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Yesterday I heard a personal account of the aftermath of a terrorist attack from Sarah Levy. This made me think of an experience of my own. In 1995 I was living in Bures-sur-Yvette near Paris and working at the Institut des Hautes Etudes Scientifiques. I used to frequently travel into Paris in the evenings to go into the library of Pompidou centre. On one occasion the train I took stopped at the outer ring. It was announced that traffic was interrupted and that those who wanted to go into the centre of town should continue with the underground, which I did. No one seemed to know what was going on but from the conversations around me I got the idea that there had been a terrorist attack. I spent the evening in town and there was a very strange atmosphere. Nobody seemed to know what exactly was going on. There were red rescue helicopters landing on the square in front of Notre Dame.

What had happened is the following. A bomb exploded in a train of the RER line D, the one I usually took to go into town shortly before it reached the station Saint-Michel, the one I usually got out at. Eight people were killed and 171 injured. The helicopters were there to bring the injured to hospitals. If I had left home one hour earlier on that day I could have been in that train. The attack was carried out by a group called the Armed Islamic Group of Algeria. Around that time they also carried out several other bomb attacks in Paris and other parts of France. This was the time when suddenly dustbins became security risks and could no longer be used normally. Given the fact that there have been tens of thousands of violent attacks by people asserting their support for Islam it is not so surprising that I should come close to one of them. As far as I can remember in those days the attack was universally condemned in the media and the origin of the perpetrators was not kept secret so to avoid encouraging discrimination. Halcyon days.

I have just read the book ‘The Parasitic Mind’ by Gad Saad. Its subject is political correctness and the decline of rationality and freedom of speech in the West. The author was born in Lebanon and escaped with his Jewish family to Canada as conditions in Lebanon became unacceptable for them. His parents made the mistake of returning to Lebanon once. They were kidnapped by terrorists and presumably tortured before they were able to return to Canada. Saad explains his strong commitment to freedom and to truth. In these things he is uncompromising and he was told by his mother that his commitment to truth was too strong. Here I feel sympathy for him since I also have a strong commitment to truth and have been criticised for it.

Having escaped from repressive conditions in Lebanon Saad was confronted in Canada with postmodernism in universities. He describes it as a parasitic mind virus. He compares it with physical parasites. One example is Toxoplasma gondii, which when it infects mice leads them to become friendly with cats, too friendly for their own good. I find the analogy quite appropriate. Our intellectual discourse is affected (infected) by a nefarious influence which could lead to the death of the West. As a young researcher who did not yet have tenure I considered whether I should concentrate my efforts on the US or the European job market. One reason I chose the latter was the spectre of political correctness in the US. In fact many examples presented by Saad indicate to me how right I was although I had no idea of the reality at that time. The events described in these examples are at first sight ridiculous but in the end really shocking.

I am not so fond of Saad’s style and choice of words which seem to me often a bit crude. For instance the word ‘lunatic’ occurs a bit too frequently for my taste. It may be that this is necessary for combatting political correctness since it is necessary to fight fire with fire. My own aesthetic feeling causes me to prefer the suave prose of Douglas Murray, as it is found in the book of his I reviewed recently. There are some formulations in Saad’s book which I liked, whereby I do not know which of those are his inventions. For instance there is ‘testicular fortitude’ and ‘tyranny of the minority’. In the context of political correctness he talks about self-flagellation. The idea of comparing the woke to flagellants is one which had previously occurred to me spontaneously.

One of the most interesting parts of the book for me is the seventh chapter. It contains a lot of interesting statistics. One simple question posed (and answered) is how many Jews there are in the world and how many Muslims. If someone had asked me that question without warning then I think I would have got the orders of magnitude right. I nevertheless found it striking to see the numbers. In a large part of the chapter data are presented which serve to illuminate the question about the nature of Islam ‘Is it a merciful, tolerant and peaceful religion or is it a religion of violence, intolerance and domination’. The numbers speak for themselves.

