A Universe Programmed with Strings of Qubits by Philip Gibbs

Dear Sir,

Your article is based on "sound mathematics" and "string theory".

Regarding mathematics, the concepts and conventions of physicists and mathematicians differ. The validity of a mathematical statement is judged from its logical consistency. The validity of a physical statement is judged from its correspondence to reality. Most of the mathematics of modern physicists are not mathematical by the above yard stick. How do you define "sound mathematics"?

String theory, which was developed with a view to harmonize General Relativity with Quantum theory, is said to be a high order theory where other models, such as supergravity and quantum gravity appear as approximations. String theory comes in five different formulations, each of which covers a restricted range of situations. A network of mathematical connections links the different string theories into one overarching system, enigmatically called M-theory. Unlike super-gravity, string theory is said to be a consistent and well-defined theory of quantum gravity, and therefore calculating the value of the cosmological constant from it should, at least in principle, be possible. On the other hand, the number of vacuum states associated with it seems to be quite large, and none of these features three large spatial dimensions, broken super-symmetry, and a small cosmological constant. The features of string theory which are at least potentially testable - such as the existence of super-symmetry and cosmic strings - are not specific to string theory. In addition, the features that are specific to string theory - the existence of strings - either do not lead to precise predictions or lead to predictions that are impossible to test with current levels of technology. With its talk of D-branes, 10 or 11 dimensional universes and a myriad of possible solutions: 10500 at the last count - string theory looks more like an arcane branch of mathematics than tangible physics. It has not told us anything new about the real world, despite almost 40 years of trying.

There are many unexplained questions relating to the strings. For example, given the measurement problem of quantum mechanics, what happens when a string is measured? Does the uncertainty principle apply to the whole string? Or does it apply only to some section of the string being measured? Does string theory modify the uncertainty principle? If we measure its position, do we get only the average position of the string? If the position of a string is measured with arbitrarily high accuracy, what happens to the momentum of the string? Does the momentum become undefined as opposed to simply unknown? What about the location of an end-point? If the measurement returns an end-point, then which end-point? Does the measurement return the position of some point along the string? (The string is said to be a Two dimensional object extended in space. Hence its position cannot be described by a finite set of numbers and thus, cannot be described by a finite set of measurements.) How do the Bell's inequalities apply to string theory? We must get answers to these questions first before we probe more and spend (waste!) more money in such research. These questions should not be put under the carpet as inconvenient or on the ground that some day we will find the answers. That someday has been a very long period indeed!

The LHC experiment that was designed to verify the validity of the Standard Model has failed to prove the existence of Higgs boson. This means the Standard Model remains a postulate only. Now there is a proposal to upgrade the facility and run it for one more year. How long a few people make merry at public expenses on false premises?

basudeba, thank you for so many good questions. I will try to answer them in several different posts

"How do you define "sound mathematics"?"

A physicist needs a consistent formalism for calculating physical quantities such as scattering amplitudes or particle masses. It has always been in the nature of quantum field theory that not everything is as well defined as mathematicians would like them to be. The "Mass Gap Problem" is an attempt to encourage mathematicians to make the subject more rigorous. In string theory all the same problems of mathematical rigour remain. String theory is not any different from quantum field theory in this respect.

Despite this there is some sound mathematics in string theory. An example which demonstrates this is the application of string theory to the moonshine conjectures by Borcherds. There are other rigorous applications of string theory to mathematical problems, so I'd say that the maths is sound.

It remains a fundamental problem to find a complete non-perturbative formulation of string theory. Given what has been achieved it would be very surprising if such a formulation does not exist, but it is very hard to find. Mathematics needs to catch up with what physicists are doing and I think this is part of the reason why it is taking so long for string theory to flourish into a complete theory for quantum gravity.

Hi all,

Dear Basudeba,

It's relevant your words, indeed the maths must be harmonized with the biggest rationality when they want explain correctly our foundamental and physical laws.It exists constants, irreversibilities, and irreducibilities.Fortunally for our evolution.

The strings are falses in the whole simply.

A string is divisible, a sphere no ......when we see the equilibrium of forces.

