The state of physics

One of the quirky things about me is that I don’t believe things I don’t understand. As a result of that, I’ve had a long turbulent relationship with the notion of black holes. See the thing is, for the longest time, I couldn’t understand how an event horizon can form if the time becomes frozen when the infalling matter approaches the point where the event horizon should form.

While I was grappling with this existential aspect of black holes, the rest of the world happily proceeded to invent wormholes, Hawking radiation, singularities, and eventually the information paradox. Together with event horizons, none of these ideas have entered the realm of establish scientific fact, which requires observational confirmation.

Eventually, I read somewhere that the reason an event horizon can form even though the time becomes frozen is because the location for the event horizon with and without this additional matter implies that the matter would past the point where a new event horizon would form in finite time. So, now I understand it and I believe that event horizons can form. But we are not done yet. What about the interior beyond the event horizon? It is still frozen in time. Where does the singularity come from? I still don’t believe that part, perhaps because I still don’t fully understand it.

In all this, the importance of the scientific method should be emphasized. Even if I don’t understand something, I would believe it if it has been observed. While event horizons may be difficult to observe directly, the singularity inside the black hole is completely impossible to observe. For that reason, it can never be part of our scientific understanding.

This year, the Nobel committee announced that the Nobel prize is award for work on black holes. Half of it goes to two people that inferred the existence of a massive black hole at the centre of the milky way galaxy based on the orbits of stars close to the centre. This work is based on scientific observation and therefore satisfies the requirements imposed by the scientific method.

The other half of the Nobel prize is awarded to Sir Roger Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity.” If I understand correctly, the award is based on the Penrose–Hawking singularity theorems. (Hawking did not share the Nobel prize because he passed away.) So what is meant by “a robust prediction” here?

Sir Roger Penrose

Sir Roger Penrose is a formidable person. During his lifetime, he has produced a remarkable collection of ideas that range over diverse fields. The originality and complexity of these ideas give evidence to Penrose’s uniquely creative intellect. However, these ideas are of a mathematical nature and they show very clearly that Penrose is primarily a mathematician. Many of these ideas have never been confirmed by scientific observations. This lack of scientific confirmation includes the work on singularities in black holes for obvious reasons explained above.

It now brings me to the question, why would the Nobel committee decide to award a prize for “a robust prediction,” instead of something that has been confirmed in a scientific manner? The answer is probably related to the current state of physics. If we look at the work that was awarded recent Nobel prizes in physics, one can see that there must a problem. The problem is that progress in fundamental physics is slowing down or has come to a complete stop. There simply is nothing else to be awarded a physics Nobel prize anymore.

This image has an empty alt attribute; its file name is 1C7DB1746CFC72286DF097344AF23BD2.png

What is your aim?

The endless debate about where fundamental physics should be going, proceeds unabated. As can be expected, this soul searching exercise includes many discussions of a philosophical nature. The ideas of Popper and Kuhn are reassessed for the gazillionth time. Where is all this leading us?

The one thing I often identify in these discussions is the narrow-minded view people have of the diversity of humanity. Philosophers and physicists alike, come up with all sorts of ways to describe what science is supposed to be and what methodologies are supposed to be followed. However, they miss the fact that none of these “extremely good ideas” have any reasonable probability to be successful in the long run.

Why am I so pessimistic? Because humanity has the ability to corrupt almost anything that you can come up with. Those structures and systems that exist in our cultures that actual do work are not the result of some “bright individuals” that decided on some sunny day to suck some good ideas out of their thumbs. No, these structures have evolved into the forms that they have today over a long time. They work because they have been tested over generations by people trying to corrupt them with the devious ideas. (It reminds me that cultural anthropology is, according to me, one of the most underrated fields of study. The scientific knowledge of how cultures evolve would help many governments to make better decisions.)

The scientific method is one such cultural system that has evolved over many centuries. The remarkable scientific and technological knowledge that we posses today stand as clear evidence of the robustness of this method. There is not much, if anything, to be improved in this system.

However, we do need to understand that one cannot obtain all possible knowledge with the scientific method. It does have limitations, but these limitations are not failing of the method that can be improved on. These limitations lie in the nature of knowledge itself. The simple fact is that there are things that we cannot know with any scientific certainty.

What is your reward?

So, the current problem in fundamental science is not something that can be overcome by “improving” the scientific method. The problem lies elsewhere. According to my understanding, this problem has one of two possible reasons, which I have discussed previously. It is either because people have lost their true curiosity in favor of vanity. Or it is because our knowledge is running into a wall that cannot be penetrated by the scientific method.

While the latter has no solution, the former may be overcome if people realize that a return to curiosity instead of vanity as the driving force behind scientific research may help to adjust their focus to achieve progress. Short term extravagant research results do not always provide the path to more knowledge. It is mainly designed to increase some individual’s impact with the aim to obtain fame and glory. The road to true knowledge may sometimes lead through mundane avenues that seem boring to the general public. Only the truly passionate researcher with no interest in fame and glory would follow that avenue. However, it may perhaps be what is needed to make the breakthrough that would advance fundamental physics.

