Making big plans

 Occasionally, you have an idea, and you can do the required research within a couple of weeks. But this is the rare exception. Most research requires months, and often years, to complete. In particle physics, with its huge experiments running for decades, this is probably even more aware to people than in many other cases. This requires plans. A very recent example of such a plan is the European Strategy on Particle Physics (Update), in which all of Europe came together to make a plan. I have contributed to this as coordinating the theory input for the national Austrian roadmap. It is a huge effort to get everyone agreeing on what to do next - and what to do in the next half-a-century. Because this is how long you have to plan in advance for the big experiments.

Aside from these big plans, there are also smaller ones. Even for me as a theoretician. Occasionally, I have to sit down, and formulate a research plan for a couple of years into the future. The reason is often that I write a so-called grant proposal to get a considerable amount of money to hire postdocs and PhD students. Such a large proposal requires you to formulate what you want to do with all these people, usually for about five years. Last year, we got one already, for dark matter.

This year, I write another one. Why again, if we just got one? Well, on the one hand each would roughly take up half my time. So, I can manage both, and thereby do more. But putting this up front is cheating. The main reason is that it is unlikely I will get it in the first attempt. As there are currently many more people wanting to do particle physics than resources are allocated for this purpose at the national and international level, these resources need to be distributed. Thus, you write a proposal to get some of these. Then some panel judges the submitted proposals, and decides, who will get resources. And thus where efforts in particle physics will be concentrated. Usually, the are many more proposals the panel would like to fund than there are resources available, and so small points tip the scale to one or the other proposals, and the others are rejected. One can then try again. On average, less than one in five proposals is successful. Thus, you often need to try again, with an optimized proposal. And thus, I already submit another one.

Coming back to the original topic: For such a proposal I need to make a five-years plan. Of course, its research. Nobody can guarantee me that I (or, more likely, someone else) will not discover something which requires a fundamental change of plans. This is always allowed. But you are still required to make a plan what you want to do, if nothing unexpected happens. Usually, in my personal experience, about half what is planned will be done, and the rest of the resources is spent on unexpected stuff. Which is as well.

Still, you need to make a plan, if everything happens as you would expect it now. And that is what I did.

The first thing you need to decide is to what part of your research you would like to base it on. If you read my blog since a while, you may have seen that I actually do quite a lot of different topics, ranging from neutron stars to quantum gravity. But not all of this research is something I would like to extend at this level. The neutron star physics is something I currently do not work too much on. It is very interesting. But I would need to focus much more efforts on it, and needed to mainly concentrate on technical details. That is not what I currently want. The quantum gravity part is very exciting, and we develop quickly new ideas. There is much more to come. But currently it is too much at an exploratory stage as I would be able to formulate a large-scale five-years program. This will have to cook for a little time longer before it warrants this kind of attention.

So, I am down to my Higgs physics and beyond-the-standard-model research. For the latter, we are currently having enough people to work on. Also, it is a bit more speculative, as we did not yet see anything new in experiments. It is thus somewhat less easy to identify where to concentrates ones efforts on. The combination of our current research and what the next few years of experiments, especially LHC Run 3, will bring, will make this clearer.

So I concentrate this time on our attempts to find some new, subtle effects from theory in experiments: That there is an additional Higgs contribution inside the proton.

Right now, what we did was making a good guess, and looked, whether experiment told us we are right. Iterating this would be a time-honed approach to identifying a new effect. But for this plan, I wanted to be more ambitious. I wanted to have some prediction that rather just guess and iterate. This is very demanding. As a suitable tool, I choose simulations. While I will not be able to really simulate an actual proton and its Higgs content, the effort made possible by such a big grant should be enough to get a decent proxy for it. Something, which is close enough to the real thing that from a guess I can move to something which only requires a few more numbers, which I can get from experiments. That would be a huge success. We then use slightly different methods to fix the numbers.

But this is not easy. Based on what we learned so far, this is a big endeavour. At least for a theoretician. I estimated that I will need about four people with PhD, plus myself, and five more doing a PhD to get there. Not to mention that many master students and bachelor students will be able to work on this as well. This also means that especially several of the PhD students will work on this project, but will complete their PhD only on a part of it, and be done before the whole project is done. This required me to break the project down into smaller workpackages, 17 in total. Each of them is a milestone in itself, and provides intermediate (and eventually final) results. Each requires several of the people, and each at least half a year of time, and some even a year. I needed to make a plan, how each of them intersect with the other, and how they depend on each other. If you are interested in how such a thing looks in the end (it has a lot of tech babble in it), contact me. But it is actually not that different from any other large scale project, even in industry, like building a house. Thus, you also need some project management skills to do research. Even as a theoretician.

I am quite pleased with how it turned out in the end. It really has a good flow, and a succession of reasonable and manageable steps. In the end, it holds the promise of a guaranteed discovery - i.e. we will see a new physics effect, as long as we just keep on with the experiments, it will happen. Likely by the end of the runtime of the LHC in about 15 years. Or with the next generation of machines latest, which are part of the Strategy mentioned in the beginning. By this, I come full circle: My small research project ties in into the big ones. And together, we push the boundaries of human knowledge just a bit further.

A personal perspective on how capitalism hurts science

In a number of my recent blog entries, and also occasionally on twitter, I have made statements about how bad our current late stage capitalism is for science. It is time that I follow up with a more detailed blog entry on this.

Before delving into it, I should discuss reasons why I hesitate to write on this subject. Those who have read my scientific blog entries may have noticed that I work on many ideas, which are unconventional. While I do my best to back them up with many different types of calculations, I have not been (yet) able to get these issues across as important. Thus, despite there have been quite a number of people in the past who did work on these subjects, and my own results are in line with theirs, there are very few contemporary people doing so. It is quite easy to be frustrated about this, especially since I think that are important things which need to be taken into considerations. Because they may change a lot of particle physics on a very fundamental level.

If you are in such a situation, it is very tempting to search guilt for your continued failure to make your stuff popular in some external reason. Hence, I am very much double guessing myself, if part of what I write here is affected by this. Probably part of it is. If I would be the only one having these thoughts it surely would be the case. However, over recent years I saw more and more studies being published or popping up on the arXiv which agree with my own perception. Hence, I am more and more convinced that a larger issue is at work here. And whether I am affected by this or not is not easy to say. Hence, I will try to avoid making any personal connections here, and just tell how in my perspective I see the results of these studies realized. Most of the studies I linked on twitter over time.

The gist of many of these studies is twofold. The way how research results are published and perceived is not necessarily correlated with its relevance. In fact, there appears to be anti-correlation between long-term relevance (measured by number of citations) and the impact factor of the journal in which the research has been published. Meaning more prestigious journals tend to not accept research where the short-term relevance is not obvious. On the other hand, also in funding there is a strong tendency that those who have get more, and bold claims are more important than well-funded statements or even checks.

While these issues are on their own troublesome, it is the way how they resemble other elements of public life, which is alarming. To say the least. And which is typical for late-stage capitalism. This is the fact that those who have get more. That those who have, or have the favor of someone who has, can do anything essentially anything, and get rewarded. While those who do not have a hard time to get anything. This is amplified by gate-keeping and a lack of diversity in academia, which is far from resolved. Of course, this is also a problem appearing in society in general.

In my personal experience, this manifests itself in a very strong tendency to create hype. If the results is only promising enough, any assumption, even if it is just wishful thinking, becomes acceptable. Theoreticians seem to be much more prone to this than experimentalists. The reason is simple. As long as no one disproves your statement, you will get attention. And if somebody, who has, picks it up and promotes it (or is actually the origin), it will gain traction. If it fails eventually, you just cook up another thing, and so on. This is in particle physics supported by our current lack of hard experimental evidence beyond the standard model. Thus it is easy to escape experimental falsification. Theoretical falsification is much more complicated. Because in sufficiently complicated theories, doing an exact falsification is technically hard. Even if you there is a lot of evidence, it is always possible to find a loop hole to not accept a falsification. And given the promises made, it is for most much better to just ignore any claim of invalidity. Especially, most of the assumptions often simplify, or even trivialize, calculations. Hence, it is possible to get results with little effort. And since they promise so much, it is easy to publish them or get funding for them.