The last chapter in the book is an appeal for people to speak up. In the recent past I have increasingly tended to formulate my political opinions clearly in public without worrying too much about the consequences. In fact this has not had negative consequences for me. There are a couple of reasons for this. One of these is that my circle of contacts, physical and virtual, is quite narrow. The other is that as a professor of mathematics rather than, for instance, sociology I am far away from the main sites of infection in the universities. In fact speaking openly has mainly led me to interesting and pleasant contacts. Why did I read this book? I did so because what I had heard about Gad Saad had aroused my curiosity. Another alterior motive is that this was a kind of preparation for reading Saad’s upcoming book ‘Suicidal Empathy’.

As I mentioned in a post I wrote a long time ago the writer I admire most is Marcel Proust. This is something which has remained constant for very many years. In fact a long time ago he was part of a trinity in my personal literary heaven together with Virginia Woolf and James Joyce. At one time when I was rereading Ulysses I lived in Berlin and had a long commute to work. I tried reading Ulysses in the train but I sometimes had to laugh so much that I found it embarrassing. After that I decided to read the book only discretely and in private. Somehow in the course of time Joyce fell back a little in my estimation leaving the other two alone on the summit. In the end I feel that for me Proust is slightly ahead of Woolf. Some thoughts related to this can be found here. Special features of Proust’s work are that he only published one novel, ‘A la recherche du temps perdu’ and that that was extremely long. I have read the whole novel twice in the original and some parts of it more often. I recently started reading a little of it again and that is what has prompted this post. The question occurred to me whether Proust’s writing would still be as attractive for me or whether I might have changed so much over the years that that might have changed. The former is the case. As an example I quote a short passage from the first pages ‘comme ceux qui partent en voyage pour voir de leurs yeux une cité désirée et s’imaginent qu’on peut goûter dans une réalité le charme du songe’. [like those who go on a journey to see a city of their desire with their own eyes and imagine that it is possible to experience in reality the charm of a dream]. The author belongs to the group of people he is describing here and I do so too.

When reading ‘A la recherche du temps perdu’ you will not find much about mathematics. I seem to remember that Henri Poincaré puts in a cameo appearance, crossing the salon of Madame Verdurin, but I do not remember that anything significant was said about him. I do, however, see a connection between Proust and mathematics which is that it is often the case in the book that we experience Proust thinking in the way mathematicians do. I, as a mathematician, found myself feeling a sense of community in these cases. I cannot cite any examples. I am not trying to make an argument of literary criticism here – I am just describing my impressions. One idea which I see in Proust’s writing is that it often makes sense to identify things which are isomorphic. Proust presumably never encountered the word isomorphism let alone its formal definition but my impression is that he understood the meaning and significance of the concept very well. Another thing I want to mention is that in the last part of the novel, ‘Le temps retrouvé’ there is a scene which can be thought of as a spacetime diagramme. Not surprisingly it is a Newtonian spacetime, not a relativistic one. Proust was distantly related to Henri Bergson who also wrote about the concept of time. I read in the biography of Proust by Jean-Yves Tadié that Proust was irritated by the fact that people liked to compare him with Bergson. I have not read Bergson but I suspect that what he wrote about time was nothing but hot air so that Proust’s indignation was justified.

What is it that makes Proust’s writing so attractive for me? Both content and form are important. On the level of content I feel that I am very much on the same wavelength as the author in matters of philosophy. I really do not know to what extent I, in my youth, found my own ideas reflected in those of Proust and to what extent I simply adopted his ideas in forming my own. On the level of form I find his use of language exceptionally beautiful. It took quite some time for me to be able to absorb his long and complicated sentences. A favourite of mine (I claim no originality for my taste here – this is one of Proust’s most famous sentences) is the sentence which begins ‘Mais quand d’un passé ancien’. When I read the sentence it evokes a picture of a mountain stream, flowing rapidly downhill, turning repeatedly to avoid large stones until it flows into open water (l’édifice immense du souvenir). This image has nothing to do with the content of the sentence, it has to do with its rhythm.

