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Old 10th January 2017, 11:44 AM   #1
sts60
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Gravitational constant and navigation

This is an offshoot of the Brilliant Light Power thread, from which posts dealing with the gravitational constant G were AAH'd for being off-topic (I think).

michaelsuede said (excerpted):
Originally Posted by michaelsuede View Post
Since the ground state is simply defined, there's no reason in theory it could not be lower.

It's like big G simply being defined, even though it changes every time we measure it.
I said this was "nonsense", and the conversation went like this:
Originally Posted by sts60
You're conflating refinement of very well-known empirical constants - which fit theory very, very well - with casual wholesale revisions of same. That is fantasy.
Originally Posted by michaelsuede
OH!! It's "refinement" - that's why the numbers are all over the board.
Originally Posted by sts60
The notion that G values are "all over the board" is flatly at odds with reality. The current standard measured value of G is about 1% different than that originally measured over two centuries ago. And if G actually varied as much as you portray, we'd never have sent spacecraft to Mars, let alone to Pluto and beyond.
Originally Posted by michaelsuede
NASA navigates the cosmos with purely Newtonian calculations where the variance of G can be great and not make a bit of difference given that most long range probes operate off of celestial navigation. Clearly we could still effectively navigate the solar system even with a very gross definition of G.
I scoffed heartily at this, because (a) michaelsuede doesn't understand how "celestial navigation" works for spacecraft. But more importantly, (b) it's silly to claim that any old value of G ("the variance can be great") can be used and expect that you're going to get where you're going over interplanetary distances.

michealsuede's followup comment in the main thread was:
Originally Posted by michaelsuede View Post
I said it was possible to navigate around the solar system using celestial navigation and a gross approximation of G, like the one that was taken by Cavendish back in 1798. I'm still struggling to understand how I'm wrong about this...

...Measurements of G are all over the place. The Scientific American has done several articles and podcasts about this. I made this claim in reference to G not being proven to be a constant, which it is not. It is simply defined, not empirically proven, to be a constant.

So, this thread is for discussion of such issues. The first topic, as I see it, is: What does he mean by "gross approximation" and "all over the place"?

The original determination of the value of G, made by Cavendish in 1798, was about 6.754 ×10-11 N m2kg-2.
The current accepted value is about G = 6.673×10-11 N m2kg-2.

In other words, the current value is about 1% different than the first value, which is hardly surprising; gravitation is by far the weakest force and this makes a precise determination of G very difficult. And I know he's talking about more than the normal evolution of measurement of a physical constant, but I'd like to make sure we're at the same starting point.

michaelsuede, what do you mean by "the variance of G can be great" in space missions? Are you talking about up to 1%? 5%? 25%? I want to be sure I'm not getting the wrong impression from your adjectives.
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Old 10th January 2017, 11:53 AM   #2
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Thanks much 'sts60' for raising this point because I had some thoughts about it as well ...

I also noticed that talk about the variation of G and I promptly thought it was just nonsense because I have never heard such wild claim before.

About the closest that I ever saw to such a thing was on a creationist web site where it was claimed that in the early period of the universe God changed the speed of light so that it was thousands of times faster than it is now. And that is how the universe go to be so very big in just the few thousands of years since God first created the universe, because God was kind enough to increase the universal speed limit way back when.

The one idea is about as weird as the other idea.
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Old 10th January 2017, 12:11 PM   #3
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Originally Posted by sts60 View Post
michaelsuede, what do you mean by "the variance of G can be great" in space missions? Are you talking about up to 1%? 5%? 25%? I want to be sure I'm not getting the wrong impression from your adjectives.
I mean whether you use G taken from a beam balance that was produced in the 18th century or G taken from a high tech atomic fountain, it makes no difference.

Measurements of G are all over the place. The Scientific American has done several articles and podcasts about this. I made this claim in reference to G not being proven to be a constant, which it is not. It is simply defined, not empirically proven, to be a constant.
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Old 10th January 2017, 12:13 PM   #4
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It's true that we define G as constant, but cannot prove it to be so.

