Einstein Aujourd'hui — Debate Part 1

0:00 Good evening. I thank you for the patience of being here this evening for this debate. Without preambule, I will give the floor to Mr. Director of the Ecole Normale Supérieure. Yes, it is first to congratulate those who are present. They have resisted to the siren of Condoleezza Rice at Sciences Po, so it is really very important. There is also a debate at the same time on the BFA report in our campus Jordan. And then, Michelle Leduc told me that she would make a word of excuse. So I didn't want to open this debate, but it was the excuse of the Ecole Normale Supérieure for having mediocre accueilli Einstein in Paris there 100 years. So I'm ready to present the excuse of the Ecole Normale Supérieure. I'm not sure that the school has been the only institution to accueillir mediocramente Einstein in France and Europe. But, at our charge, the school is a super serious institution to immediately get to what could seem like a mode. But when we put it on, we put it on. So, this morning, I visited a laboratory of physics, of the material condensate, where we martyrize des brins d'ADN, and we explained that there was a Thésar who had martyrized of the ADN for three years, and that now he would be recruited by the European Bureau of the Brevets at Zurich. So you see that we have understood the recipe and we prepare for the future Einstein. Now, it's not the subject of the day. The subject of the day, it's this merveilleux livre vert. It's a book that makes me dream. I mean, we talk about a lot of sorti de la, enfin sorti. Donc elle a contribué à la cervelle d'un seul homme, on y parle d'intrication de systèmes quantiques, on y parle de cosmologie, on y parle aussi de laser, et si on y écarte bien, on parle aussi d'ADN dans un des chapitres du livre, et pour moi un petit peu, c'est évidemment un niveau différent, mais ça m'a tout de suite rappelé à une lecture qui avait enchanté mes 15 ans, qui était les atomes de Jean Perrin.

2:30 And I believe that it is a book that is made to another level, of course, it is made for students who prepare to enter this school or in an equivalent school, and I think that it is susceptible to make it rêver. Alors, pourquoi est-ce important ? Je crois que nous avons un gouvernement qui dit qu'il croit en les vertus de l'innovation. Alors, l'innovation pour l'industrie française. Well, it's true that for innovation, there are people who are in marketing, there are excellent technologists and excellent vendors, but I think there are also, and first, scientists in the public laboratories and architects in the private laboratories who know dream. And this is not a simple problem, it is more complicated than creating a pool of competitiveness in putting three sous on it. It is a problem of motivation for young people. It is necessary to take the young people the most brilliant, the most brilliant, it is to say those who are able to dream for very long in their life professional, and then it is necessary to attract the science. And then it is not necessary to attract the science in general, because today it is true that the natural and artificial models of information, namely the biology, the informatics, and then between the two, the anthropology and the political theory, it is a bit of it that attire the young, but it is also that they are attracted by a science fondatrice, which is the physics, and I think that is really what can do this book. So I give the word to all those who are going to talk about it. It is considered as a small event among others in the World of Physics, as you know, 2005 had been declared the World of Physics at the time of the centenary of 1905, the L'année merveilleuse où Einstein a publié trois papiers, il en a publié plus que trois d'ailleurs, mais trois très célèbres, l'un sur le quantum de lumière, l'autre sur la relativité restreinte, qui est peut-être le plus célèbre, et le troisième, non moins important, sur le mouvement bronien.

5:00 So it has come to mind my friend Michel Levelac and myself who we are, who we are, who we are, who we are, who we are, who we are, that we could write a book that would not only be Einstein, because it is not an historical book, but who would try to show the diversity of subjects who have been aborded by Einstein et comment non seulement cette variété de découvertes a ensemencé toute la physique du siècle dernier, mais assez curieusement d'ailleurs continue à donner des sujets et du grain à moudre aux physiciens du XXIe siècle. Et donc nous nous sommes tournés vers nos collègues, les plus proches d'eux, mais pas seulement, français, to write a book by a certain number of physicians very competent on the domain. We are not only restricted to the domain open by the papers of 1905, but a little bit about the work of Einstein throughout his life, because we also included the Relativité General, which was, of course, a few years after the Relativité Restreinte of 1905. And so, here is how it is, the idea of this book, which just came out at the beginning of 1905. I must say that it is a book that is not very easy. There are many books on Einstein who appear. There is one of our colleague, by the way, who we talked about earlier, who is called Jean-Claude Boudeneau, of Thalès, How Einstein has changed the world, with the patience. but there are many books that are available, many books on the life, many books on the history of the ideas, many books also who try to explain to the grand public what they have done. There are also special numbers of reviews, like the special number of science, we have Mr. Boulanger with us. but this book is a little bit more avant because it is a real book of physics of physics contemporaneous which explains to other physicians non-specialized but I hope that will be fulfilled by a large number the current ideas

7:30 so it is really the physics today plus even the heritage it is the physics today that we do at the end of Einstein so that is the idea On a demandé à Philippe Boulanger pour la science d'animer ce débat. Il va vous présenter un petit peu comment ça va se passer. Il y aura pour commencer des petites questions qu'on va poser aux auteurs qui sont là pour amorcer le débat. and then you can ask questions that Philippe will take by paquets and then the panel will be able to answer. Thank you Michel. Well, a day, a cenacle of writers was meeting around the poate of Aragon. Aragon, a great poet and a sinistre memory. I don't know if he was an ancient or normal. Aragon, I don't know. He was meeting around Aragon for deciding the most great French poet. I don't know if I'm going to get the subject. There was a relationship with Einstein. So they said he was the most famous poet French, and every time that one of the writers presented a poet, Aragon said that Victor Hugo had said before and said Victor Hugo. That's the expression of Aragon, Victor Hugo, but today we can say Einstein, that's better. Because I think that the physics would not be what it was, and that's what we will see this time, but we don't anticipate it. physicians adorent se classer entre eux, se classent, et Landau avait fait toute une classification, Landau c'est un physicien très sérieux, il avait mis Einstein tout seul au numéro 0, il disait que sa classification était logarithmique, donc enfin il avait mis Einstein tout seul au numéro 0, il s'était mis en numéro 2, et à la fin de la séance on essaiera de discuter ensemble who was in number one, there were four people, four physicians, so the pareils are open unless someone has read the classification of Landau. Maybe the room will have some ideas to know who was in number one, etc. The absents are excluded, of course. So we are here in the temple of the double culture, to say again, Einstein, thank you.

10:00 and to celebrate a book that relates all the beauty of the work of Einstein, here and today. The work of Einstein is immense and the participants are very many. He does a heat in this room which is absolutely insupportable. So if we could a little bit of a temperature, there is no way. Well, it seems that the mathematicians are the fermions and the physicists are the bosons. The bosons are found between them, but when they speak, they are all seuls. So we have an example of condensation of Bose-Einstein on the plateau. Einstein is obviously a miracle. Un miracle, un petit agent de brevet à Berne ait pu publier trois papiers fondamentaux. On peut se demander si ça se reproduirait aujourd'hui. C'est un miracle que même les difficultés qu'il avait présenties, comme le paradoxe EPR dont Alain Spé pourra parler, comme la constante cosmologique dont son voisin Thibault Demour pourra parler, and all these difficulties have been extremely difficult. There is an English expression, I'm not sure that my accent is comprehensible, even for the French, but they transform the climbing blocks into stepping stones. When there was a difficulty, it would serve as a marchepied to go further. I have already said, and maybe Michel Leduc can launch the debate. On pourrait demander à Claude Cohen de nous dire quelque chose, un peu ce qu'il veut au début, mais avec Philippe on avait pensé que tu pourrais nous raconter comment tu es venu à la physique quantique, qu'est-ce qui t'a attiré, comment tu l'as rencontré. Oui, je crois que mon éveil à la physique quantique est dû à la rencontre avec un certain nombre de personnalités. Les études que j'avais faites dans les classes préparatoires et puis à l'université, qui s'appelait la faculté des sciences de Paris, ne comportaient aucune partie de mécanique quantique dans les programmes. C'était extrêmement ennuyeux. Et, en fait, heureusement, à l'école normale supérieure, nous avions un cours d'Alfred Casselet, qui m'avait absolument subjugué et qui introduisait un petit peu l'interaction matière-rayonnement,

