crème de la crème

Jai Ganesh · 2025-04-11 19:19:02

2214) David MacMillan

Gist:

Work

Catalysts, substances that accelerate chemical reactions, without becoming part of the final product, are important for chemists' ability to construct molecules. In 2000, David MacMillan and Benjamin List developed a new type of catalysis that builds upon small organic molecules. An important capacity of many such catalysts is the ability to build only one of two mirror image variants of a molecule. Such catalysts are used for example in pharmaceutical research and have made chemistry more environmentally friendly.

Summary

David W.C. MacMillan (born 1968, Bellshill, Scotland) is a Scottish-American organic chemist who developed asymmetric organocatalysis, in which a small, organic, carbon-based molecule is used as a catalyst to drive the production of a specific enantiomer (one form of a molecule that has two possible forms as mirror images of one another). The development of organocatalysis dispelled the notion that only metals and enzymes can serve as catalysts for chemical reactions and enabled the rapid construction of new drugs and materials. Moreover, organocatalysts are biodegradable, safer, and less costly than traditional catalysts; hence, their development greatly reduced the impact of chemistry on the environment. MacMillan was awarded the 2021 Nobel Prize in Chemistry for his breakthrough; he shared the prize with German chemist Benjamin List.

MacMillan studied chemistry as an undergraduate at the University of Glasgow. In 1990, after earning a bachelor’s degree, he went to the United States, where he carried out his doctoral studies at the University of California, Irvine. In 1996, having earned a Ph.D., he took a postdoctoral position at Harvard University. There his research focused on enantioselective catalysis, in which a specific enantiomer of a chiral product is generated from achiral reactants. In 1998 MacMillan joined the chemistry faculty at the University of California, Berkeley.

At Berkeley MacMillan’s research centred on the development of novel reactions and enantioselective synthesis. In 2000 he reported his first major breakthrough, the first enantioselective organocatalytic Diels-Alder reaction, in which a small organic molecule, rather than a metal, was used to drive the production of a specific enantiomer. At the time, in need of a word to describe the process, he coined the term organocatalysis. Earlier that year List independently reported that the amino acid proline is an efficient catalyst and can drive asymmetric catalysis. Both researchers subsequently developed other inexpensive stable organocatalysts that could be used for many different types of chemical reactions.

The same year that his groundbreaking paper was published, MacMillan moved his laboratory to the California Institute of Technology, where he served as a professor of chemistry. In 2006 he accepted a professorship at Princeton University, where he continued his investigations of novel methodologies for the total synthesis of compounds, particularly pharmaceuticals, where applications for organocatalysis were widespread.

MacMillan was recognized with various honours, in addition to the Nobel Prize, throughout his career. In particular, he was a recipient of the Ernst Schering Prize (2015) and the Ryoji Noyori Prize (2017). He was an elected fellow of the Royal Society (2012) and a member of the American Academy of Arts and Sciences (2012) and the U.S. National Academy of Sciences (2018).

Details

Sir David William Cross MacMillan (born 16 March 1968) is a Scottish chemist and the James S. McDonnell Distinguished University Professor of Chemistry at Princeton University, where he was also the chair of the Department of Chemistry from 2010 to 2015. He shared the 2021 Nobel Prize in Chemistry with Benjamin List "for the development of asymmetric organocatalysis". MacMillan used his share of the $1.14 million prize to establish the May and Billy MacMillan Foundation.

Education and early life

MacMillan was born in Bellshill, North Lanarkshire, Scotland, in 1968 and grew up in nearby New Stevenston. His father was a steelworker, while his grandfather was a miner. He attended the local state-funded schools, New Stevenston Primary and Bellshill Academy, and credited his Scottish education and Scottish upbringing for his success.

He received his undergraduate degree in chemistry at the University of Glasgow, where he worked with Ernie Colvin.

In 1990, he left the UK to begin his doctoral studies under the direction of Professor Larry Overman at the University of California, Irvine. During this time, he focused on the development of new reaction methodology directed toward the stereocontrolled formation of bicyclic tetrahydrofurans. MacMillan's graduate studies culminated in the total synthesis of 7-(−)-deacetoxyalcyonin acetate, a eunicellin diterpenoid isolated from the soft coral Eunicella stricta. He earned his Ph.D. in 1996.

Career and research

Upon receiving his Ph.D., MacMillan accepted a postdoctoral position with Professor David Evans at Harvard University. His postdoctoral studies centered on enantioselective catalysis, in particular, the design and development of Sn(II)-derived bisoxazoline complexes (Sn(II)box).

