#GravitationalWaves #Astronomy #Cosmology DASHEN MEMORIAL LECTURE - BARRY BARISH -- 2017 NOBEL PRIZE IN PHYSICS The discovery of gravitational waves, predicted by Einstein in 1916, is now enabling important tests of the theory of general relativity, as well as beginning multi-messenger astronomy: the combined observations of astrophysical phenomena using electromagnetic radiation, gravitational waves and neutrinos. Plans and prospects for gravitational wave science will be explored. ------------------------------------- Barry Clark Barish (born January 27, 1936) is an American experimental physicist and Nobel Laureate. He is a Linde Professor of Physics, emeritus at California Institute of Technology. He is a leading expert on gravitational waves. In 2017, Barish was awarded the Nobel Prize in Physics along with Rainer Weiss and Kip Thorne "for decisive contributions to the LIGO detector and the observation of gravitational waves". In 2018, he joined the faculty at University of California, Riverside, becoming the university's second Nobel Prize winner on the faculty. ------------------------------------- Roger Frederick Dashen (May 5, 1938 in Grand Junction, Colorado – May 25, 1995 in La Jolla) was an American theoretical physicist who studied particle physics and quantum field theory. Dashen studied physics at the Harvard University (where he also played in the football team), where he graduated "summa cum laude" in 1960. Then he went to Caltech, where he earned his PhD in 1964. After that, he was a professor at Caltech in 1967 and the Institute for Advanced Study in 1969. In 1986, he became a professor at the University of California, San Diego (UCSD) in 1988 was Head of Faculty. He played a leading role in the establishment of a supercomputer center at UCSD and in the establishment of the Institute for Theoretical Physics of the National Science Foundation at the University of California, Santa Barbara. In the 1960s he worked partly in collaboration with Murray Gell-Mann with current algebras of particle physics and models with chiral symmetry. In 1964, he worked on S-matrix methods to calculate electromagnetic corrections to strong interactions, including the mass difference between protons and neutrons with Steven Frautschi. In the 1970s, he studied with Brosl Hasslacher and André Neveu quantum field theoretical model theories (such as the Sine-Gordon model and the Gross-Neveu model) for extended particles and semiclassical approximations ([WKB approximation]) for their analysis.They developed the Dashen-Hasslacher-Neveu method (DHN) for quantization of solitons using path integrals. After the discovery of instantons in the quantum (QCD) by Polyakov, he examined it with David Gross and Curtis Callan. In the 1980s, he worked with lattic ... https://www.youtube.com/watch?v=E8FLCevSK1k

#HubbleTension #HubbleConstant #darkenergy Adam Riess is a renowned astrophysicist recognized for his groundbreaking research on the expansion of the universe with the 2011 Nobel Prize in physics Through extensive measurements and collaborations with other scientists, Riess discovered an intriguing tension in the size of the universe's expansion, which has steadily grown over the past decade. These results, reaching a significant level of more than 5 sigma, revealed an unexpected phenomenon: the rate of the universe's expansion seems to differ based on whether one starts from the beginning shortly after the big bang or from the present. This unexpected autonomy in the expansion challenged the traditional cosmological model, which tells the story of the universe's evolution from its inception to its current state. Riess's research has generated suspicion among many scientists, leading them to question whether the cosmological model itself needs revision. In his pursuit of unraveling the mysteries of the universe, Riess reminds us that advanced technology may often be mistaken for something magical. On this episode of INTO THE IMPOSSIBLE Riess explores the challenges of measuring distances in the universe and the discrepancies between measurements of the expansion rate of the universe first observed by Edwin Hubble namesake of The Hubble Constant, a pillar of cosmology. From the use of parallax (dating back to ancient Greece) to the use of Cepheid variables and Type 1a supernovae, Riess takes listeners on a journey through the cosmic distance ladder and the problem of the variation in the measurement of the Hubble constant known as the Hubble Tension. The possible role of dark energy is discussed, opening up new avenues for scientific investigation. Riess shares insights into the concept of the cosmological principle, and how it is challenged by the Hubble Tension. The conversation touches on peak experiences, the awe-inspiring encounters with nature that trigger moments of gratitude and curiosity, and the importance of sustaining these feelings in scientific exploration. Riess highlights the empirical nature of observational cosmology and the need for continued data collection and refining of models. Black holes, gravitational lensing, and Adam’s motivations to pursue precision science are discussed. [00:00:59] Adam Riess proved Einstein wrong. [00:07:21] Struggling with experiment results, seeking the truth. [00:10:22] How to measure the expansion rate of the Universe. [00:18:11] Peak experiences evoke awe and gratitude. Scientists may become desensitized to these feelings. Can curiosity be cultivated and sustained? [00:22:11] Astroscientist praises author's writing in web paper. [00:23:34] Measuring distances in the universe using parallax. [00:29:21] Observational cosmology relies on empirical calibration tools and training sets to measure the properties of celestial objects. [00:32:46] In 1998, distant supernovae showed the universe's acceleration. Researchers now use the James Webb Space Telescope to study cepheid variables, but The Hubble tension persists. [00:38:21] Claims made by Subir Sarkar suggest a revision of the cosmological principle and challenge the consensus on dark energy. [00:43:42] Looking at distant objects confirms Einstein's theory of general relativity through observations of gravitational lensing. [00:51:19] James Webb Telescope surprised astronomers with galaxies that are older than expected. [00:54:42], Theoretical implications of the Hubble Tension measurements Other Episode with Adam Reiss: https://youtu.be/WZUqzHRuzhA The Paper: An updated measurement of the Hubble constant from near-infrared observations of Type https://arxiv.org/abs/2209.02546 Join this channel to get access to perks: https://www.youtube.com/channel/UCmXH_moPhfkqCk6S3b9RWuw/join ? Watch my most popular videos:? Neil Turok https://www.youtube.com/watch?v=Dt5cFLN65fI Frank Wilczek https://youtu.be/3z8RqKMQHe0?sub_confirmation=1 Eric Weinstein vs. Stephen Wolfram https://www.youtube.com/watch?v=OI0AZ4Y4Ip4?sub_confirmation=1 Sir Roger Penrose: https://youtu.be/AMuqyAvX7Wo Sabine Hossenfelder: https://youtu.be/g00ilS6tBvs Avi Loeb: https://youtu.be/N9lUceHsLRw Follow me to ask questions of my guests: ?‍♂️ Twitter: https://twitter.com/DrBrianKeating ? Subscribe https://www.youtube.com/DrBrianKeating?sub_confirmation=1 ? Join my mailing list; just click here http://briankeating.com/mailing_list ✍️ Detailed Blog posts here: https://briankeating.com/blog.php ?️ Listen on audio-only platforms: https://briankeating.com/podcast #universe #podcast #briankeating #intotheimpossible #science #astronomy #cosmology #cosmicmicrowavebackground ... https://www.youtube.com/watch?v=b3Tx1g8gKmY