Tag Archives: particle physics

Donna Strickland, first female Nobel Prize winner in 55 years and one of only three (so far) in history

It’s been quite the fascinating week in the world of physics culminating with Donna Strickland’s shiny new Nobel Prize in physics.

For my purposes, this week in physics started on Friday, September 28, 2018 with Allesanndro Strumia’s presentation at CERN’s (European Particle Physics Laboratory) “1st workshop on high energy theory and gender” where he claimed and proved ‘scientifically’ that physics has become “sexist against men.” I’ll get back to Strumia in a moment but, first, let’s celebrate Donna Strickland and her achievements.

Only three women, including Strickland, in the history (117 years) of the Nobel Prize for Physics have won it, Marie Curie in 1903, Maria Goeppert Mayer in 1963, and, now, Strickland in 2018.

The University of Waterloo (Ontario, Canada) had this to say in an October 2, 2018 news release,

Donna Strickland wins Nobel Prize in Physics

Tuesday, October 2, 2018

Dr. Donna Strickland

Donna Strickland, a University of Waterloo professor who helped revolutionize laser physics, has been named a winner of this year’s Nobel Prize in Physics.

Strickland, an associate professor in the Department of Physics and Astronomy, shares half the $1.4 million prize with French laser physicist Gérard Mourou. The other half was awarded to U.S. physicist Arthur Ashkin.

The Royal Swedish Academy of Sciences stated that Mourou and Strickland paved the way toward the shortest and most intense laser pulses created by mankind. Their revolutionary article was published in 1985 and was the foundation of Strickland’s doctoral thesis.

Strickand conducted her Nobel-winning research while a PhD student under Mourou in 1989 at the University of Rochester in New York. The team’s research has a number of applications in industry and medicine.

It was great to have had the opportunity to work with one of the pioneers of ultrafast lasers, Gerard Mourou,” said Strickland. “It was a small community back then. It was a new, burgeoning field. I got to be part of that. It was very exciting.”

A Nobel committee member said billions of people make daily use of laser printers and optical scanners and millions undergo laser surgery.

“This is a tremendous day for Professor Strickland and needless to say a tremendous day for the University of Waterloo,” said Feridun Hamdullahpur, president and vice-chancellor of the University of Waterloo. “This is Waterloo’s first Nobel laureate and the first woman to receive the Nobel Prize in Physics in 55 years.”

During an interview, Strickland told the Globe and Mail [national newspaper]: “We need to celebrate women physicists because we’re out there, and hopefully in time it’ll start to move forward at a faster rate.”

Charmaine Dean, vice-president research at the University of Waterloo said: “Donna Strickland exemplifies research excellence at Waterloo. Her groundbreaking work is a testament to the importance of fundamental research as it has established the foundation for laser-based technologies that we see today from micromachining to laser eye surgery.”

An October 2, 2018 news item on Nanowerk focuses on the three winners,

Arthur Ashkin, an American physicist has been awarded half the prize for his invention of optical tweezers and their application to biological systems. His amazing tool has helped to reach the old dream of grabing [sic] particles, atoms, viruses and other living cells. The optical tweezers work with the radiation pressure of light to hold and move tiny object and are widely used to study the machinery of life.

French physicist Gérard Mourou and Canadian physicist Donna Strickland share the other half for their method of generating ultra-short and very intense optical pulses. Ultra-sharp laser beams have made possible to cut or drill holes in various materials extremely precisely – even in living matter. The technique this duo pioneered is called chirped pulse amplification or CPA and it has led to corrective eye surgeries for millions of people.

An Oct. 2, 2018 article by Marina Koren for The Atlantic is my favourite of the ones focusing on Strickland. One of Koren’s major focal points is Strickland’s new Wikipedia page (Note: Links have been removed),

It was about five in the morning in Ontario, Canada, when Donna Strickland’s phone rang. The Nobel Prize committee was on the line in Stockholm, calling to tell her she had won the prize in physics.

“We wondered if it was a prank,” Strickland said Tuesday [October 2 ,2018], in an interview with a Nobel official after the call. She had been asleep when the call arrived. “But then I knew it was the right day, and it would have been a cruel prank.”

Lasers, focused beams of light particles, were invented in the 1960s. Scientists immediately started tinkering with them, looking for ways to harness and manipulate these powerful devices.

