Thursday, February 7, 2019

Why there won't be warp travel in times of global crises

One of the questions I get most often at outreach events is: "What is about warp travel?", or some other wording for faster-than-light travel. Something, which makes interstellar travel possible, or at least viable.

Well, the first thing I can say is that there is nothing which excludes it. Of course, within our well established theories of the world it is not possible. Neither the standard model of particle physics, nor general relativity, when constrained to the matter we know of, allows it. Thus, whatever describes warp travel, it needs to be a theory, which encompasses and enlarges what we know. Can a quantized combination of general relativity and particle physics do this? Perhaps, perhaps not. Many people think about it really hard. Mostly, we run afoul of causality when trying.

But these are theoretical ideas. And even if some clever team comes up with a theory which allows warp travel, this does not say that this theory is actually realized in nature. Just because we can make it mathematical consistent does not guarantee that it is realized. In fact, we have many, many more mathematical consistent theories than are realized in nature. Thus, it is not enough to just construct a theory of warp travel. Which, as noted, we failed so far to do.

No, what we need is to figure out that it really happens in nature. So far, this did not happen. Neither did we observe it in any human-made experiment, nor did we have any observation in nature which unambiguously point to it. And this is what makes it real hard.

You see, the universe is a tremendous place, which is unbelievable large, and essentially three times as old as the whole planet earth. Not to mention humanity. There happen extremely powerful events out there. This starts from quasars, effectively like a whole galactic core on fire, to black hole collisions and supernovas. These events put out an enormous amount of energy. Much, much more than even our sun generates. Hence, anything short of a big bang is happening all the time in the universe. And we see the results. The earth is hit constantly by particles with much, much higher energies than we can produce in any experiment. And this since earth came into being. Incidentally, this also tells us that nothing we can do at a particle accelerator can really be dangerous. Whatever we do there has happened so often in our Earth's atmosphere, it would have killed this planet long before humanity entered the scene. Only bad thing about it, we do never know when and where such an event happens. And the rate is also not that high, it is only that earth existed already so very long. And is big. Hence, we cannot use this to make controlled observations.

Thus, whatever could happen, happens out there. In the universe. We see some things out there, which we cannot explain yet, e.g. dark matter. But by and large a lot works as expected. Especially, we do not see anything which begs warp travel to explain. Or anything else remotely suggesting something happening faster than the speed of light. Hence, if something like faster-than-light travel is possible, it is neither common nor easily happening.

As noted, this does not mean it is impossible. Only that if it is possible, it is very, very hard. Especially, this means it will be very, very hard to make an experiment to demonstrate the phenomenon. Much less to actually make it a technology, rather than a curiosity. This means, a lot of effort will be necessary to get to see it, if it is really possible.

What is a lot? Well, the CERN is a bit. But human, or even robotic, space exploration is an entire different category, some one to two orders of magnitudes more. Probably, we would need to combine such space exploration with particle physics to really get to it. Possible the best example for such an endeavor is the future LISA project to measure gravitational waves in space. It is perhaps even our current best bet to observe any hints of faster-than-light phenomena, aside from bigger particle physics experiments on earth.

Do we have the technology for such a project? Yes, we do. We have it since roughly a decade. But it will likely take at least one more decade to have LISA flying. Why not now? Resources. Or, often put equivalently, costs.

And here comes the catch. I said, it is our best chance. But this does not mean it is a good chance. In fact, even if faster-than-light is possible, I would be very surprised if we would see it with this mission. There is probably a few more generations of technology, and another order of magnitude of resources, needed, before we could see something, given of what I know how well everything currently fits. Of course, there can always be surprises with every little step further. I am sure, we will discover something interesting, possibly spectacular with LISA. But I would not bet anything valuable that it will be having to do with warp travel.