This image has an empty alt attribute; its file name is 1C7DB1746CFC72286DF097344AF23BD2.png

Transcending the impasse, part VII

Vanity in physics

In this penultimate posting in the series on transcending the impasse in fundamental physics, I’ll address an issue that I consider to be one of the major reasons for the impasse, if the main reason. It is a topic that I feel very passionate about and one that I’ve written about in my book. It is a very broad topic with various aspects that can be addressed. So, I can see this topic becoming a spin-off series on its own.

Stating it briefly, without ranting too much, one can bring this issue into the context of the scientific method itself. As remarkable as the scientific method is with all the successes associated with it, if the very foundation on which it is based starts to erode, the whole edifice in all its glory will come tumbling down.

Now what is this foundation of the scientific method that could be eroded away? Well, the scientific method shares the property with capitalism and democracy in that it is a self-regulating feedback system. Each of these mechanisms is based on a property, a driving force, found in human nature that makes it work. For democracy, it is the reaction to the conditions one finds oneself in as provided by the authorities. For capitalism, it is basically greed and the need for material possessions. For the scientific method it is curiosity and need for knowledge and understanding.

So, the basic assumption is that those that are involved in the scientific process, the scientists, are driven by their curiosity. It has to a large extent been the case for centuries, and we have the accumulated scientific knowledge obtain through this process thanks to this curiosity.

However, during the past century, things started to change. It some point, due to some key event or perhaps as a result of various minor events, the fundamental driving force for scientists started to change. Instead of being internally motivated by their curiosity, they became externally motivated by … vanity!

Today, one gets the impression that researchers are far more concerned about egos than the knowledge they create. To support this statement, I can provide numerous examples. But instead of doing that, I’ll focus on only aspect: how this vanity issue impacts and causes the current impasse. Perhaps I’ll provide and discuss those examples in followup posts.

In the aftermath of the disappointing lack of results from the Large Hadron Collider (LHC), some people blamed other prominent researchers for their ludicrously exotic proposals and predictions. None of which survived the observations of the LHC.

Why would highly respected physicists make such ludicrous predictions? The way I see it, is as a gamble with high stakes. Chances were that these predictions would not have panned out. But if one of them did receive confirmation from the LHC, the return on investment would have been extremely high. The person that made the prediction would have become extremely famous not only among physicists, but probably also among the general public. It would probably have ensured that the person receives a Nobel prize. Hence, all the needs for vanity would have been satisfied instantly.

What about knowledge? Surely, if the prediction turned out to be correct, then it must imply a significant increase in our knowledge. True, but now one should look at the reality. None of these exotic predictions succeeded. This situation is not really surprising, probably not even to the people that made these predictions, because they probably knew the probability for their success to be extremely low. In that context, the motivation for making the predictions was never about the increase in knowledge. It was purely aimed at vanity.

An extreme example is this one physicists, who shall remain unnamed. He is known for making random predictions at a remarkable rate. It is obvious to everybody that he is not making these predictions because he expects them to work out. It is simply an attempt to be the first to have made a specific prediction in the off-chance that one of them came true. Then he’ll probably hope to receive all the vanity rewards that he so desperately craves.

It might have been amusing, were it not for the fact that this deplorable situation is adversely affecting progress in physics, and probably in science in general, albeit I don’t have such extensive experience in other fields of science. The observable effect in fundamental physics is a significant slowdown in progress that is stretching over several decades.

This image has an empty alt attribute; its file name is 1C7DB1746CFC72286DF097344AF23BD2.png

Transcending the impasse, part V

Beauty as a guiding principle

Proceeding with the series on Transcending the impasse in fundamental physics, I like to address some of the issues that has been proposed as reasons for the current impasse. One such issue is the methods by which theorists come up with their theories in fundamental physics. Sabine Hossenfelder, for example, feels strongly that one should not use beauty in the mathematics as a guide to what could be a potential theoretical explanation for fundamental phenomena.

What am I talking about? Perhaps the idea that beauty can have anything to do with fundamental physics sounds ridiculous anyway. Well, beauty, as they say lies in the eyes of the beholder. To a theoretical physicist, the notion of beauty may refer to a different experience than to an artist or a lover. Potential salient aspects of the concept of beauty that would be relevant for all those that experience beauty may include things like symmetry, balance, consistency, etc.

However, it is not my intention here to philosophize about beauty and what it is. The fact of the matter is that physicist do sometimes use their notion of beauty to guide them in how they construct their theories, or in what they consider to be the correct theory. One example that springs to mind is the relativistic equation of the electron of Paul Dirac. It is said that Dirac was guided in its derivation by the beauty in the mathematics.

Paul Dirac, who apparently used beauty as a guide to derive the relativistic electron equation

The issue of whether one should use beauty, or for that matter anything else, as a guide in the construction of fundamental theories reveals a deeper issue at stake here. First, we need to identify a difference between fundamental theoretical physics and other fields of physics. I hasten to add that this is not to be interpreted as a distinction between what is inferior and what is superior.