MacMillan began his independent research career as a member of the chemistry faculty at the University of California, Berkeley in July 1998. He joined the department of chemistry at Caltech in June 2000, where his group's research interests centered on new approaches to enantioselective catalysis. In 2004, he was appointed as the Earle C. Anthony Professor of Chemistry. He became the James S. McDonnell Distinguished University Professor at Princeton University in September 2006.

He is considered to be one of the founders of organocatalysis. In 2000, MacMillan designed small organic molecules that can provide or accept electrons and therefore efficiently catalyse reactions. He developed catalysts that can drive asymmetric catalysis, in which a reaction produces more of the left-handed version of a molecule than the right-handed one (chirality), or vice versa. MacMillan's research group has made many advances in the field of asymmetric organocatalysis, and they have applied these new methods to the synthesis of a range of complex natural products. He developed chiral imidazolidinone catalysts. MacMillan catalysts [de] are used in various asymmetric syntheses. Examples include Diels-Alder reactions, 1,3-dipolar cycloadditions, Friedel-Crafts alkylations or Michael additions.

MacMillan has also extensively developed photoredox catalysis for use in organic synthesis.

Between 2010 and 2014, MacMillan was the founding editor-in-chief of the journal Chemical Science, the flagship general chemistry journal published by the Royal Society of Chemistry.

As of March 2024, MacMillan has an h-index of 125 according to Google Scholar and of 115 according to Scopus.

Visit to Brasil

In April 2024, David MacMillan was in Brazil for events at the State University of Rio de Janeiro and the University of São Paulo. In Rio, MacMillan asked to visit the headquarters of General Severiano, from Botafogo, and was received by the Club's board of directors. Later in São Paulo, MacMillan held a short panel at University of São Paulo Chemistry Institute (IQ-USP) about his history as a researcher and recent Nobel laureate. In September 2024, he will attend the Brazilian Meeting on Organic Synthesis in Bento Gonçalves, Rio Grande do Sul, as opening lecture.

Jai Ganesh · 2025-04-12 16:48:08

2215) David Julius

Gist:

Work

Our ability to sense heat, cold and touch is essential for survival and underpins our interaction with the world around us. In the late 1990s, David Julius investigated how temperature is translated into nerve impulses. He utilized capsaicin, a compound from chili peppers that induces a burning sensation, and DNA fragments, genes, which are active in heat-sensing neurons. One single gene was able to make cells capsaicin sensitive. Further experiments revealed that the gene encoded a heat-sensing receptor on the neurons.

Summary

David Julius (born November 4, 1955, Brighton Beach, Brooklyn, New York, U.S.) is an American physiologist known for his discovery of heat- and cold-sensing receptors in the nerve endings of the skin. His elucidation of a receptor known as TRPV1, along with his subsequent contributions to the discovery of additional temperature-sensitive receptor molecules, gave new insight into how the human nervous system senses heat, cold, and pain. His studies of TRPV1 further facilitated research into novel strategies for the treatment of pain. For his breakthroughs, he was awarded the 2021 Nobel Prize in Physiology or Medicine, which he shared with Lebanese-born American molecular biologist and neuroscientist Ardem Patapoutian.

Julius studied life sciences at the Massachusetts Institute of Technology, whence he graduated with a B.S. degree in 1977. He subsequently attended the University of California, Berkeley, where he investigated mechanisms underlying the processing and secretion of peptides in yeast. In 1984, after earning a Ph.D. in biochemistry, Julius went to Columbia University. There, working as a postdoctoral researcher, he applied gene cloning technologies and identified genes belonging to the serotonin receptor family. In 1989 Julius left Columbia to join the faculty at the University of California, San Francisco (UCSF).

At UCSF Julius became interested in ion channels and understanding molecular mechanisms underlying somatosensation, particularly the sensation of pain. At the time, capsaicin, the pungent principle responsible for the burning sensation associated with red peppers (Capsicum), had been recently identified as an excitatory, or activating, compound at certain somatosensory neurons. However, the specific receptor to which capsaicin bound to produce the burning sensation was unknown. Using gene cloning strategies, Julius was able to uncover a receptor in the skin that responded to heat. He subsequently isolated the molecule and identified it as an ion channel, which he called TRPV1 (transient receptor potential cation channel subfamily V member 1).

Julius later contributed to the discovery of other temperature-sensitive ion channels, which became known as the transient receptor potential, or TRP, channel family. Included in the TRP channel family was the first cold-sensing receptor to be discovered, TRPM8 (transient receptor potential cation channel subfamily M member 8), which Julius helped characterize. Together with Chinese-born biophysicist and structural biologist Yifan Cheng, Julius also deduced the structures of TRP channels, notably TRPV1 and TRPA1 (the latter sometimes also called the wasabi receptor) in near-atomic detail by using cryogenic electron microscopy. The discovery and characterization of TRP channels enabled new understanding of how temperature triggers electrical signaling and sensation in the nervous system.

