The limitations of the Standard Model of particle physicsHigh-energy physics is split in two camps. Experimentalists find that there are no differences between the Standard Model and experiments. Many (but not all) theoreticians state that the Standard Model has fundamental flaws built-in. Behind this split is a battle for funds. If a theoretician proposes a theory that does not predict any new effect, there are no funds. Even experimentalists only get money for searches for something new. So many theoreticians, to get money, incorrectly state that the present theory has flaws, back improbable new theories, and then find nothing. All parties involved crave money. Nature itself is not at the forefront any more.
Avoiding unification - and exceptionsNot many candidates for unified models have appeared in the past twenty years. You can follow this lack of ideas on arxiv and on the various physics blogs around the world. Researchers seem to avoid unification. But there are exceptions: Nicolai and his group have published a proposal. It is a very "small" expansion of the standard model; it also assumes that general relativity is valid at (almost) all energies. It is a really good sign that researchers are exploring small extensions of present theories instead of big revolutions. That definitely seems the more promising way to proceed.
On defects in space or space-timeVarious quantum gravity and cosmology researchers have explored the effects of space(-time) defects on the propagation of light. For example, they explored whether such defects have effects on the sharpness of stellar images. Most scholars assume that these defects are new, so far undiscovered objects. Few of these researchers seem to have asked whether these defects could somehow be the known elementary particles. The reason for avoiding this topic is not clear.
On unknotted tanglesIn 2014 a reader mailed me suggesting avoiding knots. In 2015, an anonymous reader posted a similar comment on a blog: Christoph Schiller's strand model is not popular because it is wrong. It is not even self-consistent. Since you bring up knot-theory in your post, let's use that as an example here: many known interactions would violate basic knot theory using Schiller's assignment of "knots" to particles. For a concrete example, take a shoelace with an overhand knot and its mirror image (a W+ and a W- particle in Schiller's terms) on it and try to turn it into an unknot (photons) ... it is not possible, and this has been proven by the mathematics of knot theory. If you don't believe this, then play with the knots on the shoelace until you get an intuitive understanding of why this is impossible. These readers had a point. In the new assignments, all particles are now rational tangles; these tangles are not knotted any more and avoid the issues introduced by overhand knots and other knotted tangles.
Arxiv and research status in 2014In the years up to 2014, professional researchers have published up to 40 papers a day in hep-th and gr-qc, with a total of about 50 000 papers. Those presenting a proposal for a final, unified theory can be counted on the fingers of one hand. Clearly, the subject is delicate. Researchers and entrepreneurs share the same choice: do they work for results or do they put other aims first, such as fame, money or fun? The ancients would say: the choice is between the path of virtue on one hand, and the path of superbia, avaritia or luxuria on the other. Various signs indicate that the search for a final, unified theory is not successful because the path of virtue has been lost. On the other hand, moralizing should never be taken too seriously – but sometimes can be a guide.
A story about Niels BohrIt has been told that Niels Bohr alternated his workdays in the following manner: on one day he would write down the most crazy ideas he could image; on the next day he would check them with reality as strictly as possible. He divided his weekdays in this way, alternating between the two poles.
What researchers can learn from entrepreneursBusinesses have success only if they value their customers. In other words, business must value reality. Entrepreneurs who follow their beliefs usually lead their companies into bankruptcy. Entrepreneurs who follow reality lead their company to success. Not only teachers, also researchers can learn from business people. If you falsely believe that truth is defined by philosophers, or by ideologies, or by your wishes, take a break and stop. Truth is correspondence with facts. You can learn more about truth from a good entrepreneur than from a bad scientist. Some telling examples follow.
On correcting mistakesEverybody makes mistakes. The important thing is to correct them. The mistaken strand model prediction on the Higgs is an example. Every mistake has a good side. In the case of the mistaken Higgs prediction, the good side is especially influential.
On microscopic models of gravity
Electromagnetic fields obey indeterminacy relations - they are fuzzy. Fields are fuzzy in the same way that the positions of quantum particles are fuzzy: the obey indeterminacy relations. The fuzziness of electromagnetic fields proves that electromagnetic fields are built of many microscopic degrees of freedom. Quantum theory implies that macroscopic electrostatic fields result from a large number of elementary excitations, which are called photons. Electrostatic fields are due to the exchange of virtual photons. As a result, the electromagnetic field has entropy. Indeed, quantum physicists, in particular experts on quantum optics, know since almost a century that electromagnetic fields have entropy.
