What makes gravity?

theorist-constant12345 said:
Hello, thank you all for the confirmations of answer. I understand what science is saying now and will apply it in simple terms so JCC may understand.

Is that about correct to summon it up in a different context?
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Your analogy is a gross distortion and ignores what you have been told.
When you are answered in a single sentence, you need to pay attention to all the words in the sentence. I have bolded the word you ignored.
rpenner said:
"What mechanism" is not a physics question¹ when talking about fundamental physical theories.

¹ http://math.ucr.edu/home/baez/crackpot.html @ 17, http://www.newrepublic.com/article/...cist-explains-why-science-not-about-certainty , http://insti.physics.sunysb.edu/~siegel/warning.html , and https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html
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Quantum Field Theory and General Relativity are fundamental physical theories because they explain the most general behavior of physical phenomena without reference to any more generally applicable physical laws. As only General Relativity speaks to gravity, then there is no more fundamental physical theory about gravity than General Relativity. Before General Relativity, the former theory of gravity was Newton's Universal Gravitation and when asked for a mechanism Newton wrote:
rpenner said:
"hypotheses non fingo".
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because fundamental physical theories describe only behavior not mechanisms.

Why? Because behavior is the only phenomena we have evidence for if the theory is fundamental -- any number of mechanisms may be proposed to "explain" a behavior and evidence doesn't let you choose between them when no evidence of any more fundamental mechanism is known to mankind.
 
rpenner said:
Your analogy is a gross distortion and ignores what you have been told.
When you are answered in a single sentence, you need to pay attention to all the words in the sentence. I have bolded the word you ignored.

Quantum Field Theory and General Relativity are fundamental physical theories because they explain the most general behavior of physical phenomena without reference to any more generally applicable physical laws. As only General Relativity speaks to gravity, then there is no more fundamental physical theory about gravity than General Relativity. Before General Relativity, the former theory of gravity was Newton's Universal Gravitation and when asked for a mechanism Newton wrote:

because fundamental physical theories describe only behavior not mechanisms.

Why? Because behavior is the only phenomena we have evidence for if the theory is fundamental -- any number of mechanisms may be proposed to "explain" a behavior and evidence doesn't let you choose between them when no evidence of any more fundamental mechanism is known to mankind.
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I understood it from James, maybe my car example was not a coherent explanation, it made sense to me, but either way I understood James and yourself, I have moved to the appropriate section of the forum to discuss the ''magic'' of gravity.
 
" What makes gravity? "


in my irrelevant opinion, positive and negative, nothing more.
 
theorist-constant12345 said:
...I have moved to the appropriate section of the forum to discuss the ''magic'' of gravity.
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Oddly enough, people rarely if ever look for a "mechanism" for or talk about "the magic of" the strong nuclear force or inertia. So why people have so much trouble accepting that gravity is fundamental is beyond me. Perhaps the reason is that laypeople have never heard of the strong nuclear force and don't know what inertia is, so they focus all of their confused ignorance on gravity?
 
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Russ_Watters said:
Yes, electricity/magnetism is the other fundamental force laypeople have heard of and sometimes go after.
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The woo-woo crowd always seems to think there is something magical about magnets but do not seem to give electricity a second thought. What is that about?
 
rpenner said:
Quantum Field Theory and General Relativity are fundamental physical theories because they explain the most general behavior of physical phenomena without reference to any more generally applicable physical laws. As only General Relativity speaks to gravity, then there is no more fundamental physical theory about gravity than General Relativity. Before General Relativity, the former theory of gravity was Newton's Universal Gravitation and when asked for a mechanism Newton wrote:
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Why is it so hard to just give the obvious answer? Spacetime Curvature.

In quantum field theory, people are leaning toward the idea of particles interacting with the Higgs Field. I think it is the particle waves interacting with the Higgs Field, and the Higgs Field is just more like spacetime itself. Why? Because, if you had two particles traveling together and they were at half wavelengths, their waves would cancel each other out. Then those particles would vanish and they would have no mass. There is that, and the Higgs Field shares a lot of similar properties of spacetime, like being a scaler, no spin, etc. Therefore, no waves = no mass.
 
origin said:
The woo-woo crowd always seems to think there is something magical about magnets but do not seem to give electricity a second thought. What is that about?
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Because of quantum, of course.
 
Layman said:
Spacetime Curvature.
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That describes a behavior, not a mechanism and is already the subject of Einstein's equation in General Relativity. A "mechanism" would explain the equals sign in Einstein's equation.

Layman said:
In quantum field theory, people are leaning toward the idea of particles interacting with the Higgs Field.
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If by leaning towards, you mean the mainstream Standard Model for 40 years, then yes. According the the Standard model, fundamental particles like quarks and electrons are fundamentally massless, but they interact with a non-zero expectation value of the scalar Higgs field to have the illusion of intrinsic mass. This preposterous idea preserves much thinking on the ideals of symmetry in quantum field theory and is evidenced as true by the discovery of the Higgs particle, an excitation of this scalar Higgs field from it's non-zero ground state.

But massless particles like the gluon and photon can still transmit energy and momentum because for a free particle:
$$E^2 = (mc^2)^2 + (pc)^2 \\ E v = c^2 p $$
regardless of whether m=0 or not.
 
