If you are aware of an interesting new academic paper (that has been published in a peer-reviewed journal or has appeared on the arXiv), a conference talk (at an official professional scientific meeting), an external blog post (by a professional scientist) or a news item (in the mainstream news media), which you think might make an interesting topic for an FQXi blog post, then please contact us at forums@fqxi.org with a link to the original source and a sentence about why you think that the work is worthy of discussion. Please note that we receive many such suggestions and while we endeavour to respond to them, we may not be able to reply to all suggestions.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Contests Home

Previous Contests

**What Is “Fundamental”**

*October 28, 2017 to January 22, 2018*

*Sponsored by the Fetzer Franklin Fund and The Peter & Patricia Gruber Foundation*

read/discuss • winners

**Wandering Towards a Goal**

How can mindless mathematical laws give rise to aims and intention?

*December 2, 2016 to March 3, 2017*

Contest Partner: The Peter and Patricia Gruber Fund.

read/discuss • winners

**Trick or Truth: The Mysterious Connection Between Physics and Mathematics**

*Contest Partners: Nanotronics Imaging, The Peter and Patricia Gruber Foundation, and The John Templeton Foundation*

Media Partner: Scientific American

read/discuss • winners

**How Should Humanity Steer the Future?**

*January 9, 2014 - August 31, 2014*

*Contest Partners: Jaan Tallinn, The Peter and Patricia Gruber Foundation, The John Templeton Foundation, and Scientific American*

read/discuss • winners

**It From Bit or Bit From It**

*March 25 - June 28, 2013*

*Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American*

read/discuss • winners

**Questioning the Foundations**

Which of Our Basic Physical Assumptions Are Wrong?

*May 24 - August 31, 2012*

*Contest Partners: The Peter and Patricia Gruber Foundation, SubMeta, and Scientific American*

read/discuss • winners

**Is Reality Digital or Analog?**

*November 2010 - February 2011*

*Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American*

read/discuss • winners

**What's Ultimately Possible in Physics?**

*May - October 2009*

*Contest Partners: Astrid and Bruce McWilliams*

read/discuss • winners

**The Nature of Time**

*August - December 2008*

read/discuss • winners

Previous Contests

read/discuss • winners

How can mindless mathematical laws give rise to aims and intention?

Contest Partner: The Peter and Patricia Gruber Fund.

read/discuss • winners

Media Partner: Scientific American

read/discuss • winners

read/discuss • winners

read/discuss • winners

Which of Our Basic Physical Assumptions Are Wrong?

read/discuss • winners

read/discuss • winners

read/discuss • winners

read/discuss • winners

Forum Home

Introduction

Terms of Use

RSS feed | RSS help

Introduction

Terms of Use

*Posts by the author are highlighted in orange; posts by FQXi Members are highlighted in blue.*

RSS feed | RSS help

RECENT POSTS IN THIS TOPIC

**Juan Ramón González Álvarez**: *on* 2/27/18 at 20:42pm UTC, wrote I forgot the attachment with the general spectral decomposition of the...

**Juan Ramón González Álvarez**: *on* 2/27/18 at 20:10pm UTC, wrote Everett's work was debunked many time ago, both in physical and...

**Cristinel Stoica**: *on* 2/22/18 at 15:51pm UTC, wrote Dean Sean and Singh, This was very impressive. This program seems to me...

**Steven Andresen**: *on* 2/22/18 at 8:35am UTC, wrote Dear Sean If you are looking for another essay to read and rate in the...

**jason Roy**: *on* 2/20/18 at 5:09am UTC, wrote Such a great place where you play stickman games free online games...

**Avtar Singh**: *on* 2/20/18 at 1:57am UTC, wrote Hi Sean and Ashmeet: Enjoyed your well-written and enlightening essay,...

**Peter Jackson**: *on* 2/15/18 at 15:57pm UTC, wrote Sean, Asmheet, I think that's the best description of Many Worlds I've...

**Luca Valeri**: *on* 2/8/18 at 13:43pm UTC, wrote Dear Sean and Asmheet, you gave a nice intuition on your research program....

RECENT FORUM POSTS

**Georgina Woodward**: "I wrote " As the EMr has periodic motion it is invariant under..."
*in* Breaking the Universe's...

**Georgina Woodward**: "That should say: Pythagorean mathematics can be used to compare the seen..."
*in* Breaking the Universe's...