But so what? This is an appropriate application of Occam's Razor. The simplest possibility is that it's constant. The simplest possibility is that we aren't special, that the laws of physics are the same everywhere and at all times. If that's NOT the case, if G changes in different places or times, then there are going to be consequences of that. If those changes are small, then the consequences would be small, and we might not notice them. But we would notice large changes. Stellar evolution, for example, is dependent on G. Stars and galaxies that evolved under radically different G's would look radically different as well. There would be visible evidence of large changes.

But there aren't. Which means that G cannot and does not vary much, if at all.

So we rightly apply Occam's Razor. In the absence of any evidence of changing G, we rightly assume that it's constant. If we ever discover evidence to suggest otherwise, then we revise our theories. But not until then. And dark matter/dark energy don't constitute such evidence.
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Old 10th January 2017, 12:21 PM   #5
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Originally Posted by michaelsuede View Post
I mean whether you use G taken from a beam balance that was produced in the 18th century or G taken from a high tech atomic fountain, it makes no difference.
OK, so when you claim that spacecraft could perform interplanetary missions with a "gross approximation" of G, you're talking to within about 1%. We'll get to that later.

Originally Posted by michaelsuede View Post
Measurements of G are all over the place. The Scientific American has done several articles and podcasts about this. I made this claim in reference to G not being proven to be a constant, which it is not. It is simply defined, not empirically proven, to be a constant.
So your definition of "all over the place" here is on the order of 500 parts per million.

Now that we've got the terminology agreed upon, let's look at what I means for your claim that G is variable. Do you claim that it can vary arbitrarily? By what percentage? Or are you saying it only varies within about the spread described in the article you cite?

What does the orbit of the Earth tell you about how much G actually isn't "constant"?
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Old 10th January 2017, 01:09 PM   #6
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Originally Posted by Ziggurat View Post
But there aren't. Which means that G cannot and does not vary much, if at all.
That's the important bit. We've narrowed down by how much G can vary. For the purposes of navigation within the solar system, any variance of G within that range makes no difference. The uncertainty in value is currently 4.7 * 10 ^-5. Further evidence that it's a constant comes from measurement of the gravitational coupling constant. That we know within 10^-45.
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Old 10th January 2017, 01:27 PM   #7
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Originally Posted by michaelsuede View Post
I mean whether you use G taken from a beam balance that was produced in the 18th century or G taken from a high tech atomic fountain, it makes no difference.

Measurements of G are all over the place. The Scientific American has done several articles and podcasts about this. I made this claim in reference to G not being proven to be a constant, which it is not. It is simply defined, not empirically proven, to be a constant.
And did you actually read the article that you cited?

I did and I got the distinct impression that the variation of G is due to the fact that it is a difficult value to determine with accuracy as opposed to some sort of variation of G itself.

Or to quote from the article:

Quote:
...

Most scientists think all these discrepancies reflect human sources of error, rather than a true inconstancy of big G. We know the strength of gravity hasn’t been fluctuating over the past 200 years, for example, because if so, the orbits of the planets around the sun would have changed, Quinn says. Still, it’s possible that the incompatible measurements are pointing to unknown subtleties of gravity—perhaps its strength varies depending on how it’s measured or where on Earth the measurements are being made?

...
I hope that clarifies things for you.
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Old 10th January 2017, 02:09 PM   #8
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Quote:
Now that we've got the terminology agreed upon, let's look at what I means for your claim that G is variable. Do you claim that it can vary arbitrarily?
The variance is not arbitrary.

Quote:
By what percentage?
That depends on the change in net charge in a given gravitational body.

Quote:
Or are you saying it only varies within about the spread described in the article you cite?
For Earth, it only varies within the spread described within the article. For other bodies that are not in electrically stable orbits, it can vary far more dramatically.

Quote:
What does the orbit of the Earth tell you about how much G actually isn't "constant"?
The orbit doesn't tell me anything. The fact that all measurements, no matter the complexity or accuracy of the system, vary over time, tells me that G not constant.