In addition to receiving the Nobel Prize, Julius received the Shaw Prize in Life Science and Medicine (2010), the Canada Gairdner International Award (2017), the Kavli Prize in Neuroscience (2020; shared with Patapoutian), and the Breakthrough Prize in Life Sciences (2020). He was a member of the U.S. National Academy of Sciences (elected 2004) and a trustee of the Howard Hughes Medical Institute (elected 2021).

Details

David Jay Julius (born November 4, 1955) is an American physiologist and Nobel Prize laureate known for his work on molecular mechanisms of pain sensation and heat, including the characterization of the TRPV1 and TRPM8 receptors that detect capsaicin, menthol, and temperature. He is a professor at the University of California, San Francisco.

Julius won the 2010 Shaw Prize in Life Science and Medicine and the 2020 Breakthrough Prize in Life Sciences. In 2020 he was awarded The Kavli Prize, and in 2021 the Nobel Prize in Physiology or Medicine jointly with Ardem Patapoutian.

Early life and education

Julius was born to an Ashkenazi Jewish family (from Russia) in Brighton Beach, Brooklyn, New York City, where he attended Abraham Lincoln High School. He earned his undergraduate degree from Massachusetts Institute of Technology in 1977. He attained his doctorate from University of California, Berkeley in 1984, under joint supervision of Jeremy Thorner and Randy Schekman, where he identified Kex2 as the founding member of furin-like proprotein convertases. In 1989, he completed his post-doctoral training with Richard Axel at Columbia University where he cloned and characterized the serotonin 1c receptor.

While at Berkeley and Columbia, Julius became interested in how psilocybin mushrooms and lysergic acid diethylamide work, which led him to look more broadly into how things from nature interact with human receptors.

Research career

He started his career as faculty at the University of California, San Francisco in 1989. In 1997, Julius's lab cloned and characterized TRPV1 which is the receptor that detects capsaicin, the chemical in chili peppers that makes them "hot". They found that TRPV1 also detects noxious heat (thermoception). TRPV1 is part of a large family of structurally related TRP (transient receptor potential) cation channels. Animals that lack TRPV1 (using genetic knockouts of the protein) lose sensitivity to noxious heat and capsaicin.

Julius's lab has also cloned and characterized TRPM8 (CMR1) and TRPA1, both members of the TRP superfamily. They demonstrated that TRPM8 detects menthol and cooler temperatures and TRPA1 detects mustard oil (allyl isothiocyanate). These observations suggested that TRP channels detect a range of temperatures and chemicals. David Julius's lab has also made contributions to the study of nociception by discovering toxins that modulate these channels, describing unique adaptations of the channels in diverse species and solving the cryo-EM structures of numerous channels.

Julius’ laboratory also made pioneering contributions to the discovery of purinergic receptors, both the P2Y class of G protein-coupled receptors, and the P2X class of ligand-gated ion channels. This included the cloning of P2Y12, the receptor for clopidogrel and related antiplatelet medications that are widely used to reduce the risk of heart disease and stroke. The group also cloned the 5HT3 receptor, a serotonin-activated ion channel and the target for drugs such as ondansentron for the treatment of nausea and vomiting.

From 2007–2020 Julius served as the editor of the peer-reviewed journal the Annual Review of Physiology.

Awards

In 2000, Julius was awarded the inaugural Perl-UNC Neuroscience Prize for his work on cloning the capsaicin receptor. In 2006, he was honored be The International Prize for Translational Neuroscience of the Max Planck Society. In 2007, Julius received the W. Alden Spencer Award by the College of Physicians and Surgeons, the Department of Neuroscience, and The Kavli Institute for Brain Science at Columbia University, and the Julius Axelrod Prize of the Society for Neuroscience. In 2008, he held the Jack Cooper Lecture at Yale School of Medicine. In 2010, he won the Shaw Prize for his work identifying the ion channels involved in various aspects of nociception. He received the Passano Award in the same year. In 2014, he was honored by Johnson & Johnson with the Dr. Paul Janssen Award for Biomedical Research for discovering the molecular basis for pain and thermosensation. In 2017, he won the Gairdner Foundation International Award and the HFSP Nakasone Award. He has also been awarded the 2010 Prince of Asturias Prize for Technical and Scientific Research, the 2020 Breakthrough Prize in Life Sciences, and the 2020 Kavli Prize in Neuroscience (together with Ardem Patapoutian) and the 2020 BBVA Foundation Frontiers of Knowledge Award.