I have just attended the conference mentioned in the title of this post. My general impression is that mathematics as I understand it is being more and more excluded by on the one hand masses of data and on the other hand by reliance on computers related to machine learning, AI etc. A cynical formulation would be to say that a research project is a machine for converting masses of data into complicated brightly coloured diagrams. The use of simple logical arguments to get real insights is becoming rarer. In my opintion this is not because such things are no longer possible or useful but decause they are no longer fashionable. Conversations with other older participants of the conference indicate to me that I am not alone in this opinion. Having got rid of some complaints let me now say something about some of the talks at the conference I liked best.

The first of these is a case where there were huge amounts of data involved and very complicated coloured pictures but there were also practical results which I found very impressive. The talk was by Bernd Bodenmiller from Zurich. In this work mass spectrometry techniques were used to produce very detailed pictures of the distribution of substances in slices of tumour tissue. I was surprised by one picture which showed the distribution of a conventional platinum-based chemotherapeutic agent within a tumour. While it was uniformly distributed through certain parts of the tumour it was more or less absent from others. Apparently cancer cells can develop methods to exclude this kind of drug from certain regions and thus survive. The one theme in the talk which caught my attention most was an application of this method to ovarial cancer. This is a very deadly cancer with frequent relapses after treatment. In the work reported on imaging techniques were use to distinguish different classes of patients and relate the differences between them to the rate of relapse. Beyond this predictions could be made which drugs might benefit which patients most. Patients were subjected to a kind of dual treatment strategy which would be illegal in Germany but which is fortunately legal in Switzerland. The idea is that on the one hand therapy decisions are considered in a conventional way and this information is given to the tumour board. Independently of this an analysis is done using the advanced imaging methods and this information also goes to the tumour board. These two sets of information are combined to make therapeutic decisions. In one case this method was applied to a patient already in palliative care, predicted to live for only a few more weeks. Five years later she is still alive and well. This is just one extreme case and the total sample size of patients is small. Nevertheless the preliminary conclusion is that this method leads to an large extension of the lifetime of the patients (I think a factor of four) in comparison to conventional approaches.

The second talk I want to mention is that of Becca Asquith. I had already heard a talk by her on a similar subject a couple of years ago and I wrote about it in a previous post. It has been observed that the KIRs an individual has can affect their ability to combat various infectious and autoimmune diseases, both positively and negatively, depending on the example. This is correlated to which MHC molecules the individual has. The subject of the talk was understanding the mechanisms behind these phenomena. One conclusion is that a determining factor is the typical lifetime of T cells. So how could KIRs modulate this lifetime? Two hypotheses are compared. One of these is that NK cells carrying the KIRs kill T cells, thus reducing their average lifetimes. Experiments were described which together with modelling, can decide between these two mechanisms. I find that this project was a beautiful combination of theory and experiment, exactly as I imagine such a project should ideally be. The whole thing, in particular the logical connections were very well described in the talk. At the end I asked the speaker why NK cells should kill T cells. Could this be of benefit to the organism or is it just a kind of collateral damage? My understanding of the answer, which I find plausible, is that any mechanism which can be used by the immune system to regulate its activity will be used.

The third talk was by Andreas Reichel, head of research at the company Bayer. He started off by mentioning a possible mechanism of action of a drug which is different to those commonly seen. This is to direct a certain protein to the proteasome so that it is destroyed. He then talked about the way in which candidate drugs are identified in the pre-clinical region. He mentioned a method in which a relatively simple ODE model can be used to obtain information. It can be used to find promising candidates. It can be used to suggest good doses for trials. (Sometimes increasing the dose produces no effect of the kind desired.) It can be used to choose optimal times for taking blood samples when testing candidates. Apparently it has been possible to convince decision makers that this theoretical work is something they can really profit from. For me this is a good example of how (relatively simple) mathematics can be used to make a significant contribution to a practical task such as drug discovery. If someone wants to develop models of this kind or apply them in an intelligent way then they need to things from analysis which I teach students on a day to day basis.