So, you see, we have to scale up, if we want to go to the stars. This means investing resources. A lot of them. But resources are needed to fix things on earth as well. And the more we damage, the more we need to fix, and the less we have to get to the stars. Right now, humanity moves into a state of perpetual crises. The damage wrought by the climate crises will require enormous efforts to mitigate, much more to stop the downhill trajectory. As a consequence of the climate crises, as well as social inequality, more and more conflicts will create further damage. Finally, isolationism, both nationally as well as socially, driven by fear of the oncoming crises, will also soak up tremendous amounts of resources. And, finally, a hostile environment towards diversity and putting individual gains above common gains create a climate which is hostile to anything new and different in general, and to science in particular. Hence, we will not be able to use our resources, or the ingenuity of the human species as a whole, to get to the stars.

Thus, I am not hopeful to see faster-than-light in my lifetime, or those of the next generation. Such a challenge, if it is possible at all, will require a common effort of our species. That would be truly one worthy endeavour to put our minds at. But right now, as a scientist, I am much more occupied with protecting a world in which science is possible, both metaphorically as well as literally.

But, there is always hope. If we rise up, and decide to change fundamentally. When we put the well-being of us as a whole in front. Then, I would be optimistic that we can get out there. Well, at least as fast as nature permits. How fast this ever will be.

Tuesday, January 8, 2019

Taking your theory seriously

This blog entry is somewhat different than usual. Rather than writing about some particular research project, I will write about a general vibe, directing my research.

As usual, research starts with a 'why?'. Why does something happen, and why does it happen in this way? Being the theoretician that I am, this question often equates with wanting to have mathematical description of both the question and the answer.

Already very early in my studies I ran into peculiar problems with this desire. It usually left me staring at the words '...and then nature made a choice', asking myself, how could it? A simple example of the problem is a magnet. You all know that a magnet has a north pole and a south pole, and that these two are different. So, how does it happen which end of the magnet becomes the north pole and which the south pole? At the beginning you always get to hear that this is a random choice, and it just happens that one particular is made. But this is not really the answer. If you dig deeper than you find that originally the metal of any magnet has been very hot, likely liquid. In this situation, a magnet is not really magnetic. It becomes magnetic when it is cooled down, and becomes solid. At some temperature (the so-called Curie temperature), it becomes magnetic, and the poles emerge. And here this apparent miracle of a 'choice by nature' happens. Only that it does not. The magnet cools down not all by itself, but it has a surrounding. And the surrounding can have magnetic fields as well, e.g. the earth's magnetic field. And the decision what is south and what is north is made by how the magnet forms relative to this field. And thus, there is a reason. We do not see it directly, because magnets have usually moved since then, and thus this correlation is no longer obvious. But if we would heat the magnet again, and let it cool down again, we could observe this.

But this immediately leaves you with the question of where did the Earth's magnetic field comes from, and got its direction? Well, it comes from the liquid metallic core of the Earth, and aligns along or oppositely, more or less, the rotation axis of the Earth. Thus, the question is, how did the rotation axis of the Earth comes about, and why has it a liquid core? Both questions are well understood, and arise from how the Earth has formed billions of years ago. This is due to the mechanics of the rotating disk of dust and gas which formed around our fledgling sun. Which in turns comes from the dynamics on even larger scales. And so on.

As you see, whenever one had the feeling of a random choice, it was actually the outside of what we looked at so far, which made the decision. So, such questions always lead us to include more into what we try to understand.

'Hey', I now can literally hear people say who are a bit more acquainted with physics, 'does not quantum mechanics makes really random choices?'. The answer to this is yes and no in equal measures. This is probably one of the more fundamental problems of modern physics. Yes, our description of quantum mechanics, as we teach it also in courses, has intrinsic randomness. But when does it occur? Yes, exactly, whenever we jump outside of the box we describe in our theory. Real, random choice is encountered in quantum physics only whenever we transcend the system we are considering. E.g. by an external measurement. This is one of the reasons why this is known as the 'measurement problem'. If we stay inside the system, this does not happen. But at the expense that we are loosing the contact to things, like an ordinary magnet, which we are used to. The objects we are describing become obscure, and we talk about wave functions and stuff like this. Whenever we try to extend our description to also include the measurement apparatus, on the other hand, we again get something which is strange, but not as random as it originally looked. Although talking about it becomes almost impossible beyond any mathematical description. And it is not really clear what random means anymore in this context. This problem is one of the big ones in the concept of physics. While there is a relation to what I am talking about here, this question can still be separated.

