[hamza (OP)]

what i mean is that is it caused by the earth's spinning motion?? or what? if not than what causes the earth to spin?? why is it spinning??

[another_someone]

The Earth's spinning motion is totally separate from gravity.

Gravity is a feature of mass, and anything that has mass will have a gravitational pull (i.e. if you have a 1Kg block of lead, that too will have a gravitational pull, but it would be so very slight that you would need extremely sensitive instruments to even measure it was there; but the earth is a massive 5.9736×10²⁴ kg, and so has many of orders of magnitude stronger gravitational pull than the 1Kg mass does).

The Sun is even more massive, and so has an even stronger gravitational pull, but because it is far further away, we feel its pull less than we feel the pull of the Earth beneath our feet.

The Earth is spinning because it was always spinning, and was created that way.  The Earth formed out of the primordial solar system, and that was a swirling cloud of gas, so everything that formed within it was spinning one way or another.

[syhprum]

The most genrally accepted theory of gravity is that put forward by A Einstein in his theory of general relatively that the presence off matter produces a distortion of space-time so that the motion of a particle that would normally move in a straight line follows a differant course so that it appears to be attracted to a mass (the shortest and least comprehensive account of general relativity published see Wiki for better ones).
The alternative theory is that gravitational attraction is mediated by an as yet hypothetical particle the Graviton but the mass of such a particle would be so small that there is no hope of detecting individual particles     

[another_someone]

The most genrally accepted theory of gravity is that put forward by A Einstein in his theory of general relatively that the presence off matter produces a distortion of space-time so that the motion of a particle that would normally move in a straight line follows a differant course so that it appears to be attracted to a mass (the shortest and least comprehensive account of general relativity published see Wiki for better ones).
The alternative theory is that gravitational attraction is mediated by an as yet hypothetical particle the Graviton but the mass of such a particle would be so small that there is no hope of detecting individual particles     

Would not the mass of a graviton have to be massless, or else gravity would have a finite range?

In any case, although difficult, we are able to detect (at least indirectly) the existence of neutrinos, which are probably massless.

George.

[syhprum]

What evidence is there that the range of gravity is infinite?, the postulated mass of the Graviton is very very small, we used to believe the neutrino was massless but we have had to get used to the idea that it has a small mass!
With the aid of very large detectors we can detect individual neutrinos but according to a 'Scientific American' article (that I cannot find) the mass of the Graviton was 10^-11 that of the Neutrino and a detector the size of Jupiter would be required to detect individual ones.
It could well be that the size of the observable universe could be too small to test whether the range of gravity is infinite.

[om]

Since almost all of the mass of individual atoms is in their nucleus, gravity must be a nuclear force.

With kind regards,
Oliver K. Manuel
www.omatumr.com

[another_someone]

Since almost all of the mass of individual atoms is in their nucleus, gravity must be a nuclear force.

Are you saying that it is exclusively a nuclear force, or merely a predominantly nuclear force?

Ofcourse, the real problem is that because gravity is such a week force, we really have little idea of how gravity behaves at sub-atomic levels.

[om]

Since almost all of the mass of individual atoms is in their nucleus, gravity must be a nuclear force.

Are you saying that it is exclusively a nuclear force, or merely a predominantly nuclear force?

Of course, the real problem is that because gravity is such a week force, we really have little idea of how gravity behaves at sub-atomic levels.

The fraction that is nuclear is the fraction of the mass that lies in the nucleus, ~99.9%.

Calculate the force of gravity at sub-nuclear distances, <10^-13 cm, to see if it is "weak."

With kind regards,
Oliver K. Manuel
www.omatumr.com

[G-1 Theory]

Since almost all of the mass of individual atoms is in their nucleus, gravity must be a nuclear force.

With kind regards,
Oliver K. Manuel
www.omatumr.com

Good to see you Prof. Manuel,

This Ed Kerls, how is your work going.
Did you ever get around to reading my paper of FIELDS OF IRON RULE THE UNIVERSE.
I have been keeping up with your work.