Strickland and [Gérard] Mourou] found a way to stretch and compress lasers to produce short, intense pulses that are now used, among other things, in delicate surgeries to fix vision problems. [Arthur] Ashkin figured out a way to maneuver laser light so that it could push small particles toward the center of the beam, hold them in place, and even move them around. This technique became the delightfully named “optical tweezer.” It allowed Ashkin to use the power of light to capture and hold living bacteria and viruses without harming the organisms.

Unlike her fellow winners, Strickland did not have a Wikipedia page at the time of the announcement. A Wikipedia user tried to set up a page in May, but it was denied by a moderator with the message: “This submission’s references do not show that the subject qualifies for a Wikipedia article.” Strickland, it was determined, had not received enough dedicated coverage elsewhere on the internet to warrant a page.

On Tuesday, a newly created page flooded with edits: “Added in her title.” “Add Nobel-winning paper.” “Added names of other women Nobelists [sic] in physics.”

The construction of the Wikipedia page feels like a metaphor for a historic award process that has long been criticized for neglecting women in its selection, and for the shortage of women’s stories in the sciences at large. To scroll through the “history” tab of Strickland’s page, where all edits are recorded and tracked, is to witness in real time the recognition of a scientist whose story likely deserved attention long before the Nobel Prize committee called.

Strickland’s historic win comes a day after CERN, the European organization that operates the world’s most powerful particle accelerator, suspended a senior scientist for saying that physics was “invented and built by men.” Alessandro Strumia, a professor at the University of Pisa, made the statement during a recent speech at a seminar on gender issues in physics that was attended by mostly female physicists. Strumia said “men prefer working with things and women prefer working with people,” and that between men and women there is a “difference even in children before any social influence.” His remarks were widely circulated online and prompted fierce backlash.

The remarks don’t faze Strickland, who very publicly proved them wrong on Tuesday. In an interview with the BBC on Tuesday, she called Strumia’s claims “silly.”

For anyone curious about the Strumia situation, there’s an October 2, 2018 CBC Radio (As It Happens) online news article. Note: Links have been removed,

Not only was Alessandro Strumia being offensive when he said that physics “was invented and built by men” — he was also wrong, says physicist Jess Wade.

“Actually, women have contributed hugely to physics throughout the whole of history, but for an incredibly long time we haven’t documented or told those stories,” Wade told As It Happens host Carol Off.

And she would know. The Imperial College London research associate has made it her mission to write hundreds of Wikipedia entries about women in science and engineering.

Wade was in the room on Friday when Strumia, a physicist at Pisa University, made the inflammatory remarks during a gender workshop in Geneva, organized by the European nuclear research centre CERN.

CERN cut ties with Strumia after the BBC reported the content of his presentation.

This article includes some of the slides in Strumia’s now infamous presentation.

Tommaso Dorigo in an October 1, 2018 posting on the Science 2.0 blog offers another analysis,

The world of particle physics is in turmoil because of a presentation by Alessandro Strumia, an Italian phenomenologist, at CERN’s “1st workshop on high energy theory and gender”, and its aftermath.

By now the story has been echoed by many major newscasters around the world, and discussed in public and private forums, blogs, twitter feeds. I wanted to stay away from it here, mainly because it is a sensitive issue and the situation is still evolving, but after all, why not offer to you my personal pitch on the matter? Strumia, by the way, has been an occasional commenter to this blog – you can find some of his comments signed as “AS” in threads of past articles. Usually he makes good points here, as long as physics is the subject.

Anyway, first of all let me give you a quick recall of the events. The three-day workshop, which took place on September 26-28, was meant to”focus on recent developments in theoretical high-energy physics and cosmology, and discuss issues of gender and equal opportunities in the field“; it followed three previous events which combined string theory and gender issues. Strumia’s presentation was titled “Experimental tests of a new global symmetry“, a physicist’s way of describing the issue of man-woman equality. It is important to note that the talk was not an invited one – its author had asked the organizers for a slot as he said he would be talking of bibliometrics, and indeed his contribution was listed in the agenda of September 28 with the innocuous title “Bibliometrics data about gender issues in fundamental theory“.