And in fact, it is not this divide what I want to talk about, at least not today. I just wanted to get away with this type of 'quantum choice'. Rather, I want to get to something else.

If we stay inside the system we describe, then everything becomes calculable. Our mathematical description is closed in the sense that after fixing a theory, we can calculate everything. Well, at least in principle, in practice our technical capabilities may limit this. But this is of no importance for the conceptual point. Once we have fixed the theory, there is no choice anymore. There is no outside. And thus, everything needs to come from inside the theory. Thus, a magnet in isolation will never magnetize, because there is nothing which can make a decision about how. The different possibilities are caught in an eternal balanced struggle, and none can win.

Which makes a lot of sense, if you take physical theories really seriously. After all, one of the basic tenants is that there is no privileged frame of reference: 'Everything is relative'. If there is nothing else, nothing can happen which creates an absolute frame of reference, without violating the very same principles on which we found physics. If we take our own theories seriously, and push them to the bitter end, this is what needs to come about.

And here I come back to my own research. One of the driving principles has been to really push this seriousness. And ask what it implies if one really, really takes it seriously. Of course, this is based on the assumption that the theory is (sufficiently) adequate, but that is everyday uncertainty for a physicist anyhow. This requires me to very, very carefully separate what is really inside, and outside. And this leads to quite surprising results. Essentially most of my research on Brout-Englert-Higgs physics, as described in previous entries, is coming about because of this approach. And leads partly to results quite at odds with common lore, often meaning a lot of work to convince people. Even if the mathematics is valid and correct, interpretation issues are much more open to debate when it comes to implications.

Is this point of view adequate? After all, we know for sure that we are not yet finished, and our theories do not contain all there is, and there is an 'outside'. However it may look. And I agree. But, I think it is very important that we very clearly distinguish what is an outside influence, and what is not. And as a first step to ensure what is outside, and thus, in a sense, is 'new physics', we need to understand what our theories say if they are taken in isolation.

Thursday, December 13, 2018

The size of the W

As discussed in an earlier entry we set out to measure the size of a particle: The W boson. We have now finished this, and published a paper about our results. I would like to discuss these results a bit in detail.

This project was motivated because we think that the W (and its sibling, the Z boson) are actually more complicated than usually assured. We think that they may have a self-similar structure. The bits and pieces of this is quite technical. But the outline is the following: What we see and measure as a W at, say, the LHC or earlier, is actually not a point-like particle. Although this is the currently most common view. But science has always been about changing the common ideas and replacing them with something new and better. So, our idea is that the W has a substructure. This substructure is a bit weird, because it is not made from additional elementary particles. It rather looks like a bubbling mess of quantum effects. Thus, we do not expect that we can isolate anything which resembles a physical particle within the W. And if we try to isolate something, we should not expect it to behave as a particle.

Thus, this scenario gives two predictions. One: Substructure needs to have space somewhere. Thus, the W should have a size. Two: Anything isolated from it should not behave like a particle. To test both ideas in the same way, we decided to look at the same quantity: The radius. Hence, we simulated a part of the standard model. Then we measured the size of the W in this simulation. Also, we tried to isolate the most particle-like object from the substructure, and also measured its size. Both of these measurements are very expensive in terms of computing time. Thus, our results are rather exploratory. Hence, we cannot yet regard what we found as final. But at least it gives us some idea of what is going on.

The first thing is the size of the W. Indeed, we find that it has a size, and one which is not too small either. The number itself, however, is far less accurate. The reason for this is twofold. On the one hand, we have only a part of the standard model in our simulations. On the other hand, we see artifacts. They come from the fact that our simulations can only describe some finite part of the world. The larger this part is, the more expensive the calculation. With what we had available, the part seems to be still so small that the W is big enough to 'bounce of the walls' fairly often. Thus, our results still show a dependence on the size of this part of the world. Though we try to accommodate for this, this still leaves a sizable uncertainty for the final result. Nonetheless, the qualitative feature that it has a significant size remains.

