What Is Frank Wilczek's Vision for Understanding Quantum Gravity and the Grid?

  • #31


marcus said:
Kev,
...
I don't think you can give an example of a something, a physical entity, that is somehow ITSELF being perceived in some other way besides thru its effects.
You started talking about Lorentz aether which is not a relevant example to the question I meant to ask. Maybe I should try to say it more clearly.

What I want is an example of something which is ITSELF detectable and is not merely detectable thru its effects. I don't think you can give me an example of such a thing.

For instance the chair I am sitting on, is, as far as I can tell, only detectable by way of its effects. It holds my behind up by the Pauli exclusion principle---the net effect being an effective upwards force on my bottom.

And then there are the effects of the chair on the photons, which it happens to reflect and which then find their way into my eyes!

So your reply to me seems to miss the point. I am trying to suggest to you that as a general rule, entities are detected by their effects, and ONLY by their effects. In this sense, what Wilczek is talking about is no different from my chair.

I concede your point, but I will add that in this sense the Wilczek grid and your chair are no different from the Lorentz aether. They are all detectable by their effects.

marcus said:
Wilczek is talking about the Vacuum of quantum field theory, which all of us know about from its well-established effects. He happens to call it the Grid, because he is writing a popular book and wants to make people take a fresh look. He has some interesting ideas about more things we can learn about the Vacuum, and will be learning (he thinks) in the next few years.
But it is still a well-established entity, quite Lorentz-invariant (although your question #2 seems to indicate you doubt this??)

I was pretty sure the grid would be Lorentz invariant ... just like the Lorentz aether.

I am curious to know what it about the grid that qualifies it as a physical entity that does not apply to the Lorentz aether. From my point of view, history has done Lorentz a great injustice and made him out to be some sort of clown who got it it all completely wrong, when in fact quantum theory gives more and more credance to the concept of the vacuum as a physical entity rather than empty space. It is about time the scientific community acknowledged the work of Lorentz and concedes that the Lorentz aether is not just bizarre non entity as is often claimed, but is in fact the quantum vacuum. Even Einstein himself acknowledged in a speach that curved spacetime is ultimately a form of the aether. Scientist is just assumed Einstein was having a bad day when he made that speech and that he taylored the speech to please the audience he was addressing. Personally, I believe Einstein had more integrity than that.

marcus said:
Kev, I think what you need to do is READ THE BOOK if you want to discuss about the Grid. Because otherwise you may not get what is being talked about. Don't just take may words about it and spin off from there---go to the source. It just takes two days to get it from amazon---I was surprised how quick they deliver. Good luck.

OK, I think I will :wink:

P.S. I am not being anti-grid. I think both Wilczek AND Lorentz may have valid, useful (and possibly related) concepts.
 
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  • #32


A "reflection on Kev's reflection".

kev said:
I concede your point, but I will add that in this sense the Wilczek grid and your chair are no different from the Lorentz aether. They are all detectable by their effects.

As I see it, perhaps the question kev "could have asked" - given marcus point that of course anything is "only" perceived by it's interaction properties - is wether the "mental image" of what is responsible for the interactions we do see is unique with respect to different interacting subsystems/observers?

Given that we have different interacting observers with this, do they all "by conincidence" form the same "mental image"?

Why, why not? And what consequences does each case have?

To inject my personal view here, in line with the above "ramblings", is that what I was hoping Wilczek meant with this "grid", that would make sense to me, is a kind of abstraction of a really a class of grids, and then one possible answer to the "are the mental images formed in the internal observer states unique" is no.

Then the question is of course, then where did objectivity go? Does this means thta the images are totally arbitrary? I don' think so.

Perhaps this is where the abstraction comes in. One possibility is that the "difference" in two images of this abstraction "perhaps some call it the grid" is the basis for their interactions! This means that there is no objective background abstractions on which the grid is defined. The grid could be the class of differing views, and this itself is the basis for grid-grid "interactions" which casues the grid-class to evolve relative to each other.

That's what I currently think of this. And I think it makes perfect sense. But how to get into calculations? I keep relating this grid to "relative information" or "relative states", and the rules of "information processing" could be the self-evolution of this. Here I picture a kind of relative ME principle. But the evolution an not be given a global description without observers, it means ALL evolution is relative. Here I connect to the all the different possible entropies - each when applied to an ME principle obviously giving result to different statistics and evolutions - to the observers. And here some ways of processing information will simply die out - we get evolution of observers and thus evolution of the "logic" and "measures" implicit in the ME principles. So survival is in my view all about "relative consistency".

Marcus, I'll probably order that book later. I've put it on my list, but I've another book to read first. Thanks for the clarification about identifiction of the horses back :) The scence I had in mind was the movie "dumb & dumber" where Harry hands the dogs some hotdogs with ketchup and mustard and orders the Dogs in his van to not "sniff hidies" (like he could prevent it), but I was unsure howto spell hidie. That's where back pop up. I think my english is at least "reasonable" given that I'm swedish but I regularly get words, spelling and the grammar way off chart :)

/Fredrik
 
  • #33


> Given that we have different interacting observers with this, do they all "by conincidence" form the same "mental image"?

Of course, this still makes little since because how do they compare "mental images" if not by communication/interaction?

This is part of one of the core points of rovelli's relational QM.

IMHO, "the same mental image" would mean that the two observers can communicate their images and find themselves in agreement - ie the are not "fightning each" other like a hot and cold sink - rather than are in equilibirum, relative to their communication channel.

/Fredrik
 
  • #34


kev said:
I read somewhere in this forum (although I can not locate it right now) that Einstein was working on a concept of mass that takes the mass energy equivalence literally. The basic idea was that all mass is just a disturbance of a background energy field, or that mass is just a way that certain patterns of energy manifest themselves. Particles are not localised in the way we normally think of but are composed of energy that is spread out possibly to infinity and in this concept, what we think of as a particle is just where the enrgy is most concentrated. In effect there is no such thing as mass, just patterns of energy. Particles are much "fuzzier" than we normally think of and are smeered out over vast distances much in the way we think of a gravitational field or the curvature of space, except the particle IS the field or part of the field and particles separated by great distances are in effect superimposed on each other. One anology is to think of the rubber sheet embedding diagram. The normal visulisation is "cannon balls" resting on the rubber sheet indetting and deforming the sheet. The mass is energy visulisation does not have the cannon balls, and the particles are the indentations rather than the cause of the indentations. Sorry this all a bit vague, but I read the article a while ago and can not rememember all the details and can not track down a reference. The point is that the "mass REALLY is just a manifestation of energy" idea of Einstein's sounds a lot like the idea of Wilczek being discussed here. Can anyone here track down Einstein's original idea and compare how it similar to that of Wilczek and how it differs?



I've been working from the other direction as the traditional approach (I.E. QG projects building the universe from the bottom up looking to produce Relativity), and arrived at that same conclusion.

Only, the rubber sheet doesn't have dents in it, it has knots.

Take the sheet on your bed, stretched taut around your mattress, grab a section of it and twist it up.

The fabric around the section you're holding will be stressed and distorted.


It's interesting seeing a bottom up approach corresponding so well to the top down image suggested by Relativity.
 

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