small g big G and we need another G Gravity

small g gravity

The gravity of Earth, denoted g, refers to the acceleration that the Earth imparts to objects on or near its surface. In SI units this acceleration is measured in metres per second per second (in symbols, m/s2 or m·s-2) or in newtons per kilogram (N/kg or N·kg-1). It has an approximate value of 9.81 m/s2, which means that, ignoring air resistance, the speed of an object falling freely near the Earth's surface increases by about 9.81 metres per second every second. This quantity is informally known as little g (contrasted with G, the gravitational constant, known as big G).

link to source

BIG G Gravity

The gravitational constant, denoted G, is an empirical physical constant involved in the calculation of the gravitational attraction between objects with mass. It appears in Newton's law of universal gravitation and in Einstein's theory of general relativity. It is also known as the universal gravitational constant, Newton's constant, and colloquially Big G.[1] It should not be confused with "little g" (g), which is the local gravitational field (equivalent to the free-fall acceleration[2]), especially that at the Earth's surface; see Earth's gravity and Standard gravity.

According to the law of universal gravitation, the attractive force (F) between two bodies is proportional to the product of their masses (m1 and m2), and inversely proportional to the square of the distance (r) between them:

link to source

and now following a three d plot from the sloan servey against colour for distence, may show alot more matter "clumping" together in filimentary structures than there should be if big G alone was shaping the universe.







so is there more matter attracted together than can be explained with current theories?




do we need a new GRAVITY to explain the objects in galaxy scale?
what about the cluster scale?
super cluster scale?




we need to formulate a new theory for the very large scale structures in the universe because BIG G does not account for the universe we see.

so what are the other forces that are involved?
could the difference in scale interaction show what the forces are

we know of dark matter



but the filimentary nature of dark matter looks surprisingly like the filimentary nature of energy




and the "clumpyness" of the universe in the face of gravity and an expanding universe shows that there is another force acting but without definition of the laws of that force it will forever be called dark matter,

so do we need a new bigger G?

(PhysOrg.com) -- ESA's Integral gamma-ray observatory has provided results that will dramatically affect the search for physics beyond Einstein. It has shown that any underlying quantum 'graininess' of space must be at much smaller scales than previously predicted.

link to source

very interesting well worth the read

xploder

yeah quite a few physicists have pointed out that the gravity equation isn't perfect. There's quite a few papers published about it.
Fixing the equation is an entirely different matter.

reply to post by XPLodER


Sometimes, I feel like a broken record, but... Scalar-Tensor-Vector Gravity explains such "extra gravity" at large scales. Not with the addition of a second force of gravity, but with a stronger force of gravity and a smaller-range anti-gravity force. In STVG, what we measure as gravity on solar-system scales is actually a combination of the stronger gravity and the anti-gravity forces. Beyond those scales, however, the anti-gravity force dissipates, and the stronger force of gravity takes over.

Not only does it explain the observation mentioned in this thread, but it also accurately recreates the rotation curves of spiral galaxies, the mass profiles of galaxy clusters, acoustic peaks in the CMB, the accelerated expansion of the universe, and the Pioneer anomaly.

reply to post by XPLodER


Interesting post..

I find it interesting how similar the force of point charges is to gravity's formula as well..




Of course the 1/4pi*epsilon zero is just a constant.. The magnetic formulas aren't much different themselves..

Normally the counter gravitational effects are associated with the cosmological constant.

It is believed that, unlike gravity, the force described by the cosmological constant acts at extreme distances rather than close-up, and tends to provide an "outwards pressure" compared with gravitational attraction.

Currently, the belief is that the cosmological constant describes the effect of vacuum energy upon matter. The "emptier" the space, the greater the likelihood of release of vacuum energy. Hence empty spaces push apart and gravity draws together, causing a clumping of matter.

Here's a Wikipedia link

reply to post by CLPrime


here ya go

MOdified Gravity (MOG)

you seem quite sure that you have the answers
can MOdified Gravity predict galaxy rotational curves?

or is cold dark energy or dark matter required?

the idea of showing small g (how things interacte on our scale)
then looking at big G and how it acts slightly different than small g
then look at the large scale and look at what the BIGGER G is and try to define the observations
in an action reaction type relationship


xploder

reply to post by chr0naut


from your link

In physical cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as a modification of his original theory of general relativity to achieve a stationary universe. Einstein abandoned the concept after the observation of the Hubble redshift indicated that the universe might not be stationary, as he had based his theory on the idea that the universe is unchanging.[1] However, the discovery of cosmic acceleration in the 1990s has renewed interest in a cosmological constant

