A Scientist Takes On Gravity

[captdude]

Even if this guy is completely off track - I have long thought there was something wrong or incomplete about our understanding of the mechanisms of gravity. Because if that were the case, it would erase, in what in my humble opinion is, the complete inelegance of dark matter and dark energy. The beginning of the article is cut and pasted below the link.

http://www.nytimes.com/2010/07/13/science/13gravity.html?pagewanted=1&_r=1&ei=5043&partner=EXCITE


It’s hard to imagine a more fundamental and ubiquitous aspect of life on the Earth than gravity.
But what if it’s all an illusion, a sort of cosmic frill, or a side effect of something else going on at deeper levels of reality?

So says Erik Verlinde, 48, a respected string theorist and professor of physics at the University of Amsterdam, whose contention that gravity is indeed an illusion has caused a continuing ruckus among physicists, or at least among those who profess to understand it. Reversing the logic of 300 years of science, he argued in a recent paper, titled “On the Origin of Gravity and the Laws of Newton,” that gravity is a consequence of the venerable laws of thermodynamics, which describe the behavior of heat and gases.

 

[SteveCNC]

Interesting read .

I can't say I can argue with his logic though an entropic force seems like it might be a little off as well . Information on the outside of the can ? not too sure about that , I think the writer of the article is to blame for that one .

I've had several thought's and idea's reguarding gravity over the years and the one that still stands out to me as the most plausible is , here goes , don't hate on me , :lol:

Gravity is the result of an object being pulled into a slower time frame . As mass can alter time and space the center of the mass is the slowest time frame and all other objects will gravitate toward that spot . The more mass there is the more space/time is warped toward the center of that mass and the more gravity there is . The closer you get to the center of the mass the slower time passes relative to a position farther out .

 

[captdude]

I am quite content with Albert's warping of space/time by mass as the basis for gravity. However, I have read how some scientists explain the overall weakness of gravity (as compared to the other fundamental forces of nature) as being due to the fact that gravity extends its influence into higher dimensions beyond the four we experience.
If that turns out to be true - then gravity could very well be influenced by energy fields (and possibly their associated particles) within those higher dimensions. I believe our understanding of gravity over vast distances will be re-examined (or something will be discovered) and my distaste for the concept of dark matter will be vindicated.

Finally, just to contradict myself; could particles within those higher dimensions interact through gravity as dark matter?

 

[currious]

What if Gravity is the sideeffect of space pressing in on a body? If space can be thought of as medium like water or more like jello. Space may try to retain its form when a body expands within it. Space would bunch up into rings or layers of compressed space immediately around the object and the effect would lessen as you moved away from it. Could it also be said that light passing through these rings of compressed space has actually travelled farther than first thought ,making the universe much older than expected? The speed of light is the ultimate expression of mass's ability to transit through this medium.

 

[undidly]

What if Gravity is the sideeffect of space pressing in on a body? If space can be thought of as medium like water or more like jello. Space may try to retain its form when a body expands within it. Space would bunch up into rings or layers of compressed space immediately around the object and the effect would lessen as you moved away from it. Could it also be said that light passing through these rings of compressed space has actually travelled farther than first thought ,making the universe much older than expected? The speed of light is the ultimate expression of mass's ability to transit through this medium.

""What if Gravity is the sideeffect of space pressing in on a body.""

What if?.

Then gravity and inertia can be explained.

The compressed space does not remain compressed for long.
Also expanded space the same.
They return to normal by spreading at the speed of light.
They are gravitational waves.

Be ready for the relativity fundamentalists who say there is no aether to compress and that gravity is caused by
the curvature or gradient of nothing at all.

 

[SpeedFreek]

Be ready for the relativity fundamentalists who say there is no aether to compress and that gravity is caused by the curvature or gradient of nothing at all.

Excuse me? Who said that gravity is caused by the curvature or gradient of nothing at all? If that is your impression, you have some serious misconceptions. Undidly, your jaded view of modern physics only belies your own ignorance of the principles involved.

 

[undidly]

Be ready for the relativity fundamentalists who say there is no aether to compress and that gravity is caused by the curvature or gradient of nothing at all.

Excuse me? Who said that gravity is caused by the curvature or gradient of nothing at all? If that is your impression, you have some serious misconceptions. Undidly, your jaded view of modern physics only belies your own ignorance of the principles involved.

""Who said that gravity is caused by the curvature or gradient of nothing at all.""

Those who say that space is empty.
They do not understand that the aether is not any sort of matter.
It is the brane that contains our universe.
It has electrical and magnetic characteristics that determine the speed of light and other characteristics that determine
the speed of gravity waves.

""serious misconceptions""
Please explain one that you think I suffer from.

 

[darkmatter4brains]

Those who say that space is empty

""serious misconceptions""
Please explain one that you think I suffer from.

well, that for one. In light of modern physics, space is not totally "empty" and it is not "nothing". Space is a seething sea of virtual particles, with a constant vacuum energy density (just don't ask what the value of the energy density is, as current theory seems to be off by 120 orders of magnitude!). In addition, spacetime is a geometrical entity called, in mathematical speak, a manifold, that actively participates in the physics of the Universe.

 

[dryson]

It goes something like this: your hair frizzles in the heat and humidity, because there are more ways for your hair to be curled than to be straight, and nature likes options. So it takes a force to pull hair straight and eliminate nature’s options.

