Fink Haysom fought tirelessly for justice and reconciliation – in South Africa and on the global stage

Source: The Conversation – Africa (2) – By Hugh Corder, Professor Emeritus of Public Law, University of Cape Town

The preamble of the South African constitution of 1996 starts as follows:

We, the people of South Africa,

Recognise the injustices of our past,

Honour those who suffered for justice and freedom in our land,

Respect those who have worked to build and develop our country, and

Believe that South Africa belongs to all who live in it, united in our diversity.

It is fitting to start with this reminder, given the extent to which these phrases sum up and embody the life and work of Nicholas (Fink) Haysom, who died in New York City on Wednesday 18 March 2026, a month short of his 74th birthday.

Tributes have poured forth from a wide range of people and quarters, appropriately given the geographical reach and indefatigable energy which characterised Haysom’s life’s work.

This tribute is more limited in scope: given my own friendship and shared experiences with him, it focuses overwhelmingly on the first half of his working life, during the last two decades of apartheid South Africa and the transitional phase to the progressive and robust constitutional democracy that came with liberation.

Notwithstanding the significant impact of his work for the United Nations from the year 2000, the qualities forged in Haysom by his intense involvement in the struggle for democratic practices both in the workplace and wider society under the extreme hostility of the apartheid capitalist order shaped his approach to conflict and strife, wherever it occurred.

It would be remiss, however, not to note the main spheres to which he devoted so much of his life.

For the record, his full names were Nicholas Roland Leybourne Haysom. But he was universally known as Fink, to all comers, and most of us who knew him cannot think of calling him otherwise.

His early life

Haysom was educated at a privileged Anglican college in South Africa’s Natal province during the 1960s. He went on to study at the University of Natal in Durban, where he completed an honours degree in politics.

Durban in the early 1970s was the setting for the nurturing and development of a number of students who became significant activists in the anti-apartheid cause. Many were inspired by the views and mentoring of academics like Rick Turner, an academic activist who was shot and killed at his home by the apartheid regime in 1978.

Among them was a future partner in their law firm, Halton Cheadle. These students were involved in supporting the strike action by dock workers in Durban port in 1972/3, which signalled the revival of independent trade unionism among black workers.

Haysom then moved to the University of Cape Town to complete his LLB (law) degree in 1978. It was in these years that he rose in prominence among the ranks of anti-apartheid activists. The National Union of South African Students (Nusas) had long been a thorn in the side of the regime. But it was rocked to its foundations in 1972 following Steve Biko’s establishment of the South African Students Organisation, founded on black consciousness.

The apartheid regime simultaneously convened the Schlebusch Commission of Inquiry into four “radical” opposition movements, among them Nusas. By 1976, only two campuses remained affiliated to Nusas: the University of Cape Town and the University of the Witwatersrand (Wits).

At the annual congress, held at Wits in December 1976, Haysom was elected president, with the task of galvanising support for Nusas on campuses as well as in broader society, in the aftermath of the 1976 Soweto uprising (when protesting black school students were killed by police).

His leadership and energy, as well as his ability to engage meaningfully with people from very diverse backgrounds and ideologies, revived Nusas. The organisation was also able to forge links more broadly across other anti-apartheid organisations within the country.

Haysom was harassed and detained without trial – then and in the ensuing years.

After graduation, he entered the attorneys’ profession. In 1982 he became a founding partner, with Halton Cheadle and Clive Thompson, of the firm Cheadle Thompson & Haysom – still very much thriving today. During the 1980s it was one of the very few firms of “struggle” attorneys.

The firm worked closely with the emergent independent trade union movement among black workers, as well as other civil movements resisting the consolidation of apartheid in urban and rural areas.

Daily life was extremely tough, and it took its toll on him and those with whom he worked. He simultaneously held an appointment as an associate professor at Wits.

The creation of a democratic state

Haysom was a member of the constitutional committee of the African National Congress and played a critical role in the negotiations which led to the constitutional settlement of 1994.

Again, his human qualities of being able to relate patiently and empathetically to so many diverse groups of people, both among the oppressors and the oppressed, and his great capacity to enjoy good social occasions served him – and the cause of freedom and justice – very well.

Many today unjustifiably downplay the dire risks inherent in the negotiations process, and the possibility of a resort to scorched earth tactics by the apartheid regime. If it was not for a few key participants on all sides in the mould of Fink Haysom, such disastrous consequences would have been realised.

President Nelson Mandela’s assessment of the value of Haysom’s qualities and contributions was realised by his appointment as constitutional and legal counsel in the Office of the Presidency, until 1999. Others have written about the myriad ways in which Mandela relied on Haysom in the heady but often tortuous years of his presidency, during which the constitution was drafted and adopted.

The international stage

Haysom was not retained by President Thabo Mbeki. His professional skills and experience were then devoted to mediating conflict and endeavouring to bring peace to many areas in Asia and Africa, in the service of the office of the secretary general of the United Nations.

The list of his areas of engagement reads like a collection of the sites of major conflicts over the past 25 years: Burundi, Iraq, Afghanistan, Somalia, Sudan, southern Africa, South Sudan.

He served under three secretary generals of the UN, the formal title given to his last and incomplete engagement being the Special Representative and Head of UN Mission in South Sudan (from 2021 till his death).

In recognition of such exemplary service in the cause of human rights, constitutionalism and conflict resolution, both in South Africa and internationally, Haysom was awarded an honorary doctorate in law by his alma mater, the University of Cape Town, in 2012, matched in 2019 by the New York Law School.

Haysom was a gregarious, ebullient person, who enjoyed good food and drink and good company. Born to a privileged lifestyle, he responded not by accepting his status and its material rewards, but by devoting his life’s work to addressing conflict and improving the lives of the poorest sectors of humanity.

The burdens occasioned by the blocking of his efforts and the obstinate clinging to brutal power and the unjustifiable resort to brutality and greed by so many with whom he had to engage wore him down: anyone who looks at a photograph of him, even in middle age, and compares it with one taken in the past ten years will be shocked by the changes.

His responsibilities also took their toll on family life and other non-work pursuits. Most people would have been tempted to quit, faced by these odds.
Yet he remained in office, as a warrior for justice and reconciliation, until his death.

Especially now, humankind needs many more like him in positions of influence.

The Conversation

Hugh Corder has in the past received funding from the National Research Foundation of South Africa. He is a director of Freedom under Law (not for profit company) and a member of the Council for the Advancement of the South African Constitution (CASAC).

ref. Fink Haysom fought tirelessly for justice and reconciliation – in South Africa and on the global stage – https://theconversation.com/fink-haysom-fought-tirelessly-for-justice-and-reconciliation-in-south-africa-and-on-the-global-stage-278922

Comment transformer des déchets plastiques en vinaigre grâce à l’énergie solaire

Source: The Conversation – in French – By Yimin Wu, Associate Professor, Tang Family Chair in New Energy Materials and Sustainability, University of Waterloo

Chaque année, des centaines de millions de tonnes de plastique sont produites dans le monde. Des recherches montrent comment on peut transformer ces déchets en quelque chose d’utile. (Unsplash/Nick Fewings)

Le plastique est un des matériaux les plus durables jamais créés. Sa durabilité l’a rendu indispensable dans les domaines de la médecine, de l’emballage alimentaire et des transports. Cependant, elle est également à l’origine d’un des problèmes environnementaux les plus graves auxquels nous sommes confrontés.

Chaque année, des centaines de millions de tonnes de plastique sont produites dans le monde. Une grande partie de ces déchets finit dans des sites d’enfouissement, des incinérateurs ou dans la nature, où ils peuvent mettre des siècles à se décomposer.

Les méthodes dont nous disposons pour lutter contre la pollution plastique présentent des inconvénients. Leur dépôt dans des sites d’enfouissements entraîne une fuite de produits chimiques et de microplastiques dans l’environnement.

L’incinération libère des fumées nocives et des toxines. Le recyclage mécanique dégrade souvent les plastiques en produits de moindre valeur, tandis que le recyclage chimique requiert des températures et des pressions élevées, ainsi que d’importantes quantités d’énergie.

Mes collègues et moi-même avons récemment publié une étude qui explore une nouvelle possibilité. Nous avons utilisé la lumière du soleil et un catalyseur à base de fer pour transformer des déchets plastiques en acide acétique, qui est le composant principal du vinaigre, mais aussi un produit chimique industriel important.

Nous avons pu démontrer que, plutôt que de considérer le plastique comme un simple déchet, nous pouvons le convertir en un produit utile dans des conditions modérées.

Tirer des enseignements d’un champignon

C’est la nature qui a inspiré nos recherches. Le champignon de la pourriture blanche du bois, Phanerochaete chrysosporium, est réputé pour sa capacité à décomposer la lignine, l’un des polymères les plus résistants que l’on trouve dans le bois. Il y parvient grâce à des enzymes qui produisent des espèces chimiques hautement réactives pouvant décomposer des structures carbonées complexes.

Nous nous sommes demandé si un matériau synthétique pouvait reproduire cette stratégie.

Le catalyseur que nous avons conçu est du nitrure de carbone dopé au fer, un semi-conducteur qui absorbe la lumière visible. Nous avons ensuite ancré des atomes de fer individuels, de manière à créer ce qu’on appelle un catalyseur à atome unique.