Also gravitational fields obey indeterminacy relations - they are fuzzy. These fields are fuzzy in the same way that the positions of quantum particles are fuzzy. The fuzziness of gravitational fields proves that gravitational fields are built of many microscopic degrees of freedom. Quantum theory implies that gravitational fields result from a large number of elementary excitations, called gravitons. Static gravitational fields are due to the exchange of virtual gravitons. In other words, space and gravity are made of virtual gravitons buzzing around. And as such, like any system that is made of many components buzzing around, space and gravity have entropy. If you falsely believe that gravity has no entropy, explore the issue and convince yourself - especially if you give lectures.
On the number of dimensions of spaceThe dimensionality of space is a measured quantity: it is found to be 3 in all experiments ever performed. What is the dimensionality at very small dimensions? Well, we know that there is a minimal measurable length in nature, the Planck length. At the latest at that scale, there is no way to measure dimensionality. In other words, a shortest measurable length implies that dimensionality is not defined at Planck scale. If you falsely believe that space has 4, 9, 10 or even more dimensions at Planck scale, take a break and convince yourself that such a statement contradicts every possible experimental check.
On the limitations of the standard model of particle physicsThe standard model does not explain many of its assumptions, including the gauge groups, the couplings and the particle masses. The standard model is incomplete. This point is undisputed and correct. On top of that, one finds hundreds of papers claiming that the standard model is also wrong or self-contradictory. Look at these arguments in detail. Even though these arguments have been repeated for over 30 years by thousands of people, every single one is unconvincing. In fact, every one is wrong. This might be the biggest lie of modern theoretical particle physics. So, if you believe any argument that claims that the standard model is wrong (in contrast to the various correct arguments which claim that it is incomplete) then you are victim of indoctrination and prejudice. And indoctrination prevents from reaching the final theory.
On supersymmetryA well-known researcher claims that supersymmetry is "predicted by experiment". Another, wiser researcher sighed: "Supersymmetry is the only game in town." One Nobel Prize winner repeats in every interview that supersymmetry will be found soon, probably at the LHC. Another Nobel Prize winner consistently repeats that supersymmetry is a "figment of human imagination." Who is right? Supersymmetry relates different particle statistics: fermions and bosons. At the Planck scale, due to the measurement uncertainties induced by quantum gravity effects, particle statistics is not measurable; in short, fermions and bosons are undefined at the Planck scale. As a consequence, supersymmetry is not valid at the Planck scale. Supersymmetry is a point symmetry. At the Planck scale, due to the measurement uncertainties induced by quantum gravity effects, points do not exist. Again, as a consequence, supersymmetry and fermionic coordinates do not exist at the Planck scale. If you falsely believe that supersymmetry and fermionic coordinates exist, take a break and convince yourself that such a statement contradicts every possible experimental check.
On being daring - IIAlmost all researchers are state employees, or in similar contractual situations. As a result, they are discouraged to take risks or to be daring. The same is true for reviewers. How can reviewers that are encouraged to play safe during all their life promote daring research? However, finding the final theory requires to take risks and to be daring. Let us see where this contradiction will lead to.
On being daring"Deru kui wa utareru" - the stake that sticks out will be hammered - is a Japanese saying about what happens when someone sticks his neck out. Lots of people think that they are entitled to hammer. Such impolite people are driven by a mixture of misguided ideology and attraction to violence. Every entrepreneur knows such stories. Every entrepreneur knows that one condition for innovation is a climate without fear. The discussion of the merits and demerits of string theory has shown that such a climate does not exist in many research institutes. As a result of this situation, searching for the final theory is avoided by many. Don't do the same! Cultivate your curiosity and courage - they make you human.
On the rarity of courageBibliographic research, using the "web of science" or "google scholar", shows something astonishing. There are only a handful of papers - besides the superstring conjecture - that claim to propose a "final theory" or a "theory of everything". And this during the last one hundred years! This shows how touchy the issue has become. There is a definite lack of courage in present researchers.