I was able to leave hospital on 28.2 (in my last post I wrongly wrote 28.4) and there is nothing spectacular to report there. There was another inaccuracy in what I wrote in the last post. The oral antibiotic I am taking now is amoxicillin, not penicillin – I got all my penicillin intravenously.

What I write here has to do with something further in the past, in the time period where the infection was at its height and was probably having some mental effects. At the beginning of my time in a hospital bed, I felt that my whole world had shrunk to the small area which was the surface of that bed. Since I was attached to a surgical drain for my wound on the one side, a urinary catheter on the other side and often also to an infusion I was confined to the bed. Perhaps more siginificant is that I was somewhat disoriented. I was not really aware that I was in a hospital ward. I just knew that I was in some room which apart from my bed seemed to be filled with a lot of equipment. Once I had an unpleasant dream related to this. It started with ideas related to clubs which could enter into associations with each other or could become members of ‘clubs of clubs’. This lead to a complicated network. The next idea was that this network was realised physically by a network of rooms. I wanted to escape from these rooms but there were a couple of problems. The rooms were full of equipment, thus mirroring my picture of the room I was actually in. It was also the case that I was attached to some of this equipment so that I could not leave. When I woke up from this dream, feeling some panic, I was completely disoriented and had no idea where I was or why. After some time I noticed a mobile phone and had the idea that it might be my mobile phone. I entered the code and it did not work. I tried a second time and it did. This was the first step in making contact with reality again.

The other thing I experienced was a certain kind of hallucinations. They were around for a couple of days. During that time the situation was as follows. If I closed my eyes I saw pictures of different kinds. One type of picture was a swarm of green dots on a black background which moved around. In particular, if I listened to music they would move around following the music. Another example was in a case where I was being transported from one part of the hospital to another in my bed. After entering a lift I closed my eyes and saw a picture which was more or less identical to the actual lift. It was almost as if I could see with closed eyes. In other cases I saw moving pictures of people, like short videos. I even had a certain power to choose the subject of these videos. The only negative thing was that these visual sequences were very short. I have never experienced anything like this at any other time in my life. I found the experience mostly positive. Sometimes I did have the impression that in some part of my field of view there was something which was evil, something to be afraid of. However I had the robust strategy that whenever I saw something like that I tried to move towards it or focus on it. Then it had no power to frighten me. This experience seems like a natural alternative to hallucinogens although the geometrical patterns I saw appeared to me significantly different from those typical for hallucinogens. During some of these experiences I felt as if I had travelled very far from normal life.

On 10.2 I suddenly felt sick, feeling cold and shivering, I once went to the toilet and on the way back I felt myself too weak to reach my office. Colleagues called an ambulance but they were not able to find anything specific. A colleague drove me home. In the next days I had high and fluctuating temperatures, up to 39,9 C. Eva and I were focussed on that issue but I also noticed some slight pain in my right leg. At one point this pain suddenly became so intense that I could hardly walk. I spent some time observing the fever and hoping that the leg (in fact in the meantime I had localised the problem to the knee) would get better spontaneously. It did not. On 13.2 I went to see my GP. She did a rapid test for thromboses and the result came out positive. She told me to go to the angiology section of the University Clinic. That institute found at most a very minor thrombosis problem and sent me on to the surgery department. There they found strong indicators of inflammation, leukocytes and CRP. For this reason they did a biopsy of the knee. When the doctor told his assistant he wanted a ‘big needle’ I asked him if he meant this in the sense of length or diameter. He said diameter and the process was correspondingly painful. The biopsy produced a lot of pus. This meant that an operation was unavoidable. First, on 14.2 they did a minimally invasive version of the operation but the results were not satisfactory. It was necessary to repeat the operation in a more radical form a few days later. All the pus was presumably from one type of bacterium and it was of key importance to find out which one so as to be able to choose the most appropriate antibiotics. Someone talked about ‘fishing with antibodies’. When they suddenly started giving me penicillin I got excited and supposed they had found the culprit. They had indeed. It is Streptococcus agalactiae. With a known enemy I immediately felt much better.