I believe Thornhill's theory of gravity is correct.

http://www.holoscience.com/wp/electr...tric-universe/

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Old 10th January 2017, 03:09 PM   #9
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Originally Posted by michaelsuede View Post
The variance is not arbitrary.



That depends on the change in net charge in a given gravitational body.



For Earth, it only varies within the spread described within the article. For other bodies that are not in electrically stable orbits, it can vary far more dramatically.



The orbit doesn't tell me anything. The fact that all measurements, no matter the complexity or accuracy of the system, vary over time, tells me that G not constant.

I believe Thornhill's theory of gravity is correct.

http://www.holoscience.com/wp/electr...tric-universe/
Wow!

You really should read your own citations.

First, the web page that you refer to concerns an article that was published August, 2008. Therefore, it can hardly be used as a current source of information.

Second, the article contains at least one glaring error that I noticed right off concerning how the speed of gravity is instantaneous.

Quote:
...

If gravity operated at the speed of light all planets would experience a torque that would sling them out of the solar system in a few thousand years.

...
However, it has been recently confirmed that gravity does indeed move at the speed of light. Therefore, the above section is quite incorrect.
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Old 10th January 2017, 03:19 PM   #10
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Old 10th January 2017, 05:22 PM   #11
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I should probably clarify my "change in net charge" response. That's really a poor choice of words that doesn't mean much.

G on Earth depends on the polarization of the Earth itself, which can be altered by adding or subtracting charge from the surface of the Earth. Ipso facto, G is not universal, it is local to each body.

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Old 10th January 2017, 06:31 PM   #12
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Originally Posted by michaelsuede View Post
I should probably clarify my "change in net charge" response. That's really a poor choice of words that doesn't mean much.

G on Earth depends on the polarization of the Earth itself, which can be altered by adding or subtracting charge from the surface of the Earth. Ipso facto, G is not universal, it is local to each body.
I seriously doubt that you know what you are talking about.
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Old 10th January 2017, 06:46 PM   #13
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Originally Posted by michaelsuede View Post
I should probably clarify my "change in net charge" response. That's really a poor choice of words that doesn't mean much.

G on Earth depends on the polarization of the Earth itself, which can be altered by adding or subtracting charge from the surface of the Earth. Ipso facto, G is not universal, it is local to each body.
How much do you think G varies from natural variations in surface charging? What is the peak amplitude of the variation over, say the last few centuries? I'm looking for some kind of ballpark percentage range. I'm not agreeing eith your claim, but I want to understand what you think the strength of this effect is.
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Old 10th January 2017, 06:46 PM   #14
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Originally Posted by michaelsuede View Post
I should probably clarify my "change in net charge" response. That's really a poor choice of words that doesn't mean much.

G on Earth depends on the polarization of the Earth itself, which can be altered by adding or subtracting charge from the surface of the Earth. Ipso facto, G is not universal, it is local to each body.
I don't think G means whart you think it means.
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Old 10th January 2017, 06:54 PM   #15
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Originally Posted by sts60 View Post
How much do you think G varies from natural variations in surface charging? What is the peak amplitude of the variation over, say the last few centuries? I'm looking for some kind of ballpark percentage range. I'm not agreeing eith your claim, but I want to understand what you think the strength of this effect is.
Seems like it'd be really easy to test, such as looking for a variation during electrical storms.
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Old 10th January 2017, 06:59 PM   #16
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How big a role does the gravity of celestial bodies play in interplanetary travel? Once you escape earth's orbit, how far into the mission do you have to worry about Mars' pull?

In any case, the number of successful landings and orbits we've done on all manner of things in the solar system leads me to believe that astrophysicists have all this stuff figured out for at least the last 60 years.
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Old 10th January 2017, 07:46 PM   #17
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Originally Posted by sts60 View Post
How much do you think G varies from natural variations in surface charging? What is the peak amplitude of the variation over, say the last few centuries? I'm looking for some kind of ballpark percentage range. I'm not agreeing eith your claim, but I want to understand what you think the strength of this effect is.
When you're measuring G, you're taking a proxy measurement of the strength of the charge, so the variance is minuscule here on Earth.