12:30 forcément avec des idées quantiques, en montrant l'importance des lois de conservation, in showing the importance of the spatial quantification of atoms, and this meeting was absolutely decisive for me. Another crucial element for the interest that I had for the physics quantic, which is also in the course that I followed at Saclay, which was given at the time by Albert Messia. Albert Messia came from the United States after his thesis. and he was trying to write his book of mechanics quantic and he experimented it on a public who would come every week to follow his courses and this public comport in particular Alfred Cattler and Jean Brossel all the laboratory to go once a week to follow the courses of Messia and it was absolutely fascinating because in the same time that Messia Anatole Abraham would make a course of resonance magnetic and we saw immediately how the mechanics quantic could be applied to some problems concrete, simple, implanting systems to two levels like spin and me Finalement, un autre élément décisif pour moi a été l'école des douches, que j'ai pu suivre de même que tous les physiciens de ma génération, et où pendant deux mois nous avions un contact étroit, quotidien, avec les meilleurs physiciens du monde comme Feynman, Schwinger, Dyson, Paoli, et ça a été vraiment une stimulation absolument extraordinaire pour rentrer dans la physique quantique. A few years later, another decisive element was the appearance of new programs in the physics and on me asked at this time to achieve a degree of mechanical engineering in what we call the certificate C3. It was a fascinating experience because I had to explain to a large audience all the mystery and beauty of the mechanical engineering and with two other colleagues, Frank Lalloy, who is also one of the authors of the book and Bernard Dieu, we wanted to transcribe this experience in writing a great book in two films of Mechanical Quantity and this was an experience absolutely passionately I would also say that at the same time the third cycle started to be installed in France and that Jean Brossel had asked to ensure a mechanical quantity at a level higher in the cadre of the third cycle and this was also for me a way to deepen mécanique quantique. Et je pense effectivement que la meilleure manière d'apprendre une discipline est de la pénétrer et de l'enseigner. Et je crois que c'est à cet enseignement

15:00 que je dois ma passion pour la physique quantique. Merci. Je me souviens... Juste une question. Est-ce que tu enseignerais de la même façon maintenant ? I think there have been a certain number of developments, it is that which is fabuleux, the mechanics quantic has remained a little, I would say, stationary for a certain number of years. we are a little vexing that there is no development allowing to put in default this discipline but we can say that for a few decades there have been some contributions essential there have been progress in our understanding of the formalism quantic there have been some progress also experimentals which allow now to aborder the quantum mechanics with a new eye and I see for testimonies for example the number of courses of information quantic which appear now which apply a little bit the paradoxes that you talked about earlier which show that these paradoxes are, of course, troublous and that they can now be used in a concrete way to crypter messages and to, of course, create a quantum computer in a future more or less distant. I think Philippe Rangy will talk about it later. C'est la première fois que je partage un micro avec un prix Nobel. Donc j'ai demandé à Michel Lebelac, Einstein on a l'impression, vu de l'extérieur, qu'il a changé la manière de penser la physique. Avant, je crois qu'un de ça a changé the physics, through the experience of thinking, and we have the impression, but probably false, that the physics, before Einstein, it was an experience, there are results wrong, we change the theory. Is Einstein not changed the theory before the experiment? not really on the experience for example for relativity he did not at all in his article of the experience of Michelson-Morley but he had quite concrete ideas for example for his article on the relativity he said that he is extremely ennuyé because the description of the induction depends

17:30 of the reference and that he poses a big problem and it is so an example because it's just a spirit and an aimant, so we can't find anything more simple. We put it in movement one than the other, and we say that it's not the same explanation depending on whether it's the spirit or the aimant. So it's extremely concrete. It's not even a experience of thought, because we can easily do it in the laboratory. And it's working on it-dessus to get to some concepts which are, they are, much more abstracts. I think that it's been its approach. It was often his approach, I'll take this example, to put it on an experiment pretty simple for later to deduce some concepts. Thank you. Do you remember the moment when you realized that Einstein had written three books fondamentals in 1905? Do you remember the day before the assassination of Kennedy? L'assassinat Kennedy, je me souviens extrêmement bien, oui. Mais les papiers de 1905, j'ai dû les lire quand j'ai commencé à enseigner la physique, c'est-à-dire dans les années... fin des années 60, mais pas avant. Avant qu'on parle de relativité, qui est peut-être le sujet que tout le monde a en tête, on voudrait peut-être aborder, pour commencer par aborder la mécanique quantique, parce que ce sont quand même des sujets qui sont bien étudiés ici d'une part, et puis d'autre part sur lesquels on a beaucoup travaillé pour ces livres. and then I would like to ask him to talk a little bit about the aspect so everyone knows now that he has done his experience for a good 20 years on what we call the paradox EPR, Einstein, Podolsky, Rosen could you tell us a little bit about what, is it really a paradox? is it a good way to call it paradox? Est-ce que c'est une bonne façon de raisonner en physique à partir de paradoxes ? Et puis nous parler un petit peu de ce que cette expérience a apporté et quels sont ses prolongements maintenant.

20:00 Oui, alors quand j'ai vu que tu écrivais le mot paradoxe, Michel, ça m'a fait un petit peu sursauter, parce que, comme tu dis, depuis une vingtaine d'années, je m'efforce surtout de ne pas parler du paradoxe en Shempodolski-Rosen. And then, as I wanted to have some arguments, I brought with myself the photocopies of the paradoxes, in one part in the little Larousse, in the other part in the little Robert, and I think that these definitions fit me in the idea that we should absolutely avoid. Because if I read, for example, in Larousse, on begins, paradoxes, opinion, chose which goes against the habit of thinking. Well, that, it goes because Einstein had a revolutionary character. So... But then... You continue... Who heurte the logic? Or, precisely, EPR, it's all the contrary. It's a... I just said... I just said to pronounce the word which seems a lot more interesting than paradox. It's an experience of thinking. And an experience of thinking, by definition, it's something that, on the contrary, we're going to use a lot of logic to take all the consequences by using a certain schéma of thinking, but by using it the most logical way possible. So, really, I pray, We can't talk more about paradoxes EPR, talk about experience of pensée Einstein-Podolsky-Rosen. This experience of pensée Einstein-Podolsky-Rosen is totally fascinating, because it is in pushing on the quantum mechanics itself, that in the EPR reasoning, we don't put absolutely not in cause the predictions of quantum mechanics. In other words, we push on the quantum mechanics to put in cause the interpretation that Bohr and the Ecole of Copenhagen do the mechanical quantum. Bohr and the Ecole of Copenhagen say that the probability of Bohr is the ultimate interpretation that we can do. And Einstein has the ultimate conviction that a theory that makes the probability of probability, we must be able to complete it. In the same way that if we have a statistical physics to describe, let's say, the distribution of Maxwell Boltzmann of molecules of this gas, in reality, we have an image sous-jacent of the movements, the chocs, the particles, etc. Einstein thinks, with the reasoning EPR, to prove that it is necessary to complete the formalism of the quantum mechanics, that otherwise, we are forced to introduce something bizarre, such as interactions more rapides than the light, something that we call today non-locality quantum.

22:30 s'inscrit profondément dans une démarche où on part du calcul quantique, on admet les résultats du calcul quantique, et qu'on cherche à développer une argumentation à partir de là. Alors ce qu'il y a de tout à fait étonnant dans cette histoire, c'est qu'il a fallu quand même une bonne trentaine d'années, je suis en train de parler à la place de Philippe là ou pas ? Non ? Bon. Il a fallu une bonne trentaine d'années pour que les gens réalisent l'importance de ce débat. This debate has been taken seriously only by Bohr and Einstein. Einstein, obviously, it's him who has raised it, but there is only Bohr who has taken the time to respond seriously to Einstein. And not once. They have ceased to advance the arguments, which we find everywhere, in the books like Albert Einstein, philosopher, scientist. There are dozens of pages of Bohr and dozens of pages of Einstein about this problem. And all the other physicists didn't worry about it, the majority didn't worry about it. Why? Because, as we said, with the recul, they had better to do. They had to use the quantum physics to elucide the structure of the matter, the chemistry, the nature of the conduction in the solids, the interaction lumière-matiere. And not only did they do great progress in understanding things, but in addition, it was even a tool for inventing new objects, because not only they understood the way how the electrons conduisent the current in the solid, the semi-conductors, but from that they did invent the transistor. Or not only did they progress in understanding the interaction of light and matière, but from that they did invent the laser. So they had better to do than to take care of the discussions between Bohr and Einstein. until... I'm too long? No, no, but it's passionnant to hear you hear a paradox. I would say that, it's been 30 years until John Bell makes a major discovery which is that, when we thought until then, and it's also one of the reasons for which the majority of physicists didn't care about it, we thought that it was just a question of interpretation. It's to say that everyone was aware on an accord sur les résultats prédits par la mécanique quantique, mais Bohr les interprétait à sa façon et Einstein interprétait à sa façon. Et John Bell a réalisé que si on prenait la position d'Einstein au sérieux, alors, eh bien, à certains moments, on précisait des choses en désaccord

