Posts by: Hamish Johnston

The Dark Matter Garden, gravitational atoms, boys and girls with toys, and more

Gravitational gardening: the Dark Matter Garden at Chelsea

Gravitational gardening: the Dark Matter Garden at this year’s RHS Chelsea Flower Show. (Courtesy: National Schools’ Observatory)

By Hamish Johnston

Gardening is something that the British take very seriously and this week’s RHS Chelsea Flower Show is the pinnacle of that obsession. Indeed, it is so popular that it is covered live on television by the BBC. One highlight of the show is the garden competition, in which designers transform an empty plot into a dazzling garden in just 10 days. This year’s entries include the Dark Matter Garden, which “brings the mysteries of the universe to Chelsea”. That’s the claim of the designers of the garden (including several astronomers), who built it for the UK’s National Schools’ Observatory. The team says that its gold-medal-winning design includes “innovative structures and planting, and represents the effect of dark matter on light”.

(more…)

Posted in The Red Folder | Tagged , , | 3 Comments | Permalink
View all posts by this author  | View this author's profile

Exploring the expanding world of high-temperature superconductors

Layer by layer:  iron (red) and arsenic (green) atoms in the conducting layer of a pnictide

Layered look: iron (brown) and arsenic (green) atoms in the conducting layer of a pnictide.

By Hamish Johnston

High-temperature (high-Tc) superconductivity has given hope and heartbreak in equal measure to physicists since the phenomenon was first discovered in 1986.

The hope is two-fold: that we will soon understand why superconductivity arises in this complex group of materials; and that this knowledge will lead us to a material that is a superconductor at room temperature. The former would be a triumph of the physics of highly correlated systems and the latter would spark a technological revolution.

(more…)

Posted in General | Tagged , | 2 Comments | Permalink
View all posts by this author  | View this author's profile

All hail the Standard Model, once again

 

By Hamish Johnston

I am a condensed-matter physicist by training and sometimes I struggle to get excited by the latest breakthrough in particle physics – usually because most don’t seem much like breakthroughs to me. The latest hot paper from physicists working on the Large Hadron Collider (LHC) at CERN is a perfect example of what I am talking about.

Writing in Nature this week, physicists working on the CMS and LHCb experiments at CERN announced the discovery of a rare decay of the strange B-meson, as well as further information regarding an even rarer decay of the B0-meson. In both cases the decays produce two oppositely charged muons. An animation of how the strange B-meson decay is detected by the CMS appears in the video above.

(more…)

Posted in General | Tagged , , | 5 Comments | Permalink
View all posts by this author  | View this author's profile

A guided tour inside D-Wave’s iconic black box

By Hamish Johnston

Has D-Wave Systems built the world’s first commercial quantum computer? The Canada-based company says it has but some physicists in the quantum-information community beg to differ. Putting aside heady questions like “Does it work?”, I think everyone agrees that the Tardis-sized black boxes that house D-Wave’s processors look great. But what exactly is inside?

(more…)

Posted in General | Tagged , | 1 Comment | Permalink
View all posts by this author  | View this author's profile

The admiral of the string-theory wars, add-male-author-gate, the Einstein font and more…

Xxxx Particle Zoo. (Courtesy: CERN)

Julie Peasley, creater of the Particle Zoo. (Courtesy: CERN)

By Hamish Johnston

Peter Woit is lauded by some for having the courage to speak the truth to the physics establishment, while others see him as an enemy of science. Woit writes the Not Even Wrong blog, which has the same title as a controversial book he once wrote about the merits of string theory. In an article in the latest issue of Nautilus, Bob Henderson profiles Woit and his three decades of doubt over various incarnations of the theory that culminated about 10 years ago in the “string wars”. Henderson’s article is called “The Admiral of the String Theory Wars” and provides a fascinating insight into how the rise of string theory caused Woit to switch from physics to mathematics and his relationships with string theorists – some of whom work in the same building as Woit at Columbia University.

(more…)

Posted in The Red Folder | Tagged , , , | 6 Comments | Permalink
View all posts by this author  | View this author's profile

What can cosmic rays tell us about dark matter?

The positron excess as seen by AMS

Alive and well: the positron excess as seen by the AMS. (Courtesy: CERN)

By Hamish Johnston

Cosmic rays, dark matter and other astrophysical mysteries are being debated with much vigour at a three-day conference that began this morning at CERN in Geneva. Called “AMS Days at CERN”, the meeting will include presentations of the latest results from the Alpha Magnetic Spectrometer (AMS).