**Joe Fisher**: "Robert Lawrence Kuhn ℅ Closer To Truth November 17, 2018 Ref: Get out..."
*in* Dissolving Quantum...

**Agus uye**: "The page is very amazing happy to be on your page I found your page from..."
*in* If the world ended...

**Joe Fisher**: "Today’s Closer To Truth Facebook page contained this peculiar..."
*in* Dissolving Quantum...

**Zimmer man**: "Excellent and useful information, thanks for the list. androdumpper apk..."
*in* Neutrino mysteries,...

**Edwin Knox**: "The genuine Earth had a genuine VISIBLE surface for many years previously..."
*in* Superhuman: Book Review...

**Joe Fisher**: "Dear Dr. Zeeya Merali, Reality am not a humanly contrived finite..."
*in* Alternative Models of...

RECENT ARTICLES

*click titles to read articles*

**Dissolving Quantum Paradoxes**

The impossibility of building a perfect clock could help explain away microscale weirdness.

**Constructing a Theory of Life**

An all-encompassing framework of physics could help to explain the evolution of consciousness, intelligence, and free will.

**Usurping Quantum Theory**

The search is on for a fundamental framework that allows for even stranger links between particles than quantum theory—which could lead us to a theory of everything.

**Fuzzballs v Black Holes**

A radical theory replaces the cosmic crunchers with fuzzy quantum spheres, potentially solving the black-hole information paradox and explaining away the Big Bang and the origin of time.

**Whose Physics Is It Anyway? Q&A with Chanda Prescod-Weinstein**

Why physics and astronomy communities must take diversity issues seriously in order to do good science.

RECENT FORUM POSTS

RECENT ARTICLES

The impossibility of building a perfect clock could help explain away microscale weirdness.

An all-encompassing framework of physics could help to explain the evolution of consciousness, intelligence, and free will.

The search is on for a fundamental framework that allows for even stranger links between particles than quantum theory—which could lead us to a theory of everything.

A radical theory replaces the cosmic crunchers with fuzzy quantum spheres, potentially solving the black-hole information paradox and explaining away the Big Bang and the origin of time.

Why physics and astronomy communities must take diversity issues seriously in order to do good science.

FQXi FORUM

November 19, 2018

CATEGORY:
FQXi Essay Contest - Spring, 2017
[back]

TOPIC: Mad-Dog Everettianism: Quantum Mechanics at Its Most Minimal by Sean M. Carroll and Ashmeet Singh [refresh]

TOPIC: Mad-Dog Everettianism: Quantum Mechanics at Its Most Minimal by Sean M. Carroll and Ashmeet Singh [refresh]

To the best of our current understanding, quantum mechanics is part of the most fundamental picture of the universe. It is natural to ask how pure and minimal this fundamental quantum description can be. The simplest quantum ontology is that of the Everett or Many-Worlds interpretation, based on a vector in Hilbert space and a Hamiltonian. Typically one also relies on some classical structure, such as space and local configuration variables within it, which then gets promoted to an algebra of preferred observables. We argue that even such an algebra is unnecessary, and the most basic description of the world is given by the spectrum of the Hamiltonian (a list of energy eigenvalues) and the components of some particular vector in Hilbert space. Everything else – including space and fields propagating on it – is emergent from these minimal elements.

Sean Carroll is a research professor at the California Institute of Technology. Ashmeet Singh is a graduate student at the California Institute of Technology.

Thought provoking essay."Spectrum",sounds like a probability distribution of energy eigen values (scalars)and associated vectors. "Energy"could imply vibrations associated with a particular direction (vector)from which fields emerge, which get entangled to give rise to geometry of "space". Emergent space sounds mathematical.Thank You.

report post as inappropriate

report post as inappropriate

"The simplest quantum ontology is that of the Everett or Many-Worlds interpretation, based on a vector in Hilbert space and a Hamiltonian." Is the preceding idea somehow related to the following?

"Connecting loop quantum gravity and string theory via quantum geometry" by Deepak Vaid, 2018, arXiv.org

report post as inappropriate

"Connecting loop quantum gravity and string theory via quantum geometry" by Deepak Vaid, 2018, arXiv.org

report post as inappropriate

This essay is an clear summary of your extreme Everett approach, which I think is very ambitious, even if I don't subscribe to it myself. One aspect of the construction was unclear to me:

"If we divide the entanglement into a small-scale ultraviolet term that determines the spacetime geometry, and a longer-scale infrared term characterizing matter fields propagating within that geometry, the change in one kind of entropy must be compensated for by a corresponding change in the other"

Presumably, the division between "infra-red" and "ultra-violet" degrees of freedom involves another tensor product decomposition of the Hilbert space or, more generally, a decomposition into "logical qubit" generalized subsystems and "the rest", as in a quantum error correcting code. My question is, how do you identify this decomposition in the first place? I can imagine it might be determined in part by the spectrum of the Hamiltonian, i.e. does a small change in the state of one component lead to a large or small change in the expectation of the energy, but I cannot see how one would go about doing that, and whether any procedure would be unique.