Au lieu de former des nanoparticules, chaque atome de fer est isolé et intégré à la structure du nitrure de carbone. Cette précision atomique est cruciale. Chaque atome de fer se comporte comme un site actif dans une enzyme naturelle, ce qui optimise l’efficacité tout en garantissant la stabilité.

Une réaction en deux étapes activée par la lumière

Le système fonctionne grâce à une cascade de réactions activées par la lumière.

Sous l’effet de la lumière du soleil et en présence de peroxyde d’hydrogène, les sites ferriques activent le peroxyde afin de générer des radicaux hydroxyles hautement réactifs. Un radical est un atome, une molécule ou un ion possédant au moins un électron non apparié, ce qui le rend très réactif sur le plan chimique.

Ces radicaux attaquent les longues chaînes de carbone qui composent les plastiques, comme le polyéthylène (qu’on trouve dans les sacs en plastique), le polypropylène (récipients alimentaires), le PET (bouteilles de boissons) et même le PVC (tuyaux et emballages).

Les polymères s’oxydent progressivement et se décomposent en molécules plus petites, jusqu’à devenir du dioxyde de carbone (CO2).


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Au lieu de laisser s’échapper le CO2, ce catalyseur remplit alors une deuxième fonction : il utilise la lumière du soleil pour réduire le CO2 en acide acétique. Autrement dit, le carbone contenu dans les déchets plastiques est d’abord oxydé, puis réassemblé pour former une nouvelle molécule utile.

Concrètement, cette approche permet de décomposer le plastique et de convertir le carbone ainsi obtenu en un produit chimique de base au sein d’un même système. C’est ce qui la distingue de la plupart des technologies de recyclage existantes.

Pourquoi de l’acide acétique ?

L’acide acétique est connu comme étant l’ingrédient acide du vinaigre, mais c’est aussi une matière première industrielle importante. On s’en sert pour fabriquer des adhésifs, des revêtements, des solvants, des fibres synthétiques et des produits pharmaceutiques.

La demande mondiale en acide acétique s’élève à plusieurs millions de tonnes chaque année, ce qui représente un marché de plusieurs milliards de dollars.

Actuellement, la majeure partie de l’acide acétique est produite par un procédé très énergivore appelé « carbonylation du méthanol », dans lequel le méthanol réagit avec du monoxyde de carbone à haute température.

La transformation des rebuts plastiques en acide acétique permet d’adopter une approche circulaire : au lieu d’extraire du carbone neuf, nous réutilisons celui qui est déjà présent dans les déchets.

Dans le cadre de nos expériences, le système a produit de l’acide acétique à des taux comparables à ceux d’autres méthodes de conversion des plastiques par la lumière. Lorsque nous avons optimisé l’utilisation de la lumière à l’intérieur du réacteur, le taux de production a considérablement augmenté.

Il est important de noter que la réaction s’est déroulée à température ambiante et à pression atmosphérique normale. Cela contraste avec de nombreuses méthodes de recyclage chimique qui nécessitent de chauffer les plastiques à plusieurs centaines de degrés Celsius.

Des plastiques courants

Les études en laboratoire portent souvent sur des plastiques purs et isolés. Or, les déchets réels sont mélangés et contaminés. Nous avons donc testé différents plastiques courants séparément, ainsi que sous forme de mélanges.

Notre catalyseur a permis de transformer plusieurs matières plastiques du commerce. Nous avons remarqué que le PVC affichait des performances particulièrement élevées. Nous pensons que le chlore libéré lors de sa dégradation pourrait générer des radicaux supplémentaires, accélérant ainsi le processus de dégradation.

Les atomes de fer restaient dispersés à l’échelle atomique après plusieurs utilisations, ce qui témoigne d’une bonne stabilité. Cet aspect est important, car la dégradation du catalyseur ou la lixiviation des métaux peuvent nuire aux performances et à la sécurité environnementale.

Le système repose sur l’ajout de peroxyde d’hydrogène, qui est consommé au cours de la réaction. Bien que le peroxyde d’hydrogène se décompose en eau et en oxygène, ce qui le rend relativement inoffensif, il faudra se pencher sur une manière durable de le fournir à grande échelle dans le cadre de travaux futurs.

De la conception à la mise en pratique

Reproduire à grande échelle un nouveau procédé chimique est toujours un défi. La pénétration de la lumière, la conception des réacteurs et la variabilité des matières premières issues des déchets plastiques ont une incidence sur l’efficacité de la réaction. Les additifs présents dans les plastiques commerciaux, tels que les stabilisants, les pigments et les plastifiants, peuvent également influencer les résultats.

Afin d’étudier la faisabilité de notre méthode, nous avons effectué une évaluation technico-économique préliminaire. Cette démarche sert à analyser les avantages économiques d’un procédé industriel ou d’un produit.

Bien qu’une optimisation supplémentaire soit nécessaire, l’évaluation suggère que le fait de combiner le traitement des déchets avec la fabrication d’un produit chimique de valeur pourrait permettre de compenser les coûts, notamment grâce aux avantages environnementaux.

Ces travaux mettent également en évidence le potentiel des catalyseurs à atome unique et de la conception bio-inspirée. En reproduisant la manière dont les enzymes contrôlent la réactivité à des sites métalliques précis, nous parvenons à effectuer des transformations chimiques complexes dans des conditions modérées, en utilisant la lumière du soleil comme source d’énergie.

Revoir le cycle de vie du plastique

Le problème de la pollution plastique ne pourra pas être résolu par une seule technologie. Il est essentiel de réduire l’utilisation de ce matériau, d’améliorer la conception des produits et de perfectionner les systèmes de recyclage.

La transformation des déchets plastiques en produits utiles constitue une stratégie complémentaire. Elle permet de considérer le plastique comme une source de carbone et non seulement comme un fardeau pour l’environnement.

Si nous réussissons à exploiter l’énergie solaire pour effectuer ces transformations de manière efficace et à grande échelle, les emballages d’hier pourraient devenir la matière première industrielle de demain.

Le défi consiste désormais à transposer nos avancées au laboratoire en systèmes robustes et adaptables. Si nous y parvenons, nous franchirons une étape importante vers une économie plus circulaire, dans laquelle les déchets ne marquent pas la fin d’une histoire, mais le début d’une nouvelle.

La Conversation Canada

Yimin Wu bénéficie d’un financement de la Chaire Tang en matériaux énergétiques nouveaux et en développement durable, du Conseil de recherches en sciences naturelles et en génie du Canada, ainsi que d’un financement de démarrage de l’Institut de l’eau (WI) et de l’Institut de nanotechnologie de Waterloo (WIN) de l’Université de Waterloo.

ref. Comment transformer des déchets plastiques en vinaigre grâce à l’énergie solaire – https://theconversation.com/comment-transformer-des-dechets-plastiques-en-vinaigre-grace-a-lenergie-solaire-278928

Des centaines d’insectes affamés, un étudiant et une combinaison en mesh… Comment une série d’expériences aide à comprendre le vol des moustiques

Source: The Conversation – in French – By David Hu, Professor of Mechanical Engineering and Biology, Adjunct Professor of Physics, Georgia Institute of Technology

En modélisant les trajectoires de moustiques volant autour d’une cible humaine, les scientifiques ont appris à prédire et caractériser leurs déplacements. David L. Hu, Georgia Tech

Derrière chaque piqûre se cache une mécanique précise : en suivant des moustiques à la trace, une équipe de chercheurs a mis au jour les lois qui gouvernent leur comportement.


« Quatre minutes, c’est trop long ».

Piqûres de moustiques
Le bras de Chris Zuo après une session avec les moustiques.
David L. Hu

Voici le message que m’a envoyé Chris Zuo, étudiant de premier cycle, accompagné de photos montrant d’innombrables piqûres de moustiques sur sa peau nue. Ce massacre sur l’ensemble du corps n’était pas le résultat d’un camping qui aurait mal tourné. Il avait passé ce laps de temps limité dans une pièce contenant 100 moustiques affamés, vêtu uniquement d’une combinaison en mesh que nous pensions capable de le protéger.

C’est ainsi qu’a débuté notre enquête de trois ans pour comprendre le comportement d’un insecte d’une simplicité trompeuse : le moustique. Cela peut ressembler au plan sadique d’un professeur, mais en réalité, nous avons respecté toutes les procédures. Le comité d’éthique de notre université a approuvé le protocole, en s’assurant que Chris était en sécurité et qu’il n’était soumis à aucune pression. Les moustiques étaient exempts de maladies et provenaient de notre État, la Géorgie. Et cette séance a donné lieu aux premières — et dernières — piqûres reçues par qui que ce soit dans le cadre de l’étude.

En plus de mon rôle de tortionnaire pour étudiants, je suis auteur et professeur à Georgia Tech, avec plus de 20 ans d’expérience dans l’étude des déplacements des animaux.

Les moustiques sont l’animal le plus dangereux au monde. Les maladies qu’ils transmettent, du paludisme à la dengue, provoquent plus de 700 000 décès par an. Les moustiques ont causé plus de morts que les guerres.

