Emergent Gravity or Potpourri of Nonsense

[ark]

On Peter Woit's blog "Not even wrong" we can find the following (BTW: Lubos is Lubos Motl):

"Frank says:
January 23, 2010 at 1:06 pm

I think that Lubos is wrong. Unruh’s proportionality between acceleration and temperature implies that gravity can be seen as an thermal/entropic effect. There is little doubt about it. If you want to get rid about the gravity-entropy relation, you must get rid of Unruh radiation – and that is impossible.

On the other hand, this does not tell anything new, as I argued in my previous comment. The reason that Lubos is against the connection between gravity and entropy is clear: he understands that the Jacobson/Verlinde argument undermines string theory, because it excludes higher dimensions. Worse, through Verlinde’s simplification for Newtonian gravity, EVERY physicist now understands that higher dimensions are out! This is Lubos’ nightmare: a simple argument that suggests that string theory is wrong. Even worse, the argument is made by one of the world’s most distinguished string theorists! We can all guess what will happen: Lubos will start discrediting the argument with the same anger with which he discredits global warming. Watch the show."

But you do not have to be string theorist in order to consider higher dimension as "real". Eisntein did it long before strong theories existed.

 

[shijing]

Thanks for the link Ark (and good to see you posting!). So let me make sure that I understand the above -- Verlinde's gravity/entropy theory suggests that higher dimensions have to be excluded (which negates string theory, by definition presumably), but you are saying that even if string theory falls, a hypothesis about higher dimensions does not have to. So if that is the case, is the gravity/entropy hypothesis still compatible with a reality that includes higher dimensions?

I am guessing by what you posted that you don't buy Verlinde's theory, but I can't quite tell. Thanks for your attention to this though, since what attracted me (as a layman non-specialist) to the description of his theory is the part where gravity is an emergent property, and therefore can't be quantified with discrete units like 'gravitons'. I also wondered about any roundabout esoteric significance of 'entropy' in this context as well.

 

[John G]

Hi Shijing, the idea of excluding higher dimensions via the entropy relationship I think would only be someone's bad use of an Occam's razor. Someone thinks they've explained everything that needs explained down in 4-dim spacetime when they really haven't. You need to have your gravity unified with electromagnetism and the nuclear forces. You need to see matter and antimatter and quantum mechanics. I also suspect he's only seeing a limited version of what dark energy is. Things likely emerge into 4-dim spacetime but that doesn't mean that the 4-dim spacetime itself didn't emerge from higher dimensions.

 

[ark]

Indeed, I am not buying explanations of gravity that are not explaining electromagnetism at the same time. There are many "explanations" of gravity. In the media they explode, then they are being forgotten. Do you remember the "Push gravity"? Not a bad theory, so nice, so simple....

 

[shijing]

You need to have your gravity unified with electromagnetism and the nuclear forces. You need to see matter and antimatter and quantum mechanics. I also suspect he's only seeing a limited version of what dark energy is. Things likely emerge into 4-dim spacetime but that doesn't mean that the 4-dim spacetime itself didn't emerge from higher dimensions.

Indeed, I am not buying explanations of gravity that are not explaining electromagnetism at the same time. There are many "explanations" of gravity. In the media they explode, then they are being forgotten. Do you remember the "Push gravity"? Not a bad theory, so nice, so simple....

OK, thanks for both of your feedback, Bluelamp and ark. As I said above, I am definitely out of my own area of study, so I don't really know how to evaluate one theory about gravity from another, and I don't want to make noise. I just know from reading the transcripts that there is something very special about it. I am able to understand that the "Push Gravity" ark referenced is a hypothesis which requires discrete units (waves or particles) and is therefore not emergent. The desire to unify the explanation of gravity with that of EM is presumably related to this from the last session:

A: Take your gravity and convert half into EM light.

since if gravity was an emergent property, it would not be convertible to EM energy (there would be nothing to convert), so that makes sense.

 

[Buddy]

Hope this is not (too far) off topic, but I wanted to ask if anybody has seen this? And could it be helpful?


The Speed of Gravity – What the Experiments Say

_http://www.ldolphin.org/vanFlandern/gravityspeed.html

 

[durabone]

I am also completely out of my league, though I sure have enjoyed the reads, thanks. I work as an electrical engineer.

My question after reading all of this is: Is there such a thing as a hot anode? Always seems like the cathodes are the hot ones.

 

[dant]

[Apologies, as this might be a bit off topic?]

What is a "hot anode" as you described it, however I know of
a "hot cathode", used for generating X-rays.... if I understood
my EE basics, current flows from anode to cathode, thus making
cathode "hot" and you are asking if it is possible to reverse
current flow to make the anode "hot"?