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so einstein did not beleive in an expanding universe and only in the face of the hubble data did he mod his theory
thanks
xploder

reply to post by rstregooski


coulombs law

Coulomb's law or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. It was studied and first published in 1783 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism. Nevertheless, the dependence of the electric force with distance had been proposed previously by Joseph Priestley[1] and the dependence with both distance and charge had been discovered, but not published, by Henry Cavendish, prior to Coulomb's works.

link to source

so the electrostatic discharge exploits difference in charge particles
and acts on particles in an inverse square manner between the charged particles




thats a good example of a force that could be acting upon the universe,
we see it in the small scale interaction,

xploder

reply to post by XPLodER


I don't have all of the answers, but, in this case, I believe STVG fits well. If you'll notice, "rotation curves of spiral galaxies" is one of the things I said it accurately reproduces.
Also, no, it doesn't involve either "dark" phenomenon. And, by the way, it's dark energy and cold dark matter.

It's really not much different than what you're implying.. instead of invoking a greater, and separate, force of gravity at large-scale distances, it invokes a force of anti-gravity at smaller-scale distances in combination with a stronger force of gravity at all scales. And STVG is justified in General Relativity, being merely a slight modification of the GR field equation.

I have wondered what could be causing the universe to be accelerating in it's expansion. And have looked beyond classical means. Since there is not a plausible explanation for electro-magnatism I have decided to look in that direction. xploder first put me on to this theorum even if I had heard of it through other means. Neutron repulsion seems to account for alot of the holes in many theories and confound many. It seems to explain some phenomena such as superpyronics, superfluidity, and other anomoulous behaviour of helium. Could it account for such large scale mysteries as well? I do not have the math skills to determine as much and there are other concerns such as quantum spookyness and related effects? Oh well just typing out loud.

Originally posted by CLPrime
I don't have all of the answers, but, in this case, I believe STVG fits well. If you'll notice, "rotation curves of spiral galaxies" is one of the things I said it accurately reproduces.

Actually it might be less confusing if you used the MOG term Xploder mentioned, because that's what the author calls it in the following paper. If you guys want to read these papers they are pretty interesting. Here is Moffat's MOG paper claiming MOG can explain the bullet cluster without any dark matter:

arxiv.org...

Excellent fits to the two-dimensional convergence kappa-map data are obtained without non-baryonic dark matter, accounting for the 8-sigma spatial offset between the Sigma-map and the kappa-map reported in Clowe et al. (2006). The MOG prediction....

note he calls it MOG and note he says it accounts for the 8 sigma spatial offset "of the center of the total mass from the center of the baryonic mass" (see below).

This claim is disputed by Clowe, who along with others, wrote the earlier bullet cluster paper here:
A direct empirical proof of the existence of dark matter

An 8-sigma significance spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law, and thus proves that the majority of the matter in the system is unseen.

So basically his initial claim was that there's no way a modified gravity law can explain what he describes in that paper, though he has some caveats.

Later, Clowe was asked about Moffat's subsequent claim that no dark matter was needed and MOG explained it, and Clowe said this:

www.foxnews.com...

"As far as we're concerned, [Moffat] hasn't done anything that makes us retract our earlier statement that the Bullet Cluster shows us that we have to have dark matter," Clowe said. "We're still open to modifying gravity to reduce the amount of dark matter, but we're pretty sure that you have to have most of the mass of the universe still in some form of dark matter."

So, he's not rejecting the idea of Moffat's MOG altogether, or other modified gravity theories. But he's apparently directly contradicting the claim in Moffat's paper that MOG can explain the bullet cluster. Apparently Clowe still feels it can't be explained without dark matter even if MOG is true.

I don't know which one is right, but I've only just started reading the papers so I haven't formed an opinion either way yet. It's interesting reading.

reply to post by CLPrime

“This is a very important result in fundamental physics and will rule out some string theories and quantum loop gravity theories,” says Dr Laurent.

sounds very interesting..........

link

xp

Originally posted by Kulkulkan
I have wondered what could be causing the universe to be accelerating in it's expansion. And have looked beyond classical means. Since there is not a plausible explanation for electro-magnatism I have decided to look in that direction. xploder first put me on to this theorum even if I had heard of it through other means. Neutron repulsion seems to account for alot of the holes in many theories and confound many. It seems to explain some phenomena such as superpyronics, superfluidity, and other anomoulous behaviour of helium. Could it account for such large scale mysteries as well? I do not have the math skills to determine as much and there are other concerns such as quantum spookyness and related effects? Oh well just typing out loud.

i am glad to have you tell me that thanks
and yes this could be a factor or force to take into account
on large cosmological scales

gets me thinking
xploder

reply to post by Arbitrageur


thank you
you answered perfectly star
i dont thinks he gets my cold dark humour (clp)
the gravatational lensing potential involved can account for this effect

note he calls it MOG and note he says it accounts for the 8 sigma spatial offset "of the center of the total mass from the center of the baryonic mass".

xploder

Well, the whole thing about gravity, and our understanding of it's specific force...