In 2021, he was awarded the Nobel Prize in Physiology or Medicine jointly with Ardem Patapoutian for their discoveries of receptors for temperature and touch.

In 2022, Julius was awarded the UCSF Medal by the University of California, San Francisco. In 2023, he received the John J. Bonica Award, by the American Society of Regional Anesthesia and Pain Medicine (ASRA). In 2025, Julius was awarded a Honorary Membership in the Society of Toxicology.

Jai Ganesh · 2025-04-13 22:26:13

2216) Ardem Patapoutian

Gist:

Work

Our ability to sense heat, cold and touch is essential for survival and underpins our interaction with the world around us. In the early 2000s, Ardem Patapoutian investigated how pressure is translated into nerve impulses. He used cells that gave off a measurable electric signal when they were poked and assumed that the cause was a receptor, an ion channel, on the cell membrane. After having identified 72 candidate genes encoding possible receptors these were silenced one at a time. The pressure-sensitive ion channel was then found.

Summary

Ardem Patapoutian (born 1967, Beirut, Lebanon) is a Lebanese-born American molecular biologist and neuroscientist known for his investigations of the molecular basis of mechanoreception, the ability of animals to detect and respond to certain kinds of stimuli, particularly touch and changes in pressure or posture. Among his key discoveries was the identification of ion channels known as Piezo1 and Piezo2, which convert mechanical force into neuronal signals. The discovery of these channels facilitated new insight into how cells respond to mechanical factors, such as stretching and pressure, and the role of those responses in body functions ranging from the regulation of temperature, blood pressure, and urination to reflexes and sensations of pain. For his discoveries, Patapoutian shared the 2021 Nobel Prize in Physiology or Medicine with American physiologist David Julius.

In 1986, after a year of studies at the American University of Beirut, Patapoutian emigrated to the United States. There he attended the University of California, Los Angeles, for undergraduate studies, earning a B.S. degree in molecular, cellular, and developmental biology in 1990. He then enrolled as a graduate student at the California Institute of Technology, where he continued his study of transcriptional regulation in developing organisms. In 1996, after completing a Ph.D. in biology, he accepted a postdoctoral fellowship at the University of California, San Francisco. During that time Patapoutian shifted his research focus to developmental programs underlying the specificity of somatosensory neurons involved in the sensations of touch and pain.

In 2000, having joined the Scripps Research Institute as an assistant professor in cell biology, Patapoutian began investigating transient receptor potential (TRP) channels, which had been discovered several years earlier by Julius. Among Patapoutian’s first major discoveries was the identification of the cold-sensing ion channel TRPM8. His research also led to the discovery of TRPA1 (the so-called wasabi receptor), which acts as a sensor for noxious stimuli, including cold and pain.

Patapoutian subsequently focused his efforts on identifying TRP channels that initiate sensations of touch and position and posture (proprioception). After carrying out functional screens in cells, in which individual genes were turned on and off and gene activity was measured in response to piezoelectric mechanical forces, Patapoutian discovered two ion channels that specialize in mechanoreception. The channels became known as Piezo1 and Peizo2. Characterization of the channels identified Piezo2 as the primary transducer for touch, while Piezo1 senses changes in blood flow and has an essential role in vascular development.

In 2017 Patapoutian became a professor of neuroscience at Scripps. In addition to the Nobel Prize, he was a recipient of the Lewis S. Rosenstiel Award for Distinguished Work in Basic Medical Research (2019; with Julius) and the Kavli Prize in Neuroscience (2020; with Julius). He was a member of the American Association for the Advancement of Science (elected 2016) and the U.S. National Academy of Sciences (elected 2017) and a Howard Hughes Medical Institute investigator (2014– ).

Details

Ardem Patapoutian (born 1 October 1967) is a Lebanese-American molecular biologist, neuroscientist, and Nobel Prize laureate of Armenian descent. He is known for his work in characterizing the PIEZO1, PIEZO2, and TRPM8 receptors that detect pressure, menthol, and temperature. Patapoutian is a neuroscience professor and Howard Hughes Medical Institute investigator at Scripps Research in La Jolla, California. In 2021, he won the Nobel Prize in Physiology or Medicine jointly with David Julius.

Early life

Ardem Patapoutian was born to a Lebanese Armenian family in Beirut, Lebanon. His father, Sarkis Patapoutian (better known by the pen name Sarkis Vahakn [hy]), is a poet and an accountant, while his mother, Haiguhi Adjemian, was the principal of an Armenian school in Beirut. He has a brother, Ara, and a sister, Houry. His grandparents settled in Lebanon from Hadjin after surviving the Armenian Genocide.