Le monde dépense 19 milliards d’euros par an en milliards de litres d’insecticides, en millions de kilos de larvicides et en millions de moustiquaires imprégnées d’insecticide – le tout pour lutter contre un insecte minuscule qui pèse dix fois moins qu’un grain de riz et ne possède que 200 000 neurones.

Et pourtant, les humains sont en train de perdre la guerre contre les moustiques. Ces insectes évoluent pour prospérer en milieu urbain et propagent les maladies plus rapidement avec le changement climatique. Comment des animaux aussi simples peuvent-ils nous repérer avec une telle facilité ?

Les scientifiques savent que les moustiques ont une très mauvaise vue et qu’ils dépendent de signaux chimiques pour compenser. Mais savoir ce qui attire un moustique ne suffit pas à prédire son comportement. On peut savoir qu’un missile à guidage thermique est attiré par la chaleur sans pour autant comprendre comment il fonctionne.

C’est là qu’intervient Chris et son sacrifice dans la pièce infestée de moustiques. En suivant les trajectoires de nombreux moustiques autour de lui, nous espérions déterminer comment ils adaptent leurs décisions à sa présence. Comprendre la manière dont les moustiques réagissent aux humains constitue une première étape pour mieux les contrôler.

Comment les moustiques repèrent leur repas

Sur les 3 500 espèces de moustiques, plus de 100 sont dites anthropophiles, c’est-à-dire qu’elles préfèrent les humains comme source de nourriture. Certaines espèces sont capables de repérer une seule personne au milieu d’un troupeau entier de bovins pour aller lui sucer le sang.

C’est une prouesse, étant donné que les moustiques ne volent pas bien. Ils cessent de voler dès qu’il y a une légère brise de 3 à 5 km/h, soit une vitesse d’air comparable à celle générée par le balancement de la queue d’un cheval. Dans des conditions plus calmes, les moustiques utilisent leur cerveau minuscule pour suivre la chaleur, l’humidité et les odeurs humaines transportées par le vent.

Le dioxyde de carbone, sous-produit de la respiration de tous les êtres vivants, est particulièrement attractif. Les moustiques le détectent aussi facilement que vous percevez l’odeur d’une benne à ordures pleine, jusqu’à environ 9 mètres de leur hôte, là où les concentrations chutent à quelques parties par million, soit l’équivalent de quelques tasses de colorant dans une piscine olympique.

Contour noir des lettres G et T dans le panneau de gauche ; dans le panneau de droite, des lignes sinueuses noires représentant les trajectoires de vol des moustiques autour des lettres.
Le contour sombre du logo de Georgia Tech plaît beaucoup aux moustiques.
David L. Hu, Georgia Tech

La vision des moustiques ne leur est pas très utile pour partir à la recherche de leur prochain repas. Leurs deux yeux comptent plusieurs centaines de petites lentilles individuelles appelées ommatidies, chacune large comme un cheveu humain. Elles produisent une image en mosaïque, légèrement floue, comme pixelisée. En raison des lois de l’optique, les moustiques ne peuvent distinguer un humain adulte qu’à quelques mètres de distance. Avec la seule vue, ils sont incapables de différencier un humain d’un petit arbre. Ils examinent donc chaque objet sombre.

Collecter des données sur les trajectoires de vol

La difficulté lorsqu’on étudie le vol des moustiques, c’est que, comme des enfants surexcités, la plupart de leurs mouvements n’ont pas vraiment de sens. Dans une pièce vide, les moustiques modifient très souvent leur vitesse et leur direction de façon complètement aléatoire. Il nous fallait donc de nombreuses trajectoires de vol pour faire émerger un signal au milieu de ce bruit.

Un homme allongé au sol, visible sur deux images affichées sur l’écran d’un ordinateur portable au premier plan.
Vêtu d’une combinaison en maille, Chris Zuo attend les moustiques, un peu perplexe.
David L. Hu, Georgia Tech

L’un de nos collaborateurs, le biologiste de l’université de Californie à Riverside Ring Cardé, nous a expliqué que dans les années 1980, les scientifiques menaient des « études de piqûres » en se mettant en sous-vêtements et en écrasant les moustiques qui se posaient sur leur peau nue. Selon lui, la nudité permettait d’éviter des variables parasites, comme la couleur du tissu d’une chemise.

Chris et moi nous sommes regardés. S’asseoir nu et attendre de servir de proie aux moustiques ? Non… Nous avons plutôt conçu la combinaison en mesh que Chris portait initialement dans la pièce infestée. Mais après avoir vu ses piqûres, il nous fallait une meilleure solution.

À la place, Chris a choisi des vêtements à manches longues, qu’il a lavés avec une lessive sans parfum, et a enfilé gants et masque. Entièrement protégé, il n’avait plus qu’à rester debout et attendre, tandis qu’un nuage de moustiques tourbillonnait autour de lui.

Les Centers for Disease Control and Prevention (CDC) des États-Unis nous ont fait découvrir le Photonic Sentry, une caméra capable de suivre simultanément des centaines d’insectes en vol dans une pièce. Elle enregistre 100 images par seconde avec une résolution de 5 mm, dans un espace de la taille d’un grand studio. En seulement quelques heures, Chris et un autre doctorant, Soohwan Kim, ont produit plus de données sur le vol des moustiques que tout ce qui avait été mesuré auparavant dans l’histoire humaine.

100 moustiques volant autour de Chris Zuo pendant 10 minutes. Seule une partie des trajectoires observées est restituée.

Pour les mathématiciens, comme nos collaborateurs Jörn Dunkel, Chenyi Fei et Alex Cohen du MIT, la géométrie du corps de Chris reste trop complexe pour étudier les réactions des moustiques. Les mathématiciens excellent dans l’art de ramener les problèmes complexes à leur essence. Chenyi a donc suggéré d’épargner Chris : pourquoi ne pas le remplacer par un simple mannequin, une boule noire en polystyrène fixée sur un support, associée à une source de dioxyde de carbone ?

Au cours des deux années suivantes, Chris a filmé sans relâche les moustiques tournoyant autour de ces mannequins en polystyrène. Puis il les aspirait à l’aide d’un aspirateur, en essayant de ne pas se faire piquer.

Décrypter les trajectoires

Un moustique vole comme on pilote un avion : il tourne à gauche ou à droite, accélère ou freine. Nous avons d’abord caractérisé son comportement de vol en fonction de sa vitesse, de sa position et de sa direction par rapport à la cible, première étape pour construire notre modèle.

Notre confiance dans ces règles de comportement s’est renforcée à mesure que nous analysions davantage de trajectoires, jusqu’à exploiter 20 millions de données concernant les positions et les vitesses des moustiques. Cette idée consistant à intégrer des observations pour étayer une hypothèse mathématique remonte à 200 ans et porte le nom d’inférence bayésienne. Nous avons ensuite illustré le comportement des moustiques observé à l’aide d’une application web.

Quatre panneaux montrant la trajectoire d’un moustique en l’absence de cible, en présence d’une cible visuelle, d’une source de CO₂, ou des deux combinées.
Le moustique adapte son vol à la cible qu’on lui présente.
David L. Hu

Grâce à notre modèle, nous avons montré que différents types de cibles modifient le vol des moustiques. Les cibles visuelles provoquent des survols, où les moustiques passent à proximité avant de continuer leur route. Le dioxyde de carbone entraîne des hésitations, les moustiques ralentissant à proximité de la cible. La combinaison d’un signal visuel et de dioxyde de carbone génère des trajectoires orbitales à grande vitesse.

Jusqu’à présent, nous avions uniquement utilisé des expériences avec des sphères en polystyrène pour entraîner notre modèle. Le véritable test consistait à voir s’il pouvait prédire le vol des moustiques autour d’un humain. Chris est retourné dans la chambre, cette fois vêtu de blanc et coiffé d’un chapeau noir, se transformant en véritable cible. Notre modèle a correctement prédit la répartition des moustiques autour de lui. Nous avons ainsi identifié des zones à risque, où la probabilité de voir des moustiques tournoyer autour de lui était élevée.

Prédire le comportement des moustiques constitue une première étape pour les déjouer. Dans les zones infestées, on conçoit par exemple des maisons dotées de dispositifs empêchant les moustiques de suivre les signaux humains et d’entrer. De même, les pièges à moustiques aspirent les insectes lorsqu’ils s’approchent trop près, mais laissent encore s’échapper entre 50 % et 90 % d’entre eux. Beaucoup de ces dispositifs reposent encore sur des essais empiriques. Nous espérons que notre étude fournira un outil plus précis pour concevoir des méthodes de capture ou de dissuasion.

Lorsque la mère de Chris a assisté à sa soutenance de master, je lui ai demandé ce qu’elle pensait du fait que son fils se soit proposé comme appât pour les moustiques. Elle m’a répondu qu’elle en était très fière. Moi aussi — et pas seulement parce que je suis soulagé que Chris ne m’ait jamais demandé de prendre sa place dans la chambre infestée de moustiques.