25:00 avec les prédictions standards de la mécanique quantique. D'où la possibilité, probablement l'une des premières fois dans l'histoire des sciences, où un débat qui avait l'air d'être un débat de nature épistémologique, d'un seul coup, va pouvoir être tranché par des expériences. Je crois que c'est une démarche de pensée absolument époustouflante, et cette démarche s'appuie sur, je crois, ce qu'il faut appeler l'expérience de pensée, Einstein, Poloski, Rosen. On sait bien qu'Einstein travaillait par expérience de pensée, mais celle-là est particulièrement intéressante. Bonjour, Poilogne. Je me donne la parole. Merci beaucoup. Vous prenez facilement le pouvoir. Monsieur le Professeur Thibaut Damour, la Relativité Générale, comme l'a écrit Jean Hansenstad, a traversé un long désert. Apparemment personne ne s'y intéressait, il ne s'était presque plus enseigné. Alors comment est-ce que vous avez vécu ce long désert ? Do you have doubts about the pertinence of the relativity general? Can we invent an experience that puts in doubt the relativity general? First of all, I had the chance to start my studies at the exit of the desert, but I didn't know it. It's true that I had a young fascination for Einstein's personality and his discoveries, and it would have been, if I had been in the middle of the desert, my career would have been ruined. But I had the chance to arrive at a moment where the Relativité Générale became important for many other reasons, so it was very good. I also had the chance that the Normal School demande for me a bourse to go to Princeton, a bourse Jane Eliza Proctor, who has played a very important role in my career. So, yes, first it is amazing that a theory invented in 1915 and whose Einstein has not seen all the consequences since he had a very profound schéma, a very profound intuition, fondée on the experience of thinking of what would be the theory. Then he created the formalism. But, even today, we discover new aspects which are contained in this formalism. There are concepts like the concept of noir, for example, even if mathematically, quite quickly, a colleague of Einstein, Schwarzschild, found a solution that we call today trou noir.

27:30 The understanding of trou noir has been done only in the 1960s, so it's a theory still in gestation at the concept level, and it's amazing that this theory, Plus on the vérifies expérimentalement, plus the accord is perfect. The last experiments that have been made in the last two years, for example, in the solar system, we were able to test it in using the Cassini's sonde, the same one who launched a piece at the other end of the solar system, but before it arrived to there, we were able to exchange electromagnetic signals between the Earth and the Cassini who passed extremely close to the solar system, and we were able to see that these signals were deviated et avait du coup un certain retard dans l'aller-retour, en fait c'est la fréquence, le changement de fréquence dans l'aller-retour, que la prédiction, l'observation par rapport à la prédiction d'Einstein était correcte à la cinquième décimale près, c'est-à-dire à 10 moins 5 près, ce qui fait une des rares théories de la physique qui sont testées à 10 moins 5 près. Et dans les six derniers mois aussi, on vient de découvrir de nouveaux pulsars binaires qui ont multiplié par deux le nombre de tests de la théorie d'Einstein en champ fort, Because the theory of Einstein, for a long time, people said that it doesn't only give a little correction to the description newtonian of the gravitation. But today, the theory of Einstein is in the cosmology primordial, the description of the neutrons, of the noir stars. And we have a lot of experiments, now a dozen, which show that in detail, the theory of Einstein is true. So, we know that there is a vast domain of physics, from the Big Bang to today, in passing by very condensed objects, like the stars and neutrons, and certainly the black dots, that Einstein's theory applies to all these domains and describes very well. Do we think that it applies to everything? No doubt not. The history of physics shows that each theory has a domain of application, which can be more or less large. and then beyond this domain, there are new phenomena of physics that enter in the game, new aspects of physics, so often a new theory. Do we have any indications that the theory of Einstein is false in any way and that it is necessary to go further because of the experience? In fact, apart, perhaps, the sondes Pioneer, but no one takes it seriously, because the little agreement in the sondes Pioneer is 1000 times more small that the rayon of the RTG, the plutonium, which is on the top of it,

30:00 so we can't take seriously this agreement. In other words, there is a system of thought which has been in gestation for 30 years, which is called the theory of the cord, which has been initiated in great part by Normandy, because it is André Neveu who is one of the creators of the theory of the cord. Longtemps, cette théorie n'a pas fait de prédiction précise. Elle prédit qu'il faut changer sans doute très profondément la physique à un niveau fondamental. Mais dans les grandes lignes, elle dit comment ça doit se présenter, mais elle ne fait pas tellement de prédiction concrète. Mais l'idée générale de la théorie, c'est que tout de même, il y aurait des violations de la théorie d'Einstein, que la théorie d'Einstein est un petit morceau de la théorie des cordes, mais que ce morceau est inclus dans un ensemble plus grand. which it should have been modified, and that, for example, the fundamental property of the gravitation that Einstein used in an experience of pensée to fund the theory of the general relativity, which is what we call the universality of the free, and the experience of Galilee, that all the corps fall with the same acceleration, or the experience of Einstein, that in an ascenseur, everyone falls with the same acceleration, and so the gravitation is effaced inside of that ascenseur, well, at a certain level, the theory of the corps says that it should be violated, and that, because there are other things, the constant of nature, like the constant of interaction, the constant of structure fine, and that, it violates its essential properties of Einstein. So, we have the hope to be able to make an experience that could maybe show the limitation of Einstein's domain, but in any case, we know that the relativity is generally a domain extremely extended, and, for example, we can use it to predict the gravitational wave that France and Europe expect to detect by the experience Virgo and the American by LIGO, since the domain in which the gravitation are produced is well verified by ailleurs. François Boucher, who was going to talk about cosmology, we are going to ask some other questions to Thibaut Damour. The cosmology and the current measures that we arrive in rafale seem to indicate that there are a lot of mystery. On parle de l'énergie noire, on parle de la matière noire, il y a longtemps qu'on sait qu'il y a une partie de la matière dont on n'arrive pas à savoir la nature.

32:30 Est-ce qu'en ayant recours à la fameuse constante cosmologique que Justin avait prévue, on arrive à voir une théorie qui explique un peu tout ça ? Ou est-ce qu'il y a finalement d'autres interprétations alternatives de ces mystères cosmologiques ? Je ne sais pas si la question est bien posée, mais... Oui, non. Sons des mystères. Il y a des faits expérimentaux. L'un que, effectivement, la matière dont nous sommes faits ne représenterait que 5% de la matière, de la densité d'énergie moyenne dans l'univers. and that the essential would be an energy of the void, that each centimeter cube in the void intergalactic, if you remove all the ordinary material and all the black material, represents something like 10-29 grams. That is 70%. That 30% would be a new type of particle that we did not yet detect and that we should absolutely detect. But this black material, as it has been predicted by some models of unification, for example, like the super-symmetric model, which, in certain interpretations of Pierre Fayet, is pretty naturally the existence of this. It is necessary that we detect in a laboratory that, in fact, this particle exists and interacts weakly, but from this point of view, it is not a big mystery. However, the fact that the energy of the void is not null, it was something that was introduced by Einstein in 1917, in the first model where he created the cosmology. He introduced it to try to satisfy other desiderata that he had at the time, and when he realized that these desiderata could be satisfied in a way, he said, we didn't want this constant, we didn't have any need. And then, every time we tried to get rid of it, the people would say yes, but finally, it is natural, it could be there. We can't say that this constant is necessarily null, or maybe it is necessary to find a symphony, a new symphony of physics, which says that this constant is null, because there is a fundamental reason. And no one has managed to find a telly symphony, and that agaçait a lot of people. And at the moment, it's true that it's one of the most gênant in theory quantic des champs, which is that the quantum ideas of Einstein show that the void is an enormous activity.