He is childhood friends with journalist and author Vicken Cheterian. He attended the Demirdjian and Hovagimian Armenian schools in Beirut. He enrolled at the American University of Beirut for a year before emigrating to the United States in 1986.He received a B.S. degree in cell and developmental biology from the University of California, Los Angeles in 1990 and a PhD degree in biology from the California Institute of Technology in 1996 under direction of Barbara Wold.

As a postdoctoral fellow, Patapoutian worked with Louis F. Reichardt at the University of California, San Francisco. In 2000, he became an assistant professor at the Scripps Research Institute. Between 2000 and 2014, he had an additional research position for the Novartis Research Foundation. Since 2014, Patapoutian has been an investigator for the Howard Hughes Medical Institute (HHMI).

Personal life

Patapoutian, a naturalized US citizen, lives in Del Mar, California with his wife Nancy Hong, a venture capitalist, and son, Luca.

Research

Patapoutian's research is into the biological receptors for temperature and touch (nociception). The knowledge is used to develop treatments for a range of diseases, including chronic pain. The discoveries made it possible to understand how heat, cold and mechanical forces trigger nerve impulses.

Patapoutian researches the signal transduction of sensors. Patapoutian and co-workers inactivated genes. In this way, they identified the gene, that made the cells insensitive for touch. The channel for the sense of touch was called PIEZO1 (transl. pressure). Through its similarity to PIEZO1, a second gene was discovered and named PIEZO2. This ion channel, the more important of the two mechanoreceptors, is essential for the sense of touch. PIEZO1 and PIEZO2 channels have been shown to regulate additional important physiological processes including blood pressure, respiration and urinary bladder control.

Patapoutian also made significant contributions to the identification of novel ion channels and receptors that are activated by temperature, mechanical forces or increased cell volume. Patapoutian and his collaborators were able to show that these ion channels play an outstanding role in the sensation of temperature, in the sensation of touch, in proprioception, in the sensation of pain and in the regulation of vascular tone. More recent work uses functional genomics techniques to identify and characterize mechanosensitive ion channels (mechanotransduction).

Awards and honors

Patapoutian has an h-index of 68 according to Google Scholar, and of 63 according to Scopus. (As of May 2020). He has been a Fellow of the American Association for the Advancement of Science since 2016, a member of the National Academy of Sciences since 2017 and of the American Academy of Arts and Sciences since 2020.

In 2017, Patapoutian received the W. Alden Spencer Award,[36] in 2019 the Rosenstiel Award, in 2020 the Kavli Prize for Neuroscience, and the BBVA Foundation Frontiers of Knowledge Award in Biology / Biomedicine.

In 2021, he was awarded the Nobel Prize in Physiology or Medicine jointly with David Julius for their discoveries of receptors for temperature and touch.

In October 2021 President of Lebanon Michel Aoun awarded Patapoutian the Lebanese Order of Merit.

In December 2021, Patapoutian received the American Academy of Achievement’s Golden Plate Award presented by Awards Council member Frances Arnold.

In 2022, Patapoutian was named by Carnegie Corporation of New York as an honoree of the Great Immigrants Award.

Recognition in Armenia

Patapoutian, the first Armenian Nobel laureate, received a hero's welcome when he visited Armenia in June 2022. Prime Minister Nikol Pashinyan awarded him the Order of St. Mesrop Mashtots, while the Armenian National Academy of Sciences elected him an honorary member,[46] and the Yerevan State Medical University awarded him an honorary doctorate. Patapoutian gifted a replica of his Nobel medal to the History Museum of Armenia. HayPost issued a stamp dedicated to him.

Jai Ganesh · 2025-04-14 21:53:06

2217) Alain Aspect

Gist:

Work

One of the most remarkable traits of quantum mechanics is that it allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart. In 1981–1982, Alain Aspect conducted groundbreaking experiments using entangled light particles, photons. These and other experiments confirm that quantum mechanics is correct and pave the way for quantum computers, quantum networks and quantum encrypted communication.

Summary

Alain Aspect (born June 15, 1947, Agen, France) is a French physicist who was awarded the 2022 Nobel Prize for Physics for his experiments with quantum entanglement. He shared the prize with American physicist John F. Clauser and Austrian physicist Anton Zeilinger. What happens to one particle in an entangled pair determines what happens to the other, even if they are really too far apart to affect each other. The laureates’ development of experimental tools has laid the foundation for a new era of quantum technology.