The Conversation

David Hu ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Des centaines d’insectes affamés, un étudiant et une combinaison en mesh… Comment une série d’expériences aide à comprendre le vol des moustiques – https://theconversation.com/des-centaines-dinsectes-affames-un-etudiant-et-une-combinaison-en-mesh-comment-une-serie-dexperiences-aide-a-comprendre-le-vol-des-moustiques-278902

À la base du bonheur finlandais, le sisu une philosophie du froid

Source: The Conversation – France in French (3) – By Xavier Pavie, Philosophe, Professeur à l’ESSEC, Directeur de programme au Collège International de Philosophie, ESSEC

Connaissez-vous le sisu ? Ce drôle de mot désigne une philosophie développée en Finlande qui se confond avec le caractère national. Cette forme de sagesse, en résonance avec les exercices spirituels venus d’autres traditions, pourrait expliquer pourquoi une fois encore la Finlande est classée comme un des pays les plus heureux au monde. Cette forme de sagesse proposant de se concentrer sur l’essentiel pour mieux en jouir, pourrait-elle inspirer nos manières de concevoir l’avenir ? En particulier, le rapport particulier que le sisu entretient avec la Nature pourrait-il nourrir nos attentes en matière de changement climatique ? Découvrez cette philosophie qui invite à « faire avec » plutôt que de s’épuiser à « s’indigner contre »…


Mes travaux ont consisté à repérer la présence d’exercices spirituels dans la société contemporaine. Cette expression désigne toute pratique destinée à transformer, en soi-même ou chez les autres, la manière de vivre et de voir les choses. Elle renvoie à la fois à un discours et à une mise en œuvre : une discipline visant à mieux vivre, à mieux être, sans être soumis à des désirs jamais assouvis. Cette notion s’élabore dans les écoles de l’Antiquité (stoïcisme, épicurisme, cynisme) qui développent des techniques (ascèse, méditation, écriture, examen de conscience, attention au corps) pour atteindre un mieux-être. Toutes placent au centre la recherche de sérénité, dans la conscience de la brièveté de la vie et des épreuves qui la traversent.

Si les exercices spirituels émergent dans la philosophie antique, ils se transforment avec le christianisme avant de réapparaître à la Renaissance, chez Érasme et Montaigne, puis chez Descartes, Rousseau, Kant ou Shaftesbury. À l’époque contemporaine, ils se prolongent chez Emerson, Thoreau, Wittgenstein, Cavell ou Foucault, sans toutefois s’inscrire dans des écoles structurées, laissant place à des formes plus diffuses.

J’ai ainsi étudié des mouvements contemporains et historiques reprenant certains traits de ces traditions : communautés comme Auroville ou Christiania, expériences comme Monte Verità, ou encore pratiques artistiques (dadaïsme, Fluxus) et corporelles (Alexander, Feldenkrais, naturisme). Si les exercices spirituels persistent aujourd’hui, ils demeurent discrets et ne constituent plus véritablement une philosophie comme mode de vie. C’est précisément l’inverse qui se produit dans le Nord européen, plus précisément en Finlande, où s’est établie depuis des temps anciens une philosophie comme art de vivre sous le nom de « sisu ».




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Et si la dette publique servait d’abord à rendre les citoyens plus heureux ?


Sisu, une philosophie comme art de vivre

Si le « sisu » n’a pas de traduction littérale dans une langue autre que la sienne, il peut s’entendre comme une articulation entre le stoïcisme, l’épicurisme et le cynisme. C’est en effet, à la fois une philosophie de l’assentiment, de la recherche de plaisirs simples et de l’autosuffisance. Le sisu ne se définit pas comme un héroïsme spectaculaire, mais comme une disposition à continuer lorsque nos ressources perçues semblent épuisées. Selon la formule de la chercheuse Emilia Lahti, le sisu « commence là où notre force perçue s’arrête » : il n’est pas l’endurance ordinaire, mais l’énergie qui se manifeste dans les moments où l’abandon paraît rationnel.

Stoïcien, le sisu l’est d’abord par son rapport à l’adversité. Il ne prend ombrage ni de la dureté du climat, ni de l’histoire marquée par la guerre et la pénurie ; il assume que certaines circonstances excèdent notre contrôle et exige une discipline intérieure capable de tenir face à elles. Mais cette fermeté n’est pas une insensibilité.

Absence ou abstention d’émotions ?

L’un des malentendus les plus répandus en Finlande consiste précisément à confondre le sisu avec une absence d’émotion. Or, si la crise impose parfois de suspendre l’expression des affects, ceux-ci doivent être reconnus et élaborés. Le sisu n’est pas un état permanent : « ce n’est pas un lieu où l’on vit, mais un lieu que l’on visite ». En cela, il relève moins d’une dureté continue que d’une capacité à entrer, ponctuellement, dans une zone d’intensité morale.

Épicurien ensuite, le sisu s’enracine dans une forme de sobriété heureuse. Les enquêtes sur le bonheur placent régulièrement la Finlande parmi les premiers pays du monde, mais ce bonheur ne se comprend ni comme accumulation ni comme ostentation. Il se définit par la paix, le silence, l’ordre, l’indépendance, la fonctionnalité et, surtout, le temps passé dans la nature.

La nature comme ressource existentielle

Celle-ci n’est pas un décor, mais une ressource existentielle : elle centre, apaise, restaure. La nature agit comme une sorte d’« antidépresseur naturel » et comme un lieu de reconnexion à une source plus profonde de force. Le sisu se nourrit aussi d’une économie du désir et du langage : parler lorsque l’on a quelque chose à dire, se contenter de peu, privilégier l’authenticité à la performance.

Enfin, cynique au sens ancien du terme, le sisu valorise l’autosuffisance et la cohérence entre les paroles et les actes. Il rejette l’exhibition de la bravoure, l’autopromotion. « Let your actions do the talking » – que les actes parlent. La franchise finlandaise, souvent perçue comme brusquerie, s’inscrit dans cette éthique de la droiture. Être ferme, mais bienveillant ; défendre ses convictions sans écraser autrui ; préférer l’intégrité à la flatterie. Le sisu ne se mesure pas à l’intensité des déclarations, mais à la constance des gestes.

Autonomie et solidarité

Il serait pourtant réducteur d’en faire une vertu strictement individuelle. Si le sisu s’active dans l’épreuve personnelle, il est aussi une énergie collective. L’histoire finlandaise, notamment la guerre d’Hiver de 1939-40, a élevé le sisu au rang de principe national, mais ce mythe fondateur ne célèbre pas seulement le courage solitaire : il souligne la capacité d’un peuple à tenir ensemble. « Nous sommes plus forts ensemble que seuls » pourrait en être la maxime. L’importance accordée à l’égalité, à la négociation collective et à la coopération sociale, montre que le sisu circule, s’encourage et se renforce mutuellement.

Ainsi compris, le sisu n’est ni une simple résilience ni une austérité morale. Il est une éthique située : une manière d’habiter l’adversité sans se laisser définir par elle, de chercher des plaisirs simples sans renoncer à l’effort, et d’assumer une autonomie qui n’exclut pas la solidarité. Entre retenue et détermination, silence et action, il dessine une forme de force discrète, profondément moderne dans des sociétés saturées de bruit, d’excès et de mise en scène.

Le sisu peut-il exister loin de la Finlande ?

Cette philosophie finlandaise pourrait-elle être appropriée dans un contexte français ? La France traverse une période marquée par une tension : d’un côté, une intensité expressive forte (débats permanents, conflictualité médiatique, mise en scène politique continue) et, de l’autre, un sentiment diffus d’impuissance face aux crises écologiques, sociales et institutionnelles.

Là où le sisu valorise l’économie du langage et la primauté de l’acte sur la déclaration, notre culture accorde souvent une place centrale à la parole, à la posture et à la dramatisation. Il ne s’agit pas de dévaluer cette tradition rhétorique, constitutive de notre histoire intellectuelle, mais de se demander si elle ne gagnerait pas à être équilibrée par une éthique de la retenue et de la constance.

Arte 2025.

Dans le contexte des transitions écologiques notamment, le sisu offre une piste précieuse, puisqu’il propose une manière d’habiter la contrainte sans la vivre uniquement comme frustration. L’histoire finlandaise, marquée par le climat rude et la pénurie, a forgé une disposition à faire avec, plutôt qu’à s’indigner contre. Appliquée à nos propres défis – sobriété énergétique, transformation des modes de vie, réorganisation des systèmes productifs – une telle attitude pourrait nourrir une culture de l’ajustement lucide plutôt que de la résistance nostalgique. Le sisu ne consiste pas à nier la difficulté, mais à accepter qu’elle fasse partie du réel et à mobiliser une énergie orientée vers l’action.

La puissance des engagements ordinaires

La France pourrait également trouver dans le sisu un correctif à une conception parfois héroïque et individualisée de la réussite. La tradition française valorise la figure du grand homme, du leader charismatique, du moment spectaculaire. Or le sisu, tel qu’il se manifeste dans la culture finlandaise, privilégie une force moins visible : celle qui se déploie sans ego excessif, sans recherche de reconnaissance immédiate. Il rappelle que la solidité d’une société ne repose pas uniquement sur des figures exceptionnelles, mais sur une multitude d’engagements ordinaires, tenus dans la durée.