As a side note, perhaps related....

There was something I recall from reading about Tesla when
he talks about "radiant energy" (or was it Floyd Sweet?) - when
they supposedly are talking about open systems as opposed to
a closed system that we have today where currents are "half-used,
half-wasted" (imbalance) resulting in "heat loss" due to the choice
of utilisation methods because the PTB prefers to control power from
which income is guaranteed from the "serfs"?

But then again, hard to know if this is disinfo as Tesla tends to
be a bit "flamboyant" but I do not know if the same applies to
Floyd Sweet (radiant triode).

 

[John G]

...a hypothesis which requires discrete units (waves or particles) and is therefore not emergent... since if gravity was an emergent property, it would not be convertible to EM energy

from 990710

A: That is very close. Consciousness is the key here.
Q: (A) Yes, so my question relates to the geometric model of gravity and consciousness.
A: Picture an endless octagonal... in three dimensions.
Q: (A) A lattice, you mean?
A: Okay.
Q: (A) Are these densities related to the mathematical concept of 'signatures of the metric?' I would like to model
densities with slices of different geometric properties, in particular slices with different properties of the distance.
A: Yes...

A lattice implies spacetime itself is discrete. You could still have things emerge like if you started with an 8-dim spacetime with it's 8-dim gravity and then made 4 of the dimensions small (a symmetry break at lower energies) so that you have a 4-dim gravity emerge. Perhaps the 4 small dimensions then give you electromagnetism and nuclear forces. That's a simplified example (aka stuff left out) of a Kaluza Klein structure.

Making things more complicated is 981218

Q: (A) Well, in a well devised Unified Field Theory, there is a place for something we may call 'graviton,' and this
something comes from, or has a similar source to an electron, but within a time vacuum. At that point I started to think of
time as a kind of field - like other fields. This field has something to do with this fifth dimension. I have a hypothesis about
how one can have time coming from a fifth dimension, and what a time vacuum means. This means that, where there is a
time vacuum, there is no time.
A: Yes.
Q: (A) Okay, now, this is one thing. At some other point we were speaking about pentagons and hexagons and I tried to
be tricky and when it came to pentagons, I wrote a mathematical formula, a symbol for a pentagon, and then there was
the question of signs. We needed five signs. I asked you whether there should be four pluses and one minus, or 3 pluses
and two minus. The answer was that there should be 3 pluses and two minuses in a pentagon. Now, what about a
hexagon? What should I put in a hexagon? Three pluses and three minuses, or four pluses and two minuses?
A: Four and two.
Q: (A) That is what I hoped for, however, I see a certain discrepancy between this pentagon, because if I start from five
dimensions, and I try to build something such as a time field from one plus and one minus, I use one dimension, which is
like a light dimension in this five dimensional space, then I end up with two pluses and one minus, which has nothing to do
with anything that we know in physics. For me there is a contradiction between three pluses and two minuses and the fact
that I need to build time as an extra field. What to do? I don't know. What should I do?
A: When we said "spring forth" from 5th dimension, what interesting possibilities does this pose?

So it looks like that signature of the metric is up to 4,2. It also looks like even though we are building gravitons, we are also talking about a light dimension. Actually getting light aka electromagnetism is going to be messy cause it requires a symmetry break and different people have different ideas about what you are allowed to do after a symmetry break.

The problem with Push Gravity aka Van Flandern is that you don't have any good math to use as a starting point.

So besides the recent transcipt, Ark was into starting with gravity and looking for electromagnetism back in '98 and the idea goes back to Einstein, who as Ark mentioned, was into extra dimensions too (and into those dimensions being circular aka complex number dimensions and this effects the metric too, possibly making 4,2 better than 3,1 and giving you some nice dark energy and maybe related to Ark mentioning de Sitter cosmology in the recent transcript, it's already messy and we haven't even mentioned the quantum stuff Ark mostly has been working on in recent times). There is such a thing as good messy and bad messy.

Let's see current and electron flow are opposite directions and there's also the flow of ions inside the battery, so heat must come from somewhere there. Luckily on paper most all batteries are ideal and thus no heat!

 

[durabone]

Do you guys buy into that one at all?

EDIT My browser choked mid-post. Sorry

 

[durabone]

A: Take your gravity and convert half into EM light.

could that 'halving be Maxwell's displacement current?