Aspect received a bachelor’s degree from the École Normale Supérieure de Cachan (ENS Cachan), passing his civil service examination (agrégation) in physics in 1969. He attended the Université d’Orsay for both of his graduate degrees in physics, receiving a master’s degree in 1971 and a Ph.D. in 1983. Aspect performed his national service as a teacher in Cameroon from 1971 to 1974, before starting his Ph.D. and taking a lecturer position at the École Normale Supérieure de Cachan in Paris in 1974. For his graduate research, Aspect developed experiments to test Bell’s inequalities with respect to entangled photons. In 1985 he accepted a position at the Collège de France in Paris as a scientist in the atomic physics department, before becoming a senior scientist at the Laboratoire Charles Fabry de l’Institut d’Optique, in Palaiseau, near Paris, and later serving as a professor and head of the atomic optics group and as a professor in the École Polytechnique.

In quantum entanglement, two particles are in a single entangled state such that measuring a property of one particle instantly determines that same property in another particle. For example, two particles are in a state where one is spin-up and the other is spin-down. Since the second particle must have the opposite value of the first particle, measuring the first particle results in a definite state for the second particle, notwithstanding the fact that the two particles may be millions of kilometres apart and are not interacting with each other at the time. In 1935, when Albert Einstein, Boris Podolsky, and Nathan Rosen devised this paradox, they thought that this conclusion was so obviously false that the quantum mechanical theory on which it was based must be incomplete. They concluded that a correct theory would contain some hidden variable feature that would restore the determinism of classical physics; that is, the particles must be in some definite spin even before they are measured.

In 1964 the Irish-born physicist John Stewart Bell devised mathematical relationships, Bell’s inequalities, that would be satisfied by a hidden variable theory in which measurement of one particle would not instantly determine the properties of the other particle. Clauser and American physicist Stuart Freedman made the first experimental tests of the Bell inequalities in 1972 and showed results in accordance with quantum mechanics and not hidden variable theory.

However, the Clauser-Freedman experiment did not test an assumption Bell made, which is that the measurement of a particle by one observer would not somehow affect the measurement of the other. For example, the Clauser-Freedman experiment used polarizers that were preset. What if the experimental setup somehow had selected only photons that did not behave in accordance with hidden variable theory?

Aspect and his collaborators in the early 1980s performed a series of experiments designed to answer such questions. The most spectacular experiment, conducted with Jean Dalibard and Gérard Roger, was a modified version of the Clauser-Freedman experiment. A pair of photons with opposite polarizations was emitted from a heated calcium source. Each of the photons traveled toward a polarizer. The polarizers were 12 metres (40 feet) apart. The time for light and thus any conceivable signal to travel between the two polarizers was 40 nanoseconds. The experiment had switches that would send the photons between two pairs of polarizers every 10 nanoseconds. Thus, each polarizer was independent of the other because no signal could travel between the two. Aspect, Dalibard, and Roger measured a quantity S that—had Bell’s inequalities held—would have been between −1 and 0. They measured S = 0.101 ± 0.02, which was not in accordance with hidden variable theory but was in accordance with the quantum mechanical value of 0.112.

Aspect is a member of several national science academies, including those of Austria, Belgium, France, the United Kingdom, and the United States. His numerous awards include the French National Centre for Scientific Research (CNRS) gold medal (2005), the Wolf Prize (2010, shared with Zeilinger and Clauser), the Niels Bohr International Gold Medal and the UNESCO Neils Bohr Gold Medal (both in 2013), and the Balzan Prize for Quantum Information Processing and Communication (2013). He wrote Introduction to Quantum Optics: From the Semi-classical Approach to Quantized Light (2010; with Gilbert Grynberg and Claude Fabre) and Einstein et les révolutions quantiques (2019).

Details

Alain Aspect (born 15 June 1947) is a French physicist noted for his experimental work on quantum entanglement.

Aspect was awarded the 2022 Nobel Prize in Physics, jointly with John Clauser and Anton Zeilinger, "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science".

Education

Aspect is a graduate of the École Normale Supérieure de Cachan (ENS Cachan, today part of Paris-Saclay University). He passed the agrégation in physics in 1969 and received his PhD degree in 1971 from the École supérieure d'optique (later known as Institut d'Optique Graduate School) of Université d'Orsay (later known as Université Paris-Sud). He then taught for three years in Cameroon as a replacement for then compulsory military service.