Other fields of physics usually have some underlying scientifically established physical theory in terms of which investigations are (or can be) done. For example, in classical optics, the fundamental theory is electromagnetism. If all else fails, one can always start with electromagnetism and derive the theoretical description of a phenomena rigorously from Maxwell’s equations for electromagnetism. If the phenomenon includes quantum effects, one may need to fall back on quantum electrodynamics (QED) for this purpose.

In fundamental physics, one does not have this commodity. In most cases one can be lucky to have some experimental results to work with. Sometimes, the only guide is a nagging feeling that the current theories are not adequate. This is the case with quantum gravity. There are some conceptual arguments why general relativity cannot explain everything, but there are no experimental observations showing that something is missing.

How does one approach such a problem? One needs some form of inspiration. Different people tend to use different forms of inspiration. Some use the beauty in mathematics as their inspiration. Perhaps too many theorists have done that and ended up with unsuccessful theories. Hence, the reaction against it.

The point is, we need to remember what it takes to arrive at a scientifically established physical theory. Regardless of what method or form of inspiration or guiding principle one uses, the resulting theory can only become a scientific theory once it has survived experimental testing. In other words, the theory must be able to make predictions that can then be compared with actually observations and then be shown to agree with such observations.

So, in the end, whatever method theorists use to produce their theories is of no consequence, as long as it can succeed as a scientific theory. To put restrictions on the guiding principles, be it beauty or whatever else, makes no sense. Instead, one should allow the diversity of perspectives and freedom in thought to come up with potential theoretical explanations, and leave it to the rigors of the scientific method to sort out the successful theoretical descriptions from those that are to be discarded.

I do not believe that the use of beauty as a guiding principle is responsible for the current impasse in fundamental physics. That dubious honor belongs to a much more inimical phenomenon. But that is a topic for another day.

This image has an empty alt attribute; its file name is 1C7DB1746CFC72286DF097344AF23BD2.png

Transcending the impasse, part III

Many-worlds interpretation

In my series on the impasse in physics and how to transcend it, I previously discussed the issue of classical vs quantum physics. Here, I want to talk about the interpretations of quantum mechanics.

There is much activity and debate on these interpretations. Part of it is related to the measurement problem. Is there such a thing as quantum collapse? How does it work?

David Mermin once said in an article in Physics Today that new interpretations are added every year and none has ever been ruled out. If this is true, then it indicates that the interpretations of quantum mechanics is not part of science, and therefore also not part of physics.

I am not going to say one should not work on such interpretations and try to make sense of what is going on, but the scientific method does not seem to help us here. Perhaps people will eventually come up with experiments to determine how nature works. I’ve seen some proposals, but they are usually associated with some new mechanisms, which in my view are unlikely to be correct.

It occurs to me that while we cannot say which of the interpretations are correct, we may just as well just pick one and work with that. So I pick the simplest one and when I want to figure out how things will work out in one of these experiments, then I can just consider how things will work according to this interpretation. If such a prediction turns out to be wrong, it would show that this interpretation (and all those that made the same prediction) is wrong after all.

The simplest interpretation according to me is the many-world interpretation. It is simple because it does not require the weird unexplained notion of quantum collapse. People don’t like it, because it seems to require such a lot of different worlds. For that reason it is also associated with the idea of a multiverse.

Hugh Everett III, the person that invented the many-worlds interpretation

Well no, those ideas are anyway misleading. In quantum mechanics, all interactions are described by unitary evolution. The picture that it represents is that there is a set of states that the universe can take on. One can think of each such state as a different description of the world. Hence “many worlds.” However, the actual state of the universe is a quantum superposition of all the possible worlds. In the superposition each world is associated with a complex probability amplitude. It means that some worlds are more likely than others. During interactions these probability amplitudes change.

That is the whole idea of unitary evolution. All the possibilities are already present right from the start. The only thing that interactions do is to change the probability amplitudes that are associated with the different worlds. During the evolution in time the different worlds in the superposition can experience constructive or destructive interference, which would change their probability amplitudes, making some less or more likely that they were before.

The number of worlds (number of terms in the superposition) stays the same. They don’t increase as a result of interactions. How many such worlds are there? Well, if we look at the properties of the set of such basis states, then it is often assumed to be a countable infinite number. However, it may turn out to be uncountably infinite, having what is called the cardinality of the continuum.

What is more is that these different worlds are not distinct unique worlds. One can redefine the basis set of worlds by forming different superpositions of the worlds in the original set to get a new set in which the worlds now look different.

How does all this relate to what we see? The dynamics of the universe causes the interferences due to the unitary evolution to favor a small set of worlds that look very similar. This coherence in what the world looks like is a result of the constructive interference produced by the dynamics.

So the world that we see at a macroscopic level is not just one of these worlds. It is, in a sense, a conglomeration of all those worlds with large probability amplitudes. However, the differences among all these worlds are so small that we cannot notice it at a macroscopic level.

OK, not everything I said here can be confirmed in a scientific way. I cannot even proof that the many-worlds interpretation is correct. However, by thinking of it in this way, one can at least get some idea of it that makes sense.

This image has an empty alt attribute; its file name is 1C7DB1746CFC72286DF097344AF23BD2.png