Let me know when you mite be in the Houston area again.

And as allways you right on with saying that GRAVITY has got to be a manitation of one of the nuclear forces.

And the Iron Cores of the Stars and planets have a lot to do with that manitation of the strong-forces in to Gravitational fields.

Also it is nice to have another on this site that is not afrid to give their full name.

Edward E. Kerls

[om]

Greetings Colonel Kerls,

Thanks for the message.

We do not understand gravity, but there is no doubt of its importance.

In fact, we have evidence that the Sun and other stars in the cosmos are not powered by hydrogen fusion.  They are instead powered by competition between

a.) attractive forces of gravity, and

b.) repulsive forces between neutrons.

Here are links to two papers where this is discussed:

1. "The Nuclear Cycle that Powers the Stars: Fusion, Gravitational Collapse and Dissociation", Hirschegg Workshop 06: Astrophysics and Nuclear Structure, Hirschegg, Austria, 15-21 Jan 2006

http://arxiv.org/abs/astro-ph/0511379

2. "On the Cosmic Nuclear Cycle and the Similarity of Nuclei and Stars", Journal of Fusion Energy 25 (2006) pp. 107-114

http://arxiv.org/abs/nucl-th/0511051

With kind regards,
Oliver K. Manuel
www.omatumr.com


 

[om]

THE ROLE OF GRAVITY IN THE COSMOS

Since almost all of the mass of individual atoms is in their nucleus, gravity must be a nuclear force.

Are you saying that it is exclusively a nuclear force, or merely a predominantly nuclear force?

Of course, the real problem is that because gravity is such a week force, we really have little idea of how gravity behaves at sub-atomic levels.

1. Gravity is a weak force over long distances.

2. Gravity cannot overcome repulsive forces between neutrons to convert neutron stars into black holes.

3. Gravity is a very strong force over very short distances.  http://arxiv.org/pdf/0905.1667v1

The Sun contains a very dense, energetic core of neutrons.  A dynamic competition between long-range attractive gravitational forces and short-range repulsive forces between neutrons generates solar luminosity, solar neutrinos, and solar-wind Hydrogen [a neutron-decay product] in exactly the proportions observed.

The Sun is an ordinary star.  It appears that other stars and galaxies also contain compact neutron cores.   On a cosmic scale, it is the dynamic competition between long-range attractive gravitational forces and short-range repulsive forces between neutrons that powers the cosmos and fills interstellar space with Hydrogen, a neutron-decay product.

If the universe is finite, then neutrons themselves may be the particle-sized black holes that were made in a Big Bang and compressed into massive, highly energetic neutron stars.
 http://arxiv.org/pdf/0905.1667v1

If the universe is infinite, then it may oscillate between expansion as interstellar space is filled with Hydrogen from neutron decay, and contraction after the neutron stars have evaporated and gravitational forces become dominant.

With kind regards,
Oliver K. Manuel
www.omatumr.com
http://myprofile.cos.com/manuelo09

[LeeE]

If the graviton is responsible for the existence of gravity, is it also responsible for its propagation?  If this is so, and gravity propagates at 'c', then the graviton would seem to be massless.

[syhprum]

Either that or more likely its mass is so small that it is beyond our technology to measure how much it deviates from c.
back in 1986 when a supernova explosion was observed with both a neutrino burst and electromagnetic radiation it was very difficult to measure any delay in the neutrino burst and it is postulated that the mass of the Graviton is 10^-11 times that of the lightest neutrino. 

[lightarrow]

A lot of times people ask: what is the cause for gravity?
I don't understand this question. Why there *must be* a cause? Then I could ask what is the cause of mass, the cause of time, the cause of space, the cause of energy........

[lyner]

Hear hear!
It's as if being able to answer that particular question actually would solve anything. Because, whatever it was that 'caused' gravity would also need a cause to explain it. The best we can hope for is to be able to predict, as well as possible, how things will behave.

[om]

A lot of times people ask: what is the cause for gravity?
I don't understand this question. Why there *must be* a cause? Then I could ask what is the cause of mass, the cause of time, the cause of space, the cause of energy........

