### 2019 - Dante, La Divina Commedia, Paradiso 33, 85-93

Nel suo profondo vidi che s’interna,

legato con amore in un volume,

ciò che per l’universo si squaderna:

sustanze e accidenti e lor costume

quasi conflati insieme, per tal modo

che ciò ch’i’ dico è un semplice lume.

La forma universal di questo nodo

credo ch’i’ vidi, perché più di largo,

dicendo questo, mi sento ch’i’ godo.

### 2019 - Naming

The tangle model promises to be a *complete description of motion*.
The expression in italics is preferable to the more sensational terms that
are used in other fields.
The term 'theory of everything' is reserved for unsuccessful esoteric healing attempts,
the term 'final theory' is reserved for titles of bad books and films,
and the term 'world formula' is reserved for calculating the optimal way to park a car
backwards.

### 2019 - Gravitation

Strands appear to describe gravity in a simple and intuitive way. This preprint makes the point in detail.

### 2019 - T-shirts and unification

In 1988, Leon Lederman was interviewed by the Chicago Tribune (see Google). ''My goal is to someday put it all on a T-shirt,'' Lederman said with a smile. ''The formula will be the rules that explain the building blocks of the universe, and the glue and cement that makes the big thing that we can touch, and see and smell. We physicists believe that when we write this T-shirt equation it will have an incredible symmetry. We'll say: `God, why didn't we see that in the beginning. It's so beautiful, I can't even bear to look at it.` ''

Also in 1988, John Barrow - as he confirmed in an email he sent to me - used the T-shirt
image as a wish for physics research in his 1988 Gifford Lectures at
Glasgow that were a precursor to his book *Theories of Everything: The
Quest for Ultimate Explanation* 1991.

The strand conjecture appears to realize these wishes.

### 2019 - The unsung fascination of the coupling constants

Observation: The strong coupling constant is the same for each quark type. The fine structure constant is the same for all quarks and all charged leptons. And a similar statement can be made for the weak coupling constant. Equivalently, all charges are quantized. This quantization is "perfect": no deviations from exact integer multiples are observed.

Why is this the case? There does not seem to be a discussion of this issue in the literature. This is a pity, because the observation is hard to explain. Why should an electron behave exactly like all the quarks, apart from an integer multiple? After all, they are rather different: they differ in their masses and in their structure - whatever it may be. Nevertheless, apart from an integer multiple, their couplings are observed to be independent of their structure.

The latest preprint about the strand conjecture discusses this issue - and proposes an explanation. It is unclear whether other unification attempts can explain this property.

### Early 2019 - Enjoying the beauty of the standard model of particle physics

If the tangle model is correct, the standard model results from a single fundamental principle.

If the tangle model is correct, the list of known elementary particles is complete.

If the tangle model is correct, the origin of gauge interactions and symmetries is understood.

If the tangle model is correct, the fundamental constants can be calculated.

If the tangle model is correct, also gravitation, cosmology, and empty space result from the fundamental principle.

If the tangle model is correct, the Bronshtein cube is confirmed and unification is possible.

It is fair to say that with these potential results, the tangle model has a certain charm. In addition, the tangle model agrees with observations; this turns its charm into downright seduction.

The fascination for the fundamental constants - elementary particle masses, coupling constants and mixing angles - is not shared by many. The quest to understand their origin is not always seen as a problem of fundamental physics. But if you do so, then you will enjoy the tangle model.

### 2018 - Steps

Some influential researchers complain that there is no progress in unification, despite a record number of researchers. The number of unification proposals in the literature is indeed low. The preprint with a new proposal is now available. Despite the simplicity of the fundamental principle, the explanation of the full set of Feynman diagrams is striking.

### Early 2018 - Polishing

Several particle tangles have been updated: now the tangle model reproduces all known experimental data in a consistent way. I gave a talk on the topic at the DPG meeting. A researcher encouraged a publication.### The limitations of the standard model of particle physics

High-energy physics is split in two camps. On the one side, many experimentalists and theorists find that there are no differences between the standard model and experiments. On the other side, certain physicists state that the standard model has flaws.

Behind this split of opinions is a battle for funds. If a researcher proposes a theory that does not predict any new effect, there are no funds. Theorists and experimentalists only get money for searches for something new. Thus, many researchers, to get money, tend to state that the present theory has flaws, tend to back improbable new theories, and finally find nothing.

The situation arises when people crave money. There sometimes is a gap between those seeking truth and those seeking money. So far, there is no reason and no data for stating that the standard model has flaws. It is incomplete, but it has no flaws. The wish for flaws is leading people astray. (December 2017)

### Avoiding unification - and exceptions

Not 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. (October 2017)

### On defects in space or space-time

Various 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. (2016)### On unknotted tangles

In 2014 a reader mailed me suggesting to avoid 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. (2016)

### Arxiv and research status in 2014

In 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 Bohr

It 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 entrepreneurs

Businesses 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 mistakes

Everybody 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.