If you have such a decomposition, you can then attempt to divide the entropy into "ultra-violet" and "infra-red" components as you suggest, but what would happen if the "ultra-violet" and "infra-red" components were entangled with each other? Then the sum of the two components of entropy would not have to be conserved, so you wouldn't get the entropy balance and Einstein equations. Or perhaps the method you imagine for identifying the "infra-red" and "ultra-violet" degrees of freedom would ensure that there is very little entanglement between them for low-lying states. Any more details of this you can give would be appreciated.

report post as inappropriate

"If we divide the entanglement into a small-scale ultraviolet term that determines the spacetime geometry, and a longer-scale infrared term characterizing matter fields propagating within that geometry, the change in one kind of entropy must be compensated for by a corresponding change in the other"

Presumably, the division between "infra-red" and "ultra-violet" degrees of freedom involves another tensor product decomposition of the Hilbert space or, more generally, a decomposition into "logical qubit" generalized subsystems and "the rest", as in a quantum error correcting code. My question is, how do you identify this decomposition in the first place? I can imagine it might be determined in part by the spectrum of the Hamiltonian, i.e. does a small change in the state of one component lead to a large or small change in the expectation of the energy, but I cannot see how one would go about doing that, and whether any procedure would be unique.

If you have such a decomposition, you can then attempt to divide the entropy into "ultra-violet" and "infra-red" components as you suggest, but what would happen if the "ultra-violet" and "infra-red" components were entangled with each other? Then the sum of the two components of entropy would not have to be conserved, so you wouldn't get the entropy balance and Einstein equations. Or perhaps the method you imagine for identifying the "infra-red" and "ultra-violet" degrees of freedom would ensure that there is very little entanglement between them for low-lying states. Any more details of this you can give would be appreciated.

report post as inappropriate

Matthew -- yes, this is a very good question; one that we're thinking a lot about right now. The answer isn't completely clear. The most straightforward idea is that there aren't actually separate UV & IR degrees of freedom, but just different amounts of entanglement between the existing degrees of freedom depending on whether they are "nearby" or "far away." That in turn can be directly fixed by the Hamiltonian (nearby factors are ones for which there is a nonzero interaction term in H).

But there may something more subtle or clever going on. In https://arxiv.org/abs/1712.02803 we suggest (following work by Dan Harlow in the AdS/CFT context) that it might be helpful to think in terms of quantum error-correcting codes. The rough idea is that the IR contribution can be identified with the entropy within a code subspace, while the UV piece comes from the physical space. But how to algorithmically construct that division is still a bit murky, at least to me.

But there may something more subtle or clever going on. In https://arxiv.org/abs/1712.02803 we suggest (following work by Dan Harlow in the AdS/CFT context) that it might be helpful to think in terms of quantum error-correcting codes. The rough idea is that the IR contribution can be identified with the entropy within a code subspace, while the UV piece comes from the physical space. But how to algorithmically construct that division is still a bit murky, at least to me.

Dear Sean

You are very right when you say “a relation to underlying reality, if any” the “if any” explains the position of the agents (us) in reality.

I also liked !“a classical limit emerges in the right circumstances” which is in concordance with “causal emergence”, meaning that there are multiple limits. Emergence is not only happening at the “if any” but also in the higher levels of emergent phenomena.

You say : “This is a version of the Everettian (ManyWorlds) approach to quantum mechanics”

In my essay “Foundational Quantum Reality Loops” I propose a different way of explaining the problems that are solved by the MWI, NOT by the splitting up of realities, but through the “choice” of probability Loops. (I hope that you can spare some time to read and comment it.

Quote: “All of the additional elements familiar in physical theories, we will argue, can be emergent from the state vector”. Is it possible that these “state vectors” are comparable to my “Reality Loops” ?

“it seems plausible that the spacetime dynamics familiar from general relativity can arise in an emergent spacetime purely from generic features of the entanglement structure of the quantum state; finding gravity ....” If we perceive entanglement as a form of wormhole-connection (interconnection of emergent space in a reality-loop) as I argue then this argument is fully comprehensible.