Strumia’s slides contain a collection of half-baked claims, coming from his analysis of InSpire data from citations and authorship of articles in theoretical physics. I consider his talk offensive on many levels. It starts by casting the woman discrimination issue in scientific academia as a test of hypothesis of whether the “man-woman” symmetry is explicitly broken (i.e. there is no symmetry) or spontaneously broken (by a difference of treatment) – something that could even raise a smile in a geeky physicist; but the fun ends there.

Dorigo offers a detailed ‘takedown’ of Strumia’s assertions. I found the post intriguing for the insight it offers into physics. Never in a million years would I have thought this title, “Experimental tests of a new global symmetry,” would indicate a discussion on gender balance in the field of physics.

As I said in the opening, it has been quite the week in physics. On a final note, Brava to Doctor Donna Strickland!

Simulating elementary physics in a quantum simulation (particle zoo in a quantum computer?)

Whoever wrote the news release used a very catchy title “Particle zoo in a quantum computer”; I just wish they’d explained it. Looking up the definition for a ‘particle zoo’ didn’t help as much as I’d hoped. From the particle zoo entry on Wikipedia (Note: Links have been removed),

In particle physics, the term particle zoo[1][2] is used colloquially to describe a relatively extensive list of the then known “elementary particles” that almost look like hundreds of species in the zoo.

In the history of particle physics, the situation was particularly confusing in the late 1960s. Before the discovery of quarks, hundreds of strongly interacting particles (hadrons) were known, and believed to be distinct elementary particles in their own right. It was later discovered that they were not elementary particles, but rather composites of the quarks. The set of particles believed today to be elementary is known as the Standard Model, and includes quarks, bosons and leptons.

I believe the writer used the term to indicate that the simulation undertaken involved elementary particles. If you have a better explanation, please feel free to add it to the comments for this post.

Here’s the news from a June 22, 2016 news item on ScienceDaily,

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The discovery of the Higgs boson at the CERN in 2012 constitutes a further step towards the confirmation of the Standard Model. However, many aspects of this theory are still not understood because their complexity makes it hard to investigate them with classical computers. Quantum computers may provide a way to overcome this obstacle as they can simulate certain aspects of elementary particle physics in a well-controlled quantum system. Physicists from the University of Innsbruck and the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences have now done exactly that: In an international first, Rainer Blatt’s and Peter Zoller’s research teams have simulated lattice gauge theories in a quantum computer. …

A June 23, 2016 University of Innsbruck (Universität Innsbruck) press release, which seems  to have originated the news item, provides more detail,

Gauge theories describe the interaction between elementary particles, such as quarks and gluons, and they are the basis for our understanding of fundamental processes. “Dynamical processes, for example, the collision of elementary particles or the spontaneous creation of particle-antiparticle pairs, are extremely difficult to investigate,” explains Christine Muschik, theoretical physicist at the IQOQI. “However, scientists quickly reach a limit when processing numerical calculations on classical computers. For this reason, it has been proposed to simulate these processes by using a programmable quantum system.” In recent years, many interesting concepts have been proposed, but until now it was impossible to realize them. “We have now developed a new concept that allows us to simulate the spontaneous creation of electron-positron pairs out of the vacuum by using a quantum computer,” says Muschik. The quantum system consists of four electromagnetically trapped calcium ions that are controlled by laser pulses. “Each pair of ions represent a pair of a particle and an antiparticle,” explains experimental physicist Esteban A. Martinez. “We use laser pulses to simulate the electromagnetic field in a vacuum. Then we are able to observe how particle pairs are created by quantum fluctuations from the energy of this field. By looking at the ion’s fluorescence, we see whether particles and antiparticles were created. We are able to modify the parameters of the quantum system, which allows us to observe and study the dynamic process of pair creation.”

Combining different fields of physics

With this experiment, the physicists in Innsbruck have built a bridge between two different fields in physics: They have used atomic physics experiments to study questions in high-energy physics. While hundreds of theoretical physicists work on the highly complex theories of the Standard Model and experiments are carried out at extremely expensive facilities, such as the Large Hadron Collider at CERN, quantum simulations may be carried out by small groups in tabletop experiments. “These two approaches complement one another perfectly,” says theoretical physicist Peter Zoller. “We cannot replace the experiments that are done with particle colliders. However, by developing quantum simulators, we may be able to understand these experiments better one day.” Experimental physicist Rainer Blatt adds: “Moreover, we can study new processes by using quantum simulation. For example, in our experiment we also investigated particle entanglement produced during pair creation, which is not possible in a particle collider.” The physicists are convinced that future quantum simulators will potentially be able to solve important questions in high-energy physics that cannot be tackled by conventional methods.