The name of this bacterium already suggests that it has something to with milk. In fact it was first found on the udders of cows suffering from a disease which was stopping them from giving milk. I find it a curious coincidence that one of the topics in my seminar in the next semester is milk fever, also a disease of dairy cows. In fact the latter is not an infectious but a metabolic disease. When a cow has a calf and starts producing a lot of milk she may not be able to maintain the calcium levels in her body. For some information about mathematical models of this phenomenon see this post.

Because I am getting penicillin at the moment I reread the part of the book ‘A Brief History of Medicine’ by Paul Strathern which describes the discovery of penicillin. Part of this is the story of how penicillin was used to treat a human for the first time. For the first time enough of the substance had been produced to make this feasible. Then there was an emergency. A policeman had pricked his finger on a rose bush and the infection had become life-threatening. He was given penicillin and after four days he was in a good state of health. Unfortunately at that point the penicillin ran out. Two days later he died from the infection. We often do not realise how much we benefit from modern medicine. Before the advent of antibiotics a simple wound could easily be fatal. Now I am conscious of how I am benifitting from the work of Alexander Fleming and others. At the same time I feel anger that Robert Kennedy is doing his best to destroy it all.

Yesterday I had a third operation. It is getting to be routine. At the moment it still looks as if I could leave hospital on 28.4, taking penicillin in oral form after that.

I just saw an article by the chemistry professor Anna Krylov from October 2025 where she explains why she refused to review an article for a journal belonging to the Nature publishing group and more generally communicated to them that she will not cooperate with them in the future, unless they change their policies. The reason is that there are grounds to believe that they are sacrificing truth to political ideology. In this way they are undermining science and truth. She gives three examples to support this view. The first is that reviewers are to be selected ‘with diversity in mind’. In other words, at this point the criterion of competence is being replaced by one of identity politics. The second is so-called ‘citation justice’. This means that the criterion for citing a paper is not its relevance but biological and social characteristics of the authors. It suggests replacing criteria in science like ‘is it true’ or ‘is it interesting’ by ‘who said it’. The third is that results of research work should be suppressed if they are potentially harmful to certain groups, whatever harmful means.

I am very conscious that the influence of truth and science in society is declining but I was shocked to see that this process has affected science itself to such an extent. I suppose that I did not notice this directly since my field, mathematics, is presumably one of the least affected. The problems pointed out by Krylov do not apply equally to all journals. Despite this, since my most recent article appeared in a journal belonging to the Nature publishing group, I feel I have to pay more attention to this type of issue in the future. When I started publishing scientific papers there was no reason to doubt the integrity of any well-known publisher. The choice of a journal to publish in was based on the quality of the scientific content alone. More recently it has become necessary to more careful due to harmful economic influences and the rise of predatory publishing. Now we have an additional factor, where the quality of the scientific literature is under attack not only due to monetary influences but also due to political ideology.

I have just read the book ‘On Democracies and Death Cults’ by Douglas Murray. It is one of the most rewarding reads I have had for a long time and it has my highest recommendation. In recent months I have thought a lot about what is happening in Gaza and Israel but I was missing a lot of background information. I am now much better informed due to reading Murray’s book. One part of the new things I have learned concerns what has happened in Israel and Gaza in the aftermath of 7.10.2023 and this is based on Murray’s extensive research on the ground which in part was done a very short time after the attack on Israel took place. The other part consists of historical information about the conflict between Israel and its neighbours.