35:00 There are permanent fluctuations of all the fields and particles. These fluctuations contain energy, which we see in the effect Casimir. This energy varies between two metal plates when we move. So we know that the energy of the void is a reality, but when we try to calculate the size of the energy of the void, in general, something that is 60 degrees or 120 degrees more large than what is observed. And why is it not nul and also small that it is still a mystery? So there, so there is a new idea, so, unfortunately, one of the explanations possible, well, unfortunately, it is that the universe is totally multiple, there is an infinities possible of universes that are made both because of the nature of quantum mechanics and because because of the fact that, in theory, there are a lot of possibilities for the conditions of energy levels in theory, and that the only universe in which there can exist is life, and so physicists who can ask the question, should be, without a doubt, contain a constant cosmological non-null and aseptic. This is the kind of explanation, which can be true, logically, we can't interredit that, but it is a little gênant because it would be a renunciation to the scientific idea of everything to explain. which was one of the fundamental questions of Einstein, to explain all the values of all the physics. The physics contains a twenty-fourth of arbitrary, a hundred dimensions. Is it that one day, the physics will be able to explain it? This is a challenge for the young physicists of the future, which is fundamental. Thank you. In mathematics, when we don't do something, when we don't do something, un théorème, on dit il est indécidable, Gödel. Les yeux des gens se révultent et on dit Gödel. En physique on dit il y a peut-être beaucoup d'univers et c'est parce que nous sommes là que nous voyons l'univers tel qu'il est donc voilà c'est une fatalité. Vous avez parlé de fluctuations sur un tourné vers Bernard Derrida. A l'époque d'Einstein, la thermodynamique c'était La science reine, c'était ce qu'on enseignait, et les fluctuations anthropodynamiques avaient un statut un peu spécial. On s'écartait un peu de l'équilibre, on y revenait assez naturellement.

37:30 Quel a été l'apport d'Einstein sur les fluctuations, et quel est le statut du mouvement bronien aujourd'hui ? Well, at the end of the 19th century, let's say, there is an evolution of the physics statistics, of the thermodynamics, which is the apparition of the physics statistics with Maxwell and Boltzmann, which gave an interpretation of the anthropology, which was introduced at the beginning by Carnot about the second principle of the thermodynamics, which was quite abstract, and the studies of statistics mechanics, in particular on the magnetic theory of gas, such as they have been carried out by Maxwell and Boltzmann, have allowed to give an interpretation to this entropy and have a microscopic understanding of the thermodynamics. But, despite this statistical interpretation, the fluctuations were quite little studied until Einstein. Einstein is the first, in two very important travaux, the movement Brownian and the theory of fluctuation dissipation, to look at the fluctuations, not only to look at them, but to look at the mathematical expressions, the quantitative expressions, to measure these fluctuations and to relate to the macroscopy properties. were known. For example, one of the important results was that the fluctuations of density of a gas are linked to its compressibility. The case of the movement Brownian is another, where Einstein managed to link the diffusion of a particle in a liquid which is simply a shock with the other molecules of liquid to the viscosity of this liquid and macroscopic. Depuis les travaux sur le mouvement brownien, c'est devenu d'une part une branche des mathématiques, ça a été à l'origine de l'introduction du calcul stochastique, en particulier à partir de l'équation de Langevin, qui sont devenues des branches des mathématiques, mais les comportements gaussiens qui ont été observés dans le cadre du mouvement brownien ou dans le cadre du théorème de fluctuation-dissipation sont devenus ce qu'on observe tous les jours. And we observe it so much every day that if you observe something like this, it doesn't matter to anyone.

40:00 It's the thing attendee, it's the thing common. And what interests the people, it's just the behavior non-gaussians, the violations of these behavior gaussians, the laws of the type Levy, for example, that we observe in the problems like the turbulence or the problems close to the critiques where we have some fluctuations non-gaussians. The development of statistical mechanics has been turned enormously towards the study of fluctuations, and most of the most interesting fluctuations are non-gaussians. That's what people have studied the most since the 30 or 40 years. Maybe you could work with you, could you give us an example, or tell us today what we do with these problems of fluctuation? Oui, le théorème de fluctuation-anticipation, c'est ce que racontait Bernard, c'est des relations entre diverses quantités macroscopiques, comme la compressibilité d'un gaz et sa densité, entre la capacité calorifique et la température, les fluctuations de température. And it allows us to describe how a system responds to an external system and to see how, in addition to this external system, the system fluctuates, present des fluctuations intrinsèques internes. Donc, c'est une fluctuation dissipation qui fait un lien entre ces deux choses qui sont a priori différentes puisqu'il y a une quantité à l'équilibre et une quantité qui est hors d'équilibre. Mais ça, c'est connu depuis très longtemps, mais on a repris un peu d'intérêt of fluctuations, it was a few decades ago, before we studied a lot of problems out of balance, in just looking at the medium, in eliminating all the fluctuations, in reading well all the problems to look at what happens in the medium, and now we are more interested in the problems more complicated, where we look at the effect of the noise, the effect of fluctuations on the problems.

42:30 Alors, pour donner un exemple, chose qui touche la vie de tout le monde et qu'on étudie en ce moment, c'est par exemple la capacité d'une route. Si on met des voitures sur une route, il y a une sorte de flux maximal qu'on peut mettre. On veut faire passer le plus grand nombre de voitures possible pour que les gens puissent aller au travail sans qu'il y ait d'embouteillage. Mais il arrive qu'il y ait une fluctuation à un moment donné, à un endroit, qui fait que quelqu'un a un petit peu ralenti, a décroché son téléphone portable, a regardé une vache sur le côté de la route, et un embouteillage peut se créer. Et une fois que l'embouteillage est créé, il est très difficile d'enlever l'embouteillage. L'embouteillage n'est pas là parce qu'il y a trop de voitures, is there because the cars are badly mises and there is an embouteillage that is created because of a fluctuation. So these fluctuations, how they develop, how they can create an embouteillage, is obviously an enormous interest now to avoid these embouteillages. Les modèles physiques aident. Les modèles physiques aident. Philippe Grangier, Alain Spey, nous a parlé de ce qu'on appelle pas un paradoxe EPR, mais il ne sourit pas une minute dans la moustache. Donc le paradoxe, le mystère EPR étant soulevé and then resolved, we realized that this difficulty could lead to practical applications in cryptography. You can see it in an informatics quantic. I'll tell you what is this famous experience of thought. What is the mystery in this affair? So this is the reasoning presented by Einstein, Podolsky and Rosen in an article in 1935, which had a gigantic retentissement, because they put it a little in cause, they put it, let's say, the ideas that are based on the quantum mechanics. So the idea is very simple. We take two particles that interact, and then, after having interacted,

45:00 they go away, arbitrarily, from one of the other. And then we have, I can put it in a box, one of these particles. So if this particle is there, as a classic physicist, I want to give him some properties, to say that his speed will be this, his impulse, his moment cinétique, all these quantities will be defined for the particle who is in front of me. And it is this idea that Einstein had deeply in mind. Or, the quantum mechanics tells us that it is impossible to do that. When my particles, which have been raised in the past, are away, If I have my particles here, these properties will be inextricably liées to the other particles. And this link inextricable is what we call now l'intrication. It is extremely surprising. It means that these two particles, even if they are very wide, form a kind of object, and we can't do anything with these particles without affecting the whole of the particles. It is so troubling, so if you want the fact that the mechanical quantic allows us to know the properties of the particle that we have in front of us, it is what Einstein said in saying that she is incomplete. She allows us to do it. But he wanted to do it. So the reasoning of Bell, which Alain talked about, consisted of quantifying this intuition of Einstein in saying that if these mysterious mysterious correlations exist, and if I do such an experience, I must find such a result. I don't need to find another result. So it's just to make an experience, to measure it, and then we will deduce, to conclude on the existence or inexistence of these famous correlations. So in practice, how does it translate? Well, if the two particles are very far away, if the correlations exist, as soon as I measure something, I must, in a way, find the same result of the other side. And then, to not prevent the particles, I can decide at the end of the moment what I will measure. So it's the idea that was introduced by Alain at the end of the 1970s. On va essayer de surprendre les particules, on les laisse partir, et puis au dernier moment, hop, on mesure, et on voit si elles sont corrélées ou pas. Donc cette expérience a été faite au début des années 80, donc par Alain et puis Jean, Dalibard et moi-même, nous étions des étudiants en thèse de troisième cycle, et on a eu le plaisir, le grand plaisir, de passer quelques minutes sur cette manie. Donc la conclusion a été absolument imparable, la mécanique quantique a raison. Ces mystérieuses corrélations existent. it is impossible to attribute the properties defined to a particle localised when we have these states intriqués

