Posts by: Hamish Johnston

Rachid Ouyed talks about quark novae and the quark stars they could produce

 

By Hamish Johnston

Recently I blogged about quark novae, which are a passion of the University of Calgary astrophysicist Rachid Ouyed. I caught up with Ouyed at the Canadian Association of Physicists Congress in Edmonton last month, where between sessions he was busy writing a paper about quark novae.

I managed to coax him away from his calculations for long enough to record the above video, in which he talks about quark novae – huge explosions that some astrophysicists believe could occur shortly after some supernovae. Ouyed also talks about the quark stars that may be left behind and how quark novae could affect how astronomers measure cosmological distances.

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A galaxy for a Galáctico and astronomers weigh in on a famous kiss

A galaxy far away: this false colour image of CR7 was taken by several telescopes (Courtesy: David Sorbal et al)

A galaxy far away: this false colour image of CR7 was taken by several telescopes. (Courtesy: David Sorbal et al.)

By Hamish Johnston

Over the past decade or so the Real Madrid football club has acquired a string of high profile players dubbed the “Galácticos”. Now the most expensive of these footballers – the Portuguese forward and Real Madrid number 7 Cristiano Ronaldo – has a distant galaxy named after him. The galaxy is dubbed “CR7” and was discovered by a team of astronomers led by David Sobral of the University of Lisbon using several different telescopes.

CR7 actually has two meanings, the second being “COSMOS Redshift 7”. COSMOS refers to the Cosmological Evolution Survey, which is using a number of telescopes to search for very old galaxies.

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Agreeing to disagree at the next Convergence conference

The closing panel. From left to right are  Patrick Brady, Stefania Gori, Immanuel Bloch, Sara Seager and Ian O'Neill

The closing panel. From left to right: Patrick Brady, Stefania Gori, Immanuel Bloch, Sara Seager and Ian O’Neill.

 

By Hamish Johnston

I have just returned from the Perimeter Institute (PI) in Waterloo, Canada where I enjoyed a fantastic few days immersed in discussions involving some of the sharpest minds in physics. The great and good were at the PI for the first Convergence conference and from what I have heard, the participants are calling it a great success.

But could it be even better next time?

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The ins and outs of black holes and a new way of thinking about general relativity

 

By Hamish Johnston

While at the Convergence conference at the Perimeter Institute (PI), Physics World’s Louise Mayor and I had dinner with Sean Gryb. He did his PhD at the PI and is now doing a postdoc at Radboud University Nijmegen in the Netherlands. In the above video he shares some of his highlights of the conference.

Gryb is working on “shape dynamics”, which is a new idea for re-evaluating Albert Einstein’s general theory of relativity (GR). The idea was initiated by Julian Barbour and Gryb became involved in the development of shape dynamics while he was at PI. He now belongs to a small international band of physicists who are developing the concept. While shape dynamics is an alternative treatment of GR, the ultimate goal of their work seems to be the creation of a new framework for a theory of quantum gravity – an important goal of theoretical physics.

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What do strange metals and black holes have in common?

Subir Sachdev

Subir Sachdev.

By Hamish Johnston in Waterloo, Canada

Harvard’s Subir Sachdev has just taken the audience here at the Convergence conference on a delightful romp through the phase diagram of the cuprate high-temperature superconductors. What I found most interesting was not the superconducting phase, but rather Sachdev’s description of the “strange metal” phase.

This phase occurs when the cuprate copper-oxide layer is highly doped with holes and has perplexed physicists for some time – hence its strange moniker. It has no quasiparticles and lots of low-energy excitations so there is no easy way to describe the collective behaviour of the electrons.

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Maria Spiropulu talks about multiple Higgs beyond the Standard Model

 

By Hamish Johnston in Waterloo, Canada

Caltech’s Maria Spiropulu has a great party trick. She can demonstrate the bizarre rotational property of a spin ½ particle using a full glass of water and a contortion of her arm without spilling a drop. This was just one of the many highlights of her talk about the future of experimental particle physics that she gave yesterday at the Convergence meeting here at the Perimeter Institute.

While Spiropulu doesn’t talk about spin in the above video, she does explain why she is looking forward to analysing data from the 13 TeV run of the Large Hadron Collider, where she is part of the CMS collaboration. So, what could Spiropulu and colleagues find when they dig into the vast amounts of data that CMS is currently producing? It just could be four more types of Higgs particle. To find out more watch the video.

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Busting dust deep underground in SNOLAB

SNOLAB's Nigel Smith (left), Ian Lawson (centre) and Chris Jillings

Squeaky clean: SNOLAB’s Nigel Smith (left), Ian Lawson (centre) and Chris Jillings.

By Hamish Johnston at the CAP Congress in Edmonton, Alberta

I’m a bit of a DIY enthusiast and one thing that I know about drilling into a masonry wall is that you should hold a vacuum-cleaner hose to the hole or you will end up with dust all over the wall and the floor below. Believe it or not, that is exactly what workers at SNOLAB in Canada do in order to keep background levels of radiation from affecting their dark-matter and neutrino detectors.

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The physics of Alzheimer’s disease

Jennifer Tang and Maikel Rheinstadter

Jennifer Tang and Maikel Rheinstadter.

By Hamish Johnston at the CAP Congress in Edmonton, Alberta

One promising route to understanding the causes of Alzheimer’s disease (AD) –  and hopefully finding a cure – is the study of how and why proteins in the brain sometimes form neurotoxic plaques. These plaques are disc-like structures that are about 50 µm in diameter and made from polypeptides. Their presence in the grey matter of the brain is strongly associated with AD and some other neurological conditions, but why they form and why they cause dementia are both not understood.

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Muzzling scientists leads to mistrust of government says physicist MP

Canadian MP Ted Hsu believes in free speech for government scientists

Canadian MP Ted Hsu believes in free speech for government scientists.

By Hamish Johnston at the CAP Congress in Edmonton, Canada

Yesterday I caught up with Ted Hsu, who is member of the Canadian parliament for Kingston and the Islands – and a former physicist. Hsu is a member of the Liberal party, which means he sits on the opposition benches. There he has been an outspoken critic of the current Conservative government over its apparent “muzzling” of scientists on the federal payroll. He believes that when governments seek to silence their experts it leads to more public mistrust of government.

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Debating warp bubbles and quark novae over beer and samosas

Photograph of Miguel Alcubierre lecturing in Edmonton

Time traveller: Miguel Alcubierre works the crowd in Edmonton.

By Hamish Johnston at the CAP Congress in Edmonton, Canada

The first day of the Canadian Association of Physicists (CAP) Congress at the University of Edmonton closed yesterday on the theme of time travel. Surely that is science fiction, you are thinking? But Miguel Alcubierre of the National Autonomous University of Mexico (UNAM) wasn’t joking when he delivered the Herzberg Memorial Lecture yesterday evening (although he did giggle a lot during his talk, which was very endearing). The session was called “Faster than the speed of light” and it was a fascinating romp through some of the more bizarre implications of Einstein’s general theory of relativity (GR) – which is 100 years old this year.

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