Regards

Steve

basudeba says

"[string theory] has not told us anything new about the real world, despite almost 40 years of trying."

Your summary of string theory is quite accurate and it is true that it has not yet told us anything new about physics. Yet there has been much progress and your outlook is too pessimistic. 40 years ago (1970) string theory was regarded as a tentative theory for the strong force. It developed into a theory of quantum gravity in the 1980's. In the 1990's string theorists discovered M-theory which appears to unify the different string theories. More recently we have seen developments such as AdS/CFT and many smaller steps.

I think it is true that progress has been slow, but work has always been ongoing. Some people might compare it with the development of relativity or quantum theory which progressed in steps over similar time periods. The main difference is that string theory has developed without any new experimental input beyond what was known when it started.

I don't think that this is a failure of string theory as some people claim. The reasons why string theory has not been able to predict low energy physics are well known and as you describe them. String theory is a theory of quantum gravity that is applicable to energies well beyond anything we can test directly at present. The fact that it has many vacua means that we cannot use it to predict physics at lower energy. Some people don't like that but the history of discovery in the laws of physics has demonstrated many times over that the universe does not care much for our philosophical prejudices. A lot of people did not like the theory of relativity, and even more don't like the indeterminacy of quantum theory, but they agree very well with experiment.

Personally I am quite comfortable with the idea that our universe is described by some random vacuum of string theory which may be selected on anthropic grounds. I did not want it to be that way, but if physics tells us that the universe works like that then I can learn to appreciate it. This does not mean that string theory will never make a prediction. When we know more about physics beyond the standard model we may be able to figure out the details of the selected vacuum. Even if we can't we may be able to put some testable constraints on it. Even if we cant do that we may be able to find some other testable prediction from string theory such as a signature from the big bang. Even if we cant do that it does not mean that string theory is wrong, just that it is terribly difficult to relate to observation.

The way we have understood string theory over the 40 years has changed dramatically every ten years or so. We still don't have the ideal formulation that string theorists seek so we may see it very differently in 10 years time. I don't think it has a sell by date after which it has failed. It will fail only if it is shown to be inconsistent with observation or if another theory is found to work better. At this time many of the best theoretical physicists still think string theory is the best approach to quantum gravity. I tend to agree. It may take a few more years for the mathematics to develop sufficiently for us to really understand it well enough to see why it is right. Then it will tell us something about the real world. In the meantime, physicists are free to explore any alternatives they can think of, but none have come as near to a theory of quantum gravity as string theory.

basudeba says

"There are many unexplained questions relating to the strings. For example, given the measurement problem of quantum mechanics, what happens when a string is measured?"

The questions you ask there are not ones that I think are especially troubling for string theorists. There are plenty of people who worry about measurement problems in general but personally I don't think this will be resolved by a theory of quantum gravity, only a few people do. The EPR "paradox" has been shown by experiment to be a feature of the laws of physics. I think people just have to reconcile it with their philosophical views. That is something I did for myself many years ago.

basudeba says

"The LHC experiment that was designed to verify the validity of the Standard Model has failed to prove the existence of Higgs boson. This means the Standard Model remains a postulate only."

The real hope is that the LHC will tell us what lies beyond the standard model. So far it has just collected a small amount of data as a by-product of the commissioning process that took place this year. Next year it will do much more physics and may provide some new positive results. At some point in the next few years it will resolve the Higgs Sector and however it turns out that will be a successful achievement.

If anything, the standard model has been too successful and physicists are keen to find something that shows it is not perfect. For the last 40 years almost every experimental result has just served to confirm that it works very well. The next few years of the LHC could finally lead to something new.

The standard model just needs an improvement of optimization due to evolution.

Our laws, proportionalities rest in a relativistic rationality.

The strings are lost in an ocean of confusions.

Furthermore it doesn't exist equations interpreting the physics with strings.

It's a kind of fashion which disappears in fact.Logic because they aren't foundamentals these strings simply.

So many hours utilized for nothing in fact.

Cheers.

