Lisa Randall

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Lisa Randall (2006)

Lisa Randall (born June 18, 1962 in New York City ) is an American professor of theoretical physics at Harvard University in Cambridge , Massachusetts . She is considered a leading theoretical physicist and expert in particle physics , string theory and cosmology and is known for the Randall-Sundrum model and the introduction of extra dimensions into phenomenological particle physics. She is also a bestselling author of popular science books.

Life

Lisa Randall is the middle of three daughters of a salesman and a teacher from the New York borough of Queens . Lisa Randall's younger sister, Dana Randall , is a professor of computer science at the Georgia Institute of Technology . Randall graduated from the science-oriented Stuyvesant High School in Manhattan , New York in 1980 .

She studied at Harvard University (bachelor's degree 1983), where she earned her doctorate in 1987 with Howard Georgi with the thesis Enhancing the Standard Model . She then worked as a post-doctoral student at the University of California, Berkeley , (as President's Fellow) and in 1989/90 at the Lawrence Berkeley National Laboratory . In 1990/91 she was a Junior Fellow at Harvard and became Assistant Professor in 1991 and Associate Professor at the Massachusetts Institute of Technology (MIT) in 1995 . In 1998, Randall was the first woman to be appointed to the chair of theoretical physics at Princeton University , where she taught until 2000. At the same time, she was Professor of Physics at MIT from 1998 to 2001. In July 2001, she moved again to Harvard University to a chair in theoretical physics.

She also wrote an opera libretto on her work (Hypermusic: A Projective Opera in Seven Planes) and co-organized a Los Angeles Art Association art exhibition on the concept of size scales.

Honors, memberships

For the period from 1999 to 2004, Lisa Randall is the most cited high-energy physicist in the world, and in 2004 she was the most cited theoretical physicist. Two of her works are in the list of the 40 most cited particle physics articles (as of 2014). She is a member of the American Academy of Arts and Sciences (since 2004), the National Academy of Sciences (since 2008), the Royal Irish Academy (since 2009), the American Philosophical Society (since 2010) and the American Physical Society , which her awarded the Julius Edgar Lilienfeld Prize 2007 and the Sakurai Prize 2019. She has received awards such as the Alfred P. Sloan Foundation Research Fellowship , the National Science Foundation Young Investigator Award, the DOE Outstanding Junior Investigator Award, and the Westinghouse Science Talent Search. In 2003 she received the Premio Caterina Tomassoni e Felice Pietro Chisesi Award from La Sapienza University in Rome. In 2006 she received the Klopsted Award from the American Association of Physics Teachers (AAPT). The Time magazine leads Randall in the Time 100 list of the 100 most influential people of 2007. 2015 she received the Julius Wess Award , 2019, the Oskar Klein Memorial Lecture .

Research priorities

Randall has been working on the further development of the two competing models of string theory for several years, trying to explain the structure of reality. It brings together relativity , quantum mechanics , gravity and this extended string theory and develops a model of interpenetrating, overlapping and rejecting " multiverses ".

One of her most important works to date is the Randall-Sundrum model , which she published in 1999 together with Raman Sundrum . Her popular science book Warped Passages (see below), published in 2005, was included in the New York Times ' One Hundred Most Noteworthy Books of 2005 .

Together with Sundrum, she was one of those who introduced the dynamic breaking of supersymmetry via anomalies ( Anomaly mediated supersymmetry breaking , AMSB).

Randall-Sundrum Theory

Lisa Randall at a lecture

Together with her colleague Raman Sundrum, Randall describes a five-dimensional model of the universe . According to Albert Einstein , space and time are not necessarily flat, but rather bent and distorted. Randall's calculations show that spacetime could be so bent that whole areas of it are inaccessible to us. So much so that there could be a fifth dimension that we cannot see because of this curvature. The observable world is then only one of many islands in the middle of a larger space. Just a few inches further there could be another universe that is inaccessible to us because we are trapped in our four dimensions.

One version of the universe model contains two so-called branes . The word is derived from «membrane». Branes are low-dimensional islands that are embedded in a higher-dimensional space. Randall explains this using the example of a shower curtain: A shower curtain is a two-dimensional brane in a three-dimensional space. In Randall's model, the universe consists of two branes and a fifth dimension sandwiched between them. We are sitting on one brane. All matter, all forces are bound to our brane - like drops of water on the shower curtain. So we couldn't find out anything about a second brane, even though it might be extremely close, only fractions of a millimeter away.

According to Randall, there is a force that, in contrast to the other three forces (the strong interaction , the weak interaction and the electromagnetic force ), can penetrate the fifth dimension: gravity . Randall states that she developed the model to explain a special characteristic of gravity, namely its incredible weakness. In their model, the vast majority of gravity is concentrated near the other brane, and there it would be about as strong as the other forces. But because the room is so curved, we only see a faint reflection of it. That would be a natural explanation for the weakness of gravity.