I agree.  What is, is. 

Good science requires us to accept what is.

Foolish science encourages us to invent a cause.

With kind regards,
Oliver K. Manuel
http://myprofile.cos.com/manuelo09 

[LeeE]

If gravity were to be exactly the same everywhere then I'd agree that there need not be a cause for it, but the fact is that the degree (or strength) of gravity is not the same everywhere, so there must be a cause for its variation, if not it's origin.

Perhaps the question should not have been 'What causes gravity? but 'What is gravity?

Even then though, there's very strong evidence that the presence of gravity is linked to the presence of matter (and I'm not going to get into arguments about it being the other way around [] )

[om]

OBSERVATIONS THAT I HAD TO ACCEPT

Below are a few of the unexpected observations that I had to accept after I started a study in 1960 to rewrite the Biblical story of Genesis, i.e., the origin of the Earth, from a scientific prospective:

1960:  Meteorites contain decay products of  short-lived I-129, Pd-107 and Pu-244  from a supernova [J. H. Reynolds, Phys. Rev. Letters 4 (1960) 8-10; V. R. Murthy, Phys. Rev. Letters 5 (1960) 539; P. K. Kuroda, Nature 187 (1960) 36-38].

1962:  Earth and meteorites formed simultaneously on the I-129 time scale [P. K. Kuroda and O. K. Manuel,  Journal of Geophysical Research 67 (1962) 4859-4862].

1964:  Some mysterious process severely mass fractionated Ne isotopes in meteorites [O. K. Manuel, Geochimica Cosmochimica Acta 31 (1967) 2413-2431].

1967:  Iron meteorites are as old and trapped as much short-lived I-129 as "primitive" meteorites [E. C. Alexander, Jr. and O. K. Manuel, Earth & Planetary Science Letters 2 (1967) 220-224].

1970:  Ne and Xe isotopes in meteorites, the Earth, Moon and Sun show a common mass fractionation [P. K. Kuroda and O. K. Manuel, Nature 227 (1970) 1113-1116]. 

1971:  The Earth's interior still contains decay products of extinct I-129 and Pu-244 at detectable levels [M. S. Boulos and O. K. Manuel, Science 174 (1971) 1334-1336].

1972:  Xe-124 from the p-process and Xe-136 from the r-process of a supernova are enriched by as much as a factor of two in the "strange" xenon observed in some meteorite minerals [O. K. Manuel, E. W. Hennecke and D. D. Sabu, Nature 240 (1972) 99-101].

1973:  Meteorites contain mono-isotopic O-16, probably from stellar fusion of helium [R. N. Clayton, L. Grossman, and T. K. Mayeda,  Science 182 (1973) 485-488].

1975:  "Strange" xenon accompanied primordial helium at the birth of the solar system; "normal" xenon was devoid of helium [R. S. Lewis, B. Srinivasan and E. Anders, Science 190 (1975) 1251-1262; O. K. Manuel and D. D. Sabu, Transactions Missouri Academy of Sciences 9, (1975) 104-122].

1976:  Different classes of meteorites and planets each have characteristic levels of oxygen-16 [R. N. Clayton, N. Onuma and T. K.  Mayeda, Earth & Planetary Science Letters 30 (1976) 10-18].

CONCLUSION:  Our elements were produced locally and condensed directly into planetary solids.  They neither entered nor traversed interstellar space.  The Sun exploded as a supernova (SN) and gave birth to Earth and the solar system [D. D. Sabu and O. K. Manuel, Transactions American Geophysical Union 57 (1976) 278; O. K. Manuel and D. D. Sabu, Science 195 (1977) 208-209; O. K. Manuel and D. D. Sabu, paper NUCL 52 presented 2 Sept 1976 at the 172nd ACS National Meeting, San Francisco, CA;  O. K. Manuel, Proceedings of the Robert Welch Foundation Conference on Chemical Research XII: Cosmochemistry (1977) 263-272; R. V. Ballad et al., Nature 277 (1979) 615-620; D. D. Sabu and O. K. Manuel, Meteoritics 15 (1980) 117-138; O. Manuel, Icarus 41 (1980) 312-315].