However, since G is not universal, the variance on other planetary systems that are undergoing a massive discharge or accumulating charge will be far greater. This is why comet directions can vary, and why comets appear to be made out of fluff according to their mass, while looking like solid boulders of burned rock. Their mass is being altered by the electrical discharge they are undergoing.

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Old 10th January 2017, 09:04 PM   #18
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Originally Posted by michaelsuede View Post
Ipso facto, G is not universal, it is local to each body.

Two bodies 1 and 2 at a distance, interacting gravitationally. F1 = F2 = some constant * m1 * m2 / d^2. We call that constant G.

If each body has its own G instead which varies as its charge (or polarity?) changes, then F1 and F2 cannot remain equal. You lose not only universal gravitation, but Newton's third law as well. Good luck with that.
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Old 10th January 2017, 09:36 PM   #19
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Originally Posted by Myriad View Post
Two bodies 1 and 2 at a distance, interacting gravitationally. F1 = F2 = some constant * m1 * m2 / d^2. We call that constant G.

If each body has its own G instead which varies as its charge (or polarity?) changes, then F1 and F2 cannot remain equal. You lose not only universal gravitation, but Newton's third law as well. Good luck with that.
Well we don't have to go throwing out Newton's laws just yet. As Newton famously said, I frame no hypotheses. He didn't care that he couldn't explain what gravity was, just that his laws could explain how it behaved.

Since the planetary bodies in our solar system are in electrically stable orbits, Newton's laws serve us just fine for the mundane task of navigating our solar system, universal G or not.

Newton's laws fall apart when something upsets the electrical stability of the solar system - such as if a rogue brown dwarf were to enter the heliosphere of our Sun. At that point, Newton's laws are going out the window.
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Old 10th January 2017, 09:41 PM   #20
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Without knowing the mass of the earth I can't measure G by measuring the force of gravity that the earth applies to some known mass. But given that we know that the mass of the earth is constant, if G varied, so would the weight of objects on the earth. Maybe G was much smaller in the past and that's why dinosaurs were able to grow so large! I think it's time to write a book.

Similarly variations in G would affect the radii of the orbits of the planets.

Measurements always have a certain amount of error and uncertainty. The question is do our measurements of G agree to within those bounds? And the answer is yes. Which means there's no case to be made for the variance of G based on the variance of those measurements. But this is a strong case to be made for its constancy to within the bounds of our measurements.

(As Zig pointed out it may still vary, but any variance is constrained by the data we have to be very small)

It also seems to me that varying G would be a source of energy, in which case if you don't want to break energy conservation you've got to suppose there is some source of energy that goes into the gravitational field in order to let G change.
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Old 10th January 2017, 09:48 PM   #21
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Originally Posted by Crossbow View Post
However, it has been recently confirmed that gravity does indeed move at the speed of light. Therefore, the above section is quite incorrect.
Yes, it's glaringly wrong, but you missed the true depths of why it's wrong. An infinite speed for gravity would mean two-body orbits would be stable forever. A finite speed doesn't mean that orbiting bodies will eventually fly off into infinity, it means that orbits will decay. So it's wrong even independent of observations demonstrating this orbital decay.
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Old 10th January 2017, 09:50 PM   #22
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Originally Posted by Roboramma View Post
Without knowing the mass of the earth I can't measure G by measuring the force of gravity that the earth applies to some known mass.
And that's precisely why we don't measure G that way. We measure G by measuring the force between two objects whose mass we do know, independently of the mass of the earth. This eliminates not only the uncertainty in the mass of the earth, but also any hypothetical variations in the mass of the earth.
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Old 10th January 2017, 09:59 PM   #23
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Originally Posted by Roboramma View Post
It also seems to me that varying G would be a source of energy
Time variations in G would indeed break energy conservation (spatial variations would break momentum conservation). But in order to appreciate that, michaelsuede would have to understand Noether's theorem, and we all know that the EU folks are allergic to math. They can't even do arithmetic, what chance do they have of understanding something that abstract?
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Old 10th January 2017, 10:05 PM   #24
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Originally Posted by Ziggurat View Post
Yes, it's glaringly wrong, but you missed the true depths of why it's wrong. An infinite speed for gravity would mean two-body orbits would be stable forever. A finite speed doesn't mean that orbiting bodies will eventually fly off into infinity, it means that orbits will decay. So it's wrong even independent of observations demonstrating this orbital decay.
Pretty vague assertion you got there.