47:30 the properties of the particle are completely localized so it is called the intrication and everyone has realized since it has been 20 years that it is really at the heart of the quantum mechanics the quantum mechanics would not work without the intrication it is at the heart of the measure everything that we do is practically liable to this affair of the intrication What does that mean? That means that if I have a pair of particles separated, the measures that I will do on the two particles will be extremely corralled. All right, what we think immediately, is that we will not use that to send information more quickly than the light. I make my measurements here, and it makes something else from the other side. That's not a chance, that's not a problem at all. We can convince, through a little reasoning that I don't want to do, that it doesn't transmit information. There is a correlation that we can constate after all, but this correlation can't be used to transmit information. Well, it's not a chance, but we can do something. And that was done much more recently, so if the two partners, we call Alice and Bob, now it's like that, it's a habit, each have each one of these two particles... They also, they have to do it, they have to do it. ...they will find measures on these two particles, they will find results extremely correlated. These results are completely aléatoires, so they don't transmit any information, they don't go faster than the light, but they have the property of being completely unknown to everyone, except Alice and Bob, and to be exactly the same for Alice and Bob. So if Alice and Bob exchange their particles, they will always find the same result, they will have the same results binaires, 1 and 0, which will be the same for each other and only known for each other. Alors, qu'est-ce qu'on peut faire avec quelque chose de pareil ? En fait, c'est génial, parce que ça, ça s'appelle une clé cryptographique. Si Alice et Bob disposent de ces bits aléatoires corrélés, ils peuvent les utiliser pour crypter des messages de façon parfaitement sûre. Et complètement inviolable, parce qu'en fait, les bits n'existaient pas avant qu'ils les aient mesurés, et ils sont les seuls à les connaître, et ils sont parfaitement corrélés entre eux. Donc, c'est devenu en fait tout un vaste domaine de recherche. cryptographies quantiques qui sont vendues dans le commerce vous les trouvez sur les sites web et qui sont donc distribu des clés secrètes en utilisant des photons dans ce cas là des photons polarisés et puis on peut faire toutes sortes de choses encore plus exotiques comme de la téléportation quantique ou même du calcul quantique toujours basé sur ces idées d'intrication

50:00 je vais peut-être m'arrêter là parce que voilà donc il ya un ensemble de protocoles quantiques which are in fact liées to the fact that when we manipulate the information codified on the quantum objects, typically, the rules of usage are completely on can't copy the information, on can't duplify the information, if we read it, we perturb it and all risk to be intruded, the particles are intruded between them. So, we can do, from these rules, a lot of things, e.g., some very quick calculations, of the cryptography, that is sure, that works, of the teleportation quantic, which consists of destroying a particle here We can't copy it, we can't read it, but we can destroy it and create it ailleurs. So, it looks like a teleportation. Actuellement, we have teleported photons. We have the quantum state of photons, the quantum state of atoms or ions. It is, of course, out of question to teleport from living organisms, for many reasons that I don't explain it here. But I think that this time, I really don't understand. Thank you, Philippe. Maybe we're staying in the very quantum physics. and we could ask Jean de Libard to talk a little bit about the condensate of Einstein because that is also a little miracle of physics, these condensate. This phenomenon, the new state of the material, had been planned in a way very speculative and theoretical way by Einstein in the 1920s and he was very close to think that it would never be observed experimental because it needed so low temperatures, so it wasn't very long after these predictions. And then, 70 years later, the physics, the progress, the refroidissement by laser which Claude has contributed a lot, have allowed to see these effects. So it's a bit amazing. Can you tell us a little bit more? Yes, I can say two words on this story of Condensation Brain-Shine. It's a story that is quite nice because I think it illustrates well the physical démarche. It's to say there are all the human aspects in it and then there are also the attachments. This story started by a young physician Bengali, Bose, who had found the black rayon of the body that Planck had demonstrated 20 years ago. different, simply in counting the photons, but in instaurant new rules to count.

52:30 He said that the photons are all identical, so it's not that I count two times the same configurations. And Bose, who was a young Indian physicist, had a problem with his reporters. That's something that many people around this table know, and then probably in the room. And so, in fear of cause, he sent his article to Einstein. And there, I think that the story begins very well, because Einstein has done something that, in any case, I have never done. Einstein a lu tranquillement l'article de Bose, il l'a trouvé très bien il l'a traduit et il l'a fait publier en allemand, et ça montre une disponibilité du personnage, je ne veux pas du tout en faire un sein c'était pas un sein, mais néanmoins ça montre une disponibilité scientifique du personnage ce qui je crois on peut signaler au-delà de ses capacités scientifiques évidemment complètement extraordinaires. Alors, ensuite Einstein, après avoir traduit l'article de Bose s'est dit, tiens, ce que Bose a fait pour des photons moi je pourrais le faire aussi pour des particules matérielles, et And for that, he had to do it because he received the thesis of De Bruyne, and so he had used the quantum concepts, which were still very strange, because De Bruyne had done his thesis, but Schrödinger did not write his equation, so the quantum mechanics was not formalized. But Einstein had used the quantum concepts to show this condensation, which was really a phenomenon mysterious at the time, because it proved that if you took an assembly of particles and that you would count as Einstein and Bose had said, well, in the middle of Parties de ces particules vont se mettre dans le même état quantique, c'est-à-dire qu'elles vont se condenser, vont s'accumuler dans cet état. Alors Einstein publie son article et aussitôt il s'est fait attaquer assez violemment par des collègues. Il avait un ami Renfest qui n'était pas du tout convaincu. Lundbeck, un élève d'Renfest, a assez violemment attaqué Einstein. C'est vrai qu'Einstein faisait des choses qui n'étaient pas très orthodoxes dans son article. Il écrivait des intégrales sans vraiment dire pourquoi est-ce qu'il avait le droit de les écrire. On sait maintenant ce qu'il faisait. Il prenait ce qu'on appelle maintenant la limite thermodynamique, c'est-à-dire qu'il considérait un système avec un nombre de particules qui tendait vers l'infini, mais un volume qui tendait aussi vers l'infini, de telle sorte que le rapport entre le nombre de particules et le volume, ce qu'on appelle la densité, était constant. Enfin, il faisait tout ça sans le dire, et donc c'était assez mystérieux. Einstein lui-même, en fait, effectivement, n'y croyait qu'à moitié. Il a écrit à son copain Renfest, c'est une belle théorie mais contient-elle une part de vérité ? So, this condensation of Einstein, like Einstein predicted, was really very controversial, and Einstein, as I said, he didn't even believe that at half. It lasted for 15 years.

55:00 At the end of 15 years, we discovered the superfluity of the liquid liquid. It's the capital of the one side, then Allen and Michelin of the other who found it. And then all of a sudden, London and TISA, people like that, who worked not far away from here, they said that maybe it was related to Einstein's hypothesis. So, since we find in the books of mechanics or physics statistics that the liquid, the superficie of the liquid liquid, the fact that the liquid liquid is going without viscosity, it is perhaps an illustration of the convention of Einstein, but at the same time, it is only an equivalent of the liquid. First, it is a liquid, so it is not at all what Einstein had looked at. Einstein avait gardé un gaz parfait, c'est-à-dire aucune interaction, alors que le liquide, il avait des interactions fortes pour le matériel à l'état liquide. Donc, ce n'était pas un très bon exemple. Et donc, comme l'a dit Michel, finalement, il a fallu attendre 1995 pour que des officiers américains, enfin, Cornel et Weimann, et puis un peu plus tard, Ketterle, ou MIT, montrent finalement ce qu'Einstein avait prévu 70 ans auparavant. Et alors maintenant, on a ces condensats, on les comprend bien. The theory of Einstein is perfectly surprised, it is not at all the status of the reality of the general with things still mysterious. The theory of the condensation at Einstein is well maîtrisée. I would say that now we are at the stage where, with this condensation of Einstein, there are things that are very close to other things that are in the other paper of Einstein. It is to say that with this condensation of Einstein, there are things that are equivalent to laser. Le laser, comme vous le savez, comme Jean-Pierre Puchot va sûrement en parler, s'est relié à un autre papier d'Einstein qui est l'émission stimulée. Et maintenant, ce qu'on fait dans les laboratoires, c'est finalement faire avec ces condensats des lasers atomes, c'est-à-dire des faisceaux cohérents de particules, tout comme les lasers qui utilisent l'émission stimulée d'Einstein servent à fabriquer des faisceaux de cohérents de photons. Donc, en quelque sorte, la boucle est bouclée, puisqu'on est parti du photon de Bose pour faire la condensation de Bose d'Einstein. and now we are now at the stage where these particles come back to the state of photons since we have done some sort of lasers. Thank you, Jean. That makes a transition for the lasers, because if there was not Einstein's mission stimulant, we would have perhaps not had an advanced understanding of how to make a laser march. So you who are in the industry of lasers, can you tell us a little bit about how they have affected our daily life?