Ce que la France peut attendre d’une telle philosophie n’est donc pas une conversion culturelle, mais l’adoption d’un nouveau point de vue. Le sisu invite à penser la force autrement, comme une endurance silencieuse, comme une capacité à entrer, lorsque les circonstances l’exigent, dans un état d’effort lucide. C’est une manière de « tenir » sans se durcir, de persévérer sans se glorifier.

Dans un moment historique où les crises semblent s’enchaîner et où la tentation du découragement ou de la radicalisation est forte, cette philosophie comme mode de vie pourrait constituer une ressource. Elle suggère que la transformation ne passe pas uniquement par des ruptures spectaculaires, mais aussi par une multitude de gestes constants, sobres et cohérents. À ce titre, le sisu n’est pas tant un exotisme nordique qu’un miroir critique pour nos propres habitudes morales et politiques.

The Conversation

Xavier Pavie ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. À la base du bonheur finlandais, le sisu une philosophie du froid – https://theconversation.com/a-la-base-du-bonheur-finlandais-le-sisu-une-philosophie-du-froid-277312

Power outages in heat waves and storms can threaten the lives of medical device users – we looked at who is most at risk

Source: The Conversation – USA (3) – By Matthew D. Dean, Assistant Professor of Civil & Environmental Engineering, University of California, Irvine

Many older adults rely on electric-powered medical equipment, such as portable oxygen and nebulizers that help them breathe. Westend61 via Getty Images

When the power goes out and stays off for hours, the result can be more than just a hassle – for millions of Americans who rely on medical equipment, losing electricity can become a medical emergency.

Your neighbor might rely on an oxygen concentrator to breathe – a machine the size of a carry-on bag that hums quietly through the night. Or they might need a CPAP – continuous positive airway pressure – machine to keep them breathing safely in their sleep, or a ventilator.

Most home medical devices run on backup batteries that last only 3 to 8 hours. Yet people in over half of U.S. counties experienced at least one outage lasting more than eight hours between 2018 and 2021. Power outages are becoming more common in the U.S., too. They grew 9% more frequent and lasted 56% longer between 2014 and 2023, driven by severe weather, winter storms, hurricanes and wildfires linked to climate change.

Studies following major blackouts show an increase in disease-related deaths, including a 25% rise during a three-day blackout in New York City in August 2003. Emergency rooms can become overwhelmed with device users seeking backup power and medical care.

But not everyone with a medical device faces the same risks during a power outage. In a new study published in the journal Environmental Research: Health, we show which groups need the most help and who is slipping through the cracks in life-threatening ways.

Four very different realities

We analyzed data from more than 2,600 households reporting the use of medical devices, drawn from a nationally representative federal survey of nearly 18,500 American homes. Using statistical modeling, we identified four distinct groups, each facing a very different situation when the power goes out.

About 60% of medically dependent households are financially stable homeowners. They face outages, but they are the most likely group to have backup generators.

A second group, roughly 20%, are homeowners who struggle to pay their energy bills and sometimes skip medicine or meals to keep the lights on, but who also tend to have backup power sources. This group had the highest likelihood of experiencing dayslong power outages in the past year, but was also more likely to have a generator or access to solar power than the average American.

A third group is apartment renters who can afford their electricity bills but are typically unable to make long-term upgrades for more resilient power supplies. For example, they can’t install solar panels or add permanent backup power because those decisions belong to their landlord, not them.

A backpack-size machine with a tube to a breathing mask.
Oxygen machines can be portable, but when the power goes out for hours, users need to be able to find a place to recharge the batteries.
Chingyunsong/istock/Getty Images Plus

The fourth class is the smallest, roughly 7% of medical device households, and by far the most at risk. These are mostly low-income urban renters, and they face two compounding problems: They struggle to pay their electricity bills every month, and they have almost no backup resources when the power goes out.

Nearly 58% of these at-risk renters said they had received a disconnection notice from their utility within the previous year. One in eight had needed medical attention because their home got too hot or too cold. This group is also disproportionately Black or Hispanic.

Our findings confirm what researchers have long suspected: Energy insecurity among medical device users is deeply tied to income, housing type and race. Our study also shows the importance of understanding where people are both energy insecure and less likely to have access to backup power sources during outages.

What communities are doing today

Some communities are finding ways to tackle pieces of this problem.

Most utility companies maintain lists of households with medical devices, and they are supposed to notify customers ahead of power shutoffs and prioritize restoring power to their homes. However, studies show that these registries capture only a fraction of the people who qualify.

If medical device users were instead automatically enrolled during a doctor’s visit, or if landlords were required to notify new tenants of these registries, those steps could help reach more people.

Portable battery programs, like those run by California’s largest utilities, provide free or low-cost rechargeable batteries and a solar panel kit to homeowners and renters with medical devices who are most at risk of power shutoffs. Contractors can work with households to choose an appropriate battery to ensure it isn’t too heavy or difficult to transport if evacuating because of a wildfire or other disaster.

As climate change makes blackouts longer and more frequent – and as federal low-income energy assistance programs face cuts – providing help to residents falls increasingly on states and cities. Knowing which households face the greatest risks can make it easier to target aid to those in need.

The Conversation

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Power outages in heat waves and storms can threaten the lives of medical device users – we looked at who is most at risk – https://theconversation.com/power-outages-in-heat-waves-and-storms-can-threaten-the-lives-of-medical-device-users-we-looked-at-who-is-most-at-risk-276501

Overconfidence is how wars are lost − lessons from Vietnam, Afghanistan and Ukraine for the war in Iran were ignored

Source: The Conversation – USA – By Monica Duffy Toft, Professor of International Politics and Director of the Center for Strategic Studies, The Fletcher School, Tufts University

Plumes of smoke and fire rise after debris from an intercepted Iranian drone struck an oil facility, according to authorities, in Fujairah, United Arab Emirates, on March 14, 2026. AP Photo/Altaf Qadri

Wars are rarely lost first on the battlefield. They are lost in leaders’ minds − when leaders misread what they and their adversaries can do, when their confidence substitutes for comprehension, and when the last war is mistaken for the next one.

The Trump administration’s miscalculation of Iran is not an anomaly. It is the latest entry in one of the oldest and most lethal traditions in international politics: the catastrophic gap between what leaders believe going in and what war actually delivers.

I’m a scholar of international security, civil wars and U.S. foreign policy, and author of the book “Dying by the Sword,” which examines why the United States repeatedly reaches for military solutions and why such interventions rarely produce durable peace. The deeper problem with the U.S. war in Iran, as I see it, was overconfidence bred by recent success.

Dismissed concerns

Before the conflict involving Iran, Israel and the U.S. escalated, Energy Secretary Chris Wright dismissed concerns about oil market disruption, noting that prices had barely moved during the 12-day war in June 2025 between Israel and Iran. Other senior officials agreed.

What followed was significant: Iranian-aimed missile and drone barrages against U.S. bases, Arab capitals and Israeli population centers. Then Iran effectively closed the Strait of Hormuz, through which roughly 20% of the world’s oil supply passes daily − not with a naval blockade, not with mines or massed anti-ship missiles, but with cheap drones.

A few strikes in the vicinity of the strait were enough. Insurers and shipping companies decided the transit was unsafe. Tanker traffic dropped to zero, although the occasional ship has made it through recently. Analysts are calling it the biggest energy crisis since the 1970s oil embargo.

President Donald Trump expressed anger on March 17, 2026, at allies who did not agree to help the U.S. force the reopening of the Strait of Hormuz to tanker traffic.

Iran’s new supreme leader, Mojtaba Khamenei, has since vowed to keep the strait closed. U.S. Sen. Chris Murphy, a Connecticut Democrat, reported after a closed-door briefing that the administration had no plan for the strait and did not know how to get it safely back open.

With no embassy in Tehran since 1979, the U.S. relies heavily for intelligence on CIA networks of questionable quality and Israeli assets who have their own country’s interests in mind. So the U.S. did not anticipate that Iran had rebuilt and dispersed significant military capacity since June 2025, nor that it would strike neighbors across the region, including Azerbaijan, widening the conflict well beyond the Persian Gulf.

The war has since reached the Indian Ocean, where a U.S. submarine sank an Iranian frigate 2,000 miles from the theater of war, off the coast of Sri Lanka – just days after the ship had participated in Indian navy exercises alongside 74 nations, including the U.S.

The diplomatic damage to Washington’s relationships with India and Sri Lanka, two countries whose cooperation is increasingly important as the United States seeks partners to manage and mitigate Iran’s blockade, was entirely foreseeable. Washington has put them in a difficult position, with India choosing diplomacy with Iran to secure passage for its vessels and Sri Lanka opting to retain its neutrality, underscoring its vulnerable position.

But U.S. planners didn’t foresee any of this.

The wrong lesson from Venezuela

The swift military intervention by the U.S. in Venezuela in January 2026 produced rapid results with minimal blowback − appearing to validate the administration’s faith in coercive action.

But clean victories are dangerous teachers.

They inflate what I call in my teaching the “hubris/humility index” − the more a leadership overestimates its own abilities, underestimates the adversary’s and dismisses uncertainty, the higher the score and the more likely disaster will ensue. Clean victories inflate the index precisely when skepticism is most needed, because they suggest the next adversary will be as manageable as the last.