This even happens in a less dramatic fashion quite often. Even without anything wrong any new field has first a lot of simple problems. They can be done with little or moderate effort. Thus, the return-on-investment is large. Therefore many people flock to these new fields, to have a large output compared to work invested. Thereby, they gain resources. As soon as the inevitable complications set in, most of these leave the field, and move to the next field of the same type. However, they take with them the resources, leaving those trying to solve the hard problems with little. While in any case resources are limited it is necessary to focus effort, this should be decided upon the relevance of the question, rather than on how easy it is to get results.

All of this mirrors trends in society. As long as one can get much without solving actual problem, everyone goes for it. And if you can gain an advantage by making too strong claims, the better. We see how this damages our society from the climate crises to the rise of authoritarianism. All of that follows this pattern. You claim that there is an easy solution how you can get profit and avoid investing solving the reason for the climate crises. See greenwashing. Or you claim social problems have an easy solution, because others are at fault, so you just need to get rid of them. Yielding the rise of rightwing extremism and authoritarian systems. All of this is fueled by capitalism, which puts profits before solutions.

And these effects find their mirror in science, as science is not set apart from society. Thus, capitalistic thinking - gathering resources, in science renown and funding, become more important than the actual solution of problems.

How can this by avoided? Well, probably the same way as in society at large. That what damages the scientific process needs to be got rid off. A scientific system which focuses on what people did instead of who did it, and a distribution of resources based on the relevance of problem rather than renown or promises, would probably go a long way. This was recognized by quite some people. And there are tentative steps ongoing. Like banishing renown as a measure of success. Putting the actual works at center, rather than how and where they are published. But it is a slow process, and one which can again be misused. Probably, only if we as a society change fundamentally science will get closer to its ideals.

Going abroad: Yes or no?

One topic which reemerges in many discussions online and offline is that many scientists, especially in (particle) physics, have to move around several times as postdocs. For me, this was after the PhD in Germany first going to Brazil, then back to Germany, then to Slovakia, Austria, Germany, and finally back to Austria.

The discussion evolves usually around whether this is good or bad, and whether the price tag in terms of private life associated with so many moves is worth what one gains from it. There are three aspects, I would like to address, especially from personal experience. One is the cost to one's social net. The other is the personal and professional gain. And the last is suffering because of a lack of predictability. Because you usually do not know, where it will go to in one or two years.

Let me start with the most obvious price tag: Social contacts. And especially partnership. The last one is the most individual point. Here, it is really up to you and your family members, how all of you think about it. But this needs to be addressed well before you start with such moves. How many are acceptable? How long may it take? Which countries are acceptable? And so on. That has to be agreed upon by everyone involved, and that is really different for every one.

More general is the question of the general social net. Despite modern communication methods, a social net will tear if someone moves away. Without direct contact, it is for most people hard to hold contact. Even with video communication, its is not easy to transfer everything. And not everyone is able to keep a connection in written form. Especially if it is not clear when, or even if, one will meet again in person. In addition, even when moving somewhere and building a new social net, this will tear again with the next move. And so can easily leave behind several fragmented nets. It depends, of course, on how much you rely on our own social net, and what kind of people are in there. But too me, this was always the highest cost. Because building a new net takes time, and the old one is missed.

If the cost is so high, how could I even consider moving to be a good thing? Before I did it, I would actually would have no good thing to think about other than our current scientific society is requiring it. And I will come back to this later. Already during the first place, my opinion changed. I expected that just by working with other on a day-by-day basis, not so much would change in my own work. But the constant exposure to very different approaches to science, emphasizing very different aspects and questions, has fundamentally changed the way I think about my own research, and about how I should perform research. At the same time, the need to live in a very different society than the one I came from also taught me a lot about people, and about how to deal with life. In hindsight, I am very sure that I would have been both a lesser person and a lesser scientist if not for these other places I lived and worked at. Again, this is my very own experience, though I heard similar stories by most people. Especially those people who went to a place, which was welcoming to them, if not always simple to deal with.

So, I have now both a strong argument against moving and in favor of moving. And really, I could not decide for me, which is now the stronger point. I am pretty sure that everyone has an opinion about this, but this is probably very individual. Still, in my personal experience most people who have moved to different places are better scientist, and also often show better abilities in dealing with the not hardcore-technical part of science.

While their maybe no optimal choice for everyone on the previous issue, there is certainly one part, in which we can make the whole story better for everyone: Predictability. Right now, you usually move to a place, and while there, you somehow need to get a new position somewhere else for the time afterwards. Usually on a two-year or three-year basis. Until you hit jackpot, and get a permanent position. Which, depending on the country, can take a decade or so. Especially not knowing where things go next, and how long, is in my experience something which makes everything, especially with social nets, much, much harder. On top of this, especially older scientists, insist that some places are as a place important, and you have to go there to be a good scientist. This latter point is very annoying, because it usually boils down to where money is, and where the best people in marketing are, and this creates a self-sustaining cycle. But this is an aspect of late-stage capitalistic science I will write about sometimes else.

Thus, in my opinion, the best compromise between the drawbacks of moving and the advantages of moving could be achieved by making this predictable. Say, you have six years to move around, including say three moves, and there is an assessment every two years, and if all of them are sufficiently positive, then you have a permanent position at the place where you came from. This should make it possible to plan your life. Also, knowing that the stress on the social net is only temporary, this may more often than not preventing it from tearing.

Sure, this will still not be a workable solution for everyone. There are too many individual issues, which cannot be taken into account with a one-fits-all solution. Thus, it is still necessary to help individual researchers to work around their individual situations.

Still, in the end, this means arguably that I think moving around, at least for a while, is important. It is just right now not supported in a good way. However, it will likely be impossible to quantify my personal experience generally. There are far too many soft factors involved. And, of course, I also encountered the occasional exception.

The take-home message for me from these considerations is that I will put effort into making going abroad more sustainable, but will not argue against it. Also, I will counsel everyone about all the aspects one has to think about, and the deliberate obstructions one currently faces, as well as the impact it has beyond work. Thus, everyone can at least make an informed decision, though unfortunately not yet a free one. I hope that I can contribute in changing this.

About toxic working culture in science

Recently, I have read this excellent article on mental health in academia. It emphasizes the consequences of a toxic working culture in academia on mental health, with a focus on PhD students. I would like to provide here a few reflections on my own experience with this topic, both as a scientist, but also as a professor.

The first experience is that I very often encounter the phrase that 'we should be grateful that we have the opportunity to do what we like/love' to justify bad working conditions. While I am certainly happy that I do something I like to do, this should never be used in any circumstances to justify circumstances. Because it puts us as people being only granted something, and which equally well can be taken away. Because its meaning can be easily shifted to 'we should be thankful that it is not worse', and thus to justify the status quo for being afraid of consequences when trying to improve the situation. And ultimately to paint the picture of willful suffering just to be able to do something which is important to one.

This is then used to justify almost anything. Even more so, it is seen as an act of individual heroism to still do science, in face of such conditions. I have often witness scenes where people have tried to outdo others by the sheer amount of hours/week they worked. Or how many days of holiday they did not use. Of course, this is fired up by a perpetual overcommitment of people, necessitated often by all the various things we have to do. As scientists, we are expected not only to do science, but also teaching, outreach, presentation in form of talks and paper writing, fact checker as reviewers, marketing in form of research grants, and administrative duties both for research grants as well as within University and for national and international infrastructure in many commissions, i.e. management. While at the same time it is expected to explored with creativity and solve the deepest problems of research. To this comes often the impression of our own grandeur that we know everything better and we cannot delegate anything because we are the only ones who can get it done right. Which is outright wrong.