A starting point for the book is that while the attack on Israel took place on 7.10 there was already an anti-Israel demonstration in Times Square on 8.10. Murray was there and taking photos. This was at a time when the rape and murder in Israel was still going on. Similar events were observed in other Western countries including Germany, France and Canada. They were out of control of the police. A theme which is central to the book is the paradoxical nature of the reactions to the attack on Israel in the Western world. Instead of the natural reaction of solidarity with Israel there was condemnation of Israel, a particularly blatant example of victim blaming. There was not a single protest against Hamas. All this can be seen as symbolic of a wider trend with Israel playing the role of the Western world. At present many people in the Western world who are publicly visible (such as politicians, intellectuals and journalists) tend to condemn the Western world, its traditions and culture. At the same time they generously pardon the crimes of its enemies to the point of even acting to prevent people from talking about those crimes and their perpetrators by any means possible. Murray feared that people would deny the atrocities that had happened in the attack and he travelled to Israel (and to Gaza) as soon as possible so as to document the events. He was able to view the famous compilation of videos showing the horror of the attack. He was struck by the fact that the terrorists appeared to be enjoying what they were doing and to be proud of it. One of them contacted his parents via WhatsApp and sent them pictures of about ten people he had killed with his own hands. His parents were delighted. Murray quotes the journalist, publisher and diplomat George Weidenfeld as stating that there are people who are worse antisemites than the Nazis. While the Nazis tried to hide their worst crimes from outside observers Hamas publicised their crimes as much as possible. To try to understand this phenomenon better Murray talked to many people, including survivors of the attack, families of those killed and those kidnapped to Gaza, members of the Israeli security forces and Israeli politicians including Benjamin Netanjahu.

Murray explains how the takeover of Iran by Ayatollah Khomeini is at the root of many of the present problems in the Middle East. The enemies surrounding Israel are now like the tentacles of the Iranian regime. The change of government in Iran was praised by many left-wing intellectuals in the West, including Michel Foucault. There may be an exceptional concentration of evil in Hamas but they could not have acted as they have done without weapons, training and other support from Iran. The question of how the disaster of 7.10 could have happened is not one which is answered in the book. However there is one suggestion of something which could have been an important contributing factor: hubris. Israel was known to others and to itself as being a master of defending itself and it seems that the Israeli authorities thought that they had Gaza completely under control, which turned out to be a grave error. A feature of the relations between Israel and Gaza has been the exchanges of huge numbers of Palestinians who were in Israeli prisons (of whom many had committed terrible crimes) for a few hostages. In this context Israel is the perfect target for blackmail. I learned from the book that Yahya Sinwar, the mastermind of the attack on 7.10, was one of more than a thousand Palestinians released in return for just one soldier who had been a hostage. While in prison a doctor discovered that Sinwar was suffering from a brain tumour. He was treated for this in an Israeli hospital. On 7.10 several relatives of that doctor were killed or kidnapped. One of them was an 85 year old holocaust survivor, Yaffa Adar, who had been in the Warsaw Ghetto. She was taken to Gaza and held for 49 days before being released.

Murray was shown around the village of Nir Oz where of about 400 inhabitants about 100 were killed or kidnapped and was told the stories of what had happened to them. There was for instance Bracha Levinson, 74 years old, child of holocaust survivors. The terrorists who came into her house took her cell phone and filmed her murder. Then they took a picture of her lying dead in a pool of blood and uploaded it to her Facebook page so that all her family and friends could see it. Murray visited a bomb shelter where at least 11 Thai workers had been taken and brutally murdered. There was blood everywhere, on the floor, on the walls (including hand prints of the victims) and on the ceiling. He met a young man who had escaped from the Nova festival and who told his story while showing what he had filmed with his phone. He had managed to reach his car but did not dare to drive off. It is important to know that the wave of Hamas terrorists from Gaza was followed by a wave of civilians who went around the scene of the carnage, looting everything they could find. A group of looters was coming closer, going from car to car. Outside the car was another man but he was afraid to get in in case he might be seen. Eventually the group came so close that the man in the car felt he had to drive away, leaving the other man behind. It was possible to escape in the car but the man left behind was lynched by the Palestinians.