57:30 Well, first of all, it was actually relevant to Einstein to have established in 1917, in an article famous, the process of simulation simulation, in the interaction of the lumière-matiere. It had to wait for the 1960s to ensure that the first laser was actually demonstrated experimentally. In 1963, there was the third conference of electronics quantum computing, and at this occasion, Pierre Aigrin had formulated, in a very provocative phrase, the philosophy or the phrase suivant, it's that with the laser, we have the solution, but we don't have the problem. It is clear that, just a little, in coming to Redulme, I saw on a carousel of a car, a publicity for the laser laser. It's the most big market of the laser in the United States. So, it is clear that today, you see, an exotic application of the laser, it's the laser, and it's actually going to work. No, not yet! Well, to be more serious, first of all, the lasers have a considerable place in our daily life, but sometimes insoupçonnée. Of course, we can take the example of the compact disk which allows to stock more and more information. Actuality, we are passing from the CD to DVD, and tomorrow you will see that the Blu-ray will be released, which will be a system of optical stock which will be used in the blue and which will allow, for example, to stock a dozen hours of films on a single CD. These are things that are classic in the industry, to program the evolution of the technology and then to make it live. You want to say that it will have to buy new devices very cheap? Yes, of course. It's the reason for the market and the industry. Thank you, Einstein. Ah, non, ça va devenir plus en plus simple, mais vous n'avez plus qu'un CD. Donc, on va manipuler plusieurs disques. Bien. Mais, encore une fois, revenons un peu plus sérieusement sur ces choses-là. En fait, ce qu'il faut savoir, c'est que ce composant qui est la diode laser, c'est le composant, en fait, qui met en application la physique quantique. C'est-à-dire qu'on utilise, en fait, dans ces diodes laser,

1:00:00 le principe de base de la mécanique quantique which consists of studying, for example, a particle in a potential potential. The particle in question in the laser diode, it's the electrons and the trous. And if we know how to do these structures ultra-fines of materials and semiconductors, we are forced to realize the transports of these particles in materials and semiconductors to take into account all this which has been elaborated by the quantum mechanics and the quantum physics. So, every day, you are like Mr. Jourdain, in fact, the properties of the physical and quantic without the knowledge every day. Then, what are the new axes, the new perspectives that are offered in the laser? They are immense. They are immense in the moment where we can do micro-objects that will emit light in the field, in the field, in the field, in the field of ultraviolet. We can see all the advances and all the impacts that will have these sources dans le domaine par exemple de la biologie et puis de l'autre côté on est de plus en plus à traiter maintenant l'émission dans le domaine des terahertz et aujourd'hui on sait faire de l'imagerie par exemple à travers des corps opaques sans avoir utilisé des rayons X mais uniquement utiliser les propriétés d'émission de ces diodes qui permettent donc de couvrir des domaines pour lesquels beaucoup de matériaux sont transparents et puis ensuite il y a le deuxième extrême je dirais qui est là la physique disons des champs intenses Aujourd'hui on sait faire des sources laser qui délivrent des puissances crêtes phénoménales, qui sont de la classe de plusieurs centaines de TWh, et qui ne sont pas aussi volumineuses que l'on pouvait le penser il y a encore de cela quelques années, puisque aujourd'hui un système qui délivre 100 TWh, donc c'est 110 puissance 15 W, tient grossièrement sur la demi-estrade. And this, if you focus on the cells with this power on a small surface, you will have very important, very important, very conséquent, which allow, for example, to engendry the plasma ultra-ultra-chauds, allowing, at the end, even, to simulate in laboratoire in fact, the supernova. So, this is a new field of instrumentation, which will benefit from this tool. of this beautiful thing, which is the laser.

1:02:30 The applications, again once, are immense. They interpell all the domains, whether applications civil or defense. In the civil, for example, it is important that today, the parameters that allow to predict the time are liable to use a laser system which allows to evaluate to evaluate the speed of the wind in altitude or to measure, for example, the concentrations of certain chemical species which can be more or less nocive for our environment. Well, thank you very much. Thank you very much. There is an extraordinary fact that we thought that the laser was a phenomenon of laboratory and we told us that we saw the lasers in the sky, there were the amplifiers that work like the lasers. So it is very important to think that Einstein thought it was a phenomenon which was found in nature, and we can also think that if it hadn't been predicted, we wouldn't have seen it. Jean-Claude Boudneaux, you have written a beautiful book, How Einstein changed the world, which came to be released. And what do you think that Einstein changed the world? Are you really thinking that the world would be different if there was not Einstein, ou si les gens auraient trouvé les choses après le coup ? Ou si les gens qui sont autour de cette estrade auraient tout fait ? En tout cas, je pense qu'on peut dire qu'Einstein et son année merveilleuse de 1905, ça marque une rupture, parce qu'il est sur tous les fronts, il est à la fois sur la naissance de la mécanique antique, sur la relativité, sur la conception d'atomes, and that it is really a rupture that coincide with the end of the classical mechanics. I think that we could make a parallel between Einstein and Newton, who are certainly the two best physicians of all the time, and that Newton has also marked a rupture, and also his year miraculous, in 1664 and 1665, because this year, he discovered the differential, the differential, the reflection, He made his theory of colors, and at the same time, he had the idea of the universe's gravitation, which marked a rupture.

1:05:00 And by the way, if we sit a century after this miraculous year of 1664, in 1764, we could make a Newton's year. It was perfectly in the atmosphere, and it was far away from being finished. So I think there's an espoir, 2005, it's not the end of Einstein's years, Newton has survived to that for quite a long time. Now, Newton said, if I saw more than others, I was sitting on the legs of giants, and obviously, he pensed to Copernic, Galilee, and Wiggins. So I think we can say that Einstein, if he saw more than others, it was also sitting on the legs of giants, and the giants, in fact, In fact, it's Maxwell, Boltzmann, Lorenz, Planck, Poincaré, so the terrain was obviously favorable. How Einstein changed the world? I think we can start from the article that he was written in 1905. The first article was the most revolutionary article. It was on the interpretation of the constant of Planck. Il faut savoir que Planck ne croyait pas à sa constante, à tel point que si la constante s'appelle H, c'est parce que H, c'est la première lettre du mot Ilfe, allemand qui veut dire auxiliaire, il essayait de s'en débarrasser, et qu'Einstein, lui, il a donné naissance, une naissance physique à cette constante de Planck. Et également une petite anecdote extraordinaire, c'est qu'en 1913, lorsque Planck a soutenu la candidature d'Einstein à l'Académie de Berlin, Einstein a introduit Beaucoup de nouvelles idées Absolument géniales en physique De temps en temps Il se trompe par exemple Sur l'interprétation du quanta lumineux Mais on ne saurait lui en tenir rigueur 1913, quand même 8 ans Après l'interprétation d'Einstein Dans son fameux Donc article du 17 mars 1905 Sur l'interprétation des faits photoélectriques who is a great physician, said that we could not imagine that a century later, he talked about in 2000, that a third of the BRD of the most great nation of the United States would take directly profit from this discovery of the constant of Planck. Effectivement, all the electronics industry, on the view of the optics of the electronics, is directly linked to its work on the interpretation of the constant of Planck and on the quanta.

1:07:30 The second article is Mouvenbronien, which dates from March 1905. Mouvenbronien, the question that was asked, it was the atoms. It is important to know that in 1906, for example, a great physicist like Ernst Mack said to not believe in atoms. Today, we see the atoms daily in the laboratory, we manipulate them. For example IBM, it is already a few times, has made its sigle with atoms. we can materialize the differences of thought, and today the technology, which we talked about earlier, for example the famous diode laser to read the DVD, is maîtrisée at the atomic level, so it's absolutely a necessity for the technology today to control the matter, the growth at the atomic level. The third article is obviously the relativity restreinte, so 30th of 1905. With the relativity restreinte, daily we have several applications. Today, there is a big synchrotron, which is the Synchrotron Soleil, which is building on the plateau of Saclay. So, it accelerates the electrons at the speed of the lumière. And what we do in this acceleration is to use the rayon of these electrons, this rayon of synchrotron, to discover even more things in the material, but also to do the technology. For example, to do the lithographies by rayons X, to do the gravure, and then we use this synchrotron. So it's a formidable tool that depends on the relativity. And another point on the relativity, it's the GPS. It's important that the GPS takes care of the relativistic corrections, the dilatation of the durée, the effect of the retard of the time in a intense range of gravitation. These two corrections, if we didn't take care of it, there would be an error of 12 km per day on the GPS So, we can see that the relativity is something that is quite concrete. The last article, well, it's the article in which, the 27th September, is written EGMC2. So, today, we can say, 100% more later, that 80% of energy energy in France goes directly from a transformation of material, of mass energy. So, it's directly linked to this famous equation, but also, for example, For example, the cameras, the cameras, the cameras, which are used in medicine, use completely this transformation of energy and material, and inversement. I think that Einstein, in any case at his time, these three ruptures,