The Randall-Sundrum model tries to solve the hierarchy problem by introducing a single additional dimension - this is what distinguishes the model from the string theories . What is new and exciting for science is that Randall formulated experiments that could prove the extra dimension. For the time being, however, she does not expect the Randall-Sundrum Radion to be confirmed by the Large Hadron Collider particle accelerator.

Further hypotheses

In her book Dark Matter and Dinosaurs , she advocates the controversial hypothesis that periodic asteroid impacts on Earth, including the impact that led to mass extinction, including the dinosaurs on the Cretaceous-Paleogene border , are due to gravitational perturbations that periodically pass through the solar system the galactic plane (for the scientific background see Nemesis ). Randall postulates a disk-shaped concentration of dark matter in the galactic plane, which in principle should be observable by precisely measuring the orbits of nearby stars (e.g. with the Gaia space telescope ). In general, the thesis of Raup and Sepkoski from the 1980s about periodic impacts by large asteroids or comets and the resulting mass extinctions has long been considered outdated (see the corresponding section in the article on mass extinctions ), especially since most of the biological crises in the Phanerozoic were clearly terrestrial Causes decline. According to Randall, it is likely that dark matter consists of different particles with different interactions, including some that are previously unknown and that could have caused such a partial collapse of the originally spherical distribution of dark matter in the galaxy.

literature

  • Lisa Randall: Warped Passages. Unraveling the Mysteries of the Universe's Hidden Dimensions . New York 2005, ISBN 0-06-053108-8 (published in German in October 2006 under the title: Verborgene Universen. A journey into extradimensional space , S. Fischer Verlag, ISBN 3-10-062805-5 ).
  • Lisa Randall: Knocking on Heaven's Door. How Physics and Scientific Thinking Illuminate the Universe and the Modern World . Random House UK Ltd, September 2011, 464 pages, ISBN 1-84-792069-1 (published in German under the title: " Measuring the Universe: How the Physics of Tomorrow is on the Track of the Last Secrets", S. Fischer Verlag, 2012, ISBN 3-10-062806-3 ).
  • Lisa Randall: Higgs Discovery: The Power of Empty Space . The Bodley Head, August 2012, 64 pages, ISBN 1-84-792257-0
  • Lisa Randall: Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe . Ecco Verlag, October 2015, 432 pages, ISBN 978-0062328472 (published in German in June 2016 under the title: Dark matter and dinosaurs: The amazing connections of the universe , S. Fischer Verlag, ISBN 3-10-002194-0 .) .
  • List of academic papers on Lisa Randall's Harvard Web Site List .

Web links

Commons : Lisa Randall  - Collection of images, videos and audio files

swell

  1. ↑ Lisa Randall in the Mathematics Genealogy Project (English)Template: MathGenealogyProject / Maintenance / id used
  2. ^ Lisa Randall, Career in Physics , American Physical Society
  3. ^ American Physical Society, Careers in Physics, Lisa Randall
  4. ↑ Top Cited Articles of All Time (2014 edition), Inspire.net . These are the two works with Sundrum from 1999 A Large mass hierarchy from a small extra dimension in 5th place and An Alternative to compactification in 13th place.
  5. ^ Members: Lisa Randall. Royal Irish Academy, accessed May 11, 2019 .
  6. ^ Member History: Lisa Randall. American Philosophical Society, accessed November 5, 2018 (with biographical notes).
  7. ↑ Julie Rawe: The 2007 TIME 100: Scientists & Thinkers - Lisa Randall. Time, May 3, 2007, accessed December 5, 2013 .
  8. ↑ Randall, Sundrum, Out of this world supersymmetry breaking, Nuclear Physics B, Vol. 557, 1999, pp. 79-118, Arxiv
  9. ↑ In addition, these were: Gian Giudice, Markus Luty, Hitoshi Murayama, Riccardo Rattazzi: Gaugino mass without singlets, Journal of High Energy Physics, 1998, 9812 (12): 027, Arxiv
  10. ↑ Tobias Hürter, Max Rauner: Are there other universes - and how many? Die Zeit, May 3, 2012, p. 58 , accessed on January 12, 2013 .
  11. ^ Matthias MM Meier, Sanna Holm-Alwmark: A tale of clusters: no resolvable periodicity in the terrestrial impact cratering record . In: Monthly Notices of the Royal Astronomical Society . 467, No. 3, June 2017, pp. 2545-2551. doi : 10.1093 / mnras / stx211 .
  12. ↑ Anatoly D. Erlykin, David AT Harper, Terry Sloan, Arnold W. Wolfendale: Mass extinctions over the last 500 myr: an astronomical cause? . In: Palaeontology . 60, No. 2, March 2017, pp. 159–167. doi : 10.1111 / pala.12283 .
  13. ↑ Unsolvable problems are always welcome in FAZ from July 16, 2016, p. 12
personal data
SURNAME Randall, Lisa
BRIEF DESCRIPTION American physicist
DATE OF BIRTH June 18, 1962
PLACE OF BIRTH New York City