Steve

The standard model requires more than just some evolutionary optimisation. The final outcome must include gravity, but gravity is built into physics in a way that is very different from the forces unified in the standard model. To include gravity you need a revolutionary development. String theory is the best indication that we are intellectually capable of bringing it about.

Your paper is remarkably similar to mine. I work out some of the Q-bit theory along the lines of Duff et al.. I work on duality with AdS spacetimes, similar to the case of a BTZ black hole in an AdS_3. The event horizon contains the same holographic information as does the AdS boundary. So the entanglement types ~ black hole types by the Kostant-Sekiguchi correspondence holds for the AdS spacetime, and Dp-branes.

From G_abcdψ^aψ^bψ^c = 0 and for M^{ab} = G^{abcd} ψ^bψ^c the elliptic curve is defined from the hyperdeterminant

y^2 = det(M)

This will be modular of course due to the A. Wiles proof of the Tanayama-Shimira conjecture. An explicit realization of this modularity comes from the equivalency with the AdS_n, and in particular with the near horizon condition AdS_{n+2} - -> AdS_2xS^n, which is conformal QM SL(2,R). This is the modular group, or its discrete subgroup SL(2,Z) defines the braid group.

Certain orbits of modular functions are identified with the Riemann ζ-function. My paper makes connections with discrete path integrals, and it is my suspicion that this may connect with general ζ-function realizations.

Cheers LC

String theory is not without a few indicators. In solid state physics aspects of string theory and even AdS~CFT have been detected and found. Dp-branes are analogous to Fermi surfaces and in condensed matter some stringy analogues have been discovered. Also the matter of extra-large dimensions indicates that BPS-type black holes at low energy may exist if Calabi-Yau compactification scales in a T-dual manner with momentum. So we may get some experimental signatures of this physics in the next 10-15 years.

The anthropic principle, or weak AP, has been around for a long time. Bethe employed it to explore the nuclear force as a source of solar energy. The AP indicated the world or Earth had been around for 100's of millions of years by geology and evolution. So physics had to accommodate that. We have a more subtle form of this with landscape issues. There really is not that surprising about this. I tend to think there is a more general extremization of local complexity principle. The foundations of physics must be configured in some way as to give rise to a maximal complexity in a local region and with a given scale. We happen to be in such a location.

The AP also has a ying-yang element to it as well. We humans are also 7 billion ground apes exponentially rampaging out of control, consuming everything and making garbage.

Cheers LC

Never!

The strings are garbages and just a fashion of some universities.A pure joke.

The standard model I insist is foundamental and the gravity is explained with the spinning entanglement and its pure finite number.the sense of rot and the volumes of entanglement.

If strings are the best way, thus of course me I am the queen of england.

The strings aren't foundamental, and its extrapolations are just winds in the whole.

The gravity is the same than all and is the coded system and thus it's the sense of rotation which becomes the key.Thus and it's very important, the codes is intrinsic in these mass(EVOLVING)

Where are the strings in all our proportionalities?answer anywhere.

The standard model respects a precise road.It is like improving the foundamentals towards the Planck scale.But for all that a real form , balanced is necessary.if not it's a joke for our proportionalities and constants.

In fact frankly I don't understand why people focus on these strings.

And don't say me that higgs exist please, these external causes of mass.The gravity possesses the codes of evolution and the rotation imply the specificities.Where are these strings in our proportionalities even our fields and the entropy at this scale.

Regards

Steve

No I have not posted it yet. I might send it to you first and see initially what you think. I intend to post it early next week.

The thought occurred to me that the quantum computer technology might get its start through quantum gravity and SUGRA string theory. I must confess I question whether I would want to live in an age where quantum computers are ubiquitous. Things are pretty fast paced already, and a quantum computer world would make the pace of life now look like a Sunday afternoon nap.

Cheers LC

Phil, it's not String Theory! Your appreciation of hyperdeterminants is wonderful, and quite relevant to M Theory, but you have to give up the idea that traditional stringy physics is correct.