I thank you very much for an essay that helped me evolving my own thoughts.

Best regards

Wilhelmus

report post as inappropriate

You are very right when you say “a relation to underlying reality, if any” the “if any” explains the position of the agents (us) in reality.

I also liked !“a classical limit emerges in the right circumstances” which is in concordance with “causal emergence”, meaning that there are multiple limits. Emergence is not only happening at the “if any” but also in the higher levels of emergent phenomena.

You say : “This is a version of the Everettian (ManyWorlds) approach to quantum mechanics”

In my essay “Foundational Quantum Reality Loops” I propose a different way of explaining the problems that are solved by the MWI, NOT by the splitting up of realities, but through the “choice” of probability Loops. (I hope that you can spare some time to read and comment it.

Quote: “All of the additional elements familiar in physical theories, we will argue, can be emergent from the state vector”. Is it possible that these “state vectors” are comparable to my “Reality Loops” ?

“it seems plausible that the spacetime dynamics familiar from general relativity can arise in an emergent spacetime purely from generic features of the entanglement structure of the quantum state; finding gravity ....” If we perceive entanglement as a form of wormhole-connection (interconnection of emergent space in a reality-loop) as I argue then this argument is fully comprehensible.

I thank you very much for an essay that helped me evolving my own thoughts.

Best regards

Wilhelmus

report post as inappropriate

I have no comment, but I wonder if Sean has ever come across the criticism of general relativity presented in my essay, A Tale of Two Relativities?

report post as inappropriate

report post as inappropriate

Dear authors,

to me, this is one of the most exciting essays in the contest so far (well, of those I've read, anyhow). There is some similarity, at least in spirit, to von Weizsäcker's old idea of 'ur-theory', which postulated that the phenomenology of the world, gravity, particles and all, should be derivable from an 'abstract quantum theory' of 'simple alternatives' (the urs---'ur'...

view entire post

to me, this is one of the most exciting essays in the contest so far (well, of those I've read, anyhow). There is some similarity, at least in spirit, to von Weizsäcker's old idea of 'ur-theory', which postulated that the phenomenology of the world, gravity, particles and all, should be derivable from an 'abstract quantum theory' of 'simple alternatives' (the urs---'ur'...

view entire post

report post as inappropriate

Sean, Asmheet,

What is fundamental is what the universe is and does before we look or even think about it.

Quantum mechanics is our most ontological theory. It is possible to get the metaphysical equivalent. We have to match the probability of finding a particle with the equal probability for the particle to be there. There is a simple underlying rule that compels the particle to be there with a certain probability i.e. the “existing” of the particle much match our “finding” of the particle.

The causality is hidden in the wave function ..... and the background. My essay invites us to ask “why” instead of “how” in order to take us out of the equation and address the logical state of the underlying reality.

Best of luck,

Marcel,

report post as inappropriate

What is fundamental is what the universe is and does before we look or even think about it.

Quantum mechanics is our most ontological theory. It is possible to get the metaphysical equivalent. We have to match the probability of finding a particle with the equal probability for the particle to be there. There is a simple underlying rule that compels the particle to be there with a certain probability i.e. the “existing” of the particle much match our “finding” of the particle.

The causality is hidden in the wave function ..... and the background. My essay invites us to ask “why” instead of “how” in order to take us out of the equation and address the logical state of the underlying reality.

Best of luck,

Marcel,

report post as inappropriate

Dear Authors,

Thank you for your essay.

I will be grateful if you could explain in brief the essence of your two Refs. on deriving the Born probability rule in this approach.

To me, the occurrence of probabilities in a theory is a signature of randomness, either in the initial conditions, or in the dynamics. How do we understand randomness in Everettianism?

Since quantum linear superposition of position states [cat states] has not been experimentally established for objects with masses larger than about 10,000 a.m.u. and since the apparent random breakdown of linear superposition occurs for masses larger than these, I feel there should be a major world-wide effort to confirm /rule out stochastic theories such as GRW, which predict departures from quantum theory in the macro-limit. [If GRW is ruled out, then one has a strong case for Everettianism, in my opinion. On the other hand I once heard a Bohmian say that if GRW is ruled out, that will prove Bohmian mechanics is right!. How do we choose between Bohm and Everett?]

It is puzzling to me that while such experiments are being carried out in Europe, there seems to be no such effort in North America, to the best of my knowledge. Is there a reason for that?