The other thing are the would-be constituents. We indeed can identify some kind of lumps of quantum fluctuations inside. But indeed, they do not behave like a particle, not even remotely. Especially, when trying to measure their size, we find that the square of their radius is negative! Even though the final value is still uncertain, this is nothing a real particle should have. Because when trying to take the square root of such a negative quantity to get the actual number yields an imaginary number. That is an abstract quantity, which, while not identifiable with anything in every day, has a well-defined mathematical meaning. In the present case, this means this lump is nonphysical, as if you would try to upend a hole. Thus, this mess is really not a particle at all, in any conventional sense of the word. Still, what we could get from this is that such lumps - even though they are not really lumps, 'live' only in areas of our W much smaller than the W size. So, at least they are contained. And let the W be the well-behaved particle it is.

So, the bottom line is, our simulations agreed with our ideas. That is good. But it is not enough. After all, who can tell if what we simulate is actually the thing happening in nature? So, we will need an experimental test of this result. This is surprisingly complicated. After all, you cannot really get a measure stick to get the size of a particle. Rather, what you do is, you throw other particles at them, and then see how much they are deflected. At least in principle.

Can this be done for the W? Yes, it can be done, but is very indirect. Essentially, it could work as follows: Take the LHC, at which two protons are smashed in each other. In this smashing, it is possible that a Z boson is produced, which smashes of a W. So, you 'just' need to look at the W before and after. In practice, this is more complicated. Since we cannot send the W in there to hit the Z, we use that mathematically this process is related to another one. If we get one, we get the other for free. This process is that the produced Z, together with a lot of kinetic energy, decays into two W particles. These are then detected, and their directions measured.

As nice as this sounds, this is still horrendously complicated. The problem is that the Ws themselves decay into some leptons and neutrinos before they reach the actual detector. And because neutrinos escape essentially always undetected, one can only indirectly infer what has been going on. Especially the directions of the Ws cannot easily be reconstructed. Still, in principle it should be possible, and we discuss this in our paper. So we can actually measure this size in principle. It will be now up to the experimental experts if it can - and will - be done in practice.

Wednesday, October 24, 2018

Looking for something when no one knows how much is there

This time, I want to continue the discussion from some months ago. Back then, I was rather general on how we could test our most dramatic idea. This idea is connected to what we regard as elementary particles. So far, our idea is that those you have heard about, the electrons, the Higgs, and so on are truly the basic building blocks of nature. However, we have found a lot of evidence that indicate that we see in experiment, and call these names, are actually not the same as the elementary particles themselves. Rather, they are a kind of bound state of the elementary ones, which only look at first sight like they themselves would be the elementary ones. Sounds pretty weird, huh? And if it sounds weird, it means it needs to be tested. We did so with numerical simulations. They all agreed perfectly with the ideas. But, of course, its physics, and thus we need also an experiment. The only question is which one.

We had some ideas already a while back. One of them will be ready soon, and I will talk again about it in due time. But this will be rather indirect, and somewhat qualitative. The other, however, required a new experiment, which may need two more decades to build. Thus, both cannot be the answer alone, and we need something more.

And this more is what we are currently closing in. Because one has this kind of weird bound state structure to make the standard model consistent, not only exotic particles are more complicated than usually assumed. Ordinary ones are too. And most ordinary are protons, the nucleus of the hydrogen atom. More importantly, protons is what is smashed together at the LHC at CERN. So, we have a machine already, which may be able to test it. But this is involved, as protons are very messy. They are already in the conventional picture bound states of quarks and gluons. Our results just say there are more components. Thus, we have somehow to disentangle old and new components. So, we have to be very careful in what we do.

Fortunately, there is a trick. All of this revolves around the Higgs. The Higgs has the property that interacts stronger with particles the heavier they are. The heaviest particles we know are the top quark, followed by the W and Z bosons. And the CMS experiment (and other experiments) at CERN has a measurement campaign to look at the production of these particles together! That is exactly where we expect something interesting can happen. However, our ideas are not the only ones leading to top quarks and Z bosons. There are many known processes which produce them as well. So we cannot just check whether they are there. Rather, we need to understand if there are there as expected. E.g., if they fly away from the interaction in the expected direction and with the expected speeds.