Phil, I enjoyed reading your very lucid essay, although the technical bits about String Theory were beyond me. Your relating a possible basic structure of nature to Information Theory and to qubits was inspiring. The Fermi photon findings are new to me and I will have to study why it is believed they disprove a basic granularity in space-time if I understand the argument correctly. Could that be (to use your words) "a product of years of education which brainwashes us" about something basic which turns out not to be so basic? In any case, don't qubits need to be embodied in an 'it' ? This recalls the well-worn arguments about how e/m waves need an ether to propagate in! String Theorists as a group have been criticized as being close-minded, but I found your approach the opposite, as you thoughtfully examined in turn various topics related to the theme of this essay .

It is better to say that spacetime is embedded in the Qubits. A quantum wave function exists in configuration space. Configuration space is the standard position coordinate space. So a wave function with many eigenstates has many copies of this configuration space. The configuration space has a cotangent bundle T*M which consists of the coordinates and their conjugate momentum. This then defines a symplectic structure. Every cotangent bundle is a symplectic space, but not every symplectic space is a T*M. So symplectic structure is more fundamental than coordinates or momentum.

So the entanglement structure corresponding to a black hole type contains many copies of the configuration space. In fact this has to be, for the correspondence is a real to complex valued relationship. So the wave function, or equivalently quantum bits, is what construct spacetime.

LC

Steve, I think our views on particle physics are so far apart that I could not find any common ground, but thanks for your comments all the same.

I think it is all part of a bigger picture. Your QI work is still very interesting to me even if you don't see it going in the same direction.

Vladinir, yes we all spend many years in education and almost everything we learn is correct, so it is easy to put too much faith in the formalisms and extrapolate them to new areas as if things have to work the same way. To do fundamental physics it is important to have a good feel for why we believe in certain things. If it is because mathematical logic or experiment confirms that they are right, then that's fine. If it is just because we have grown used to the formalism then we need to question if it is the right way to go forward.

I think the choice between continuous and discrete mathematics in theories of quantum gravity is a good example. Classical physics gets us used to working with continuous functions and it is only when we do quantum physics that some discrete theory comes in. Even then the formalism is usually portrayed as continuous with discrete aspects arising from solutions to differential equations of bound systems. People who have come through a physics education tend to favour continuous formalisms because that is what they have always used

Some people who are less steeped in physics as their education take the opposite view and think that things have to be discrete ultimately because infinities are illogical. That is not really correct either. There is nothing logically wrong with continuous mathematics or infinity.

I don't know whether the laws of physics will ultimately be expressed using continuous or discrete mathematics but aspects of both seem to be important at our current level of understanding so it is important to keep an open mind.

The Fermi findings which rule out some discrete theories are an important clue that must be taken into account, but so is the holographic principle which seems to point in the direction of discrete bits. We have to find a way to incorporate all the indicators we get.

I don't think that string theorists as a group are close-minded. I don't personally fit the profile of a typical string theorist, but I have talked with some and read the work of others. They all seem willing to consider new ideas. They are just unwilling to look at alternatives to string theory that seem less promising.

There are some powerful arguments that string theory is the right road to quantum gravity. There must be some logically consistent description of the interaction between particles and gravity in the limit of weak fields and almost flat spacetimes. Perturbative string theory is the only solution we have for that. It's not a watertight argument, but until someone provides an alternative that achieves the same thing I think we will see people continuing to do string theory.

Personally I do like to look at the alternatives even if they do not succeed where string theory does. You have to understand the failures to know how to succeed. Loop Quantum Gravity does not work at a perturbative level but it provides some pointers about the kind of mathematics that applies to non-perturbative gravity and its origins are close to those of string theory. Its offshoots such as spin foams, group field theory, quantum graphity etc have some nice mathematics that may be clues about how to formulate string theory non-perturbatively. I find it more sad that people working on these things reject string theory than that string theorists reject the alternatives. Everybody seems to work in a very narrow band of ideas. Instead they need to stand back and take in the big picture, think about what works and what does not work in different approaches, then consider how lessons learnt can be brought together.

You should use the equation feature for your latex

[math]G_abcd\psi^a\psi^b\psi^c = 0[/math]

[math]M^{ab} = G^{abcd} \psi^b\psi^c[/math]

etc.