Political scientist Robert Jervis demonstrated decades ago that misperceptions in international relations are not random but follow patterns. Leaders tend to project their own cost-benefit logic onto opponents who do not share it. They also fall into “availability bias,” allowing the most recent operation to stand in for the next.

The higher the hubris/humility index, the less likely there is to be the kind of strategic empathy that might ask: How does Tehran see this? What does a regime that believes its survival is at stake actually do? History shows that such a regime escalates, improvises and takes risks that appear irrational from an outside perspective but are entirely rational from within.

Recent cases reveal this unmistakable pattern.

The United States in Vietnam, 1965–1968

American war planners believed material superiority would force the communists in Hanoi to surrender.

It didn’t.

American firepower alone didn’t lead to military defeat, much less political control. The Tet Offensive in 1968 – when North Vietnamese and Viet Cong forces launched coordinated attacks across South Vietnam – shattered the official U.S. narrative that the war was nearly won and that there was “light at the end of the tunnel.”

Athough the U.S. and South Vietnamese forces ultimately repelled the attacks, their scale and surprise caused the public not to trust official statements, accelerating the erosion of public trust and decisively turning American opinion against the war.

The U.S. loss in Vietnam didn’t occur on a single battlefield, but through strategic and political unraveling. Despite overwhelming superiority, Washington was incapable of building a stable, legitimate South Vietnamese government or recognizing the grit and resilience of the North Vietnamese forces. Eventually, with mounting casualties and large-scale protests at home, U.S. forces withdrew, ceding control of Saigon to North Vietnamese forces in 1975.

A helicopter taking off from the roof of a building.
In this April 29, 1975, file photo, a helicopter lifts off from the U.S. Embassy in Saigon, South Vietnam, during a last-minute evacuation of authorized personnel and civilians.
AP Photo.

The U.S. failure was conceptual and cultural, not informational. American analysts simply couldn’t picture the war from their opponent’s perspective.

Afghanistan: Deadly assumptions

The Soviet Union in Afghanistan in 1979 and the United States in Afghanistan after 2001 conducted two different wars but held the same deadly assumption: that external military force can quickly impose political order in a fractured society strongly resistant to foreign control.

In both cases, great powers believed their abilities would outweigh local complexities. In both cases, the war evolved faster − and lasted far longer − than their strategies could adapt.

Russia, Ukraine and the Strait of Hormuz

This is the case that should most haunt Washington.

Ukraine demonstrated that a materially weaker defender can impose huge costs on a stronger attacker through battlefield innovation: cheap drones, decentralized adaptation, real-time intelligence, and the creative use of terrain and chokepoints to find asymmetrical advantages. The U.S. watched it all unfold in real time for four years and helped pay for it.

Iran was also watching − and the Strait of Hormuz is the proof.

Iran didn’t need a navy to close the world’s most important energy chokepoint. It needed drones, the same cheap, asymmetric technology Ukraine has used to blunt Russia’s onslaught, deployed not on a land front but against the insurance calculus of the global shipping industry.

Washington, which had underwritten much of that playbook in Ukraine, apparently never asked the obvious question: What happens when the other side has been taking notes? That is not a failure of U.S. intelligence. It is a failure of strategic imagination − exactly what the hubris/humility index is designed to highlight.

Iran does not need to defeat the U.S. conventionally. It needs only to raise costs, exploit chokepoints and wait for a fracture among U.S. allies and domestic political opposition to force a fake U.S. declaration of victory or a genuine U.S. withdrawal.

Notably, Iran has kept the strait selectively open to Turkish, Indian and Saudi vessels, rewarding neutral countries and punishing U.S. allies, driving wedges through the coalition.

Historian Geoffrey Blainey famously argued that wars start when both sides hold incompatible beliefs about power and only end when reality forces those beliefs to align.

That alignment is now happening, at great cost, in the Persian Gulf and beyond. The Trump administration scored high on the hubris index at exactly the moment when it most needed humility.

The Conversation

Monica Duffy Toft does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Overconfidence is how wars are lost − lessons from Vietnam, Afghanistan and Ukraine for the war in Iran were ignored – https://theconversation.com/overconfidence-is-how-wars-are-lost-lessons-from-vietnam-afghanistan-and-ukraine-for-the-war-in-iran-were-ignored-278604

Why Colorado River negotiations stalled, and how they could resume with the possibility of agreement

Source: The Conversation – USA (2) – By Karen Schlatter, Director, Colorado Water Center, Colorado State University

The reservoir behind the Glen Canyon Dam is extremely low. Jim West/UCG/Universal Images Group via Getty Images

The seven U.S. states that make up the Colorado River basin are struggling to agree on how best to manage the river’s water as its supply dwindles due to climate change and a period of prolonged drought. Their negotiations, which are not open to the public, missed a Feb. 14, 2026, deadline the federal government had established, after which federal officials said they would impose their own plan.

The federal government has not yet done so, but the prospect of such an action is not good news for the nearly 40 million people who depend on the Colorado River for water, energy, agriculture and recreation, nor for the estimated US$1.4 trillion in economic activity the river supports.

We have led or participated in complex water management discussions from the river’s headwaters in Colorado to its delta in Mexico and elsewhere in the arid Southwest and around the world. Even on less contentious issues, the keys to success involve learning together, understanding one another’s interests, working through conflict and developing inclusive solutions for diverse participants. And that works best with an outside facilitator.

The five most common sources of conflict between people are values, data, relationships, interests and structure. The current Colorado River negotiations include all five. We believe a process designed and facilitated by negotiation experts could help break the logjam.

We recognize it can be very hard to reach an agreement when what’s at stake are countless lives, massive amounts of money, enormous quantities of hydroelectric power and not nearly enough water.

But compromise on Colorado River management is possible and, in fact, was achieved to curb California’s water use in the 2000s, to negotiate an interim agreement to coordinate operations at the Lake Mead and Lake Powell reservoirs in 2007, and to enact contingency plans to manage drought in 2019. But this time around, circumstances are different.

Previous negotiations

The negotiations leading up to those agreements were often facilitated by officials from the U.S. Bureau of Reclamation who focused on reaching broad agreements on general principles and concepts before delving into details. Federal staff also actively guided key agreements and provided the science and computer models to make well-informed decisions. And the states’ negotiators knew the Department of Interior would act unilaterally to make damaging cuts to water supply if states couldn’t come to their own agreement.

The negotiators for the states had long-standing relationships and built trust by frequently communicating outside formal meetings and seeking to listen to and understand other states’ perspectives, even if they didn’t agree.

The states also agreed to use the bureau’s computer model for analyzing scenarios of climate change and management decisions. That meant all the negotiators were looking at the same data when delving into possible options. And the political and social environment was less polarized than today.

The current situation

In this round of negotiations, federal leadership has been lagging. The Department of the Interior has not made clear what the consequences might be for the states if they fail to agree. The U.S. Bureau of Reclamation has been without a permanent commissioner since President Donald Trump retook office in January 2025.

And federal staff have only recently begun helping to facilitate the discussions.

The states are fractured into subgroups, according to whether they are in the river’s Upper Basin – Colorado, Wyoming, Utah and New Mexico – or the Lower Basin, which includes Arizona, Nevada and California. Each basin group holds strong positions and has generally been unwilling to shift.

Each basin group is using a different set of assumptions for the bureau’s computer model to explore options. And the discussion often gets stuck on details, which prevents progress toward broader agreements.

In addition, the political context has shifted significantly, with increased polarization and politicization of the issues, creating barriers to effective dialogue and deliberation. Today, compromise can seem unattainable.

But those relatively new challenges to Colorado River compromise are not an excuse for failure.

A group of people sit around a table in a formal meeting room.
Interior Secretary Doug Burgum, center between flags, meets with governors and representatives of the seven Colorado River basin states in January 2026.
U.S. Department of the Interior via X

A way forward?

The current negotiations have all been done behind closed doors. From talking with people involved in the negotiations, we understand the negotiators have been left to set their own agendas and meeting plans and conduct their own communications and follow-up, with no formal facilitators.

It’s reasonable to expect the negotiators to be ready to represent their states’ interests, working through an incredibly complicated landscape of hydrology, climate and management scenario modeling, water law and administration, and politics. But we believe it’s unreasonable – and unrealistic and unfair – to expect them to also be experts at designing and facilitating an effective process for sorting out their differences.

Federal officials are not necessarily the best people to run the process either. And if the agency that ultimately needs to approve any deal is the one leading the process, real or perceived biases about the states or key issues in the agreement could further complicate the discussions.

We believe that agreement between the seven states is still possible. It may be less effective to bring in a third-party facilitator at this stage in the negotiation process, though, because of the degraded trust, hardened positions and shortage of time.

One possible outcome is that the Bureau of Reclamation will select and enforce one of the five management alternatives it outlined in January 2026. But that could lead to decades of litigation going up to the Supreme Court. No one wins in this scenario.

A more hopeful possibility is that the bureau adopts short-term rules that would give the states another chance to negotiate a longer-term deal – ideally with an unbiased third-party facilitator for support.