On the lack of courage of committees - IIThere is an organization that only supports research towards the final theory. It has funded over hundred research projects. How many of the projects it has funded are proposals for a final theory? You will not believe it: just one. Over 99% of the money is wasted. If you ever want to support the search for a final theory, think about what you are doing.
On the lack of courage and vision of committeesThere are many cash prizes offered for the solution of various outstanding famous physics or math problems. Did you know that there is not a single cash prize in the whole world for finding the final theory? Do a Google search to convince yourself of how much committees shy away from this topic.
On saying what nobody says - on the limitation of symmetries and on 137The search for a final theory of physics is often said to follow from the search for the final symmetry of nature. In fact, past research makes the opposite point. All symmetries known in physics fail to fix the coupling strengths and the particle masses. But explaining the coupling strengths, such as the famous fine structure constant 1/137.036, and explaining the particle masses are the main open point in physics! Knowing that a body has spherical symmetry does not determine its radius. Therefore, anybody who looks for larger symmetries is blocking himself from understanding the fine structure constant and all the other open points in fundamental physics.
On saying what nobody says - on the lack of larger symmetriesThe search for a final theory of physics is often said to follow from the search for the final, all-encompassing symmetry of nature. Not only is the connection wrong; worse, there is not the slightest evidence that any unknown symmetry exists in nature. No experiment has ever provided an argument that symmetries larger than the known ones exist. In other words, anybody who looks for larger symmetries is putting aside the connection to experiment.
On thinking what nobody thinks - on the requirements for a final theoryThe search for a final theory of physics is almost a hundred years old. Despite the effort, there does not seem to be, anywhere in the research literature, a list of requirements that the final theory has to fulfil. The lack of such a canonical list, and even the lack of proposed lists, is a sign for how much researchers forbid themselves to think clearly. Research articles and even physics textbooks are full of another list: the list of issues that are unexplained by both quantum field theory and general relativity. But a list of requirements for the final theory is found nowhere! This lack is a clear sign that many physics researchers are in a mental blockade. (Every researcher can test himself on this point.) The lack of a generally discussed requirement list is a bizarre lacune of modern theoretical physics. The sixth volume of the Motion Mountain text proposes such a requirement list in chapter 7; see also a summary of this list here. If you are a researcher in fundamental physics and have never put together a list of requirements that the final theory has to fulfil, your research has most probably been driven by personal preferences or prejudices, and not by the desire to really find out. But do not publish your list: you will get into trouble - even if it is correct.
On thinking what nobody thinks - on the final theoryThe first half of the sixth volume deduces the requirements for a final theory. They all appear when quantum physics and general relativity are combined. No requirement follows from one theory alone. In fact, as a result of unification, each requirement for the final theory contradicts both quantum physics and general relativity! In other words, researchers searching for a final theory are in a tough situation. It is hard to break loose, and if they do, they are treated with scorn by their peers. The easy way out is to search for unification by remaining in your own research field (either particle physics or general relativity). This approach ensures that at least half the researchers are not against you. But the easy approach is also the wrong one. The correct approach is not the easy one: the correct approach requires to contradict all researchers. In other words, anybody who searches for unification but at the same time wants to appease some present group of researchers is doomed.
On simple mathematics and the final theorySince the final theory is not based on points and manifolds, the evolution of observables is not described by differential equations. This implies, among others, that the final theory is not described by complicated mathematics. This conclusion is one of the hardest to swallow for most modern physicists. Physicists are used to think that progress in physics has always been tied to progress in mathematics. This is an old prejudice, but it is wrong. Progress never has been tied to math in this way. In fact, the idea that the final theory is simple, i.e., algebraic, is at least 50 years old. In other words, if you think that the final theory requires the most complex mathematical concepts available, reconsider the reasons for your prejudice.
On being trapped by one's own prejudicesA well-known researcher on the final theory stresses in every talk that the final theory must get rid of the concepts of point and manifold. But his own proposal is based on these two concepts! Update: there at least three internationally known researchers living with this contradiction. If you are working on the theory of everything, be aware of such traps.
Theory and experimentThe value of a theory is decided by its correspondence with experiment. So far, no experiment yet found a deviation from the standard model of particle physics. This is precisely what is predicted by the strand model, the approach presented in volume VI of the Motion Mountain Physics Text. All other approaches to the final theory predict deviations; so do many researchers in particle physics. Stay tuned.
* * *