[quote author=Bluelamp]nice dark energy[/quote]


[quote author=me, in a very old email]Professors at universities have spent a lot of time describing the phenomenon of deep space dispersion to their students. In an ionized media, a plasma, conditions can create a form of dispersion where lower energy/frequency photons move at a much slower speed. Sometimes 10,000 times slower. You thought the speed of light is constant?! Apparently not at all frequencies.

Deep space is a very thin plasma, and this fact implies that there may be many more low frequency photons in the universe than previously accounted prior to 1990. When I look at a star with a hypothetical broadband sensor that can see from say 0.00001 Hz all the way out past Gamma Rays (>> Hz) the arriving rate of photons from a distant, stable star (I mean it doesn’t change much in the 20 light years its photons take to reach us) matches its spectral profile quite well. But the fact is, that due to deep space dispersion, the lower frequency photons may be significantly older than the higher frequency ones.

This means that the number of lower frequency photons “in the pipe” is greater. Any attempt to estimate the amount of radiant energy in the universe must take this fact into account. I conferred with a scientist in the “Dark Matter/Energy” group, and he told me that the group had not considered these things as of 2005. [/quote]

Do you guys buy this notion?

 

[durabone]

Confirmed. Deep space dispersion is deeply accepted, from as far back as 1997. Standard technique for some comm schemes is to correct for it. Finding a full-spectrum dispersion curve that covers down to < 1Hz, that is another matter. Anyone know a source? Thanks.

 

[John G]

A: Take your gravity and convert half into EM light.

could that 'halving be Maxwell's displacement current?

[quote author=me, in a very old email]
...But the fact is, that due to deep space dispersion, the lower frequency photons may be significantly older than the higher frequency ones.

This means that the number of lower frequency photons “in the pipe” is greater. Any attempt to estimate the amount of radiant energy in the universe must take this fact into account. I conferred with a scientist in the “Dark Matter/Energy” group, and he told me that the group had not considered these things as of 2005.

[/quote]

The dark energy, dark matter, ordinary matter ratios come from WMAP data which is the Cosmic Microwave Background photons which are all supposed to be as old as photons get.

Maxwell's displacement current shouldn't be anything that isn't handled by Maxwell's equations. One could probably come up with a few things that clue could be for and relating gravity to Maxwell's equations could I suppose be one of them.

 

[durabone]

[quote author=Bluelamp]The dark energy, dark matter, ordinary matter ratios come from WMAP data which is the Cosmic Microwave Background photons which are all supposed to be as old as photons get.[/quote]

Thank you very much Bluelamp. I first learned about this from Helliwell's treatise on whistler mode propagation where a lightning bolt signal that has traveled through the ionosphere has its <1Hz content time-shifted by more than a second. The normally vertical-looking bolt signals look like a j-hook in a spectrogram and they make a distintictive high-to-low pitched tone that matches. Problem is that when I look at galactic bursts, the dispersion can be seen, but there must be a plethora of pathways since the signal seems to fatten rather than cleanly be delayed like the lightning bolts. The part I can't fathom is why they cut off at low-freq in our ground-based instruments. It might be shielding by VanAllen belts or geomagnetic field? Unfortunately the only spacecraft data that I have been able to assay is from DEMETER, and the response is simply not there. Plus spacecraft motion interferes as the spacecraft rotation moves the coil, inducing current. The prof who quoted me delays of 10000x is reputable, but so far I have not seen it.

 

[durabone]

[quote author=Bluelamp]Maxwell's displacement current shouldn't be anything that isn't handled by Maxwell's equations. One could probably come up with a few things that clue could be for and relating gravity to Maxwell's equations could I suppose be one of them.[/quote]

Thank you again, really I appreciate!

I tried to follow that business over several years and investigations. But the nomenclature is confusing. The electric displacement D in Gauss' law is related to the E-field by epsilon and is simply charge. Those are in Heaviside's simplified Maxwell theory (the big four equations). But in his more involved 20-equation theory discussed in his "Dynamical Theory..." the displacement there is not synonomous with the D of Gauss' law. Maxwell seems to blur it qualtiatively by saying that it affects atoms but is not electrons being absorbed. Is it or is it not? If not then he is talking about massless charge effects.

Maxwell was keen to state: “When the electromotive force is removed, the dielectric does not instantly return to its primitive state.” He likened the action of “Electric Displacement” to a viscous fluid that slowly rebounds back to shape after being crushed. But no electrons are being absorbed by the atoms, hence no "charge" in the sense of rho and Q?

I don't think his treatment of this last phenomenon is more formal anywhere. (But I have missed many things that should be apparent!). Even in Einstein's 1912 manuscript, he solves the question by making the same conclusion as Heaviside did that the displacement current is rho, the charge density. And all of this leaves me ... confused.