Of course, this is driven by precarious working conditions until one reaches a permanent position, often for decades, at payment levels which are very low compared to research and development positions in industry. By making the resource of permanent employment scarce and competitive, essentially by turning science into another branch of capitalism, the same happens as everywhere else in capitalism: To ensure ones survival, one puts up with being slowly destroyed by the working conditions. This gets its toxic turn by accusing people of not having enough dedication if they do not overwork themselves. This goes on at a reduced level once permanency is reached, by making resources to do our work scarce and getting them again competitive.

Given that research into work has established that peak effectivity is attained around thirty hours of work a week, this is actually damaging science. When we work much longer, we usually do not get so much more work done. And at some point, we get even less work done, because we start to err too often. Of course, this is a distribution, and there are tails. But an average scientist is also an average human being. Scientist may still overpopulate the tail of this distribution, but this is then selected by the working conditions, and who can suffer them, and not by the brilliance and creativity of the researcher.

Of course, it is easy to buy into the picture of the never-tiring scientist, working all time to discover the greatest secrets. This is how we are often depicted in literature or film. Can you name any scientist, who actually saves the day, who is regularly working only forty hours? I cannot. And especially as a young person, it is even easier to find oneself in pursuit of such a heroic idealization. At the time we get a permanent position, most just carry on like this, because it has become very internalized.

My own experience is in the beginning quite like this. I wanted to solve the scientific problem. I cannot remember actually to reflect upon my working times, or even track it. It was certainly much more than I got paid for. And when many years later I started to change this, I had a very bad consciousness when moving my actual work time towards the amount of time I was paid for. Even though I realized quite quickly that I still get essentially the same amount of work done. Thus proving to myself that what I written about peak effectivity is true for me. However, I have been quite privileged in this development, because failing in getting a permanent position was quite acceptable for me. And even now I do not feel the urge to 'discover something really big' or 'getting acknowledge by grants or prizes', the later being recognized to be just another tool to exploit scientists by letting them actively fight against each other for scraps of resources.

Now, as a professor, I feel the obligation to bring through these points to students. Which turns out to be very complicated. I hear my younger self echoed too often. Like I want to finish fast, or I think this is too important. It is very hard arguing, because the counter argument is self care. And we have so often seen the trope of the scientists sacrificing themselves for the greater good. How can I be a good scientist (or even a good human being), when I do not put the greater good of science above petty personal necessities?

Well, the true answer is that a sane, well-cared for scientist will be doing just as much as an overworked one. And will do so for a much longer time. Not only bodily, because I can better avoid problems like cardiac arrest by stress, by also mentally. Just as the article points out.

What do I do concretely? Besides trying to implement the points mentioned in the article, I do my best to reduce the capitalistic structures in science. By using my influence wherever possible to create easier career paths, and by generally attempting to espouse a cooperative rather than a competitive culture. I certainly fail far too often in this endeavour. Because it means unlearning something I have engulfed in for far too long. But I listen to those doing research about work, about mental and bodily well-being, and to those I work with. Perhaps I can improve it at least a little bit.

Reflection, self-criticism, and audacity as a scientist

Today, I want to write a bit about me as a scientist, rather than about my research. It is about how I deal with our attitude towards being right.

As I still do particle physics, we are not done with it. Meaning, we have no full understanding. As we try to understand things better, we make progress, and we make both wrong assumptions and actual errors. The latter because we are human, after all. The former because we do not yet know better. Thus, we necessarily know that whatever we do will not be perfect. In fact, especially when we enter unexplored territory, what we do is more likely not the final answer than not. This led to a quite defensive way of how results are presented. In fact, many conclusions of papers read more like an enumeration what all could be wrong with what was written than what has been learned. And because we are not in perfect control of what we are doing, anyone who is trying to twist things in a way they like, they will find a way due to all the cautious presentation. On the other hand, if we would not be so defensive, and act like we think we are right, but we are not - well, this would also be held against us, right?

Thus, as a scientist one is caught in an eternal limbo about actually believing one's own results and thinking that they can only be wrong. If you browse through scientist on, e.g, Twitter, you will see that this is a state which is not easy to endure. This becomes aggravated by a science system which was geared by neoliberalism towards competition and populist movements who need to discredit science to further their own ends, no matter the cost. To deal with both, we need to be audacious, and make our claims bold. At the same time, we know very well that any claims to be right are potentially wrong. Thus enhancing the perpetual cycle of self-doubt on an individual level. On a collective level this means that science gravitates to things which are simple and incremental, as there the chance to being wrong is smaller then when trying to do something more radical or new. Thus, this kind of pressure reduces science from revolutionary to evolutionary, with all the consequences. It also damns us to avoid taking all consequences of our results, because they could be wrong, couldn't they?

In the case of particle physics, this slows us down. One of the reasons, at least in my opinion, why there is no really big vision of how to push forward, is exactly being too afraid of being wrong. We are at a time, where we have too little evidence to do evolutionary steps. But rather than to make the bold step of just go exploring, we try to cover every possible evolutionary direction. Of course, one reason is that because of being in a competitive system, we have no chance of being bold more than once. If we are wrong with this, this will probably create a dead stop for decades. Of course, it other fields of science the consequence can be much more severe. E.g. in climate sciences, this may very well be the difference between extinction of the human species and its survival.

How do I deal with this? Well, I have been far too privileged and in addition was lucky a couple of time. As a consequence, I could weather the consequences to be a bit more revolutionary and bit more audacious than most. However, I also see that if I would not have been, I would probably had an easier career still. But this does not remove my own doubt about my results. After all, what I do has far-reaching consequences. In fact, I am questioning very much conventional wisdom in textbooks, and want to reinterpret the way how the standard model (and beyond) describes the particles of the world we are living in. Once in a while, when I realize what I claim, I can get scared. Other times, I feel empowered by how things seem to fall into place, and I do not see how edges not fit. Thus, I live in my own cycle of doubt.

Is there anything we can do about the nagging self-doubt, the timidity and the feeling of being an imposter? Probably not so much as individuals, except for taking good care of oneself, and working with people with a positive attitude about our common work. Much of the problems are systemic. Some of them could be dealt with by taking the heat of completion out of science, and have a cooperative model. This will only work out, if there is more access to science positions, and more resources to do science. After all, there are right now far too many people wanting a position as a scientist than there are available. No matter what we do, this always creates additional pressure. But even that could be reduced by having controllable career paths, more mentoring, easier transitions out of science, and much more feedback. But this not only requires long-term commitments on behalf of research institutes, but also that scientists themselves acknowledge these problems. I am very happy to see that this consciousness grows, especially with younger people getting into science. Too many scientist I encounter blatantly deny that these problems exist.

However, in the end, also these problems are connected to societal issues at large. The current culture is extremely competitive, and more often than not rewards selfish behavior. Also, there is, both in science and in society, a strong tendency to give those who have already. And such a society shapes also science. It will be necessary that society reshapes itself to a more cooperative model to get a science, which is much more powerful and forward-moving than we have today. On the other hand, existential crises of the world, like the climate crises or the rise of fascism, are also facilitated by a competitive society. And could therefore likely be overcome by having a more cooperative and equal society. Thus, dealing with the big problems will also help solving the problems of scientists today. I think this is worthwhile, and invite any fellow scientist, and anyone, to do so.

Creativity in physics

One of the most widespread misconceptions about physics, and other natural sciences, is that they are quite the opposite to art: Precise, fact-driven, logical, and systematic. While art is perceived as emotional, open, creative, and inspired.

Of course, physics has experiments, has data, has math. All of that has to be fitted perfectly together, and there is no room for slights. Logical deduction is central in what we do. But this is not all. In fact, these parts are more like the handiwork. Just like a painter needs to be able to draw a line, a writer needs to be able to write coherent sentences, so we need to be able to calculate, build, check, and infer. But just like the act of drawing a line or writing a sentence is not what we recognize already as art, so is not the solving of an equation physics.

We are able to solve an equation, because we learned this during our studies. We learned, what was known before. Thus, this is our tool set. Like people read books before start writing one. But when we actually do research, we face the fact that nobody knows what is going on. In fact, quite often we do not even know what is an adequate question to pose. We just stand there, baffled, before a couple of observations. That is, where the same act of creativity has to set in as when writing a book or painting a picture. We need an idea, need inspiration, on how to start. And then afterwards, just like the writer writes page after page, we add to this idea various pieces, until we have a hypotheses of what is going on. This is like having the first draft of a book. Then, the real grinding starts, where all our education comes to bear. Then we have to calculate and so on. Just like the writer has to go and fix the draft to become a book.

