?
Well heres the Newtonian one, which predicts some positive effect of gravity at any distance:

And if I understood the presentation of the general realitivity model earlier, theres also some positive effect predicted at any distance, though negligible at some point.

So, the question is empirically indeterminate - too small to test, beyond a point.
(no points for either option)
But, as I understand, no model we currently use predicts absolutely no positive effect at any distance. All models predict some effect.
(+1 point for some gravity everywhere)

Some gravity everywhere wins 1 to nil!

Since this thread has put the emphasis on gravity as being a force, general relativity makes it very clear gravity does not exist.
Gravity can be thought of as a fictitious or fake force which can only be experienced by observers in accelerated frames of reference.
Inertial observers or observers in stationary frames or frames moving at a constant velocity do not experience gravity.
A non technical explanation for this was given in the video in my previous post.

 

[sjastro]

My take is that zero gravity does not exist, unless God himself suspends it.

Until He does, one electron at the edge of the universe exerts a pull on an electron at the the opposite edge.

This is why your challenges are nonsensical for posting in a science forum.
Since "Goddidit" has been presented as an explanation show us the evidence of "God doing it", "how God did it" and even the metaphysical question of "why God did it".

And while you are at it the electrostatic force of repulsion between two electrons is over 10³⁶ X greater than the gravitational force or over 1000000000000000000000000000000000000 times greater which would require God to suspend the electrostatic force in order for electrons at the edge of the universe to exert a pull on each other.

If you decide to use one of your standard Bible misquotes for the answer you are going to be hit with the Peter verse about those who misquote the Bible for their own means.

 

[AV1611VET]

Since "Goddidit" has been presented as an explanation show us the evidence of "God doing it", "how God did it" and even the metaphysical question of "why God did it".

Do you have a post number for this?

 

[sjastro]

Do you have a post number for this?

​

Try looking at your previous post #52.

 

[SelfSim]

Then can I suggest that we say that the effects are considered to be negligible...according to theory...until shown to be otherwise.

Y'know, you had me agreeing with that statement, (to a fairly high degree of critical thinking), and then @sjastro came up with his post #53, GR: 'gravity does not exist', (which I take as being all about the differing contexts of the respective theories).

All of which brings me back to my original criticism of the OP, which did not state the context in which the question would acquire his specific meaning. We've sort of drifted to cosmological contexts but there's the other end of the size spectrum where gravity falls apart as well.

 

[AV1611VET]

Try looking at your previous post #52.

You mean these?

My take is that zero gravity does not exist, unless God himself suspends it.

Until He does, one electron at the edge of the universe exerts a pull on an electron at the the opposite edge.

Since "Goddidit" has been presented as an explanation ...

Do you see why I call these "challenges" now?

 

[SelfSim]

You mean these?
Do you see why I call these "challenges" now?

"Goddidit" was in quotes and therefore doesn't mean he has to have done it. "Goddidit" is the standard explanation thrown at such issues whenever someone's back is against the wall (which yours is in this case .. because of your making unspecific goading-style (provoking) threads in a science forum .. about gravity of all things!)

 

[AV1611VET]

"Goddidit" was in quotes and therefore doesn't mean he has to have done it. "Goddidit" is the standard explanation thrown at such issues whenever someone's back is against the wall (which yours is in this case .. because of your making unspecific goading-style (provoking) threads in a science forum .. about gravity of all things!)

Do you see why I call these "challenges" now?

Would it have been better if I would have said:

My take is that zero gravity does not exist.

One electron at the edge of the universe exerts a pull on an electron at the the opposite edge.