With regards,

Tejinder

report post as inappropriate

Thank you for your essay.

I will be grateful if you could explain in brief the essence of your two Refs. on deriving the Born probability rule in this approach.

To me, the occurrence of probabilities in a theory is a signature of randomness, either in the initial conditions, or in the dynamics. How do we understand randomness in Everettianism?

Since quantum linear superposition of position states [cat states] has not been experimentally established for objects with masses larger than about 10,000 a.m.u. and since the apparent random breakdown of linear superposition occurs for masses larger than these, I feel there should be a major world-wide effort to confirm /rule out stochastic theories such as GRW, which predict departures from quantum theory in the macro-limit. [If GRW is ruled out, then one has a strong case for Everettianism, in my opinion. On the other hand I once heard a Bohmian say that if GRW is ruled out, that will prove Bohmian mechanics is right!. How do we choose between Bohm and Everett?]

It is puzzling to me that while such experiments are being carried out in Europe, there seems to be no such effort in North America, to the best of my knowledge. Is there a reason for that?

With regards,

Tejinder

report post as inappropriate

https://arxiv.org/pdf/gr-qc/9703089.pdf

The following is an argument given in ARXIV against the Many worlds interpretation

quote

it is argued that frequency operator

theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves

provide a probability interpretation for quantum mechanics, and thus neither

support existing MWI nor would be useful in constructing new MWI. Comments

are made on papers by Geroch and Deutsch that advocate MWI. It is

concluded that no plausible set of axioms exists for an MWI that describes

known physics.

I would welcome your commentary on this article, and to see if you reject this articles premises.

You are welcome to review my essay as well as of December 21st

report post as inappropriate

The following is an argument given in ARXIV against the Many worlds interpretation

quote

it is argued that frequency operator

theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves

provide a probability interpretation for quantum mechanics, and thus neither

support existing MWI nor would be useful in constructing new MWI. Comments

are made on papers by Geroch and Deutsch that advocate MWI. It is

concluded that no plausible set of axioms exists for an MWI that describes

known physics.

I would welcome your commentary on this article, and to see if you reject this articles premises.

You are welcome to review my essay as well as of December 21st

report post as inappropriate

Hi

It is really a big shame that this wonderful essay is being ignored or not appreciated. So I guess I should not be disappointed either if nobody is killing himself trying to understand mine.

I agree with your essay because it goes to the heart of the physics problem without the usual extra heavy philosophical gymnastics. Moreover, I think my essay is similar if not identical to your idea.

Please visit the Essay

Thank you

report post as inappropriate

It is really a big shame that this wonderful essay is being ignored or not appreciated. So I guess I should not be disappointed either if nobody is killing himself trying to understand mine.

I agree with your essay because it goes to the heart of the physics problem without the usual extra heavy philosophical gymnastics. Moreover, I think my essay is similar if not identical to your idea.

Please visit the Essay

Thank you

report post as inappropriate

SC

Your essay deals with many topics. I have two comments.

A Hilbert space and a quantum Hamiltonian H with its spectra determine your physical outcome. Take a classical Hamiltonian p^2+q^4 and, following conventional procedures, the quantum Hamiltonian is given by P^2+Q^4 and its spectra. Without further information we could also have chosen p^4+q^2 and also P^4+Q^2. These two operators have the same spectra which could cause confusion. To help the situation I choose q to represent how many steps I need to cross my room and I choose p to relate to the uniform speed I take to cross my room. It.seems that a full understanding of a given problem rests on the meaning of the variables that are chosen.

You have a short story about the Wheeler-DeWitt (WDW) equation written as H |psi>=0. The normal way to write the WDW as H(x)|psi>=0 where x is a spatial coordinate and int H(x) dx =H. It follows, however, that [H(x) , H(y) ] |psi> =/=0 because there are second class constraints that forbid an =0 result. (An example of second class constraints is. Q|phi> =0 and P|phi>=0 but [Q , P ] |phi>=/=0.)

Both Wheeler and DeWitt disowned this equation before they died. I even heard DeWitt say that “he wished his name had never been attached to that equation”.

report post as inappropriate

Your essay deals with many topics. I have two comments.

A Hilbert space and a quantum Hamiltonian H with its spectra determine your physical outcome. Take a classical Hamiltonian p^2+q^4 and, following conventional procedures, the quantum Hamiltonian is given by P^2+Q^4 and its spectra. Without further information we could also have chosen p^4+q^2 and also P^4+Q^2. These two operators have the same spectra which could cause confusion. To help the situation I choose q to represent how many steps I need to cross my room and I choose p to relate to the uniform speed I take to cross my room. It.seems that a full understanding of a given problem rests on the meaning of the variables that are chosen.