You may now wonder whether this part of creativity is only limited to the great minds, and at the inception of a whole new step in physics? No, far from it. On the one hand, physics is not the work of lone geniuses. Sure, somebody has occasionally the right idea. But this is usually just the one idea, which is in the end correct, and all the other good ideas, which other people had, did just turn out to be incorrect, and you never hear of them because of this. And also, on the other hand, every new idea, as said above, requires eventually all that what was done before. And more than that. Creativity is rarely borne out of being a hermit. It is often by inspiration due to others. Talking to each other, throwing fragments of ideas at each other, and mulling about consequences together is what creates the soil where creativity sprouts. All those, with whom you have interacted, have contributed to the idea you have being born.

This is, why the genuinely big breakthroughs have often resulted from so-called blue-sky research or curiosity-driven research. It is not a coincidence that the freedom of doing whatever kind of research you think is important is an, almost sacred, privilege of hired scientists. Or should be. Fortunately I am privileged enough, especially in the European Union, to have this privilege. In other places, you are often shackled by all kinds of external influences, down to political pressure to only do politically acceptable research. And this can never spark the creativity you need to make something genuine new. If you are afraid about what you say, you start to restrain yourself, and ultimately anything which is not already established to be acceptable becomes unthinkable. This may not always be as obvious as real political pressure. But if whether you being hired, if your job is safe, starts to depend on it, you start going for acceptable research. Because failure with something new would cost you dearly. And with the currently quite common competitive funding prevalent particularly for non-permanently hired people, this starts to become a serious obstruction.

As a consequence, real breakthrough research can be neither planned nor can you do it on purpose. You can only plan the grinding part. And failure will be part of any creative process. Though you actually never really fail. Because you always learn how something does not work. That is one of the reasons why I strongly want that failures become also publicly available. They are as important to progress as success, by reducing the possibilities. Not to mention the amount of life time of researchers wasted because they fail with them same attempt, not knowing that others failed before them.

And then, perhaps, a new scientific insight arises. And, more often than not, some great technology arises along the way. Not intentionally, but because it was necessary to follow one's creativity. And that is actually where most technological leaps came from. So,real progress in physics, in the end, is made from about a third craftsmanship, a third communication, and a third creativity.

So, after all this general stuff, how do I stay creative?

Well, first of all, I was and am sufficiently privileged. I could afford to start out with just following my ideas, and either it will keep me in business, or I will have to find a non-science job. But this only worked out because of my personal background, because I could have afforded to have a couple of months with no income to find a job, and had an education which almost guarantees me a decent job eventually. And the education I could only afford in this quality because of my personal background. Not to mention that as a white male I had no systemic barriers against me. So, yes, privilege plays a major role.

The other part was that I learned more and more that it is not effort what counts, but effect. Took me years. But eventually, I understood that a creative idea cannot be forced by burying myself in work. Time off is for me as important. It took me until close to the end of my PhD to realize that. But not working overtime, enjoying free days and holidays, is for me as important for the creative process as any other condition. Not to mention that I also do all non-creative chores much more efficiently if well rested, which eventually leaves me with more time to ponder creatively and do research.

And the last ingredient is really exchange. I have had now the opportunity, in a sabbatical, to go to different places and exchange ideas with a lot of people. This gave me what I needed to acquire a new field and have already new ideas for it. It is the possibility to sit down with people for some hours, especially in a nicer and more relaxing surrounding than an office, and just discuss ideas. That is also what I like most about conferences. And one of the reasons I think conferences will always be necessary, even though we need to make going there and back ecologically much more viable, and restrict ourselves to sufficiently close ones until this is possible.

Sitting down over a good cup of coffee or a nice meal, and just discuss, is really jump starting my creativity. Even sitting with a cup of good coffee in a nice cafe somewhere and just thinking does wonders for me in solving problems. And with that, it seems not to be so different for me than for artists, after all.

Acquiring a new field

I have recently started to look into a new field: Quantum gravity. In this entry, I would like to write a bit about how this happens, acquiring a new field. Such that you can get an idea what can lead a scientist to do such a thing. Of course, in future entries I will also write more about what I am doing, but it would be a bit early to do so right now.

Acquiring a new field in science is not something done lightly. One has always not enough time for the things one does already. And when you enter a new field, stuff is slow. You have to learn a lot of basics, need to get an overview of what has been done, and what is still open. Not to mention that you have to get used to a different jargon. Thus, one rarely does so lightly.

I have in the past written already one entry about how I came to do Higgs physics. This entry was written after the fact. I was looking back, and discussed my motivation how I saw it at that time. It will be an interesting thing to look back at this entry in a few years, and judge what is left of my original motivation. And how I feel about this knowing what happened since then. But for now, I only know the present. So, lets get to it.

Quantum gravity is the hypothetical quantum version of the ordinary theory of gravity, so-called general relativity. However, it has withstood quantization for a quite a while, though there has been huge progress in the last 25 years or so. If we could quantize it, its combination with the standard model and the simplest version of dark matter would likely be able to explain almost everything we can observe. Though even then a few open questions appear to remain.

But my interest in quantum gravity comes not from the promise of such a possibility. It has rather a quite different motivation. My interest started with the Higgs.

I have written many times that we work on an improvement in the way we look at the Higgs. And, by now, in fact of the standard model. In what we get, we see a clear distinction between two concepts: So-called gauge symmetries and global symmetries. As far as we understand the standard model, it appears that global symmetries determine how many particles of a certain type exists, and into which particles they can decay or be combined. Gauge symmetries, however, seem to be just auxiliary symmetries, which we use to make calculations feasible, and they do not have a direct impact on observations. They have, of course, an indirect impact. After all, in which theory which gauge symmetry can be used to facilitate things is different, and thus the kind of gauge symmetry is more a statement about which theory we work on.

Now, if you add gravity, the distinction between both appears to blur. The reason is that in gravity space itself is different. Especially, you can deform space. Now, the original distinction of global symmetries and gauge symmetries is their relation to space. A global symmetry is something which is the same from point to point. A gauge symmetry allows changes from point to point. Loosely speaking, of course.

In gravity, space is no longer fixed. It can itself be deformed from point to point. But if space itself can be deformed, then nothing can stay the same from point to point. Does then the concept of global symmetry still make sense? Or does all symmetries become just 'like' local symmetries? Or is there still a distinction? And what about general relativity itself? In a particular sense, it can be seen as a theory with a gauge symmetry of space. Makes this everything which lives on space automatically a gauge symmetry? If we want to understand the results of what we did in the standard model, where there is no gravity, in the real world, where there is gravity, then this needs to be resolved. How? Well, my research will hopefully answer this question. But I cannot do it yet.

These questions were already for some time in the back of my mind. A few years, I actually do not know how many exactly. As quantum gravity pops up in particle physics occasionally, and I have contact with several people working on it, I was exposed to this again and again. I knew, eventually, I will need to address it, if nobody else does. So far, nobody did.

But why now? What prompted me to start now with it? As so often in science, it were other scientists.

Last year at the end of November/beginning of December, I took part in a conference in Vienna. I had been invited to talk about our research. The meeting has a quite wide scope, and also present were several people, who work on black holes and quantum physics. In this area, one goes, in a sense, halfway towards quantum gravity: One has quantum particles, but they life in a classical gravity theory, but with strong gravitational effects. Which is usually a black hole. In such a setup, the deformations of space are fixed. And also non-quantum black holes can swallow stuff. This combination appears to make the following thing: Global symmetries appear to become meaningless, because everything associated with them can vanish in the black hole. However, keeping space deformations fixed means that local symmetries are also fixed. So they appear to become real, instead of auxiliary. Thus, this seems to be quite opposite to our result. And this, and the people doing this kind of research, challenged my view of symmetries. In fact, in such a half-way case, this effect seems to be there.