Do we live in a two body solar system?

What constitutes a finite speed to you? Light speed?

Why shouldn't decay lead to instability?

Van Flandern did a tremendous amount of work on this. He came to rather different conclusions.

http://www.sciencedirect.com/science...75960198006501

When the moon is aligned with the Sun, the pull of the Sun's gravity is twice as strong on the moon as compared to the Earth's. I always found this fact puzzling in terms of the standard model.

Further, since the Sun is in motion through the galaxy, in order for the Earth to orbit the Sun, it has to know where the Sun is right now, not where it was several minutes ago.

Oh one more thing. Where does the speed of light fit into Newton's equations of gravity again? Don't we navigate the solar system with those?

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Old 10th January 2017, 10:19 PM   #25
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Originally Posted by michaelsuede View Post
When the moon is aligned with the Sun, the pull of the Sun's gravity is twice as strong on the moon as compared to the Earth's. I always found this fact puzzling in terms of the standard model.

But… if that were true the moon would accelerate toward the sun all the time!

Oh, wait, yeah, it does that. As does the earth.

So where's the puzzling part?
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Old 10th January 2017, 10:19 PM   #26
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Originally Posted by michaelsuede View Post
When you're measuring G, you're taking a proxy measurement of the strength of the charge, so the variance is minuscule here on Earth.

However, since G is not universal, the variance on other planetary systems that are undergoing a massive discharge or accumulating charge will be far greater. This is why comet directions can vary, and why comets appear to be made out of fluff according to their mass, while looking like solid boulders of burned rock. Their mass is being altered by the electrical discharge they are undergoing.
Except that G is a universal constant, because we can use it to predict exoplanet orbits, star orbits, and other celestial bodies. In every instance we can use G. Orbits have been so constant that ancient civilizations were able (without knowing the value or G or why this all worked) to predict orbits and chart out planetary and lunar positions for thousands of years ahead of time.

Take an astronomy course, you'll learn a lot more than you ever would by reading Holoscience.
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Old 10th January 2017, 10:23 PM   #27
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Originally Posted by Myriad View Post
But… if that were true the moon would accelerate toward the sun all the time!

Oh, wait, yeah, it does that. As does the earth.

So where's the puzzling part?
The puzzling part is why the moon remains in a stable orbit around the Earth if the pull of the Sun, when in alignment, is twice as strong as that of the Earth's.

Only a rocket scientist would be unable to understand the simple point I'm making here.
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Old 10th January 2017, 10:33 PM   #28
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Originally Posted by Ziggurat View Post
And that's precisely why we don't measure G that way. We measure G by measuring the force between two objects whose mass we do know, independently of the mass of the earth. This eliminates not only the uncertainty in the mass of the earth, but also any hypothetical variations in the mass of the earth.
Yep, but my point was that while we can't get a value of G from that, we can get the fact that it doesn't vary.

Measuring G with known masses is hard because G is small and the masses are small. But the earth is very large and so the force due to gravity is large enough that we can measure that quite easily. Take a 100kg mass and put it on a scale and the scale will read it as weighing 100kg. Without being able to measure the value of G from this, we can still see that if G varied that readout would vary as well (within the accuracy of the scale).