You have a short story about the Wheeler-DeWitt (WDW) equation written as H |psi>=0. The normal way to write the WDW as H(x)|psi>=0 where x is a spatial coordinate and int H(x) dx =H. It follows, however, that [H(x) , H(y) ] |psi> =/=0 because there are second class constraints that forbid an =0 result. (An example of second class constraints is. Q|phi> =0 and P|phi>=0 but [Q , P ] |phi>=/=0.)

Both Wheeler and DeWitt disowned this equation before they died. I even heard DeWitt say that “he wished his name had never been attached to that equation”.

report post as inappropriate

Hi Sean and Ashmeet,

Thanks for this fascinating essay. I got a little lost in some of the details, but really enjoyed reading it nonetheless, and I love the ambition of deriving everything from such basic principles.

Quick question: what does the "mad dog" refer to??

Recently I've been interested in showing how objectivity -- a central part of classicality -- can emerge from a quantum substrate. A really nice paper showed that, whenever the system of interest is connected to a sufficiently large environment, objectivity emerges (i.e. different observers will agree on their measurements) even when no assumptions are placed on the Hilbert space or the Hamiltonian (https://arxiv.org/abs/1310.8640). I've been extending their results to infinite dimensions (paper in preparation!).

This is probably a naive thought, but I wonder if some of the other aspects you covered (space-time, gravity, etc) are also an inherent part of the mathematical structure of quantum mechanics, rather than being properties of the specific Hamiltonian or Hilbert space?

All the best,

Paul

report post as inappropriate

Thanks for this fascinating essay. I got a little lost in some of the details, but really enjoyed reading it nonetheless, and I love the ambition of deriving everything from such basic principles.

Quick question: what does the "mad dog" refer to??

Recently I've been interested in showing how objectivity -- a central part of classicality -- can emerge from a quantum substrate. A really nice paper showed that, whenever the system of interest is connected to a sufficiently large environment, objectivity emerges (i.e. different observers will agree on their measurements) even when no assumptions are placed on the Hilbert space or the Hamiltonian (https://arxiv.org/abs/1310.8640). I've been extending their results to infinite dimensions (paper in preparation!).

This is probably a naive thought, but I wonder if some of the other aspects you covered (space-time, gravity, etc) are also an inherent part of the mathematical structure of quantum mechanics, rather than being properties of the specific Hamiltonian or Hilbert space?

All the best,

Paul

report post as inappropriate

Dear Sean Carroll

I read your critique on crackpot theorists. Cant say that endeared you to me, but I wont let that effect my judgment of the work you present now.

Just letting you know that I am making a start on reading of your essay, and hope that you might also take a glance over mine please? I look forward to the sharing of thoughtful opinion. Congratulations on your essay rating as it stands, and best of luck for the contest conclusion.

My essay is titled

“Darwinian Universal Fundamental Origin”. It stands as a novel test for whether a natural organisational principle can serve a rationale, for emergence of complex systems of physics and cosmology. I will be interested to have my effort judged on both the basis of prospect and of novelty.

Thank you & kind regards

Steven Andresen

report post as inappropriate

I read your critique on crackpot theorists. Cant say that endeared you to me, but I wont let that effect my judgment of the work you present now.

Just letting you know that I am making a start on reading of your essay, and hope that you might also take a glance over mine please? I look forward to the sharing of thoughtful opinion. Congratulations on your essay rating as it stands, and best of luck for the contest conclusion.

My essay is titled

“Darwinian Universal Fundamental Origin”. It stands as a novel test for whether a natural organisational principle can serve a rationale, for emergence of complex systems of physics and cosmology. I will be interested to have my effort judged on both the basis of prospect and of novelty.

Thank you & kind regards

Steven Andresen

report post as inappropriate

Respected Prof Sean Carroll

Dear Ashmeet Singh

You have very nicely interpreted that the "quantum mechanics" is one of the most fundamental things of the universe. ........ Many-Worlds interpretation, based on a vector in Hilbert space and a Hamiltonian vis a vis an algebra of preferred observables. You argue that even such an algebra is unnecessary, and even went for the most basic...

view entire post

Dear Ashmeet Singh

You have very nicely interpreted that the "quantum mechanics" is one of the most fundamental things of the universe. ........ Many-Worlds interpretation, based on a vector in Hilbert space and a Hamiltonian vis a vis an algebra of preferred observables. You argue that even such an algebra is unnecessary, and even went for the most basic...

view entire post

report post as inappropriate

Dear Sean and Asmheet,

you gave a nice intuition on your research program. In fact given a wave function of the universe and a Hamiltonian governing the evolution, one should in principle be able to derive our observable universe. Of course the reverse engineering from our observable universe to the universal wave function is much more difficult.