However, in a full quantum gravity theory, the game changes. Then also space deformations become dynamical. At the same time, black holes need no longer to have the characteristic to swallow stuff forever, because they become dynamical, too. They develop. Thus, to answer what happens really requires full quantum gravity. And because of this situation, I decided to start to work actively on quantum gravity. Because I needed to answer whether our picture of symmetries survive, at least approximately, when there is quantum gravity. And to be able to answer such challenges. And so it began.

Within the last six months, I have now worked through a lot of the basic stuff. I have now a rough idea of what is going on, and what needs to be done. And I think, I see a way how everything can be reconciled, and make sense. It will still need a long time to complete this, but I am very optimistic right now. So optimistic, in fact, that a few days back I gave my first talk, in which I discussed this issues including quantum gravity. It will still need time, before I have a first real result. But I am quite happy how thing progress.

And that is the story how I started to look at quantum gravity in earnest. If you want to join me in this endeavor: I am always looking for collaboration partners and, of course, students who want to do their thesis work on this subject 😁

Asking questions leads to a change of mind

In this entry, I would like to digress a bit from my usual discussion of our physics research subject. Rather, I would like to talk a bit about how I do this kind of research. There is a twofold motivation for me to do this.

One is that I am currently teaching, together with somebody from the philosophy department, a course on science philosophy of physics. It cam to me as a surprise that one thing the students of philosophy are interested in is, how I think. What are the objects, or subjects, and how I connect them when doing research. Or even when I just think about a physics theory. The other is the review I have have recently written. Both topics may seem unrelated at first. But there is deep connection. It is less about what I have written in the review, but rather what led me up to this point. This requires some historical digression in my own research.

In the very beginning, I started out with doing research on the strong interactions. One of the features of the strong interactions is that the supposed elementary particles, quarks and gluons, are never seen separately, but only in combinations as hadrons. This is a phenomenon which is called confinement. It always somehow presented as a mystery. And as such, it is interesting. Thus, one question in my early research was how to understand this phenomenon.

Doing that I came across an interesting result from the 1970ies. It appears that a, at first sight completely unrelated, effect is very intimately related to confinement. At least in some theories. This is the Brout-Englert-Higgs effect. However, we seem to observe the particles responsible for and affected by the Higgs effect. And indeed, at that time, I was still thinking that the particles affected by the Brout-Englert-Higgs effect, especially  the Higgs and the W and Z bosons, are just ordinary, observable particles. When one reads my first paper of this time on the Higgs, this is quite obvious. But then there was the results of the 1970ies. It stated that, on a very formal level, there should be no difference between confinement and the Brout-Englert-Higgs effect, in a very definite way.

Now the implications of that serious sparked my interest. But I thought this would help me to understand confinement, as it was still very ingrained into me that confinement is a particular feature of the strong interactions. The mathematical connection I just took as a curiosity. And so I started to do extensive numerical simulations of the situation.

But while trying to do so, things which did not add up started to accumulate. This is probably most evident in a conference proceeding where I tried to put sense into something which, with hindsight, could never be interpreted in the way I did there. I still tried to press the result into the scheme of thinking that the Higgs and the W/Z are physical particles, which we observe in experiment, as this is the standard lore. But the data would not fit this picture, and the more and better data I gathered, the more conflicted the results became. At some point, it was clear that something was amiss.

At that point, I had two options. Either keep with the concepts of confinement and the Brout-Englert-Higgs effect as they have been since the 1960ies. Or to take the data seriously, assuming that these conceptions were wrong. It is probably signifying my difficulties that it took me more than a year to come to terms with the results. In the end, the decisive point was that, as a theoretician, I needed to take my theory seriously, no matter the results. There is no way around it. And it gave a prediction which did not fit my view of the experiments than necessarily either my view was incorrect or the theory. The latter seemed more improbable than the first, as it fits experiment very well. So, finally, I found an explanation, which was consistent. And this explanation accepted the curious mathematical statement from the 1970ies that confinement and the Brout-Englert-Higgs effect are qualitatively the same, but not quantitatively. And thus the conclusion was what we observe are not really the Higgs and the W/Z bosons, but rather some interesting composite objects, just like hadrons, which due to a quirk of the theory just behave almost as if they are the elementary particles.

This was still a very challenging thought to me. After all, this was quite contradictory to usual notions. Thus, it came as a very great relief to me that during a trip a couple months later someone pointed me to a few, almost forgotten by most, papers from the early 1980ies, which gave, for a completely different reason, the same answer. Together with my own observation, this made click, and everything started to fit together - the 1970ies curiosity, the standard notions, my data. That I published in the mid of 2012, even though this still lacked some more systematic stuff. But it required still to shift my thinking from agreement to really understanding. That came then in the years to follow.

The important click was to recognize that confinement and the Brout-Englert-Higgs effect are, just as pointed out in the 1970ies mathematically, really just two faces to the same underlying phenomena. On a very abstract level, essentially all particles which make up the standard model, are really just a means to an end. What we observe are objects which are described by them, but which they are not themselves. They emerge, just like hadrons emerge in the strong interaction, but with very different technical details. This is actually very deeply connected with the concept of gauge symmetry, but this becomes quickly technical. Of course, since this is fundamentally different from the usual way, this required confirmation. So we went, made predictions which could distinguish between the standard way of thinking and this way of thinking, and tested them. And it came out as we predicted. So, seems we are on the right track. And all details, all the if, how, and why, and all the technicalities and math you can find in the review.

To make now full circle to the starting point: That what happened during this decade in my mind was that the way I thought about how the physical theory I tried to describe, the standard model, changed. In the beginning I was thinking in terms of particles and their interactions. Now, very much motivated by gauge symmetry, and, not incidental, by its more deeper conceptual challenges, I think differently. I think no longer in terms of the elementary particles as entities themselves, but rather as auxiliary building blocks of actually experimentally accessible quantities. The standard 'small-ball' analogy went fully away, and there formed, well, hard to say, a new class of entities, which does not necessarily has any analogy. Perhaps the best analogy is that of, no, I really do not know how to phrase it. Perhaps at a later time I will come across something. Right now, it is more math than words.

This also transformed the way how I think about the original problem, confinement. I am curious, where this, and all the rest, will lead to. For now, the next step will be to go ahead from simulations, and see whether we can find some way how to test this actually in experiment. We have some ideas, but in the end, it may be that present experiments will not be sensitive enough. Stay tuned.

Reaching closure – completing a review

I did not publish anything here within the last few months, as the review I am writing took up much more time than expected. A lot of interesting project developments happened also during this time. I will write on them as well later, so that nobody will miss out on the insights we gained and the fun we had with them.

But now, I want to write about how the review comes along. It has now grown into a veritable almost 120 page document. And actually most of it is texts and formulas, and only very few figures. This makes for a lot of content. Right now, it has reached the status of a release candidate 2. This means I have distributed it to many of my colleagues to comment on it. I also used the draft as lecture notes for a lecture on its contents at a winter school in Odense/Denmark (where I actually wrote this blog entry). Why? Because I wanted to have feedback. What can be understood, and what may I have misunderstood? After all, this review not only looks at my own research. Rather, it compiles knowledge from more than a hundred scientists over 45 years. In fact, some of the results I write about have been obtained before I was born. Especially, I could have overlooked results. With by now dozens of new papers per day, this can easily happen. I have collected more than 330 relevant articles, which I refer to in the review.

And, of course, I could have misunderstood other people’s results or made mistakes. This needs to be avoided in a review as good as possible.

Indeed, I had many discussions by now on various aspects of the research I review. I got comments and was challenged. In the end, there was always either a conclusion or the insight that some points, believed to be clear, are not as entirely clear as it seemed. There are always more loopholes, more subtleties, than one anticipates. By this, the review became better, and could collect more insights from many brilliant scientists. And likewise I myself learned a lot.

In the end, I learned two very important lessons about the physics I review.

The first is that many more things are connected than I expected. Some issues, which looked to my like a parenthetical remark in the beginning became first remarks at more than one place and ultimately became an issue of their on.