One month after the attack on Israel Murray went into Gaza with the IDF. They passed through the hole in the fence where most Gazans had crossed into Israel on the day of the attack. Then they proceeded until they reached the main road from north to south where Gazans were following the Israeli orders to leave the north. Many of them were shot by Hamas to prevent them doing so. Murray saw them queueing up to pass the control post. The fact that he was deep inside Gaza makes his account more authoritative than those of people giving their opinions from Israel or from thousands of miles away from Gaza.

The book discusses the antisemitic activities in Ivy League Universities. This is a development which I had followed on my own from a distance but here I learned some more things. It is discussed how the German left moved from supporting Israel to supporting the ‘Palestinians’. This had to do with always wanting to be on the side of the oppressed. It has parallels with what has happened in the US and elsewhere in the West in the last two years. There is a description of the highjacking of a plane by Germans and Palestinians in 1976. The hostages were separated by the Germans into Jews, who were to be held, and non-Jews, who were to be released. The criterion was not being Israeli but being Jewish. One of the hostages showed the terrorists the number tattooed on his arm which showed that he had been in a concentration camp. He told them in German that he thought that something had changed in Germany since the time of the Nazis but that he suspected from the behaviour of these people that he had been mistaken. There is a discussion of antisemitism which contains two interesting quotes. The first, due to Vasily Grossman, is ‘Tell me what you accuse the Jews of – I’ll tell you what you’re guilty of’. The second is an adaptation of this to the present, due to Murray, ‘Tell me what you accuse the Jews of – I’ll tell you what you believe you are guilty of.

Murray talks about how impressed he was by some young women he met in Israel. One of them, nineteen years old, was an army recruit and was helping in an operation to collect the last human remains from vehicles which had been destroyed in the attack on the Nova Festival. Another, twenty-three years old, was working as an intelligence expert on Yemen. He was very impressed by these and other young women he met and contrasted them with women of the same age he had met in other Western countries and who often seemed to him like spoiled children. Being in a war can sometimes bring out the best in people. It is easy to see parallels between the Nazis and Hamas but it is not so well known that there is a direct connection. This connection is explained in the book. The Grand Mufti of Jerusalem was an ally of Hitler and collaborated with him in the annihilation of Jews. The Mufti was the one war criminal of the Second World War of this caliber who was able to live openly and without being brought to trial after the war. He was given a warm welcome in his home country of Egypt and praised in the highest terms by the leader of the Muslim Brotherhood, an organisation of which Hamas is one of the descendants.

Murray visited some of the Palestinians who had been taken prisoner during the attack on 7.10. He was able to see them in their cells. He recognised some of them as the killers he had seen in the horrific videos. They looked surprisingly like normal human beings. When Sinwar was finally killed Murray heard about it and immediately travelled to the place in Rafah where it had happened. When Sinwar was shot (by a nineteen year old soldier) without his identity being known he was able to escape, badly wounded, into a building and sit in an armchair. There he bled to death. Murray saw the traces of blood Sinwar had left during his escape and sat in the bloodstained chair where his life had ended. He looked out at the ruins of Rafah and speculated about what thoughts might have gone through Sinwar’s mind as he sat there.

This book reports on many horrors but the author found something positive at the end. He was encouraged by seeing the heroism of young men and women in Israel who had risen to the occasion and shown what is possible. Anyone interested in Gaza should read this book.