Located on the International Space Station, the AMS measures the energy of high-energy charged particles from the cosmos – otherwise known as cosmic rays. These particles are of great interest because they offer us a window into some of the most violent processes in the universe. Some cosmic rays have probably been accelerated during supernova explosions while others could be produced as matter is sucked into the supermassive black holes that lie at the centres of many galaxies.

(more…)

Posted in General | Tagged , , | 3 Comments | Permalink
View all posts by this author  | View this author's profile

Night visions, the sky 10 billion years ago and unexplained sounds from around the world

View from an Earth-like planet 10 million years ago

Good old days: the view from an Earth-like planet 10 billion years ago. (Courtesy: NASA/ESA/Z Levay (STScI))

By Hamish Johnston

This week’s Red Folder is inspired by a vision I had last night while I was putting out the garbage bins. I happened to look up at the sky just as the International Space Station (ISS) was travelling over Bristol. It was a very bright and impressive sight as it zipped overhead before disappearing at the eastern horizon. If you happen to be on an arc through northern Europe between Penzance and Poznań, you should also have a great view of the ISS this evening; you can find out when and where to look at the ISS Astroviewer website.

The ISS is one thing that you would definitely not see if you could look at the sky as it was 10 billion years ago – but have you ever wondered what that view would be? Zolt Levay at the Hubble Heritage Information Center has, and the above image is his vision of what the sky would look like from a hypothetical planet within a Milky Way-like galaxy 10 billion years ago. The work was inspired by a new collection of nearly 2000 images of galaxies as they appeared at that time in the history of the universe. Taken by a number of different telescopes including Hubble, “the new census provides the most complete picture yet of how galaxies like the Milky Way grew over the past 10 billion years into today’s majestic spiral galaxies”, according to NASA.

(more…)

Posted in The Red Folder | Tagged , , | 1 Comment | Permalink
View all posts by this author  | View this author's profile

Where is the coldest experiment on Earth?

Image of a refocused cloud of rubidium atoms

Chilly peak: a refocused cloud of rubidium atoms. (Courtesy: Tim Kovachy et al./Physical Review Letters)

By Hamish Johnston

California might be suffering a punishing drought, but a tiny corner of the Golden State is now the coldest place on Earth. This tiny super-cold patch was created at Stanford University by Mark Kasevich and colleagues, who have used “matter-wave lensing” to cool a cloud of about 100,000 rubidium atoms to less than 50 pK. That is just 50 × 10–12 degrees kelvin above absolute zero.

The temperature of a cloud of atoms is defined by the average velocity of the atoms as they drift about. Kasevich’s team used a series of lenses to reduce this average motion to less than 70 µm/s, which corresponds to 50 pK. This shatters the previous record of 1 nK for matter-wave lensing and represents “record-low kinetic temperatures” according to Physical Review Letters, where the research is described.

(more…)

Posted in General | Tagged | 5 Comments | Permalink
View all posts by this author  | View this author's profile

Protons return to the Large Hadron Collider

Aerial view of the LHC

Up and running: The first proton beams have been injected into the LHC in preparation for its second run. (Courtesy: Maximilien Brice/CERN)

By Hamish Johnston

The first proton beams of the second run of the Large Hadron Collider (LHC) were circulated earlier today. Travelling in opposite directions around the collider at CERN in Geneva, each beam was injected at 450 GeV. If all goes well over the next few days, the energy of each beam will be increased to the operating energy of 6.5 TeV.

(more…)

Posted in General | Tagged | 4 Comments | Permalink
View all posts by this author  | View this author's profile

Florida’s declining Space Coast, naming mountains on Pluto and silly rock bands

 

Artist's impression of Pluto

Name game: does that crater look like a Steve, or maybe a Carol? (Courtesy: IAU/L Calçada)

By Hamish Johnston

When I was a young lad back in the late 1960s, my family would join the annual March migration of Canadians to Florida. Along with alligator farms and the endless beaches, the Kennedy Space Center was a popular tourist destination and I can still remember visiting it and getting a solar spinner globe as a souvenir. Sadly, since the end of the Space Shuttle programme in 2011, Florida’s “Space Coast” has fallen on hard times. While there are still rocket launches – there are two planned for April – thousands of NASA employees have been let go and the surrounding communities look worse for wear. The New York-based photographer Rob Stephenson has put together a collection of images taken in and around the centre that he calls “Myths of the Near Future”. To me the photographs evoke the allure of the space age as well as the inevitable decline of any human endeavour.

(more…)

Posted in The Red Folder | Tagged , , | 2 Comments | Permalink
View all posts by this author  | View this author's profile