Foundation for a new research field

It was only a few years ago that the idea to combine high-energy and atomic physics was proposed. With this work it has been implemented experimentally for the first time. “This approach is conceptually very different from previous quantum simulation experiments studying many-body physics or quantum chemistry. The simulation of elementary particle processes is theoretically very complex and, therefore, has to satisfy very specific requirements. For this reason it is difficult to develop a suitable protocol,” underlines Zoller. The conditions for the experimental physicists were equally demanding: “This is one of the most complex experiments that has ever been carried out in a trapped-ion quantum computer,” says Blatt. “We are still figuring out how these quantum simulations work and will only gradually be able to apply them to more challenging phenomena.” The great theoretical as well as experimental expertise of the physicists in Innsbruck was crucial for the breakthrough. Both Blatt and Zoller emphasize that they have been doing research on quantum computers for many years now and have gained a lot of experience in their implementation. Innsbruck has become one of the leading centers for research in quantum physics; here, the theoretical and experimental branches work together at an extremely high level, which enables them to gain novel insights into fundamental phenomena.

Here’s a link to and a citation for the paper,

Real-time dynamics of lattice gauge theories with a few-qubit quantum computer by Esteban A. Martinez, Christine A. Muschik, Philipp Schindler, Daniel Nigg, Alexander Erhard, Markus Heyl, Philipp Hauke, Marcello Dalmonte, Thomas Monz, Peter Zoller, & Rainer Blatt.  Nature 534, 516–519 (23 June 2016)  doi:10.1038/nature18318 Published online 22 June 2016

This paper is behind a paywall.

There is a soundcloud audio file featuring an explanation of the work from the lead author, Esteban A. Martinez,

Hydrogels and cartilage; repurposing vehicles in space; big bang has ‘fingerprints’

The American Institute of Physics (AIP) has made a selection of four articles freely available (h/t Mar. 9, 2015 news item on Azonano).

From a March 6, 2015 AIP news release,

WASHINGTON D.C., March 6, 2015 — The following articles are freely available online from Physics Today (www.physicstoday.org), the world’s most influential and closely followed magazine devoted to physics and the physical science community.

You are invited to read, share, blog about, link to, or otherwise enjoy:

1) STIFF AND SUPPLE CARTILAGE SUBSTITUTE

Physics Today‘s Ashley Smart reports on hydrogels that mimic the tricky nature of cartilage thanks to magnetically aligned nanosheets.

“In the realm of bioengineering, hydrogels are something of an all-purpose material. Made up of networks of interlinked, hydrophilic polymers, they tend to be soft, biocompatible, and highly absorbent…. The new material mimics the articular cartilage that lubricates our joints: It can support a heavy load along one direction while stretching and shearing with ease in the others.”

MORE: http://dx.doi.org/10.1063/PT.3.2707

2) GIVING SPACECRAFT A SECOND LEASE ON LIFE WHILE HURTLING THROUGH THE COSMOS

Physics Today‘s Toni Feder reports on the innovative processes undertaken to repurpose various spacecraft in flight, including Kepler, Voyager, Deep Impact, Spitzer, and the Hubble Space Telescope.

“A comeback like Kepler’s is ‘not unique, but it’s unusual,’ says Derek Buzasi of Florida Gulf Coast University, who reinvented the Wide-Field Infrared Explorer (WIRE) after it failed following its 1999 launch. ‘Spacecraft are built for a specialized purpose, so they are hard to repurpose. You have to come up with something they are capable of at the same time they are incapable of their original mission.’

Deep Impact’s original mission was to hurl a copper ball at a comet and watch the impact. In its continued form as EPOXI, the spacecraft went on to visit another comet and, on the way, served as an observatory for user- proposed targets.”

MORE: http://dx.doi.org/10.1063/PT.3.2713

3) CONGRESSMAN & FUSION RESEARCHER REFLECTS ON SCIENCE POLICY

Physics Today‘s David Kramer interviews Rush Holt, the New Jersey congressman who retired from office and this past December took the helm of the American Association for the Advancement of Science.