So what a master student and myself do is the following. We use a program, called HERWIG, which simulates such events. One of the people who created this program helped us to modify this program, so that we can test our ideas with it. What we now do is rather simple. An input to such simulations is how the structure of the proton looks like. Based on this, it simulates how the top quarks and Z bosons produced in a collision are distributed. We now just add our conjectured additional contributions to the proton, essentially a little bit of Higgs. We then check, how the distributions change. By comparing the changes to what we get in experiment, we can then deduced how large the Higgs contribution in the proton is. Moreover, we can even indirectly deduce its shape, i.e. how in the proton the Higgs is located.

And this we now study. We iterate modifications of the proton structure with comparison to experimental results and predictions without this Higgs contribution. Thereby, we constraint the Higgs contribution in the proton bit by bit. At the current time, we know that the data is only sufficient to provide an upper bound to this amount inside the proton. Our first estimates show already that this bound is actually not that strong, and quite a lot of Higgs could be inside the proton. But on the other hand, this is good, because that means that the expected data in the next couple of years from the experiments will be able to actually either constraint the contribution further, or could even detect it, if it is large enough. At any rate, we now know that we have a sensitive leverage to understand this new contribution.

Thursday, September 27, 2018

Unexpected connections

The history of physics is full of stuff developed for one purpose ending up being useful for an entirely different purpose. Quite often they also failed their original purpose miserably, but are paramount for the new one. Newer examples are the first attempts to describe the weak interactions, which ended up describing the strong one. Also, string theory was originally invented for the strong interactions, and failed for this purpose. Now, well, it is the popular science star, and a serious candidate for quantum gravity.

But failing is optional for having a second use. And we just start to discover a second use for our investigations of grand-unified theories. There our research used a toy model. We did this, because we wanted to understand a mechanism. And because doing the full story would have been much too complicated before we did not know, whether the mechanism works. But it turns out this toy theory may be an interesting theory on its own.

And it may be interesting for a very different topic: Dark matter. This is a hypothetical type of matter of which we see a lot of indirect evidence in the universe. But we are still mystified of what it is (and whether it is matter at all). Of course, such mysteries draw our interests like a flame the moth. Hence, our group in Graz starts to push also in this direction, being curious on what is going on. For now, we follow the most probable explanation that there are additional particles making up dark matter. Then there are two questions: What are they? And do they, and if yes how, interact with the rest of the world? Aside from gravity, of course.

Next week I will go to a workshop in which new ideas on dark matter will be explored, to get a better understanding of what is known. And in the course of preparing for this workshop I noted that there is this connection. I will actually present this idea at the workshop, as it forms a new class of possible explanations of dark matter. Perhaps not the right one, but at the current time an equally plausible one as many others.

And here is how it works. Theories of the type of grand-unified theories were for a long time expected to have a lot of massless particles. This was not bad for their original purpose, as we know quite some of them, like the photon and the gluons. However, our results showed that with an improved treatment and shift in paradigm that this is not always true. At least some of them do not have massless particles.

But dark matter needs to be massive to influence stars and galaxies gravitationally. And, except for very special circumstances, there should not be additional massless dark particles. Because otherwise the massive ones could decay into the massless ones. And then the mass is gone, and this does not work. Thus the reason why such theories had been excluded. But with our new results, they become feasible. Even more so, we have a lot of indirect evidence that dark matter is not just a single, massive particle. Rather, it needs to interact with itself, and there could be indeed many different dark matter particles. After all, if there is dark matter, it makes up four times more stuff in the universe than everything we can see. And what we see consists out of many particles, so why should not dark matter do so as well. And this is also realized in our model.