My approach to the quantum measurement problem is similar to Everett’s relative state formulation of quantum mechanics, but with no branching and no external decoherence.

As in your essay a quantum measurement is described as consisting of 3 systems: the quantum system H_{q}, the apparatus H_{a} and the environment (or the rest of the universe) H_{e}. The time evolution is given such, that all the 3 systems can get entangled. However contrary to the decoherence program I assume, that the environment must be in a very special symmetric state, such that the environment does not get entangled with the H_{q} and H_{a} subsystem. Such states of the environment exists. The evolution on the subsystem can be described by a unitary evolution. This is a condition that the properties of H_{q} can be measured or defined. The (from within the system) unobservable absolute quantities can be averaged out, which reduces the density matrix of the subsystem. This reduction is objective and immune against Wigner’s friend type objections because if Wigner (the environment) would like to observe the system it must get entangled with the subsystem. But then the conditions of a successful measurement would be broken.

I would love, if you find the time to comment on my essay The quantum sheep - In defence of a positivist view on physics.

Best regards

Luca

report post as inappropriate

you gave a nice intuition on your research program. In fact given a wave function of the universe and a Hamiltonian governing the evolution, one should in principle be able to derive our observable universe. Of course the reverse engineering from our observable universe to the universal wave function is much more difficult.

My approach to the quantum measurement problem is similar to Everett’s relative state formulation of quantum mechanics, but with no branching and no external decoherence.

As in your essay a quantum measurement is described as consisting of 3 systems: the quantum system H

I would love, if you find the time to comment on my essay The quantum sheep - In defence of a positivist view on physics.

Best regards

Luca

report post as inappropriate

Sean, Asmheet,

I think that's the best description of Many Worlds I've read. Very interesting, well written and explained.

However. I do derive a finding in my essay which suggests that either you may*"..have just gone mad."*, or more likely that NO 'interpretation' beyond classical mechanics may be needed!! (I was conservative with the exclamation marks). Which is exactly as John Bell believed and stated.

Few are qualified to analyse the sequence of ontological mechanisms reproducing QM's predictions, I hope you are; I've just written a short outline on John Klauders string which will assist.

Declan Traill's short essay confirms the matching code gives the CHSH >2 Cos^2 plots as well as the steering >1 closing the detector loophole. My top scored 2015 'red/green sock trick' essay started the construction (as a test of a rational SR solution). Shockingly if correct there is no 'non-locality' and QM and SR unify!

I look forward to questions.

Well done for your excellent essay anyway.

Peter Jackson

report post as inappropriate

I think that's the best description of Many Worlds I've read. Very interesting, well written and explained.

However. I do derive a finding in my essay which suggests that either you may

Few are qualified to analyse the sequence of ontological mechanisms reproducing QM's predictions, I hope you are; I've just written a short outline on John Klauders string which will assist.

Declan Traill's short essay confirms the matching code gives the CHSH >2 Cos^2 plots as well as the steering >1 closing the detector loophole. My top scored 2015 'red/green sock trick' essay started the construction (as a test of a rational SR solution). Shockingly if correct there is no 'non-locality' and QM and SR unify!

I look forward to questions.

Well done for your excellent essay anyway.

Peter Jackson

report post as inappropriate

Hi Sean and Ashmeet:

Enjoyed your well-written and enlightening essay, especially the discussion regarding the fundamental ontology of QM.

It is intriguing that while quantum theory describes the evolution of a state vector in a complex Hilbert space, I present a simple relativity based model that describes the universal physical reality as a set of relativistic mass/energy/space/time states in various frames of observer references with varying velocity V. Using this model, we can bridge the gap between quantum and relativistic ontology without the need of uncertainty and statistical nature of quantum mechanics. My model shows that the fundamental reality is relativistic and not quantum. Heisenberg’s uncertainty is shown to be an artifact of the measurement error caused by measuring a dominantly relativistic (commonly labelled as quantum, V close to C) phenomenon with dilated space-time in a classical fixed space-time.