I think that measurement of the variance of G can be done more easily than any experiment that can measure the actual value of G. Hell, if G varied by a large enough amount you'd be able to feel it. Of course as you say there's the possibility that the mass of the earth is changing but I think that the mass of the earth is well enough constrained that we don't need to worry about it for these purposes.

I suppose it depends on how much variance michaelsuade is positing though.
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Old 10th January 2017, 10:37 PM   #29
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Originally Posted by michaelsuede View Post
The puzzling part is why the moon remains in a stable orbit around the Earth if the pull of the Sun, when in alignment, is twice as strong as that of the Earth's.

Only a rocket scientist would be unable to understand the simple point I'm making here.
The moon is in orbit around the sun. Did you think it wasn't?
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Old 10th January 2017, 11:55 PM   #30
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Can we just merge this with ' Continuation The Electric Comet Theory Boogaloo (Part 2)'?
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Old 11th January 2017, 02:58 AM   #31
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Originally Posted by michaelsuede View Post
The puzzling part is why the moon remains in a stable orbit around the Earth if the pull of the Sun, when in alignment, is twice as strong as that of the Earth's.........
What do you mean by this?
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Old 11th January 2017, 06:03 AM   #32
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Originally Posted by michaelsuede View Post
The puzzling part is why the moon remains in a stable orbit around the Earth if the pull of the Sun, when in alignment, is twice as strong as that of the Earth's.

Only a rocket scientist would be unable to understand the simple point I'm making here.
OK thanks.

You have clearly shown that you do not know what you are talking about.
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Old 11th January 2017, 06:05 AM   #33
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Originally Posted by michaelsuede View Post
Pretty vague assertion you got there.

Do we live in a two body solar system?
That you're even asking demonstrates your ignorance - not of the fact that we aren't, but the fact that you don't know why it matters. Two-body orbits in classical Newtonian gravity are always stable. Three-body orbits don't have to be, and since they can't generally be solved analytically, it's impossible to prove they are.

Quote:
What constitutes a finite speed to you? Light speed?
Anything less than infinity is finite, so yes, light speed is finite.

Quote:
Why shouldn't decay lead to instability?
Decay IS instability, but it's instability in the opposite direction. The objects won't fly away from each other, they will spiral in and collide.

Quote:
Van Flandern did a tremendous amount of work on this. He came to rather different conclusions.
He's wrong. He's treating the field of a moving object as if it's still a simple 1/r2 field, but just shifted to account for delay. It's not. It's more complicated than that. We know he's wrong because his argument has already been proven wrong in the case of electromagnetism.

Quote:
When the moon is aligned with the Sun, the pull of the Sun's gravity is twice as strong on the moon as compared to the Earth's. I always found this fact puzzling in terms of the standard model.
It's not puzzling, it's just counter-intuitive. But the puzzle is trivial to solve.

For a circular orbit, acceleration is a=v2/r. For the earth traveling around the sun, that gives a = (3x104 m/s)2/1.5x1011 m = 0.006 m/s2. The moon will be experiencing about the same acceleration from the sun. The moon's acceleration from the earth is a = (1x103 m/s)2/3.85x108 m = 0.0026 m/s2.

Presto! We have half the acceleration, and therefore half the force. And that applies (roughly) at all times, not just when the sun/earth/moon are aligned. Furthermore, it applies INDEPENDENT of our model of gravity, since we didn't need gravity to calculate it. But applying the theory of gravity (Newtonian OR GR) will give you the same answer.

It's amazing what you can do with a little math.

Quote:
Further, since the Sun is in motion through the galaxy, in order for the Earth to orbit the Sun, it has to know where the Sun is right now, not where it was several minutes ago.
Relativity: we can do the problem in any reference frame we want. We can do it in the reference frame where the solar system is stationary (and the galaxy is moving), in which case no issues. Or we can do it in the frame where the galaxy is stationary, and the solar system is moving. But in that reference frame, the field of the sun is the field of a moving object, which is distorted compared to the field of a stationary object. Those distortions will compensate for that motion, and the answer you get will be the same for either frame.