The second is that the standard modelof particle physics is even more special and more balanced than I thought. I was never really thinking that the standard model is so terrible special. Just one theory among many which happen to fit experiments. But really it is an extremely finely adjusted machinery. Every cog in it is important, and even slight changes will make everything fall apart. All the elements are in constant connection with each other, and influence each other.

Does this mean anything? Good question. Perhaps it is a sign of an underlying ordering principle. But if it is, I cannot see it (yet?). Perhaps this is just an expression of how a law of nature must be – perfectly balanced. At any rate, it gave me a new perspective of what the standard model is.

So, as I anticipated writing this review gave me a whole new perspective and a lot of insights. Partly by formulating questions and answers more precisely. But, and probably more importantly, I had to explain it to others, and to either successfully defend or adapt it or even correct it.

In addition, two of the most important lessons about understanding physics I learned were the following:

One: Take your theory seriously. Do not take a shortcut or use some experience. Literally understand what it means and only then start to interpret.

Two: Pose your questions (and answers) clearly. Every statement should have a well-defined meaning. Never be vague when you want to make a scientific statement. Be always able to back up a question of “what do you mean by this?” by a precise definition. This seems obvious, but is something you tend to be cavalier about. Don’t.

So, writing a review not only helps in summarizing knowledge. It also helps to understand this knowledge and realize its implications. And, probably fortunately, it poses new questions. What they are, and what we do about, this is something I will write about in the future.

So, how does it proceed now? In two weeks I have to deliver the review to the journal which mandated it. At the same time (watch my twitteraccount) it will become available on the preprint server arxiv.org, the standard repository of all elementary particle physics knowledge. Then you can see for yourself what I wrote, and wrote about

Getting better

One of our main tools in our research are numerical simulations. E.g. the research of the previous entry would have been impossible without.

Numerical simulations require computers to run them. And even though computers become continuously more powerful, they are limited in the end. Not to mention that they cost money to buy and to use. Yes, also using them is expensive. Think of the electricity bill or even having space available for them.

So, to reduce the costs, we need to use them efficiently. That is good for us, because we can do more research in the same time. And that means that we as a society can make scientific progress faster. But it also reduces financial costs, which in fundamental research almost always means the taxpayer's money. And it reduces the environmental stress which we exercise by having and running the computers. That is also something which should not be forgotten.

So what does efficiently mean?

Well, we need to write our own computer programs. What we do nobody did before us. Most of what we do is really the edge of what we understand. So nobody was here before us and could have provided us with computer programs. We do them ourselves.

For that to be efficient, we need three important ingredients.

The first seems to be quite obvious. The programs should be correct before we use them to make a large scale computation. It would be very wasteful to run on a hundred computers for several months, just to figure out it was all for naught, because there was an error. Of course, we need to test them somewhere, but this can be done with much less effort. But this takes actually quite some time. And is very annoying. But it needs to be done.

The next two issues seems to be the same, but are actually subtly different. We need to have fast and optimized algorithms. The important difference is: The quality of the algorithm decides how fast it can be in principle. The actual optimization decides to which extent it uses this potential.

The latter point is something which requires a substantial amount of experience with programming. It is not something which can be learned theoretically. And it is more of a craftsmanship than anything else. Being good in optimization can make a program a thousand times faster. So, this is one reason why we try to teach students programming early, so that they can acquire the necessary experience before they enter research in their thesis work. Though there is still today research work which can be done without computers, it has become markedly less over the decades. It will never completely vanish, though. But it may well become a comparatively small fraction.

But whatever optimization can do, it can do only so much without good algorithms. And now we enter the main topic of this entry.

It is not only the code which we develop by ourselves. It is also the algorithms. Because again, they are new. Nobody did this before. So it is also up to us to make them efficient. But to really write a good algorithm requires knowledge about its background. This is called domain-specific knowledge. Knowing the scientific background. One reason more why you cannot get it off-the-shelf. Thus, if you want to calculate something new in research using computer simulations that means usually sitting down and writing a new algorithm.

But even once an algorithm is written down this does not mean that it is necessarily already the fastest possible one. Also this requires on the one hand experience, but even more so it is something new. And it is thus research as well to make it fast. So they can, and need to be, made better.

Right now I am supervising two bachelor theses where exactly this is done. The algorithms are indeed directly those which are involved with the research mentioned in the beginning. While both are working on the same algorithm, they do it with quite different emphasis.

The aim in one project is to make the algorithm faster, without changing its results. It is a classical case of improving an algorithm. If successful, it will make it possible to push the boundaries of what projects can be done. Thus, it makes computer simulations more efficient, and thus satisfies allows to do more research. One goal reached. Unfortunately the 'if' already tells that, as always with research, there is never a guarantee that it is possible. But if this kind of research should continue, it is necessary. The only alternative is waiting for a decade for the computers to become faster, and doing something different in the time in between. Not a very interesting option.

The other one is a little bit different. Here, the algorithm should be modified to serve a slightly different goal. It is not a fundamentally different goal, but subtly different so. Thus, while it does not create a fundamentally new algorithm, it still does create something new. Something, which will make a different kind of research possible. Without the modification, the other kind of research may not be possible for some time to come. But just as it is not possible to guarantee that an algorithm can be made more efficient, it is also not always possible that an algorithm with any reasonable amount of potential can be created at all. So this is also true research.

Thus, it remains exciting of what both theses will ultimately lead to.

So, as you see, behind the scenes research is quite full of the small things which make the big things possible. Both of these projects are probably closer to our everyday work than most of the things I have been posting before. The everyday work in research is quite often grinding. But, as always, this is what makes the big things ultimately possible. Without such projects as these two theses, our progress would be slowed down to a snail's speed.

Writing a review

As I have mentioned recently on Twitter, I have been given the opportunity, and the mandate, to write a review on Higgs physics. Especially, I should describe how the connection is established from the formal basics to what we see in experiment. While I will be writing in the next time a lot about the insights I gain and the connection I make during writing, this time I want to talk about something different. About what this means, and what the purpose of reviews is.

So what is a review good for? Physics is not static. Physics is about our understanding of the world around us. It is about making things we experience calculable. This is done by phrasing so-called laws of nature as mathematical statements. Then making predictions (or explaining something what happens) is, essentially, just evaluating equations. At least in principle, because this may be technically extremely complicated and involved. There are cases in which our current abilities are not even yet able to do so. But this is technology and, often, resources in form of computing time. Not some conceptual problem.

But there is also a conceptual problem. Our mathematical statements encode what we know. One of their most powerful feature is that they tell us themselves that they are incomplete. That our mathematical formulation of nature only reaches this far. That are things, we do not even yet know what they are, which we cannot describe. Physics is at the edge of knowledge. But we are not lazy. Every day, thousands of physicists all around the world work together to push this edge daily a little bit farther out. Thus, day by day, we know more. And, in a global world, this knowledge is shared almost instantaneously.

A consequence of this progress is that the textbooks at the edge become outdated. Because we get a better understanding. Or we figure out that something is different than we thought. Or because we find a way to solve a problem which withstood solution for decades. However, what we find today or tomorrow is not yet confirmed. Every insight we gain needs to be checked. Has to be investigated from all sides. And has to be fitted into our existing knowledge. More often that not some of these insights turn out to be false hopes. That we thought we understood something. But there is still that one little hook, this one tiny loop, which in the end lets our insight crumble. This can take a day or a month or a year, or even decades. Thus, insights should not directly become part of textbooks, which we use to teach the next generation of students.

To deal with this, a hierarchy of establishing knowledge has formed.

In the beginning, there are ideas and first results. These we tell our colleagues at conferences. We document the ideas and first results in write-ups of our talks. We visit other scientists, and discuss our ideas. By this we find many loopholes and inadequacies already, and can drop things, which do not work.

Results which survive this stage then become research papers. If we write such a paper, it is usually about something, which we personally believe to be well funded. Which we have analyzed from various angles, and bounced off the wisdom and experience of our colleagues. We are pretty sure that it is solid. By making these papers accessible to the rest of the world, we put this conviction to the test of a whole community, rather than some scientists who see our talks or which we talk to in person.