A mathematical description of the behavior of two particles under gravitation, as rpenner has said, is basic science.

The direction in which they are attracted is also basic science, but leaves open the question of the mechanism, for such particles have no means of determining the direction to each other's exact centers without instruments or a degree in mathematics including calculus or topology.

The mathematical description of the n-body gravitational problem for n>>3 continues to be a poser (in question) because the outer 1/3 of spiral galaxies already are traveling at greater than escape velocity, according to the research of Vera Rubin, an astrophysicist from Cornell. This is the research that strongly suggests that gravitation on very large scales does not seem to conform to existing mathematical descriptions of gravitation, including the theory of General Relativity.

After the discovery of the boson connected with the Higgs mechanism, I came here to try and find out if there was a consensus about whether the Higgs, known to be responsible for endowing certain subatomic particles (quarks, electrons, their antiparticles) with the property of inertia, could possibly, through means of General Relativity theory's principle of equivalence, be connected with gravitational mass? Matt Strassler ("Of Particular Significance" blog) has written extensively about this question, and has good reason to believe that the Standard Model does not imply a direct connection. I generally agree, but make up your own mind after reading what he has written.

It is an attractive idea to think that the reason the cause of gravity and its disparity with other forces may be related to matter interaction with vacuum energy and fields, and this would also explain that "spooky" action at a distance gravitational physicists get on about. Such bosons can easily penetrate planet sized bodies and find their exact centers, indirectly imparting inertia (or not imparting it, as the case may be) in exactly the right direction. This mechanism would be both invisible and also much more energetic than interaction of matter with the boson known as the photon. Objects made of matter tend to fall under the influence of gravity in a manner that is difficult to ignore, don't they?

You have asked the right question in the right forum. I was completely satisfied with the responses on both sides of the issue.
 
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danshawen said:
according to the research of Vera Rubin, an astrophysicist from Cornell. This is the research that strongly suggests that gravitation on very large scales does not seem to conform to existing mathematical descriptions of gravitation, including the theory of General Relativity.
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No -- it suggests that galaxies are associated with extra bits of mass called "dark matter" because they didn't show up on Prof. Rubin's count of star-associated matter. The same dark matter also shows up in cosmology. Dark matter does not require modification of any law of gravity.

http://www.physics.ucla.edu/~cwp/articles/rubindm/rubindm.html
http://www.amnh.org/education/resources/rfl/web/essaybooks/cosmic/p_rubin.html

05 Feb 2015 - Planck released its latest cosmology results today. Technical preprints are available on the arxiv. The 6 parameter Λ CDM model is an excellent fit to the Planck data.
The parameters of the 6-parameter ΛCDM model fit to Planck TT power spectrum plus the Planck measured CMB lensing are given in paper I as : ΩΛ = 0.692 ± 0.012; the baryon density = 0.4181 ± 0.0043 yoctograms per cubic meter; the cold dark matter density = 2.228 ± 0.038 yoctograms per cubic meter; CDM:baryon density ratio = 5.36 ± 0.10; dark energy density = 3352 ± 125 eV/cc; H0 = 67.80 ± 0.9 km/sec/Mpc; and the age of the Universe = 13.799 ± 0.038 Gyr. The above values are from CMB data alone.
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http://www.astro.ucla.edu/~wright/cosmolog.htm
​
http://www.esa.int/Our_Activities/Space_Science/Planck/Planck_reveals_first_stars_were_born_late
http://arxiv.org/abs/1502.01582

0.42 yoctograms per cubic meter ($$4.2 \times 10^{-31} \, \textrm{grams}/\textrm{cm}^3$$) works out to be about 1/4 hydrogen atoms per cubic meter as an average matter density of the universe. Thus intergalactic space is pretty empty.
 
do you people have brains of your own? what if there is only 1 force? would it work?

If Coulombs's law stands universally, we should assume that every atom or charged particle are connected by their force field across the whole space.

An atoms force field does not end at atom radius, but extend to infinity. In whole, an atom or planet maybe electrically neutral, but Every charge within has its own force field beyond distance, those forces overlapped to produce chemical bonding, magnetism and gravity. Ever wonder why is Fe=q1q2/r^2, Fg=m1m2/r^2, and mass proportional to proton numbers within it?
 
jcc said:
do you people have brains of your own? what if there is only 1 force? would it work?

If Coulombs's law stands universally, we should assume that every atom or charged particle are connected by their force field across the whole space.

An atoms force field does not end at atom radius, but extend to infinity. In whole, an atom or planet maybe electrically neutral, but Every charge within has its own force field beyond distance, those forces overlapped to produce chemical bonding, magnetism and gravity. Ever wonder why is Fe=q1q2/r^2, Fg=m1m2/r^2, and mass proportional to proton numbers within it?
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please move down to your mental level and leave this place. thanks.
 
As opposed to your illogical and unsupportable "view"?

How many repetitions of what we already know about gravity will it take for you to abandon this nonsense and leave here?
 
jcc said:
let's hear your better view? more logical and supported by math.
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You can read it in any physics textbook or in countless places on the web - if you are intelligent enough to understand it. It is not my job to recite standard physics to you. It is your job, as the proponent of a new theory (supposedly), to show why it is an improvement on this.
 
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