Quote:
Oh one more thing. Where does the speed of light fit into Newton's equations of gravity again?
It doesn't. Newtonian gravity is a very good approximation under many conditions, but it's still wrong.

Quote:
Don't we navigate the solar system with those?
Yes, we do, because even though they're wrong (see the procession of Mercury's orbit), they are CLOSE ENOUGH. Spacecraft have to course correct anyways (even things like thermal radiation can exert a pressure that can push them off-course if uncorrected), so the minor perturbation from gravity's finite velocity doesn't matter enough to include most of the time. But the faster you're moving, and the larger the gravitational field you move through, the more the finite speed makes a difference. That's why the effects are observable for Mercury but not for Earth. That's also why black holes orbiting each other can decay much more rapidly, producing the gravitational wave signature we recently detected. Their fields are ginormous, and their orbits become VERY rapid when they get close, so orbital decay becomes quite dramatic.

You're out of your depth here. None of this is actually a mystery, all of it is actually well-understood. And the fact that you don't understand it is no big deal. Why would you, if you haven't formally studied physics for many years? But at the end of the day, you don't know what you're talking about. You haven't discovered some hidden flaw that the professionals missed. Thornhill isn't an unappreciated genius. And the numbers don't lie. I just gave you more calculations than you will probably ever see from any Electric Universe proponent.
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Old 11th January 2017, 06:39 AM   #34
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Thanks much 'Ziggurat'.

Hopefully your well reasoned rebuttal will make some sense to him.
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Old 11th January 2017, 06:55 AM   #35
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Originally Posted by Ziggurat View Post
That you're even asking demonstrates your ignorance - not of the fact that we aren't, but the fact that you don't know why it matters. Two-body orbits in classical Newtonian gravity are always stable. Three-body orbits don't have to be, and since they can't generally be solved analytically, it's impossible to prove they are.



Anything less than infinity is finite, so yes, light speed is finite.



Decay IS instability, but it's instability in the opposite direction. The objects won't fly away from each other, they will spiral in and collide.



He's wrong. He's treating the field of a moving object as if it's still a simple 1/r2 field, but just shifted to account for delay. It's not. It's more complicated than that. We know he's wrong because his argument has already been proven wrong in the case of electromagnetism.



It's not puzzling, it's just counter-intuitive. But the puzzle is trivial to solve.

For a circular orbit, acceleration is a=v2/r. For the earth traveling around the sun, that gives a = (3x104 m/s)2/1.5x1011 m = 0.006 m/s2. The moon will be experiencing about the same acceleration from the sun. The moon's acceleration from the earth is a = (1x103 m/s)2/3.85x108 m = 0.0026 m/s2.

Presto! We have half the acceleration, and therefore half the force. And that applies (roughly) at all times, not just when the sun/earth/moon are aligned. Furthermore, it applies INDEPENDENT of our model of gravity, since we didn't need gravity to calculate it. But applying the theory of gravity (Newtonian OR GR) will give you the same answer.

It's amazing what you can do with a little math.



Relativity: we can do the problem in any reference frame we want. We can do it in the reference frame where the solar system is stationary (and the galaxy is moving), in which case no issues. Or we can do it in the frame where the galaxy is stationary, and the solar system is moving. But in that reference frame, the field of the sun is the field of a moving object, which is distorted compared to the field of a stationary object. Those distortions will compensate for that motion, and the answer you get will be the same for either frame.



It doesn't. Newtonian gravity is a very good approximation under many conditions, but it's still wrong.



Yes, we do, because even though they're wrong (see the procession of Mercury's orbit), they are CLOSE ENOUGH. Spacecraft have to course correct anyways (even things like thermal radiation can exert a pressure that can push them off-course if uncorrected), so the minor perturbation from gravity's finite velocity doesn't matter enough to include most of the time. But the faster you're moving, and the larger the gravitational field you move through, the more the finite speed makes a difference. That's why the effects are observable for Mercury but not for Earth. That's also why black holes orbiting each other can decay much more rapidly, producing the gravitational wave signature we recently detected. Their fields are ginormous, and their orbits become VERY rapid when they get close, so orbital decay becomes quite dramatic.

