Adventures in big G

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Adventures in big G

Postby hyksos on December 9th, 2015, 11:06 am 

The gravitational constant G, is a scaling factor used in all modern and classical theories of gravity. The problem with "big G" is that it cannot be expressed in a relationship to any other known constants in physics. This forces us puny humans of the 21st century to measure big G experimentally. Because gravity is both universal for all mass, and its so weak relative to other forces, experimentally measuring it is very difficult even for the most expensive and sensitive lab equipment. There is no agreed-upon method for measuring G, and the results of measurements performed all over the world often disagree on the value to as much as 0.6% error.

If sixth tenths of a percent seems "small" to you, consider this fact: The distance from the earth to the moon is known to an experimental error of 3 centimeters. So an error as large as 0.6% in a fundamental constant of nature, in the year 2015, is an embarrassment.

In the following linked article, you can follow various lab teams from the USA, Europe, and Russia, as they devise ever more clever methods of measuring G, in their collective battle to find its true value.

http://www.npl.washington.edu/eotwash/bigG
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Postby Faradave on December 9th, 2015, 1:26 pm 

Re: A Slice of piε0

It seems reasonable to imagine: Universal properties arise from the universe's structure.

That would include universal speed limit c (a.k.a. c0 to explicitly specify in vacuum), with its parameters ε0 and (the vacuum permittivity and permeability of free space respectively) among others. In fact G, despite the upper case treatment, seems directly analogous to Coulomb's constant ke where:
ke = 1/(4piε0).

That would suggest a γ0, such that G = 1/(4piγ0). 4pi is the solid angle encompassed by spherical fields. Since Maxwell gave us:
c2 = 1/ε0μ0,

one wonders if there could be an analogous description relating our γ0 to c.
Perhaps c2 = 1/γ02 would make a reasonable starting point. From Einstein's E = mc2,
c2 = E/m, so, γ02 = E/m,
γ0 = √(E/m) = (1/c)? Just playing around.

When asked what he was experimenting on Cavendish replied "I'm weighing the earth."
I weighed it myself this morning. It's 180 lbs. I know because that's how hard it was pressing on the bottom of the bathroom scale upon which I was standing. ;o)
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Re: Adventures in big G

Postby Casnew on July 17th, 2017, 1:31 pm 

[The problem with "big G" is that] it cannot be expressed in a relationship to any other known [constants in physics]

Up until Nov. 20, 2016 the underlined was true. Since then, things have changed.

I direct you to that online lecture found on DailyMotion. Search for "gravitational constant equation"

It's a 15 min. video showing the mathematical proof of a new equation for "big G"
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Re: Adventures in big G

Postby someguy1 on July 17th, 2017, 3:33 pm 

"Does this value of G make me look fat?"
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Re: Adventures in big G

Postby Casnew on July 17th, 2017, 7:00 pm 

http://www.dailymotion.com/gravitationalconstant

Absolutely nothing wrong with mathematic and science related merchandise. In fact, more of it could aid in getting future minds involved in these fields. (well done someguy1! Love the jovial comment! …a specific scenario embracing mathematics and science in its fashion/attire)
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Re: Adventures in big G

Postby Watson on July 17th, 2017, 7:29 pm 

The link doesn't work. It just goes to search results of various sites? Is that what you want, us to guess??
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Re: Adventures in big G

Postby Casnew on July 17th, 2017, 8:17 pm 

Watson, the link in my last post should work, it's the channel homepage (only one video on the channel). Alternatively, here is direct link to video...

http://www.dailymotion.com/video/x5tgma3
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Re: Adventures in big G

Postby Casnew on July 18th, 2017, 10:53 am 

Hi Watson, when you said "the link doesn't work" I believed you were referring to the links I posted.... But, it seems you we referring to Hyksos's link.... My mistake. Yes, you are correct, the link Hyksos posted does not work.

Watson, have you watched the proof lecture yet? Anything I can answer for you?
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Re: Adventures in big G

Postby hyksos on July 20th, 2017, 6:20 pm 

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