In the early 1980s, while working on his doctorat d'État (habilitation thesis), he performed the Bell test experiments that showed that Albert Einstein, Boris Podolsky and Nathan Rosen's putative reductio ad absurdum of quantum mechanics, namely that it implied 'ghostly action at a distance', did in fact appear to be realized when two particles were separated by an arbitrarily large distance (see EPR paradox and Aspect's experiment). A correlation between the particles' wave functions remains, as long as they were once part of the same undisturbed wave function before one of the child particles was measured. He defended his doctorat d'État in 1983 at Université Paris-Sud (today part of Paris-Saclay University).

Aspect received an honorary doctorate from Heriot-Watt University in 2008.

Research

Aspect's experiments, following the first experiment of Stuart Freedman and John Clauser in 1972, were considered to provide further support to the thesis that Bell's inequalities are violated in its CHSH version, in particular by closing a form of the locality loophole. However, his results were not completely conclusive since there were loopholes that allowed for alternative explanations that comply with local realism.

After his work on Bell's inequalities, Aspect turned toward studies of laser cooling of neutral atoms, and Bose–Einstein condensates at the Kastler-Brossel Laboratory.

Aspect was deputy director of the French "grande école" École supérieure d'optique until 1994. He is a member of the French Academy of Sciences and French Academy of Technologies, and a professor at the École Polytechnique.

Distinctions

Aspect was elected a Foreign Member of the Royal Society (ForMemRS) in 2015. His certificate of election reads

For his fundamental experiments in quantum optics and atomic physics. Alain Aspect was the first to exclude subluminal communication between the measurement stations in experimental demonstrations that quantum mechanics invalidates separable hidden-variable theories and the first to demonstrate experimentally the wave–particle duality of single photons. He co-invented the technique of velocity-selective coherent population trapping, was the first to compare the Hanbury Brown-Twiss correlations of fermions and bosons under the same conditions, and the first to demonstrate Anderson localization in an ultra-cold atom system. His experiments illuminate fundamental aspects of the quantum-mechanical behaviour of single photons, photon pairs and atoms.

In 2005 he was awarded the gold medal of the Centre national de la recherche scientifique, where he is Research Director. The 2010 Wolf Prize in physics was awarded to Aspect, Anton Zeilinger and John Clauser. In 2013 Aspect was awarded both the Niels Bohr International Gold Medal and the UNESCO Niels Bohr Medal. In 2011, he was assigned the Medal of the City of Paris. In 2013, he was also awarded the Balzan Prize for Quantum Information Processing and Communication. In 2014, he was named Officer of the Legion of Honour.

Asteroid 33163 Alainaspect, discovered by astronomers at Caussols in 1998, was named after him. The official naming citation was published by the Minor Planet Center on 8 November 2019 (M.P.C. 118220).

Aspect was awarded the 2022 Nobel Prize in Physics alongside John F. Clauser and Anton Zeilinger "for experiments with entangled photons, establishing the violation of Bell's inequalities and pioneering quantum information science".

Jai Ganesh · Yesterday 17:21:56

2218) John Clauser

Gist:

Work

One of the most remarkable traits of quantum mechanics is that it allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart. In 1972, John Clauser conducted groundbreaking experiments using entangled light particles, photons. This and other experiments confirm that quantum mechanics is correct and pave the way for quantum computers, quantum networks and quantum encrypted communication.

Summary

John F. Clauser (born December 1, 1942, Pasadena, California, U.S.) is an American physicist who was awarded the 2022 Nobel Prize for Physics for his experiments with quantum entanglement. He shared the prize with French physicist Alain Aspect and Austrian physicist Anton Zeilinger. What happens to one particle in an entangled pair determines what happens to the other, even if they are really too far apart to affect each other. The laureates’ development of experimental tools has laid the foundation for a new era of quantum technology.

Clauser graduated from the California Institute of Technology in 1964 with a bachelor’s degree in physics. He continued his study of physics at Columbia University, where he earned a master’s degree in 1966 and a doctorate in 1969. He held postdoctoral positions from 1969 to 1975 at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, before serving as a research physicist at Lawrence Livermore National Laboratory until 1986. During the late 1980s Clauser worked in the private sector as a senior scientist at Science Applications International Corporation (SAIC) and as a private consultant and inventor. In 1990 he joined the physics faculty of the University of California, Berkeley, as a research scientist. Since 1997 he has been self-employed as a private consultant.

In quantum entanglement two particles are in a single entangled state such that measuring a property of one particle instantly determines that same property in another particle. For example, two particles are in a state where one is spin-up and the other is spin-down. Since the second particle must have the opposite value of the first particle, measuring the first particle results in a definite state for the second particle, notwithstanding the fact that the two particles may be millions of kilometres apart and are not interacting with each other at the time. In 1935, when Albert Einstein, Boris Podolsky, and Nathan Rosen devised this paradox, they thought that this conclusion was so obviously false that the quantum mechanical theory on which it was based must be incomplete. They concluded that the correct theory would contain some hidden variable feature that would restore the determinism of classical physics; that is, the particles must be in some definite spin even before they are measured.