a.): "Normal" xenon came from the iron-rich deep interior of the supernova.
b.): "Strange" xenon came from the outer, helium-rich layers of the supernova.
c.): The Sun exploded axially; Chemical SN layers remained in the equatorial plane.
d.): Elements and isotopes were not homogenized, nor ejected to interstellar space.
e.): H|He|C|O|Mg|Si|S|Fe regions formed diamonds/graphite, SiC, silicates, sulfides & metals. 
f.): Iron-rich SN debris near the Sun formed iron meteorites; cores of rocky planets.
g.): Earth accreted heterogeneously, first forming its core from iron meteorites.
h.): Iron cores of inner planets became accretion sites for silicate meteorites.
i.): Material from outer SN layers formed giant, gaseous planets like Jupiter.
j.): The p- and r-processes made "strange" xenon in outer, helium-rich SN layers
k.): The s-process made mirror-image xenon where SiC carborundum formed.

The above conclusion has been confirmed by many measurements over the past 33 years, many designed and conducted by my students, colleagues, and me.  It was also confirmed by measurement made by others, including many who refused to accept the close association of all primordial helium with "strange" xenon at the birth of the solar system.

The above conclusion was the basis for our 1983 prediction that the Galileo probe would find "strange" xenon in the helium-rich atmosphere of Jupiter [O. K. Manuel and Golden Hwaung, Meteoritics 18 (1983) 209-222].  The prediction was confirmed when the xenon isotope data from Jupiter were released in 1998 [O. Manuel, Meteoritics and Planetary Science 33 (1998, extended abstract 5011) A97. 

With kind regards,
Oliver K. Manuel
http://myprofile.cos.com/manuelo09
http://www.omatumr.com

[om]

ACCEPTANCE IS THE ANSWER

Hear hear!
It's as if being able to answer that particular question actually would solve anything. Because, whatever it was that 'caused' gravity would also need a cause to explain it. The best we can hope for is to be able to predict, as well as possible, how things will behave.

Sophiecentaur is correct.

Acceptance of observations is the first requirement of intellectual honesty in science.

Most NASA-funded scientists refused to accept empirical evidence of:

a.) Severe mass fractionation because they did not know the cause.
b.) Primordial helium linked to "strange" xenon because they didn't know why.
c.) Poorly mixed supernova debris forming the solar system because it didn't fit textbook descriptions.
d.) "Strange" xenon in Jupiter because that would destroy the illusion of homogeneity in the solar system.

Their research programs "died on the well-nourished vine" of federal research funds.

Neither did I anticipate any of the observations cited above, but I accepted "what is" (perhaps because I was too poorly educated to know better).  That was the key to the natural evolution of my research from:

a.) Genesis (The Origin of the Earth) to
b.) The Evolution of Planet Earth to
c.) The Origin of the Solar System to
d.) Local Element Synthesis to
e.) The Composition of the Sun to
f.) The Source of Solar Energy, Solar Neutrinos and Solar-Wind Hydrogen Pouring From The Surface of An Iron Sun to
g.) Interactions between Nucleons (Neutrons and Protons) in the Nucleus to
h.) Neutron Penetration of Gravitational Barriers in Neutron Stars to
i.) The Similarity of Nuclei and Stars to
j.) Dynamic Competition between Long-range Attractive Gravitational Forces and Short-range Repulsive Forces between Neutrons As the Driving Force That Powers the Cosmos and Fills Interstellar Space with Hydrogen, a Neutron-decay Product.

I will be forever grateful that my research mentor, the late Professor Paul Kazuo Kuroda, started me on this joyous "road less traveled" almost 50 years ago.

With kind regards,
Oliver K. Manuel
http://www.omatumr.com

[DoctorBeaver]

erm... can I ask a silly question? If you hypothesise that gravity is a nuclear force, how does it affect photons?