1:10:00 the quanta relativity atom, has changed the world, and that is not done. Thank you very much. Now comes the very difficult moment of questions on Einstein. The moment is difficult because Einstein is so prenant that many people think that he could do better. They come to a conference to explain why he could do better. This is not the place here. You are here to try to dialogue with the other conférenciers who are there, to ask them some précisions, but these questions are not affirmations and theories. of theory. So we're going to try to group them, that's to say, one person will answer a question and we're going to ask if people want to précise them. We're going to try to group them by two or three. And before, I'm going to do my test, which was the number one? What were the 4 physicians who were number one? Joe Einstein, 2 Landau. There was Bohr, but... Galilée... Ah, on a droit, on a droit à tout. Pythagore, Pythagore. Newton, Newton, Newton. and the 4th, he was pronounced, no, well, he didn't give it my choice, he gave it Planck. Yes, it would have to be, I mean... Descartes, Descartes would have to... Well, he would have to... No, no, but it's not... Well, I would have left to fight between you. Monsieur, Monsieur, Alors, essayez de préciser la question pour qu'on puisse grouper un peu les questions, sinon ça va être difficile. Et vous pouvez donner votre nom ? Le veugle. Je ne suis malheureusement pas issu de cette maison, mais d'une maison pas très loin d'ici.

1:12:30 Aussi, vous comprenez qu'il peut y avoir quelques subtiles difficultés. Ma question est essentiellement celle-ci. Est-ce qu'on peut vraiment attribuer à Einstein les trois chefs-d'oeuvre dont il vient d'être parlé abondamment, réalisés en 1905 ? D'accord. Ça, ça dérive d'être précis et d'être court. Y a-t-il d'autres questions dans ce sens ? C'est-à-dire sur la véritable paternité d'Einstein. Des articles par Einstein, oui. The role of Einstein and Poincaré. It's true that Einstein doesn't cite grand monde. So Thibaut Damour can answer. Is there another question in this sense? All right, let's move on. Thibaut Damour? Well, I can't pronounce it. Micro. Micro. Micro. First question, because I'm not entirely agree with Thibaut D'Amour, it's pretty curious, the history of the relativity is controversial while the interpretation is not, while the history of the quantum mechanics is not controversial, while the interpretation is very controversial. Merci. Alors, comment ? C'est des variables complémentaires, absolument, oui. Oui, alors, j'ai trouvé dans un des nombreux dossiers Einstein qui sont parus, donc, récemment, la phrase suivante. Autant la relativité restreinte répondait à un blocage en physique, autant la relativité générale n'était pas indispensable à la compréhension du monde de l'époque. It's on the first part of the phrase that I wanted to answer. In fact, I think it's absolutely false to say that there was a blockage in 1905.

1:15:00 Lawrence and Poincaré had a theory that was not the relativity, because they thought that there was an ether, and they thought that there was a reference in movement compared to the ether, and that for the observers in movement, all happened as if the light of the light was equal to c. There is no ether in all the reference, the observators see the same speed for the light, whatever their movement, and we have no reference privilege. But from the operational point of view, all the equations are as well in the articles of Lorentz and Poincaré that Einstein. Einstein, toutes les lois de transformation, les lois de transformation du champ électromagnétique, les invariants du champ, sont dans l'article de Poincaré, dans l'article d'Einstein, évidemment. Alors, par quoi se distingue Einstein ? Je crois qu'il y a un point important, c'est que pour Poincaré et Lorentz, c'est un peu un aboutissement. Ils se sont posés des problèmes sur l'électrodynamique, ils pensent les avoir résolus et ils sont arrivés et ça s'arrête là. Einstein, who has a much more revolutionary vision of things, he says, no, I don't stop there, I continue, and he continues. And the first thing, it is E equals MC2. And he can arrive at E equals MC2 because his conception is quite different. He can arrive more easily than what would have done Poincaré or Lorenz, who would have been able to arrive also. But by the fact of his revolutionary conception, Einstein arrives immediately. and then he continues to reflect in the same direction and two years later, it's the principle of equivalence and there also, it's an enormous step in front that he can do because he has his modern conception of this reference to the inertia while Poincaré and Lawrence have a conception which is not the one that has to happen in our days I agree with what was said, but I want to add a more precise point which is, in fact, the theories are not equivalents. It's to say, contrairement to what many people say, who have not looked in detail the papers of Poincaré, when we look very precisely what did Poincaré,

1:17:30 because Poincaré, one of the arguments of some of the anti-Einstein, is to say that Poincaré also discussed the synchronization of Horlèges in movement, which is true, he did it in the first order, in V sur C, in 1900. In 1904, he still talks about it, but it's not clear if he did it exactly or not. And he gives a conference in Paris, next to the Sorbonne, on the top of the synchronization of the horloges in the movement in 1906, which was published a lot later, and he also published an article on 1908. But when we look at the result of Poincaré, we realize that it is not the result of Einstein, because he always suppose that the horloges in the movement mark the same time, obviously, that the absolute time, because it is the only thing that exists for him. and so there is a factor that is the factor of dilation of the time which is essential because it is what happens in Einstein that the time of an horloge movement is not the same than the time of an horloge to repose it is the paradox of the jumeaux and there the word paradox is important because it is still a common concept of the time that 99,999% of people have that the time exists and it is what Einstein changed and in his article, immediately Einstein said and consequence experimentals one horloge movement which comes back his sister who stayed at the ground until 1905. And Poincaré, in 1906, 1907 and 1908, publiced papers where he calculated something else, where there is no matter of this factor. So it doesn't mean... And in 1905, Poincaré knew that he had to use the time of the Lorenz T' which contained this factor, but it means that he didn't think. I mean, Poincaré, when it was just doing math, could use things, but when he thought the horrors in movement, he didn't think the time, and so he didn't think this prediction, which is really the essential of the relativity restreint, that the time change. And for the other unique characteristics of Einstein in 1905, we say that, as it was said briefly, Planck absolutely believed in the constant H. There was something in 1900, Planck said to his son, you see, in this day, I made a significant discovery that Newton, because he discovered that there was a new constant fundamental of physics. So he knew absolutely that discovering H, even without understanding what he wanted to say, was a major revolution of physics. But Planck, Croydier, dans cet article-là, n'a jamais découvert la quantification de l'énergie d'un oscillateur en 1900. Jamais Planck, en 1900, n'a dit que l'énergie d'un oscillateur est quantifiée. Le premier qui a parlé de quantification d'énergie d'un oscillateur matériel, c'est Einstein en 1906, après avoir trouvé le quantum de lumière en 1906. Donc la mécanique quantique

1:20:00 a été définitivement créée par Einstein et pas par Planck. Et effectivement, la question était vraie. Il n'y a pas besoin de parler de E égale MC2 pour parler d'énergie nucléaire, ça n'a pas grand-chose energy of a nuclear bomb, uranium, and electric energy, in fact, and we have absolutely not to know E equal MC2 for that. So it is not that the grandeur of the discovery of Einstein in 1905. Yes, but finally, the mass is still in energy. No, the grandeur is the discovery of the ephemeral of the matter. During centuries, since Lavoisier, the quantity of material, the mass, was constant. Yes, there is still a question about Lorenz. How is it that Lorenz, in 1920, he declared that it was Poincaré who had discovered the relativity and that he was baptized as well? And it is for this reason, according to M. Leveug, in the book that I read, it is for this reason, that there is no Nobel Prize accorded to the relativity. William Vienne avait envoyé au Comité Nobel une proposition pour attribuer conjointement le prix Nobel à Lorenz et Einstein. Donc il y a une lettre d'ailleurs qui est tout à fait remarquable de William Vienne dans ce sens. Je pense que ce qu'on peut dire quand même, c'est que dans les débats actuels sur la paternité, la relativité entre Einstein, Lorenz ou Pancaré, On devrait citer beaucoup plus souvent les auteurs, en particulier on devrait citer ce que dit Einstein au sujet de la contribution de Lorenz, ce que dit Lorenz au sujet de la contribution d'Einstein, parce que c'est extrêmement intéressant. The first one who discovered the relativity in Einstein's books is Max Planck. And Max Planck wrote in his first paper, the relativity recently discovered by Lorenz and Einstein. He put the two names together in his book of 1906. I just want to finish on a point regarding the relationship Huygens-C2. It is remarkable that in the paper of 1905 Einstein, Einstein said that it could be the origin of the source of energy, of the radioactivity. At the time, obviously, the radium had been discovered in 1898. Between 1898 and 1905, people would ask the question of which was the origin of this famous energy. Einstein, since 1905, dit que c'est peut-être la demonstration de la transformation de masse en énergie.