In 1964 the Irish-born physicist John Stewart Bell devised mathematical relationships, Bell inequalities, that would be satisfied by a hidden variable theory in which measurement of one particle would not instantly affect the properties of the other particle. Clauser became interested in experimental testing of the Bell inequalities. He and his collaborators published work in 1969 that proposed a version of a Bell inequality that could be experimentally tested.

Clauser and Stuart Freedman used an apparatus from a previous experiment that used the decay of excited calcium atoms to generate pairs of photons that had opposite polarizations. Each photon was then measured by a polarizer. Their work, published in 1972, was the first experimental test of the Bell inequalities. They measured the rate of detection of both photons when the angle between the two polarizers was 22.5° and when it was 67.5°. In the Bell inequality they tested, those rates were divided by the rate of detection when both polarizers were removed; the absolute value of the difference between those two rates minus ¼ should have been less than or equal to zero to satisfy the Bell inequality. Their measurement of 0.05 ± 0.008 showed a clear violation of the Bell inequality, and their measurements at other angles were in accordance with those predicted by quantum mechanics and not with hidden variable theory.

Clauser is the recipient of the Reality Foundation Prize (1982, shared with Bell) and the Wolf Prize (2010, shared with Zeilinger and Aspect) and was named the Thompson-Reuters Citation Laureate in Physics (2011).

Details

John Francis Clauser (born December 1, 1942) is an American theoretical and experimental physicist known for contributions to the foundations of quantum mechanics, in particular the Clauser–Horne–Shimony–Holt inequality. Clauser was awarded the 2022 Nobel Prize in Physics, jointly with Alain Aspect and Anton Zeilinger "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science".

Early life

Clauser was born in Pasadena, California. His father, Francis H. Clauser, was a professor of aeronautical engineering who founded and chaired the aeronautics department at Johns Hopkins University. He later served as the Clark Blanchard Millikan Professor of Engineering at the California Institute of Technology (Caltech). His mother, Catharine McMillan, was the humanities librarian at Caltech and sister of 1951 Nobel Prize in Chemistry laureate Edwin McMillan.

He received a Bachelor of Science in physics from Caltech in 1964, where he was a member of Dabney House. He received a Master of Arts in physics in 1966 and a Doctor of Philosophy in physics in 1969 from Columbia University under the direction of Patrick Thaddeus.

Career

From 1969 to 1975, he worked as a postdoctoral researcher at the University of California, Berkeley and Lawrence Berkeley National Laboratory. In 1972, working with Berkeley graduate student Stuart Freedman, he carried out the first experimental test of the CHSH-Bell's theorem predictions. This was the first experimental observation of a violation of a Bell inequality. In 1974, working with Michael Horne, he first showed that a generalization of Bell's Theorem provides severe constraints for all local realistic theories of nature (a.k.a. objective local theories). That work introduced the Clauser–Horne (CH) inequality as the first fully general experimental requirement set by local realism. It also introduced the "CH no-enhancement assumption", whereupon the CH inequality reduces to the CHSH inequality, and whereupon associated experimental tests also constrain local realism. Also in 1974 he made the first observation of sub-Poissonian statistics for light (via a violation of the Cauchy–Schwarz inequality for classical electromagnetic fields), and thereby, for the first time, demonstrated an unambiguous particle-like character for photons.

Starting in 1973, Clauser published the newsletter Epistemological Letters, which was created because mainstream academic journals were relunctant to publish articles about the philosophy of quantum mechanics. Clauser worked as a research physicist mainly at Lawrence Livermore and Berkeley from 1975 to 1997. In 1976 he carried out the world's second experimental test of the CHSH-Bell's Theorem predictions.

Clauser was awarded the Wolf Prize in Physics in 2010 together with Alain Aspect and Anton Zeilinger. The three were also jointly awarded the 2022 Nobel Prize in Physics.

Climate change denial

In May 2023, Clauser joined the board of the CO2 Coalition, a climate change denial organization. Later that year, Clauser called himself a "climate denier" and claimed "there is no climate crisis". Clauser's views on climate change have been described as "pseudoscience". His belief that cloud cover has more of an impact on Earth's temperature than carbon dioxide emissions is contradicted by the overwhelming scientific consensus on climate change. Observational evidence shows the overall current cloud feedback amplifies global warming and does not have a cooling effect.

Personal life

Clauser is an atheist. He has emphysema due to smoking cigarettes in his youth.

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