And this is how it works. The scenario I will describe (you can download my talk already now, if you want to look for yourself - though it is somewhat technical) finds two different types of stable dark matter. Furthermore, they interact. And the great thing about our approach is that we can calculate this quite precisely, giving us a chance to make predictions. Still, we need to do this, to make sure that everything works with what astrophysics tells us. Moreover, this setup gives us two more additional particles, which we can couple to the Higgs through a so-called portal. Again, we can calculate this, and how everything comes together. This allows to test this model not only by astronomical observations, but at CERN. This gives the basic idea. Now, we need to do all the detailed calculations. I am quite excited to try this out :) - so stay tuned, whether it actually makes sense. Or whether the model will have to wait for another opportunity.

Monday, August 13, 2018

Fostering an idea with experience

In the previous entry I wrote how hard it is to establish a new idea, if the only existing option to get experimental confirmation is to become very, very precise. Fortunately, this is not the only option we have. Besides experimental confirmation, we can also attempt to test an idea theoretically. How is this done?

The best possibility is to set up a situation, in which the new idea creates a most spectacular outcome. In addition, it should be a situation in which older ideas yield a drastically different outcome. This sounds actually easier than it is. There are three issues to be taken care of.

The first two have something to do with a very important distinction. That of a theory and that of an observation. An observation is something we measure in an experiment or calculate if we play around with models. An observation is always the outcome if we set up something initially, and then look at it some time later. The theory should give a description of how the initial and the final stuff are related. This means that we look for every observation for a corresponding theory to give it an explanation. To this comes the additional modern idea of physics that there should not be an own theory for every observation. Rather, we would like to have a unified theory, i.e. one theory which explains all observations. This is not yet the case. But at least we have reduced it to a handful of theories. In fact, for anything going on inside our solar system we need so far just two: The standard-model of particle physics and general relativity.

Coming back to our idea, we have now the following problem. Since we do a gedankenexperiment, we are allowed to chose any theory we like. But since we are just a bunch of people with a bunch of computers we are not able to calculate all the possible observations a theory can describe. Not to mention all possible observations of all theories. And it is here, where the problem starts. The older ideas still exist, because they are not bad, but rather explain a huge amount of stuff. Hence, for many observations in any theory they will be still more than good enough. Thus, to find spectacular disagreement, we do not only need to find a suitable theory. We also need to find a suitable observation to show disagreement.

And now enters the third problem: We actually have to do the calculation to check whether our suspicion is correct. This is usually not a simple exercise. In fact, the effort needed can make such a calculation a complete master thesis. And sometimes even much more. Only after the calculation is complete we know whether the observation and theory we have chosen was a good choice. Because only then we know whether the anticipated disagreement is really there. And it may be that our choice was not good, and we have to restart the process.

Sounds pretty hopeless? Well, this is actually one of the reasons why physicists are famed for their tolerance to frustration. Because such experiences are indeed inevitable. But fortunately it is not as bad as it sounds. And that has something to do with how we chose the observation (and the theory). This I did not specify yet. And just guessing would indeed lead to a lot of frustration.

The thing which helps us to hit more often than not the right theory and observation is insight and, especially, experience. The ideas we have tell us about how theories function. I.e., our insights give us the ability to estimate what will come out of a calculation even without actually doing it. Of course, this will be a qualitative statement, i.e. one without exact numbers. And it will not always be right. But if our ideas are correct, it will work out usually. In fact, if we would regularly not estimate correctly, this should require us to reevaluate our ideas. And it is our experience which helps us to get from insights to estimates.

This defines our process to test our ideas. And this process can actually be well traced out in our research. E.g. in a paper from last year we collected many of such qualitative estimates. They were based on some much older, much more crude estimates published several years back. In fact, the newer paper already included some quite involved semi-quantitative statements. We then used massive computer simulations to test our predictions. They were indeed as good confirmed as possible with the amount of computers we had. This we reported in another paper. This gives us hope to be on the right track.

So, the next step is to enlarge our testbed. For this, we already came up with some new first ideas. However, these will be even more challenging to test. But it is possible. And so we continue the cycle.

Tuesday, June 12, 2018

How to test an idea

As you may have guessed from reading through the blog, our work is centered around a change of paradigm: That there is a very intriguing structure of the Higgs and the W/Z bosons. And that what we observe in the experiments are actually more complicated than what we usually assume. That they are not just essentially point-like objects.