Not all such results remain. In fact, many of these are later to be found to be only partly right, or still have overlooked a loophole, or are invalidated by other results. But this stage already a considerable amount of insights survive.

Over years, and sometimes decades, insights in papers on a topic accumulate. With every paper, which survives the scrutiny of the world, another piece in the puzzle fits. Thus, slowly a knowledge base emerges on a topic, carried by many papers. And then, at some point, the amount of knowledge has provided a reasonable good understanding of the topic. This understanding is still frayed at the edges towards the unknown. There is still here and there some holes to be filled. But overall, the topic is in fairly good condition. That is the point where a review is written on the topic. Which summarizes the finding of the various papers, often hundreds of them. And which draws the big picture, and fits all the pieces into it. Its duty is also to point out all remaining problems, and where the ends are still frayed. But at this point usually the things are well established. They often will not change substantially in the future. Of course, no rule without exception.

Over time, multiple reviews will evolve the big picture, close all holes, and connect the frayed edges to neighboring topics. By this, another patch in the tapestry of a field is formed. It becomes a stable part of the fabric of our understanding of physics. When this process is finished, it is time to write textbooks. To make even non-specialist students of physics aware of the topic, its big picture, and how it fits into our view of the world.

Those things, which are of particular relevance, since they form the fabric of our most basic understanding of the world, will eventually filter further down. At some point, the may become part of the textbooks at school, rather then university. And ultimately, they will become part of common knowledge.

This has happened many times in physics. Mechanics, classical electrodynamics, thermodynamics, quantum and nuclear physics, solid state physics, particle physics, and many other fields have undergone these level of hierarchies. Of course, often only with hindsight the transitions can be seen, which lead from the first inspiration to the final revelation of our understanding. But in this way our physics view of the world evolves.

Structuring internationality

I wrote some time ago about the immense importance of diversity and multiculturality for research. How important exchange is by going abroad and to have people from many different places around oneself. Also, and probably even more important so, at home. How this is indispensable to make research possible, especially at the utmost frontiers of human knowledge.

This is, and remains, true. There is no progress without diversity. In this entry, I would like to write a bit about what we did recently to foster and structure such exchange.

The insight that diversity is important is something fortunately embraced also by the European Union. As a consequence, they offer various support options to help with this goal. One possibility are so-called COST networks. These actually involve countries, rather than individuals, with the intention to foster exchange across borders.

Since mid of October, Austria is now member of one such network within one of my core research areas, the physics governing quarks and gluons at high temperatures and densities, relevant for how the early universe evolved, and what the properties of supernovas and neutron stars in today's universe are. In this network I am one of the two representatives of Austria, i.e. speaking on behalf of the scientists in Austria being members of this network. Representatives of the (so far) 26 member countries have met in Brussels in the mid of October to discuss how this exchange should be organized in the future. One important part of this agenda, also very much encouraged by the European Union, is the promotion of minorities and gender equality and to support scientists from countries with economically less support for science.

On this first meeting, which was actually only on these and other issues and not on scientific content, we have established an agenda how the funds available to us in this network will be prioritized to achieve this goal. This includes the possibility for members of the aforementioned groups to receive travel support to meetings and collaboration partners and/or preferential participation in events. We want them to be part of this effort as fully as possible. We need them, and their perspectives, to make progress, and also to reevaluate our own views and endeavors.

Of course, there were also many other issues to be discussed, many of them rather administrative in nature. There were also discussions involved, when there were some different opinions on which was the ideal way forward. But, as a democratic process, this was resolved in a way to which everyone could commit.

It was certainly a quite uplifting experience to sit together with scientists from so many different countries, not with the aim to find an answer to a physics problems as at a conference, but rather with the goal to get people together, to connect. In the roughly four years this structure will run we will have several more meetings. The ultimate goal will be a joint series of so-called white papers. White papers are statements describing the most urgent and challenging problems in a given branch of research. Their aim is to structure future research and to make it more efficient by separating the irrelevant from the relevant questions.

These white papers will then be a truly international effort. People from almost thirty countries will provide a mutual view on some of the most challenging problems at the frontier of human knowledge. Questions important for our origin and of the world we live in. Without such a network, this would surely not happen. Rather, the many groups in different countries would be more isolated. And then there would be too many smaller groups trying to achieve the same purpose. But without such a broad and international basis and connection, the outcome would certainly not have such a broad collection of perspectives. And only by enough views coming together, we may eventually identify the point were all eyes look on, giving us the clue, where the key to the next big leap forward could be hidden.

How to search for dark, unknown things: A bachelor thesis

Today, I would like to write about a recently finished bachelor thesis on the topic of dark matter and the Higgs. Though I will also present the results, the main aim of this entry is to describe an example of such a bachelor thesis in my group. I will try to follow up also in the future with such entries, to give those interested in working in particle physics an idea of what one can do already at a very early stage in one's studies.

The framework of the thesis is the idea that dark matter could interact with the Higgs particle. This is a serious possibility, as both objects are somehow related to mass. There is also not yet any substantial reason why this should not be the case. The unfortunate problem is only: how strong is this effect? Can we measure it, e.g. in the experiments at CERN?

We are looking in a master thesis in the dynamical features of this idea. This is ongoing, and something I will certainly write about later. Knowing the dynamics, however, is only the first step towards connecting the theory to experiment. To do so, we need the basic properties of the theory. This input will then be put through a simulation of what happens in the experiment. Only this result is the one really interesting for experimental physicists. They then look what any kind of imperfections of the experiments change and then they can conclude, whether they will be able to detect something. Or not.

In the thesis, we did not yet had the results from the master student's work, so we parametrized the possible outcomes. This meant mainly to have the mass and the strength of the interaction between the Higgs and the dark matter particle to play around. This gave us what we call an effective theory. Such a theory does not describe every detail, but it is sufficiently close to study a particular aspect of a theory. In this case how dark matter should interact with the Higgs at the CERN experiments.

With this effective theory, it was then possible to use simulations of what happens in the experiment. Since dark matter cannot, as the name says, be directly seen, we needed somehow a marker to say that it has been there. For that purpose we choose the so-called associate production mode.

We knew that the dark matter would escape the experiment undetected. In jargon, this is called missing energy, since we miss the energy of the dark matter particles, when we account for all we see. Since we knew what went in, and know that what goes in must come out, anything not accounted for must have been carried away by something we could not directly see. To make sure that this came from an interaction with the Higgs we needed a tracer that a Higgs had been involved. The simplest solution was to require that there is still a Higgs. Also, there are deeper reasons which require that dark matter in this theory should not only arrive with a Higgs particle, but should be obtained also from a Higgs particle before the emission of the dark matter particles. The simplest way to check for this is that there is besides the Higgs in the end also a so-called Z-boson, for technical reasons. Thus, we had what we called a signature: Look for a Higgs, a Z-boson, and missing energy.

There is, however, one unfortunate thing in known particle physics which makes this more complicated: neutrinos. These particles are also essentially undetectable for an experiment at the LHC. Thus, when produced, they will also escape undetected as missing energy. Since we do not detect either dark matter or neutrinos, we cannot decide, what actually escaped. Unfortunately, the tagging with the Higgs and the Z do not help, as neutrinos can also be produced together with them. This is what we call a background to our signal. Thus, it was necessary to account for this background.

Fortunately, there are experiments which can detect, with a lot of patience, neutrinos. They are very different from the one we at the LHC. But they gave us a lot of information on neutrinos. Hence, we knew how often neutrinos would be produced in the experiment. So, we would only need to remove this known background from what the simulation gives. Whatever is left would then be the signal of dark matter. If the remainder would be large enough, we would be able to see the dark matter in the experiment. Of course, there are many subtleties involved in this process, which I will skip.