You're out of your depth here. None of this is actually a mystery, all of it is actually well-understood. And the fact that you don't understand it is no big deal. Why would you, if you haven't formally studied physics for many years? But at the end of the day, you don't know what you're talking about. You haven't discovered some hidden flaw that the professionals missed. Thornhill isn't an unappreciated genius. And the numbers don't lie. I just gave you more calculations than you will probably ever see from any Electric Universe proponent.
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ahhhhhhh.
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Old 11th January 2017, 07:37 AM   #36
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Originally Posted by Ziggurat View Post
<excellent explanations>

If you want something that's legitimately puzzling at first glance, consider the question of why, if the sun's gravitational pull on the earth is double the moon's, the lunar tides are much stronger than the solar tides.

The answer is that the cause of the apparent tidal "force" isn't the gravitational pull itself (the sun, moon, and earth are all in free fall, so that pull is no more apparent than the earth's strong gravitational pull is apparent to astronauts in the ISS). The cause of the apparent tidal "force" is the much smaller variation of that pull between one place on the earth (or whatever system is being considered) and another. The moon's pull is weaker but, because the moon is so much closer to the earth, that pull varies much more across the space the earth occupies.
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Old 11th January 2017, 08:04 AM   #37
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By the way ...

If 'michaelsuede' is sure that electrical production/presence can alter the value of G, then that should be a relatively easy thing to test for.

After all, there is portable equipment which can be used to measure G so just take that equipment near some high power electrical lines, or near a power plant, or near an electrical substation and see what the value of G is and compare it to the published value.
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Old 11th January 2017, 09:08 AM   #38
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Originally Posted by michaelsuede View Post
I should probably clarify my "change in net charge" response. That's really a poor choice of words that doesn't mean much.

G on Earth depends on the polarization of the Earth itself, which can be altered by adding or subtracting charge from the surface of the Earth. Ipso facto, G is not universal, it is local to each body.
Polarize what?
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Old 11th January 2017, 09:12 AM   #39
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Originally Posted by michaelsuede View Post
When you're measuring G, you're taking a proxy measurement of the strength of the charge, so the variance is minuscule here on Earth.

However, since G is not universal, the variance on other planetary systems that are undergoing a massive discharge or accumulating charge will be far greater. This is why comet directions can vary, and why comets appear to be made out of fluff according to their mass, while looking like solid boulders of burned rock. Their mass is being altered by the electrical discharge they are undergoing.
Just for fun I translated this into Swedish
Quote:
När du mäter G, du tar en proxy mätning av styrkan av avgiften, så variationen är mycket liten här på jorden.

Eftersom G är inte universell, kommer variansen på andra planetsystem som genomgår en massiv urladdning eller ackumulera laddning vara mycket större. Detta är anledningen till komet riktningar kan variera, och varför kometer verkar vara gjord av fluff enligt deras massa, medan ser ut som fasta block av bränt rock. Deras massa ändras av den elektriska urladdning de genomgår.
And then back to English
Quote:
When you measure G, you take a proxy measurement of the strength of the charge, so the variation is very small here on earth.

Since G is not universal, the variance in other planetary systems undergoing a massive discharge or accumulate charge to be much larger. This is why the grain directions may vary, and why comets seems to be made of fluff according to their mass, while looking like solid blocks of burnt rock. Their lot is changed by the electric discharge they undergo.
It makes a little more sense but not really,
Should I try Japanese?
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Old 11th January 2017, 09:27 AM   #40
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Well Ziggurat, I guess we have to disagree. I don't believe you can wash over the problems presented with reference frames. That's basically a mathematical way of ignoring the whole system and instead treating each component as if it was in its own independent universe. Sure, you can get a mathematically correct answer by doing that, but that doesn't mean it represents reality in anyway. And Van Flandern is not wrong about the speed of gravity.

GR really doesn't have any meaning to it. It's just a mathematical description.

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