(G = 6.67*10^-11 meters per second acceleration per kilogram over meter separation)

...is that we can only verify this through inference and educated estimation.

For example, we know what the force of gravity by observing how planets move, and by knowing their mass.

But the thing is, we don't really know their mass with absolute certainty, because we can't really "Weigh" the Sun, or the Earth, or the Moon.

And weighing entire solar systems and galaxies is also quite a challenging feat.

So, these little errors and inconsistencies crop up in our knowledge of the force of gravitational attraction.

"Dark Matter" and "Dark Energy" are theories that attempt to explain these inconsistencies with our understanding of the strength and drop-off magnitude of gravitation, and what we actually observe in reality with our giant telescopes.

Now, the dark matter could be local gravitational singularities, some form of exotic or degenerate matter that does not interact electromagnetically (neutrino's for example) or what have you.

But the problem is not that we need a new "G" to account for these forces... we just need better equations and understanding of our existing gravitational constants.

For example, we can calculate the depth and shape of a gravitational well, and thus the strength of gravity by observing "Gravitational Lensing" effects on distant massive objects (galaxies, quasars, whatever) but if we are not accounting for local terminator shock, heliospheric, and heliopause hydrogen plasma refraction effects on photon vectors, then we may have under or overestimated the approximate strength and falloff rate of the force of gravity.

The real answer is, that we just don't know enough about gravity to know what we don't know.

This is a good post.

This subject is getting a bit bizarre at this point. We actually have enough observational data now from enough different points in space to begin to create a map of the entire known physical universe. And what is emerging is a sort of organic, spongy structure.

I haven't followed the "dark matter" argument. It is so counter-intuitive! They are telling us we need to assume a bunch of matter exists that we have found no way to detect except for its gravitational effects which we are assuming must be present because otherwise our assumptions about how the universe hangs together don't work.

Well, the other obvious choice is that our assumptions about how the universe hangs together are incorrect!

At any rate, the maps give one the chance to stand back and and just sort of take in this structure and get a feel for what impressions one gets from it. For me, it looks like a giant communications network. Or some sort of huge record or map. It looks a little like how our roads and urban centers look like at night, for instance, when the lights are on. The planetary layout of roads and cities records in some way the historical movements of people across the land. Could the web-like patterns of the cosmos be recording something similar? Perhaps the movements of the ancient beings who hung this universe together in the first place? Each star a marker, so to speak, of a place one stopped to rest for a little while, or where they congregated with friends and strangers to compare notes, before continuing on their separate or collective journeys of creation.

Originally posted by Arbitrageur

Originally posted by CLPrime
I don't have all of the answers, but, in this case, I believe STVG fits well. If you'll notice, "rotation curves of spiral galaxies" is one of the things I said it accurately reproduces.

Actually it might be less confusing if you used the MOG term Xploder mentioned, because that's what the author calls it in the following paper.

I call it Scalar-Tensor-Vector Gravity because that's actually descriptive of the theory. Plus, MOG is just silly. But, then, whatever Moffat calls it, I guess....

I happened across this article today that may interest the OP:

Quantum 'Graininess' of Space at Smaller Scales? Gamma-Ray Observatory Challenges Physics Beyond Einstein

The European Space Agency's Integral gamma-ray observatory has provided results that will dramatically affect the search for physics beyond Einstein. It has shown that any underlying quantum 'graininess' of space must be at much smaller scales than previously predicted.

Einstein's General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach.

One of the great concerns of modern physics is to marry these two concepts into a single theory of quantum gravity.

Now, Integral has placed stringent new limits on the size of these quantum 'grains' in space, showing them to be much smaller than some quantum gravity ideas would suggest.

I'm not sure if this is related to the topic, but I figured I would throw it out here.

reply to post by Aggie Man


thanks

Some theories suggest that the quantum nature of space should manifest itself at the 'Planck scale': the minuscule 10-35 of a metre, where a millimetre is 10-3 m.

However, Integral's observations are about 10 000 times more accurate than any previous and show that any quantum graininess must be at a level of 10-48 m or smaller.

link to source

that is significantly smaller and the acuracy is much greater than previous estimites
very interesting implications for quantum and clasical physics


thanks Aggie Man

xp

reply to post by Arbitrageur


hi Arbitrageur

here is a thread i wrote a while ago about how gravitational lensing can "potentially" account for what we see in the bullet cluster
ATS thread gravitational microscoping

xploder