A collaborative and consensus-based planning process in the Yakima River Basin in Washington state in the early 2010s is evidence that while nobody gets everything they want in a negotiated agreement, “if they can (all) get something, that’s really the basis of the plan,” as a Washington state official told The New York Times.

The Conversation

Sharon B. Megdal is principal investigator on multiple grants and contracts, none of which funded or influenced the content of this essay. Megdal served as an elected member of the Central Arizona Project Board of Directors from 2009 through 2020.

Karen Schlatter does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Why Colorado River negotiations stalled, and how they could resume with the possibility of agreement – https://theconversation.com/why-colorado-river-negotiations-stalled-and-how-they-could-resume-with-the-possibility-of-agreement-278029

Federal judge temporarily blocks RFK Jr.’s vaccine agenda – an epidemiologist answers questions parents may have

Source: The Conversation – USA (3) – By Katrine L. Wallace, Epidemiologist, University of Illinois Chicago

A lawsuit brought by six medical organizations seeks to block several changes that federal health officials made to vaccine policy. Jackyenjoyphotography/Moment via Getty Images

Public health advocates have largely applauded a Massachusetts judge’s ruling on March 16, 2026, to temporarily block major changes to vaccine policy made by the Department of Health and Human Services since 2025.

The ruling pauses two major actions ushered in by HHS Secretary Robert F. Kennedy Jr. since he stepped into the role. First, it blocks Kennedy’s restructuring of a key vaccine panel called the Advisory Committee on Immunization Practices in June 2025. Second, it suspends HHS’s overhaul of the childhood vaccine schedule in January 2026, which cut the number of routine vaccinations children are recommended to receive from 17 to 11.

As an epidemiologist who studies vaccine hesitancy and a public-facing science communicator, I view these HHS actions as extremely damaging to public health, and I am relieved they have been paused, at least while legal proceedings are ongoing.

However, I also worry that this back-and-forth is detrimental to trust in science, especially for families who are already uneasy about vaccinating their kids or feel hesitant to do so.

What exactly happened?

The March 16 decision follows a lawsuit originally brought in July 2025 by six medical organizations, including the American Academy of Pediatrics. The medical organizations argued that HHS’s changes were implemented without following established legal and scientific processes.

The ruling seems to align with that view, concluding that the government’s overhaul of the vaccine committee likely “fails to comport with governing law” and that its changes to the vaccine schedule were “arbitrary and capricious.”

The judge’s action suggests that the court believes the plaintiffs are likely to succeed in showing that the HHS changes violated federal law.

A temporary ruling reverses changes to the childhood vaccine schedule while the case against HHS proceeds.

The ruling returns recommendations on the childhood vaccine schedule – made by the Centers for Disease Control and Prevention, one of HHS’s primary divisions – to their pre–June 2025 status while the case proceeds. It also blocks HHS’s replacement of members of the Advisory Committee on Immunization Practices, which reviews evidence and develops recommendations that guide vaccine-related decisions by the Centers for Disease Control and Prevention.

The ruling effectively pauses the vaccine committee’s work. The members appointed by Kennedy cannot serve at the moment, and the previous members do not automatically return, leaving the committee inactive for now.

Officials from HHS have indicated that they are likely to appeal the ruling.

Does the ruling change people’s ability to access vaccines?

Not at the moment, because right now nothing has changed about what vaccines children should receive. Pediatricians should be following the long-standing vaccine schedule as it existed before the HHS’s change in June 2025. Most physicians already are, having followed the American Academy of Pediatrics’ decision not to back HHS’s revised schedule.

Additionally, private insurers as well as federal health programs such as Medicaid, the Children’s Health Insurance Program and Vaccines for Children had already agreed to continue covering all the vaccines through 2026, even before the judge intervened.

From a health economics perspective, data shows that the downstream costs of treating vaccine-preventable illnesses are much higher than the cost of reimbursing vaccines, so insurance companies may be motivated to continue covering them.

Moving forward, however, the ongoing court case could affect vaccine availability because many insurance companies and public programs rely on recommendations from the Advisory Committee on Immunization Practices to determine which vaccines are covered or provided at no cost.

If your children are behind on any vaccines, it would be a good idea to get them now, given the uncertainty.

What effect might the ruling have longer term?

It’s important to remember that even though policy shifts in vaccine recommendations can be confusing, the data on the safety and efficacy of childhood vaccines has not changed. There were no safety alerts or new clinical trials that precipitated HHS’s change to the vaccine schedule.

Even with the prior recommendations back in place, however, all the back-and-forth in the headlines may create confusion for parents. Mistrust of vaccines and public health is at an all-time high, fueled by disinformation, poor communication on the part of public health agencies, and other factors that arose mostly during the COVID-19 pandemic.

Parents have long considered health agencies such as the CDC to be trustworthy but increasingly look upon them with skepticism. A survey in January 2026 showed public trust in federal health agencies has declined following HHS’s changes to the childhood vaccine schedule.

Immunization rates, meanwhile, are on the decline, particularly for measles. An analysis released by Reuters on March 18, 2026, of vaccination data from Michigan suggests the number of toddlers receiving routine vaccines fell sharply from January 2025 to January 2026, and that Kennedy’s attack on vaccines influenced parents’ decisions to forgo them.

Rebuilding trust in vaccines and public health will take time and will require consistent, transparent communication and strong engagement between clinicians and families. The court ruling potentially represents an initial step in that process.

For parents with questions about vaccines, the best source of information remains their child’s pediatrician. Parents can also look to evidence-based vaccine schedules maintained by health groups such as the American Academy of Pediatrics.

The Conversation

Katrine L. Wallace does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Federal judge temporarily blocks RFK Jr.’s vaccine agenda – an epidemiologist answers questions parents may have – https://theconversation.com/federal-judge-temporarily-blocks-rfk-jr-s-vaccine-agenda-an-epidemiologist-answers-questions-parents-may-have-278709

‘Project Hail Mary’ explores unique forms of life in space – 5 essential reads on searching for aliens that look nothing like life on Earth

Source: The Conversation – USA – By Mary Magnuson, Associate Science Editor, The Conversation

The universe is filled with countless galaxies, stars and planets. Humans may one day discover extraterrestrial life. ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi

Project Hail Mary,” the movie adaptation to Andy Weir’s 2021 novel about a science teacher attempting to save the Earth from sun-eating microbes, was released in March 2026 to stellar ratings from critics and audiences alike. The movie explores a few unique forms that extraterrestrial life could take, from space microorganisms that produce both infrared light and an unfathomable amount of energy, to rocklike aliens that live under crushing pressure and breathe ammonia.

Over the past decade, scientists have come up with a variety of frameworks to guide their search for life in the universe. While it’s most convenient to start looking for life using the knowledge that biologists have about life on Earth, scientists have also begun integrating broader conceptions of life, including life that perhaps evolved in different chemical environments.

To expand on the idea that life out in space might look nothing like life on Earth, here are five articles The Conversation U.S. rounded up from our archives, and written by astronomers and astrobiologists.

1. Why base the search on life on Earth?

Astronomers participating in the Search for Extraterrestrial Intelligence typically start by identifying potentially habitable planets. And to do that, they look for what sustains life on Earth: water.

Planets that are close enough to their Sun that liquid water wouldn’t freeze, but far enough away that it wouldn’t evaporate, fall into what’s called the Goldilocks Zone. But why base the search on water, which complex life on Earth uses to survive, if an extraterrestrial life-form might use different chemistry?

Cole Mathis, a physicist and astrobiologist at Arizona State University who studies complex adaptive systems, explained that out of convenience, astronomers start by looking for signals similar to those produced by life on Earth.

Detecting chemical signatures using the instruments on telescopes is tricky – it’s like playing hide-and-seek, but you’re outside the house and can only peer in through the window. You might as well start by ruling out the easy and more obvious hiding spots.

A diagram showing a small planet passing in front of a star, and the brightness level dipping when it blocks the star's light
By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet.
NASA Ames

Missions to Mars have looked for signs of photosynthesis – the process by which plants take in energy – and telescopes peering deep into space look for oxygen, which organisms on Earth release into the atmosphere.

“Most astronomers and astrobiologists know that if we only look for life that’s like Earth life, we might miss the signs of aliens that are really different,” Mathis wrote. “But honestly, we’ve never detected aliens before, so it’s hard to know where to start. When you don’t know what to do, starting somewhere is usually better than nowhere.”




Read more:
Why do astronomers look for signs of life on other planets based on what life is like on Earth?


2. Finding patterns of purpose

Sometimes, scientists find chemical ingredients that make up life on Earth out in space, but they can’t assume that these ingredients on their own indicate life. Geological and environmental processes on planets may produce these chemical signatures without any living organisms involved.

The key difference, to Amirali Aghazadeh, a computational scientist at the Georgia Institute of Technology, is purpose. Life grows, adapts and changes over time to better fit its environment.

His research team came up with a framework that, instead of looking for a specific type of life-form, looks at patterns in collections of chemicals and evaluates whether they could have been produced by processes like metabolism and evolution.

“If we assume that alien life uses the same chemistry, we risk missing biology that is similar – but not identical – to our own, or misidentifying nonliving chemistry as a sign of life,” wrote Aghazadeh.