In my paper– “What is Fundamental – Is C the Speed of Light”, I propose the missing physics of spontaneous mass-energy conversion (as observed in wave-particle behavior) that bridges QM and relativity while resolving the paradox of the missing dark energy that is revealed as the relativistic kinetic energy and the model derives a physics based mathematical equation (no more a fudge constant) for the Cosmological Constant . It also resolves the paradox of the collapse of the wave function that is explained via transition to the classical space-time from the fully dilated space-time when a measurement is made, the black hole singularity of GR eliminated via mass dilation at small R, and solution is obtained to other current inconsistencies as well as weirdness (QM) of mainstream theories as described in my book.

I would greatly appreciate your time and feedback on my paper?

Thanking you in advance,

Best Regards

Avtar Singh

report post as inappropriate

Enjoyed your well-written and enlightening essay, especially the discussion regarding the fundamental ontology of QM.

It is intriguing that while quantum theory describes the evolution of a state vector in a complex Hilbert space, I present a simple relativity based model that describes the universal physical reality as a set of relativistic mass/energy/space/time states in various frames of observer references with varying velocity V. Using this model, we can bridge the gap between quantum and relativistic ontology without the need of uncertainty and statistical nature of quantum mechanics. My model shows that the fundamental reality is relativistic and not quantum. Heisenberg’s uncertainty is shown to be an artifact of the measurement error caused by measuring a dominantly relativistic (commonly labelled as quantum, V close to C) phenomenon with dilated space-time in a classical fixed space-time.

In my paper– “What is Fundamental – Is C the Speed of Light”, I propose the missing physics of spontaneous mass-energy conversion (as observed in wave-particle behavior) that bridges QM and relativity while resolving the paradox of the missing dark energy that is revealed as the relativistic kinetic energy and the model derives a physics based mathematical equation (no more a fudge constant) for the Cosmological Constant . It also resolves the paradox of the collapse of the wave function that is explained via transition to the classical space-time from the fully dilated space-time when a measurement is made, the black hole singularity of GR eliminated via mass dilation at small R, and solution is obtained to other current inconsistencies as well as weirdness (QM) of mainstream theories as described in my book.

I would greatly appreciate your time and feedback on my paper?

Thanking you in advance,

Best Regards

Avtar Singh

report post as inappropriate

Such a great place where you play stickman games free online games completely free of cost.

report post as inappropriate

report post as inappropriate

Dear Sean

If you are looking for another essay to read and rate in the final days of the contest, will you consider mine please? I read all essays from those who comment on my page, and if I cant rate an essay highly, then I don’t rate them at all. Infact I haven’t issued a rating lower that ten. So you have nothing to lose by having me read your essay, and everything to...

view entire post

If you are looking for another essay to read and rate in the final days of the contest, will you consider mine please? I read all essays from those who comment on my page, and if I cant rate an essay highly, then I don’t rate them at all. Infact I haven’t issued a rating lower that ten. So you have nothing to lose by having me read your essay, and everything to...

view entire post

report post as inappropriate

Dean Sean and Singh,

This was very impressive. This program seems to me very difficult, but you made it look very natural and the advances are impressive. I don't believe in MWI, but I am sure that in a parallel world you convinced me :)) (just kidding!)

There's something that bothers me for some time. You said that the Hilbert space of a compact region of space is...

view entire post

This was very impressive. This program seems to me very difficult, but you made it look very natural and the advances are impressive. I don't believe in MWI, but I am sure that in a parallel world you convinced me :)) (just kidding!)

There's something that bothers me for some time. You said that the Hilbert space of a compact region of space is...

view entire post

report post as inappropriate

Everett's work was debunked many time ago, both in physical and mathematical grounds. Alternative attempts presented in the last 50 years by Graham, DeWitt, Geroch, Deuthch,... have been debunked as well.

Not only Many-Worlds isn't a valid interpretation of QM, but its proponents disagree. E.g. Deuth's Many-Worlds is not Everett's Many-Worlds. Next link contains rebuttal of early Everett...

view entire post

Not only Many-Worlds isn't a valid interpretation of QM, but its proponents disagree. E.g. Deuth's Many-Worlds is not Everett's Many-Worlds. Next link contains rebuttal of early Everett...

view entire post

report post as inappropriate

I forgot the attachment with the general spectral decomposition of the Hamiltonian

attachments: Spectral_decomposition.png

report post as inappropriate

attachments: Spectral_decomposition.png

report post as inappropriate

Login or create account to post reply or comment.