I wouldn't put faith in anything this guy says or teaches. He is not looking at gravity from a physics perspective but instead has added emotions nature likes options to the theory. Nature is all of the biological bodies, bacteria all the way up the cahin to humans that make choices based on the ability to make those choices. Energy does not have emotions. A photon does not up and say one day "Hey I think I will go this way today even though there has not been any equal and opposite reaction to effect the direction of travel in which I travel." Energy works on equal and opposite reactions that occur because of the energetic properties of each atom along with the medium in which the atom is contained in where the medium will effect the atoms time based upon the mediums energetic properties and how both elements effect each other.
This guy is an intelligent design proponent where he has hidden religion, which is also based off of human emotions which is the same as saying nature likes options which liking something is based on a personal preference in science.
If there was a Junk Science site I would definately put this guy on the A-List.

 

[csmyth3025]

Those who say that space is empty

""serious misconceptions""
Please explain one that you think I suffer from.

well, that for one. In light of modern physics, space is not totally "empty" and it is not "nothing". Space is a seething sea of virtual particles, with a constant vacuum energy density (just don't ask what the value of the energy density is, as current theory seems to be off by 120 orders of magnitude!). In addition, spacetime is a geometrical entity called, in mathematical speak, a manifold, that actively participates in the physics of the Universe.

I've been thinking about this and I have a question.

According to the Wikipedia article here:

http://en.wikipedia.org/wiki/Vacuum_energy

The energy of a cubic centimeter of empty space has been calculated to be one trillionth of an erg [1], based on the upper limit of the cosmological constant. However, in both Quantum Electrodynamics (QED) and Stochastic Electrodynamics (SED), consistency with the requirement of Lorentz invariance and with the magnitude of the Planck Constant leads to the much larger figure of 10^107 Joules per cubic centimeter or 10^113 Joules per cubic meter.[3][4]

If a sphere of space ~0.62035 cm in radius "pops up" out of vacuum energy, how much energy does it take to move all of the matter/energy of the universe ~0.62035 cm radially outward? This value would, of course, depend on how much matter/energy is contained in the whole universe - as opposed to the observable universe. It seems to me that it would be a lot more than a trillionth of an erg.

The reason I say this is that Wikipedia gives an estimate for the matter content of the observable content here:

http://en.wikipedia.org/wiki/Observable ... ar_density

As follows:

Taking the mass of Sol (2 × 10^30 kg) as the mean stellar mass (on the basis that the large population of dwarf stars balances out the population of stars whose mass is greater than Sol) and rounding the estimate of the number of stars up to 10^22 yields a total mass for all the stars in the observable universe of 3 × 10^52 kg.[27] However, as noted in the "matter content" section, the WMAP results in combination with the Lambda-CDM model predict that less than 5% of the total mass of the observable universe is made up of visible matter such as stars, the rest being made up of dark matter and dark energy.

If we divide 3x10^52 by .05 we get 6x10^53 kg or 6x10^56 g. I'm not sure how to calculate this, but if I take this mass/energy for the observable universe and multiply it by (0.62035cm/sec)^2 I think that gives ~2.3x10^56 ergs.

The same wikipedia article states that the size of the entire universe could be as follows:

According to the theory of cosmic inflation and its founder, Alan Guth, the lower bound for the diameter of the entire Universe could be at least in the range of 10^23 to 10^26 times as large as the observable universe.

If the diameter of the whole universe is 10^23 as large as the observable universe, then I think the volume would be (D^3)/8 or 1.25x10^68 times as large. Assuming the same matter density throughout, the energy value would be in the area of 2.9x10^124 ergs, or about 3x10^117 joules.

Obviously, I'm figuring this wrong. So how is the vacuum energy calculated based on the cosmological constant?

Chris

 

[darkmatter4brains]

Obviously, I'm figuring this wrong. So how is the vacuum energy calculated based on the cosmological constant?

Chris

Well, nobody really knows how to calculate it yet - it's the famous 120 orders of magnitude problem - meaning that the value we calculate is 120 orders or magnitude off from the observered value! You can't get much worse than that ;-)

EDIT: btw, another neat thing that gives "empty" space more life is the transition of the electron in a hydrogen atom (or any other for that matter) from an excited state back to the ground state. This problem cannot be solved without invoking some QFT and taking the vacuum into consideration. Otherwise, the electron would never transition back to the ground state but, in actuality, we know that excited states "decay" to the ground state in fractions of a fraction of a second. Kinda neat, really!

 

[csmyth3025]

Obviously, I'm figuring this wrong. So how is the vacuum energy calculated based on the cosmological constant?

Chris

Well, nobody really knows how to calculate it yet - it's the famous 120 orders of magnitude problem - meaning that the value we calculate is 120 orders or magnitude off from the observered value! You can't get much worse than that ;-)

EDIT: btw, another neat thing that gives "empty" space more life is the transition of the electron in a hydrogen atom (or any other for that matter) from an excited state back to the ground state. This problem cannot be solved without invoking some QFT and taking the vacuum into consideration. Otherwise, the electron would never transition back to the ground state but, in actuality, we know that excited states "decay" to the ground state in fractions of a fraction of a second. Kinda neat, really!

Okay - I guess the next question would be : How do we come up with an observed value for vacuum energy?

Chris

 

[ramparts]

Assuming the acceleration of the Universe is due to a cosmological constant, it's easy to measure that constant from observations of the acceleration - for example, the supernovae observations. From there, you can translate the measured value of the cosmological constant into a vacuum energy if you further assume that that cosmological constant is due to the quantum vacuum.

 

[QED]

Deja vu... I just posted this the other day.

My take is this theory here has a LOT of holes.

 

[csmyth3025]

Deja vu... I just posted this the other day.

My take is this theory here has a LOT of holes.

I can't locate the post your talking about. Are you saying that quantum mechanics has a lot of holes in it , or are you refering to vacuum energy specifically?

Chris