This is a very bold claim, as it touches upon very basic things in the standard model of particle physics. And the interpretation of experiments. However, it is at the same time a necessary consequence if one takes the underlying more formal theoretical foundation seriously. The reason that there is not a huge clash is that the standard model is very special. Because of this both pictures give almost the same prediction for experiments. This can also be understood quantitatively. That is where I have written a review about. It can be imagined in this way:

Thus, the actual particle, which we observe, and call the Higgs is actually a complicated object made from two Higgs particles. However, one of those is so much eclipsed by the other that it looks like just a single one. And a very tiny correction to it.

So far, this does not seem to be something where it is necessary to worry about.

However, there are many and good reasons to believe that the standard model is not the end of particle physics. There are many, many blogs out there, which explain the reasons for this much better than I do. However, our research provides hints that what works so nicely in the standard model, may work much less so in some extensions of the standard model. That there the composite nature makes huge differences for experiments. This was what came out of our numerical simulations. Of course, these are not perfect. And, after all, unfortunately we did not yet discover anything beyond the standard model in experiments. So we cannot test our ideas against actual experiments, which would be the best thing to do. And without experimental support such an enormous shift in paradigm seems to be a bit far fetched. Even if our numerical simulations, which are far from perfect, support the idea. Formal ideas supported by numerical simulations is just not as convincing as experimental confirmation.

So, is this hopeless? Do we have to wait for new physics to make its appearance?

Well, not yet. In the figure above, there was 'something'. So, the ideas make also a statement that even within the standard model there should be a difference. The only question is, what is really the value of a 'little bit'? So far, experiments did not show any deviations from the usual picture. So 'little bit' needs indeed to be really rather small. But we have a calculation prescription for this 'little bit' for the standard model. So, at the very least what we can do is to make a calculation for this 'little bit' in the standard model. We should then see if the value of 'little bit' may already be so large that the basic idea is ruled out, because we are in conflict with experiment. If this is the case, this would raise a lot of question on the basic theory, but well, experiment rules. And thus, we would need to go back to the drawing board, and get a better understanding of the theory.

Or, we get something which is in agreement with current experiment, because it is smaller then the current experimental precision. But then we can make a statement how much better experimental precision needs to become to see the difference. Hopefully the answer will not be so much that it will not be possible within the next couple of decades. But this we will see at the end of the calculation. And then we can decide, whether we will get an experimental test.

Doing the calculations is actually not so simple. On the one hand, they are technically challenging, even though our method for it is rather well under control. But it will also not yield perfect results, but hopefully good enough. Also, it depends strongly on the type of experiment how simple the calculations are. We did a first few steps, though for a type of experiment not (yet) available, but hopefully in about twenty years. There we saw that not only the type of experiment, but also the type of measurement matters. For some measurements the effect will be much smaller than for others. But we are not yet able to predict this before doing the calculation. There, we need still much better understanding of the underlying mathematics. That we will hopefully gain by doing more of these calculations. This is a project I am currently pursuing with a number of master students for various measurements and at various levels. Hopefully, in the end we get a clear set of predictions. And then we can ask our colleagues at experiments to please check these predictions. So, stay tuned.

By the way: This is the standard cycle for testing new ideas and theories. Have an idea. Check that it fits with all existing experiments. And yes, this may be very, very many. If your idea passes this test: Great! There is actually a chance that it can be right. If not, you have to understand why it does not fit. If it can be fixed, fix it, and start again. Or have a new idea. And, at any rate, if it cannot be fixed, have a new idea. When you got an idea which works with everything we know, use it to make a prediction where you get a difference to our current theories. By this you provide an experimental test, which can decide whether your idea is the better one. If yes: Great! You just rewritten our understanding of nature. If not: Well, go back to fix it or have a new idea. Of course, it is best if we have already an experiment which does not fit with our current theories. But there we are at this stage a little short off. May change again. If your theory has no predictions which can be testable in any foreseeable future experimentally. Well, that is a good question how to deal with this, and there is not yet a consensus how to proceed.