Read more:
Can scientists detect life without knowing what it looks like? Research using machine learning offers a new way


3. Lessons from complex, evolving systems

Like Aghazadeh, many astrobiologists are starting to look more broadly at how complexity emerges, rather than searching for a specific type of molecule that could indicate the presence of extraterrestrial life. Other forms of life may be made up of entirely different chemical ingredients to humans, but to be considered life, they would still have to adapt and evolve over time.

Evolution is the process of change in systems. It can describe how a group of something becomes more complex – or even just different – over time.

Chris Impey, an astronomer from the University of Arizona, attended a workshop where scientists across disciplines came together to try to understand how and why systems in the universe – from organisms to languages and information – change or grow more complex over time.

Figuring out these underlying drivers of complexity, or finding signals that indicate the presence of a complex system, could help scientists search for unique forms of life in the universe.

“As astrobiologists try to detect life off Earth, they’ll need to be creative,” Impey wrote. “One strategy is to measure mineral signatures on the rocky surfaces of exoplanets, since mineral diversity tracks terrestrial biological evolution. As life evolved on Earth, it used and created minerals for exoskeletons and habitats.”




Read more:
Extraterrestrial life may look nothing like life on Earth − so astrobiologists are coming up with a framework to study how complex systems evolve


4. Beyond biology: Looking for ‘technosignatures’

Another option for searching for life has nothing to do with biology. Some scientists, wrote astronomers Macy Huston and Jason Wright from Penn State University, look for “technosignatures:” signals that would come from technology originating beyond Earth.

Human technology – from TV towers to satellite and spacecraft communications – emits enough radio waves to create faint but detectable signals traveling through space. Scientists use this idea to search for artificial signals that could potentially come from an extraterrestrial civilization.

Other technosignatures could include chemical pollution, artificial heat or light from industry, or signals from a large number of satellites.

An artist's depiction of a planet covered in cities and with a chemically altered atmosphere.
Advanced civilizations may produce a lot of pollution in the form of chemicals, light and heat that can be detected across the vast distances of space.
NASA/Jay Freidlander

“While many astronomers have thought a lot about what might make for a good signal, ultimately, nobody knows what extraterrestrial technology might look like and what signals are out there in the universe,” wrote Huston and Wright.




Read more:
Signatures of alien technology could be how humanity first finds extraterrestrial life


5. Evaluating extraordinary claims

Detecting extraterrestrial life in any form would be a momentous occasion, so, as Impey wrote, making a declaration might not be cut-and-dried. In “Project Hail Mary,” the fictional scientists sample and study the “space dots” they find extensively before drawing a conclusion.

Scientists must first rule out any possible non-biological explanations for a discovery, meaning the discovery would have to be unexplained by any chemical or geological processes. If scientists ever found a potential life-form very different from all life on Earth, it might take extensive research before they could rule out all other possibilities and determine that it’s a living organism. But setting this bar so high protects scientists from making a claim they would later need to walk back.

“A detection of life would be a remarkable development,” Impey wrote. “On scales large and small, astronomers try to set a high bar of evidence before claiming a discovery.”




Read more:
‘Extraordinary claims require extraordinary evidence’ − an astronomer explains how much evidence scientists need to claim discoveries like extraterrestrial life


This story is a roundup of articles from The Conversation’s archives.

The Conversation

ref. ‘Project Hail Mary’ explores unique forms of life in space – 5 essential reads on searching for aliens that look nothing like life on Earth – https://theconversation.com/project-hail-mary-explores-unique-forms-of-life-in-space-5-essential-reads-on-searching-for-aliens-that-look-nothing-like-life-on-earth-278757

HBO’s ‘The Pitt’ nails how hospital cyberattacks create chaos, endanger patients and disrupt critical care

Source: The Conversation – USA – By Jeffrey Tully, Associate Clinical Professor of Anesthesiology, University of California, San Diego

HBO Max’s enormously popular television series “The Pitt” is receiving plaudits for its realistic depiction of the trials and tribulations of health care in an urban emergency room.

Now in its second season, which premiered on Jan. 8, 2026, the show follows Dr. Michael “Robby” Robinavitch (played by Noah Wyle) and his colleagues through a single 15-hour clinical shift, divided into one-hour episodes. The team treats patients against a backdrop of all-too-common American societal plagues, from substance use disorder to medical bankruptcies and mass shootings.

Spoiler alert: About halfway through the season, Dr. Robby and the staff at the fictional Pittsburgh Trauma Medical Center grapple with chaos ensuing from a less commonly depicted disaster – a hospital cyberattack. The hospital’s network and computers were incapacitated, resulting in scenes of millennial residents struggling with fax machines, laboratory orders disappearing in a shuffle of papers, and constant communication breakdowns culminating in a missed life-threatening diagnosis.

All this might prompt viewers to wonder: Does this actually happen in real life?

As physicians who study cyberattacks and their impact on patient care, we have seen many of the same events depicted in “The Pitt” play out in the real world.

These attacks have severe clinical consequences. In an unfortunate case of art imitating life, the show’s cyberattack story arc began on the same day that the University of Mississippi Medical Center suffered the same fate, resulting in the sudden closure of more than 30 affiliated clinics across the state while also disrupting Mississippi’s only Level I trauma center.

Modern health care is critically dependent on digital technologies, such as electronic health records, laboratory machines and radiology platforms, that shut down when hospital networks are taken offline. Losing access to these tools for prolonged periods of time puts patients’ lives at grave risk.

A ransomware attack sent the fictional Pittsburgh Trauma Medical Center emergency room back to the dark ages.

What’s at stake

The most dire real-life cyberattacks on hospitals involve ransomware, a class of malicious software that encrypts data and locks down computers and networks, demanding significant amounts of cash for the promise of relief. Unfortunately, these events are not rare. Comparitech, a cybersecurity research firm, recorded 445 ransomware attacks on hospitals and clinics in 2025 – a new peak following several years of annual increases.

Such attacks are especially dangerous for patients with time-sensitive emergencies like strokes, heart attacks or sepsis, but they affect hospital outcomes broadly. For example, a 2026 analysis of Medicare data found that hospitalized patients had a 38% higher risk of death during a ransomware attack.

Moreover, the health impacts of ransomware are not confined to the hospitals under attack. “The Pitt” demonstrates this phenomenon well in earlier episodes. When Westbridge, another hospital in the community, is struck first, a wave of patients arriving by ambulance strains Pittsburgh Trauma Medical Center’s already packed emergency room, leading to delays in care and overwhelming already-strained clinicians. Our team found that a hospital cyberattack cut the odds of surviving a cardiac arrest without devastating brain damage by nearly 90% at nearby hospitals, not just the one that was attacked.

And even when a hospital’s computer systems are restored and normal care resumes, a cyberattack leaves enormous financial damage in its wake. Class action lawsuits, fragmented billing and steep regulatory fines due to patient privacy breaches and other issues often result in tens to hundreds of millions of dollars of losses.

In the worst cases, hospitals or clinics in rural areas have been forced to shutter their doors, leaving their communities with one less place to receive care and exacerbating existing health care deserts.

Modern health care depends on digital technologies, which leaves hospitals vulnerable to crippling cyberattacks.

Protecting cyber infrastructure

We have no doubt that Dr. Robby will rally his team to ultimately save the day from malicious cyberattacks on “The Pitt.” But what is the prognosis for the rest of us, in the real world?

The good news is that a number of efforts are underway to improve the cybersecurity of the U.S. health care system.

The federal government has recognized the particular risk posed to rural and critical access hospitals and has identified increased investment in cybersecurity technologies as one of the goals of the Rural Health Transformation Program, a US$50 billion package distributed across all 50 states.

Several states, including New York and Connecticut, have taken further action, enshrining new bills in 2025 and 2026 mandating hospitals develop specific cybersecurity plans to protect patients. And the Food and Drug Administration now evaluates the cybersecurity of new medical devices prior to their arrival to market, and can issue recalls of those found to have significant vulnerabilities.

Cybersecurity remains one of the few bipartisan issues on Capitol Hill. A health care cybersecurity bill co-sponsored by Senators Bill Cassidy, R-La., and Mark Warner, D-Va., introduced in December 2025, would require hospitals to adopt security practices, including multifactor authentication and data encryption, allocate additional grants for hospitals and clinics, and strengthen the pipeline for cybersecurity professionals working in the health care sector, among other provisions.

However, this problem isn’t going away. Artificial intelligence and the expansion of remote and virtual care mean that malicious hackers have sophisticated new tools and increased opportunities to target hospitals. Researchers like us will have to find new ways to prevent cyberattacks when possible and protect patients when they inevitably erupt.

The Conversation

Jeffrey Tully is the co-founder of Inoculum Labs. He receives funding from the Advanced Research Projects Agency for Health. He is affiliated with the Healthcare and Public Health Sector Coordinating Council Cybersecurity Working Group.

Christian Dameff co-founded inoculum labs. He receives funding from ARPA-H.

ref. HBO’s ‘The Pitt’ nails how hospital cyberattacks create chaos, endanger patients and disrupt critical care – https://theconversation.com/hbos-the-pitt-nails-how-hospital-cyberattacks-create-chaos-endanger-patients-and-disrupt-critical-care-278795