1:22:30 Donc c'est quand même une contribution qui est tout à fait remarquable. Alors, je ne sais pas, on va essayer. J'ai bien retenu que vous voulez poser une question, monsieur. Est-ce qu'il y a d'autres questions ? Monsieur a déjà pris la parole. Monsieur, au fond. For Lefebvre College of France, I am a specialist in neutrinos. I have heard recently that neutrinos, which are the fermions well known, part of the leptons, could, according to Smyrnov, Smyrnov, the S of MSW, have, in a way, to have a statistic of Bose-Einstein. This paper has 20 days. There was a question. There was a reflection. You have to have a question. I have to ask you later. Is there anyone can disserter? Jean Delibard? Spirnoff? I don't want to disserter. Just for the people not informés. Normalement, the classification boson-fermion is well established now. The boson are the particles of spin entire. The fermion are the particles of spin demi-entiers. The spin of neutrinos is demi-entiers. I don't think there is a doubt about it. So it's quite paradoxical. All I can say is that, when Einstein had predicted his convention of Einstein, he, on the other hand, he didn't even know this rule, and he applied his statistics to the electrons, which is also paradoxical as for the neutrinos. So Einstein, in his article, what would now be a very big error at the level of the 3rd cycle. Is Mr. Smirnoff also a big error at the level of the 3rd cycle, or are these 20 days are the appearance of a new star in physics? I don't know. Well, I'm going to ask you, and I'm going to write your name for the first part of the cabinet of the U.S. Well, Monsieur, mais quand vous dites que vous étiez dans une école proche, c'est polytechnique. Je croyais que c'était chimie.

1:25:00 Non, ce que je voulais dire, je m'excuse monsieur, la première personne, ce que je vais dire maintenant, et le résultat d'une découverte toute récente fondée sur des documents absolument indiscutables. Une question, monsieur, pas une réponse. Une question. Ah, bon. Non. La question est la suivante. Là, alors, je vais la poser sous forme de question. Le véritable premier interprète de la théorie de la relativité de Poincaré, c'est Hilbert à Göttingen, et je crois qu'on peut le démontrer. Non mais, on prend des questions suivantes, je donne du mal. Donc, c'est pas une question. Bon, je me déclare incompétent. Mais, je voudrais juste faire une remarque. discours auxquels je suis habitué, c'est mon rôle de les écouter, quelquefois de les entendre. Il est très difficile de penser qu'un siècle après, on comprenne aussi mal la relativité, et que ce soit un tel effort pour les étudiants, pour les adultes, de comprendre ce qu'a pensé Einstein. Je ne sais pas ce que ça veut dire. S'il y a There are geniuses who are above everyone that we can't understand them, or that the theory is going to be difficult, but I think it's one of the difficulties of our civilization to not be able to make, at the end of a century, ideas that have changed the world. Monsieur disait que 30% de l'énergie du produit intérieur brut des Etats-Unis était due à Einstein. Si on ajoute le GPF, si on ajoute l'énergie nucléaire, on va arriver à la moitié. And, despite all, I encourage you to read the two books that have been announced today to know more.

1:27:30 But it's a bit paradoxical that we have enough difficulty. Mr. Alain Spey. I was a little bit surprised by this affirmation. Personally, I find the quantum mechanics much more difficult to understand than the relativity restreint. I'm going to say that the relativity is restrained. But in the relativity is restrained, there is still the paradox of the jumeaux, of the angevin, and things like that. Personally, I find the mechanical mantis much more difficult. It's not a question. No, but there is a real question, actually. Mr. Guillaume, after you, On sait qu'à la fin du XIXe siècle, les thermodynamiciens ou Maxwell sont très impressionnés par leur formation de mécaniciens, Thomson aussi. Einstein va avoir des contributions mécaniques pour le mouvement brownien, il va s'intéresser finalement à la vitesse de sédimentation, à des choses qui finalement sont assez simples. Can we say that Einstein has had a role for Einstein? We always cite his little work on the feuilles of tea which are in the middle of a coupe. Is it important to think of Einstein, this mechanical vision? I think it's in the movement Brownian that he will use this result. — Certainement, pour arriver au résultat sur le mouvement Brunia, il s'agit de décrire l'évolution d'une petite particule soumise à toutes les collisions des particules. Et donc ça ramène réellement ces problèmes de fluctuation à un problème de mécanique classique. Maintenant, la connaissance d'Einstein de la théorie des milieux continus, je ne saurais pas la dire en mécanique. Yes, you have recommended to read the two books. So, I read the book of Mr. Baudenot, page 46. Henry Poincaré is the first to have discovered the equivalent between mass and energy. He wrote in 1900, well, page 46. So, I would say that it's been made in cause today. So, what would you think? Poincaré has made a calculation in 1900, in which he didn't write explicitly EGMC2,

1:30:00 but his calculation is enough to do it to see that he is understood by this equivalence. In a paper of Einstein in 1906, the second on the equivalence of mass energy, he cite Poincaré in saying that the calculation was made by Poincaré and that he would take another approach to reach the result. So the difference between Poincaré and Einstein, I think we can say in a way objective, is that Einstein, in his paper of 1905, even if his demonstration is not of absolute absolute, he pressent all the generalities of the equivalence between mass and energy. So, he pressent from 1905, and he continues in this path in 1906. So the calculation of Poincaré is published, he is exact, he is not commentated beyond that in the article of 1908. Yes, because there is an interesting comment of Poincaré in 1908 where he talks about the effects of recul during the emission of rayon, and he says if I have a core who recul because he emets particles, I understand, but if he emets the rayon, I don't understand, because he writes explicitly in 1908, the energy has no mass. C'est-à-dire Poincaré n'a jamais pensé E égale mc2, alors ne faisons pas de plaisanterie. C'est Einstein le premier qui l'a pensé. Poincaré était un génie mathématique, mais ce n'était pas un physicien. Il était bloqué par ses préjugés du conventionnalisme, et il n'a jamais découvert la relativité ni E égale mc2. Alors l'article que vous citez n'est pas de 1908, mais de 1906. Si, de 1908. Si on se réfère à... 1900, pardon, 1900. Non, non, 1908. M. Bonneau n'est pas d'accord. C'est un autre article. J'ai une dernière remarque à faire. Non, non, non. Il n'y a pas une dernière remarque. E égale mc2 est faux puisque M est un scalaire et E fait partie d'un quadro vecteur. Donc E égale mc2 a été remis en question. C'est E0 égale mc2. Il y a eu un article d'un théoricien russe qui ne rappelle plus son nom, Irvine, qui a bien précisé ça. C'est E0 égale mc2. Je le signale aux étudiants. C'est jamais E égale mc2. Donc, Poincaré n'a pas fait l'erreur en écrivant cette formule qui est fausse. Et je peux vous le signer quand vous voulez. Bon. Au moins, voilà monsieur qui a de fortes convictions et il a le droit de les partager.

1:32:30 À vous, monsieur. Je suis Nathalie Deruelle et je voudrais poser une question un petit peu dans la ligne de celle que vous posiez sur la difficulté de la compréhension de la relativité. Parce qu'une des difficultés, Thibault Damour l'a mentionné un petit peu, et qui peut-être explique un peu pourquoi Poincaré est arrivé à un certain blocage et Einstein est allé plus loin, c'est sur ce que c'est que le temps. And as we are in a school that is both scientific and literary school, I think it's a good place to ask the question, particularly to Thibaut Damour, but also to Quanticien, to know how these two revolutions at the beginning of the 20th century changed the notion of time, especially the absolute time of Newton. Thibaut Damour. they don't always consider that science is a humanism and that science teaches us something existent and important about reality, because the positivist vision imposed by the circle of Vienne and all the epistemological current has reduced, and by the end, also, has reduced science to be models that were supposed to explain the results of the laboratory, but without worrying about the notion of reality, while Einstein has in any case an exigence of understanding the reality. He discovered the experience of thought of Einstein, because he was interrogated without a doubt, beyond the equations, what it means. And I think that, indeed, we still have to look at the debate on Poincaré and Einstein. Thank you.

1:35:00 Thank you.