“PT: What do you consider to be your accomplishments in Congress?

HOLT: I focused a lot on science education. Our real problem is not that we’re failing to produce excellent scientists, because we are [producing them], but rather that we have failed to maintain an appreciation for and understanding of science in the general population. I was able to keep a spotlight on the need but wasn’t able to accomplish as much as I wanted. We got science included in the subjects emphasized by federal law. But we haven’t really improved teacher professional development and other things we need to do.”

MORE: http://dx.doi.org/10.1063/PT.3.2714

4) PARTICLE PHYSICS AND THE COSMIC MICROWAVE BACKGROUND

In this article, physics researchers John Carlstrom, Tom Crawford and Lloyd Knox discuss the fingerprints of the Big Bang and quantum fluctuations in the early universe, which may soon reveal physics at unprecedented energy scales.

“With its empirical successes, inflation is by consensus the best paradigm—notwithstanding some notable dissenting views—for the mechanism that generated the primordial density fluctuations that led to all structure in the universe. Its success has motivated physicists to search for the siblings of those fluctuations, the gravitational waves, via their signature in the polarization of the CMB. If discovered, that gravitational imprint would open up an observational window onto quantum gravitational effects, extremely early times, and extremely high energies.”

MORE: http://dx.doi.org/10.1063/PT.3.2718

I have checked; all of the links do lead to the articles.

From the quantum to the cosmos; an event at Vancouver’s (Canada) Science World

ARPICO (Society of Italian Researchers & Professionals in Western Canada) sent out an April 9, 2014 announcement,

FROM THE QUANTUM TO THE COSMOS

May 7 [2014] “Unveiling the Universe” lecture registration now open:

Join Science World and TRIUMF on Wednesday, May 7, at Science World at TELUS World of Science in welcoming Professor Edward “Rocky” Kolb, the Arthur Holly Compton Distinguished Service Professor of Astronomy and Astrophysics at the University of Chicago, for his lecture on how the laws of quantum physics at the tiniest distances relate to structures in the universe at the largest scales. He also will highlight recent spectacular results into the nature of the Big Bang from the orbiting Planck satellite and the South Pole-based BICEP2 telescope.

Doors open at 6:15pm and lecture starts at 7pm. It will be followed by an audience Q&A session.

Tickets are free but registration is required. Details on the registration page (link below)
See http://www.eventbrite.ca/o/unveiling-the-universe-lecture-series-2882137721?s=23658359 for more information.

You can go here to the Science World website for more details and another link for tickets,

Join Science World, TRIUMF and guest speaker Dr Rocky Kolb on Wednesday, May 7 [2014], for another free Unveiling the Universe public lecture about the inner space/outer space connection that may hold the key to understanding the nature of dark matter, dark energy and the mysterious seeds of structure that grew to produce everything we see in the cosmos.

I notice Kolb is associated with the Fermi Lab, which coincidentally is where TRIUMF’s former director, Nigel Lockyer is currently located. You can find out more about Kolb on his personal webpage, where I found this description from his repertoire of talks,

Mysteries of the Dark Universe
Ninety-five percent of the universe is missing! Astronomical observations suggest that most of the mass of the universe is in a mysterious form called dark matter and most of the energy in the universe is in an even more mysterious form called dark energy. Unlocking the secrets of dark matter and dark energy will illuminate the nature of space and time and connect the quantum with the cosmos.

Perhaps this along with the next bit gives you a clearer idea of what Kolb will be discussing. He will also be speaking at TRIUMF, Canada’s national laboratory of particle and nuclear physics, from the events page,

Wed ,2014-05-07    14:00    Colloquium    Rocky Kolb, Fermilab     Auditorium    The Decade of the WIMP
Abstract:    The bulk of the matter in the present universe is dark. The most attractive possibility for the nature of the dark matter is a new species of elementary particle known as a WIMP (a Weakly Interacting Massive Particle). After a discussion of how a WIMP might fit into models of particle physics, I will review the current situation with respect to direct detection, indirect detection, and collider production of WIMPs. Rapid advances in the field should enable us to answer by the end of the decade whether our universe is dominated by WIMPs.

You may want to get your tickets soon as other lectures in the Unveiling the Universe series have gone quickly.