So the student simulated both cases, and determined the signal strength. From that she could deduce that the signal grows quickly with the strength of the interaction. She also found that the signal became stronger if the dark matter particles become lighter. That is so because there is only a finite amount of energy available to produce them. But the more energy is left to make the dark matter particles move the easier it gets to produce them, an effect known in physics as phase space. In addition, she found that if the dark matter particles have half the mass of the Higgs their production became also very efficient. The reason is a resonance. Just like two noises amplify each other if they are at the same frequency, so such amplifications can happen in particle physics.

The final outcome of the bachelor thesis was thus telling us for the values of the two parameters of the effective theory how strong our signal would be. Once we know these values from our microscopic theory in the master project, we know whether we have a chance to see these particles in this type of experiments.

Some small changes in the schedule

As you may have noticed, I have not written a new entry since some time.

The reasons have been twofold.

One is that being a professor is a little more strenuous than being a postdoc. Though not unexpected, at some point it takes a toll.

The other is that in the past I tried just to keep a regular schedule. However, that often required of me to think hard about a topic as there was no natural candidate. At other times, I had a number of possible topics, which where then stretched out rather than to be written when they were important.

As a consequence, I think it is more appropriate to write entries when something happens that is interesting to write about. This will be at least any time we put out a new paper, so that I will still update you on our research. I will also write something whenever somebody new starts in the group, or otherwise we start a new project. Also, some of my students want to also contribute, and I will be very happy to give them the opportunity to do so. Once in a while, I will also write some background entries, such that I can offer some context for the research we are doing.

So stay tuned. It may be in a different rhythm, but I will keep on writing about our (and my) research.

An international perspective

This time, I would like to write a little bit about a very important part of our work: Being international.

Right now, in our complete particle physics group, we have with about 25 people about 12 nationalities. So, being international is a very basic part of our daily life. This yields a long list of effects. It starts from using a common language so that everyone one can speak to everyone (which is today English, but has been a different one in the past, and may again be a different one in the future. English as the language of science is only there since less than a century). Thus, we need to educate also all our students in this language somehow. And this not only pertains to normal speaking, but also the specialized vocabulary of our topic.

Being international also requires us to pay attention to many more administrative aspects, which appear due to the existence of different nations. The question of who can represent our work in which country, because it is possible to get a visa, is not an entirely simple problem. Being from the European Union myself puts me in a privileged position, as I can get into most countries with little or no effort. But this is not true for many other people, giving us often headaches and requires long-range planning, if we want someone particular to go somewhere. Furthermore, when students come from abroad, they may have learned different things, and therefore have a different background, which needs to be leveled, so that everyone can talk to everyone. And, finally, this may also manifest on how to incorporate different cultures and habits. This does not only touch upon the personal, but can very much also affect the way how we work together. In some areas of the world, it is still usual that less experienced people accept that what more experienced people do without questioning, probably since childhood, as an example. This does not help in doing science: Everyone has to speak open, and also criticize to find out errors. None of us is error free, and therefore everyone must contribute in nailing errors.

This list can be continued almost indefinitely.

Why do we put up with this? It appears a lot of extra work, just to do science.

But here comes into play how science today operates: On a global scale. And this is very good for two reasons.

One is that the problems we have to deal with becomes more and more specialized, and thus a smaller and smaller percentage of scientists can work on them. To still have a sizable workforce requires therefore to include as many people as possible. Otherwise, too specialized subgroups may loose contact, and become adrift, with no possibility to regain the overarching picture. This could also be put the other way around: Today's problems are far too complex that any single country, even the largest ones, could have enough scientific workforce to deal with them. Everyone is needed. And this not even touches upon having enough resources to do certain kinds of research.

The other is that we need diversity. The different educational, cultural, and habitual backgrounds also play an important role in science. Everyone has learned in school and during studies something in a particular style. Everyone has adopted certain view points, and certain strategies. But science lives in the unknown. There is no gold-plated way how to deal with the unknown. Therefore, there is no special preparation which is the best way to be prepared for doing science. We need many different minds, vastly different minds, such that we can get many perspectives. We need people with different backgrounds, with a different lookout on everything, to find new angles how to deal with problems. We need all ways of seeing things, even those which at first may look not intuitive to ourselves. But we have to learn and listen to all the view points. Thus, everyone who is willing to support the scientific process, the ever turning wheel of creating a theory and putting it through myriads of experimental tests, can provide a new point of view. Thus, diversity is essential for us. New problems need different points of view.

This is one of the points which also explains the many travels scientists do, often for years. Every new surrounding, every new group of peoples, provides a new perspective. Changing one's perspective by traveling, or by bringing many different peoples to our homes, helps us in broadening our view, in giving us the opportunity to learn adopt to take new perspectives. This is demanding for the individual, as it implies being around the world rather than at home, but our understanding profits from being used to seeing things from many perspectives.

The ability to see from different perspectives is not only supported by talking to other scientists. But experiencing different cultures, different surroundings in general, and trying to understand them, gives us the ability. So, diversity is essential to our ability to understand.

This is why being international is so extremely important for modern research, and why diversity counts so much for basic research.

And this also implies that already living in a diverse culture in a single spot will already help us in becoming better in understanding. If we are used to experience the new, and trying to understand it, in everyday live, it prepares us also to face the new at the boundary of our knowledge.

Can we tell when unification works?

Some time ago, I wrote about the idea that the three forces of the standard model, the electromagnetic force, the weak force, and the strong force, could all be just different parts of one unified force. In the group I am building I have now a PhD student working on such a theory, using simulations.

Together, we would like to answer a number of questions. The most important one is, whether such a theory is consistent with what we see around us. That is necessary to make such a theory relevant.

Now, there is almost an infinite number of versions of such unified theories. We could never hope to check each and every one of them. We could pick one. But hoping it would be the right one is somewhat too optimistic. We therefore take a different approach. We aim to get a general criterion such that we can check out many of the candidate theories at the same time.

For this reason, we ignore for the moment that we would like to reproduce experiments. Rather, we ask ourselves what are common traits of these theories. We have done that. What we are currently doing is to construct the simplest possible theory which has as many of these traits as possible. We have almost completed that. This reduced theory will become indeed very simple. Of known physics, it contains the weak force and the Higgs. As with every unified theory, it also contains a number of additional particles. But they are not dangerous, if they will be too heavy to be visible to us. At least, as long as we do not have more powerful experiments. The last ingredient are the interactions between the different particles. That is what we are working on now. Having the simplest possible theory has also another benefit - it demands small enough computer resources to be manageable.

After fixing the theory, how do the questions look like? One of the traits of such theories is that there are many new particles. What is there fate? How is it arranged that we cannot see them? If we think of the theory describing only rather small changes to the standard model, we can use perturbation theory. With this, we would just follow pretty old footsteps, and the answer can essentially be guessed form the experience of other people. The answer will be that all the surplus stuff is indeed very, very heavy. In fact, so heavy that our experiments will not be able to see it in any foreseeable future, except as very indirect effects. We get out what we put in.

But here comes the new stuff. As I have described earlier, there are many subtleties when it comes to the Higgs of the standard model. But in the end, everything collapses to a rather simple picture. Almost a miracle. Almost, but not quite. The reason is the structure of the standard model, which is very special in the number and properties of particles. The other one is that the parameters, things like masses, just fits.

The natural question is hence: Does the miracle repeats itself for this type of unified theory? Is the new stuff really heavy? Is the known stuff light enough? If the almost-miracle repeats itself, the answer is yes. Should it repeat itself? Well, we will test under which conditions it repeats itself, by playing around both with the number of particles, their structures, and the parameters. We assume right now that we can get it to work, but that we can also break it. And we would like to understand very precisely when it breaks and why it breaks. And finally, the most obvious question, do we want that it repeats itself? Probably the most obvious question, arguably the hardest to answer. If it does not repeat itself, a whole class of ideas becomes more problematic. Ideas, which are conceptually pretty attractive. So, in principle, we would like to see it repeating itself. But then, would it not be more interesting if we needed to start afresh? Probably also true. But in the end, our preference should not play a role. After all, nature decides, and we are just the spectators, trying to figuring out what goes on. And our preferences have nothing to do with it, and therefore we should keep them out of the game.