A frequent approach to studying T cell activation is based on the idea that properties of the chemical binding of the T cell receptor to an antigen determine whether the cell is activated or not. This applies in particular to the work I have written about here and here. An alternative idea is that mechanical properties also play a role in this process. We have studied this in a new preprint with Yogesh Bali and Wolfgang Quapp. What happens when two molecules are chemically (non-covalently) bound and we apply a force which tends to pull them apart? A simple scenario would be to assume that the greater the force the greater the chance the bond will break. This is what is called a slip bond. However there is also another possibility. It may be that in a certain range the applied force actually stabilises the bond. This is what is called a catch bond. It is related to what is called a Chinese finger trap. This is a toy with the following property. If you push a finger into it it is difficult to get it out again and pulling harder only makes it worse. The way to escape is to push instead of pull.

In this work we study a model with two mechanical degrees of freedom which are the extension of the bond between T cell and the pMHC and the angle between the T cell receptor and the cell membrane. The dynamics is described by a potential depending on these two variables. Stable and unstable bonds correspond to minima and saddle points of this potential. The potential depends on a constant external force as a parameter and varying this parameter leads to bifurcations. In the paper this behaviour is studied while trying to incorporate as much experimental data as possible related to this system.

I have recently been reading the book ‘Foundations of Chemical Reaction Network Theory’ by Martin Feinberg. In the past I have spent a lot of time studying Feinberg’s classic lecture notes on Chemical Reaction Network Theory and I have read (parts of) many of his papers. Thus many things in the book are familiar to me. However there are also many things which are not and I feel that I am profiting a lot from reading it. One subject which plays a marginal role in most of Feinberg’s writings is thermodynamics and the related concept of detailed balancing. This is different in the book since there are two chapters (Chapter 13 and Chapter 14) devoted to these topics. On p. 274 we read ‘The mathematical foundations of thermodynamics remain somewhat murky, at least to me.’ My response to this statement is ‘me too’. In fact I have often experienced that mathematically inclined people say that they never understood thermodynamics. My own difficulties with the subject influenced my career. As a student I was irritated by the equation . When I asked the lecturer who was teaching us a course on thermodynamics he was not able to give me an explanation which I found satisfactory. As a schoolboy physics was the subject which interested me most. After my second year at university I had to decide between doing a degree in physics, a degree in mathematics or a joint degree in both. My decision for the second alternative was strongly influenced by that thermodynamics conundrum. Another experience which contributed to my decision was that at one time I happened to have two courses on the same topic, Fourier series, in the same term, one in physics and one in mathematics. The second was quite transparent to me, the first obscure. The fact that I had
a more positive experience with mathematics than with physics as a student probably had to do with the fact that the relative quality of the lecturers in mathematics was better. At the same time it has to with the nature of the subjects themselves. To come back to Feinberg’s book, on p. 281 he writes ‘When I was an undergraduate student, classical thermodynamics appeared to be a beautiful (and somewhat kabbalistic) subject, but its purpose was not clear. … I didn’t really understand what was happening.’ Feinberg and many other people seem to have made peace with thermodynamics although remaining with an uneasy feeling. This does not apply to me. Perhaps it is an aesthetic thing: Feinberg found the subject ‘beautiful’, even as a student, while I must say that I experienced it as ugly.

Thermodynamics is a part of physics which seems to be difficult to relate to rigorous mathematics. In this sense it bears a resemblance to the much more prominent example of quantum field theory. What does the word thermodynamics mean to me? I want to try to answer this question without reading what anyone else says about the subject. (I can do that later, if desired.) I start with an etymological approach. This indicates that the subject has to do with heat and the way that a system evolves in time. Another approach is a historical approach. I have the impression that a motivation for the subject was understanding the efficiency of steam engines. Yet another approach is to try to make contact to statistical mechanics. A gas is made up of an enormous number of molecules and it is impossible to keep track of them individually. Thus we pass to a statistical description. This involves some probability theory or possibly even quantum mechanics. Getting to thermodynamics involves discarding some information about the system and nevertheless ending up with a description which is to some extent self-contained.