Posts by: Louise Mayor

Physics World at 25: Puzzle 2

By Louise Mayor

Welcome to the second instalment of the Physics World at 25 Puzzle. The first puzzle was released last week and your second challenge lies below. #PW25puzzle


Is Schrödinger’s cat alive or dead?

1. Schrödinger’s cat is alive.
2. Schrödinger’s cat is dead.
3. Exactly one of statements 6 and 9 is true.
4. Exactly one of statements 2 and 6 is false.
5. Statements 4, 5 and 10 are all false.
6. Exactly one of statements 1 and 10 is false.
7. Exactly 5 statements are true.
8. Exactly one of statements 3 and 10 is false.
9. Exactly one of statements 6 and 10 is true.
10. Exactly one of statements 1 and 2 is false.
11. Statements 1, 8 and 11 are all false.

Enter your answer as a list, in numerical order, of the number(s) of the statements that are definitely true, as a single string with no spaces, such as, for example, 25811.

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Physics World at 25: Puzzle 1

By Louise Mayor

Physics World at 25 Puzzle

This month is the 25th anniversary of Physics World – the member magazine of the Institute of Physics – and in addition to a special celebratory issue, we’ve decided to set you a challenge.

In fact, we have teamed up with GCHQ – one of the UK’s three Intelligence Agencies and home to some of the country’s hottest code-breaking talent – to create with us a set of five physics-themed puzzles. The puzzles have been devised by three GCHQ members of staff, who today we still know only as Colin, Nick and Pete. (Thank you, guys!)

Below is Puzzle 1, the first of the five. The rest will be released on successive Tuesdays throughout October on this blog. The first is the easiest – they only get harder from here on in!


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An afternoon of quantum theory

By Louise Mayor

Yesterday I had an exciting trip out of the office.

This month's cover story

This month’s cover story.

Earlier this week, one of Physics World’s freelance writers, Jon Cartwright, told how me he’d been invited to the Bristol University theory department’s weekly seminar. Felix Flicker, a 2nd-year PhD student who organizes these events, had seen Jon’s article “The life of psi” in this month’s Physics World, which discusses a theorem published in Nature Physics. The theorem is interesting because if its assumptions hold, it rules out one of the four interpretations of quantum mechanics and leaves us with three.

I wanted in on the seminar action!

Last year when I was planning the Physics World special issue on quantum frontiers (which was out in March and is still available as a free PDF download), I had approached Jon to ask whether he’d like to tackle a quantum topic, and he let me know he was interested in covering the paper by Matthew Pusey, Jonathan Barrett and Terry Rudolph. Jon had seen the story reported elsewhere but had found these accounts were light on the details and didn’t get to the bottom of the science. I liked the idea and Jon went ahead. Once the story arrived in my inbox I was hooked! I found it to be one of those stories that covers some tricky concepts but if you let yourself become immersed in the story and think through what’s being explained, is very rewarding.


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Towards a ‘Year of Light’

Varenna seen from Lake Como (CC BY-SA/Idéfix)

By Louise Mayor

One of the good things about being a science journalist is getting to travel to the same places as all the jammy scientists.

This week I’m heading over to Varenna – an idyllic town on the shores of Lake Como, Italy. If the name of the lake sounds familiar, that might be because it’s famous as a filming location for Casino Royale and Star Wars Episode II: Attack of the Clones, and it apparently has villas belonging to the likes of George Clooney, Sting and Richard Branson.

But I’m not going for the views, the laid-back atmosphere, the fabulous food and the wine – well okay, just a bit. This Friday 16 September, Varenna will host Passion for Light, an international workshop jointly arranged by the European and Italian physical societies (EPS and SIF, which will launch the idea of an International Year of Light (IYOL) in 2015.

Other recent “international years” with a scientific theme have included physics (2005), astronomy (2009) and chemistry (this year). Huge successes have been reported, with the International Year of Astronomy having at least 815 million participants in 148 countries.

But you needn’t be in Varenna to stay in the loop; on Friday you can tune in to a live, streamed video of the one-day event at the Passion for Light webpage.

Opening addresses will kick off at 9.30 a.m. (CEST) led by Luisa Cifarelli, president of EPS-SIF (previously interviewed in this video.

The rest of the day sees an all-star cast of 11 scientists talking about the role of light in many diverse areas of physics, with speakers including Nobel-prize-winners Ted Hänsch and Claude Cohen-Tannoudji. The full line-up of scientific talks is available here.

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Become a Wikipedian!

By Louise Mayor

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Being online right now, chances are you’ve recently been to the fifth most visited site on the Web: Wikipedia.

I am happy to admit that I use Wikipedia frequently and find it very useful – particularly for physics. It’s great when I want an introduction to a phenomenon or technique, or to get the cogs going again on something I learned long ago at university.

However, I do remember a time when using Wikipedia was a bit more hit and miss. It was pot luck whether an article would be either well written and accessible, or an impenetrable wall of techno-speak and equations.

Now, thanks to more than a billion edits since Wikipedia’s inception, the odds of finding a well-written article are much higher and article quality continues to improve every day.

But there’s still a long way to go before the site’s eventual goal is achieved: to assemble a complete overview of human knowledge. And this is where you come in. Yes, you! With a lay or professional interest in physics, you are ideally placed to contribute.

According to Martin Poulter, a new media manager at the University of Bristol, and Mike Peel, an astrophysicist at the University of Manchester, it is rewarding work. In “Physics on Wikipedia”, an article published this month in Physics World, Poulter and Peel argue that if you have knowledge you can share, Wikipedia needs you.

Also, how about images you can share? You may be ideally placed, for example, to capture photographs of things the public would not normally be able to see, such as pieces of equipment or research facilities. The image at the top of this blog entry (By ESO/Yuri Beletsky (ybialets at ( [CC-BY-3.0, via Wikimedia Commons is a great example of this, and was picture of the year 2010 on Wikimedia Commons, an online respository where you can upload your images for free use.

Read “Physics on Wikipedia” now to find out why you should click that edit button.

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Messing with your brain

By Louise Mayor

Last night I attended an event at the Royal Society in London celebrating 100 years of superconductivity. Hosted by Oxford Instruments and the Institute of Physics, the evening’s entertainment included talks by top scientists Stephen Blundell, Mark Lythgoe, Steven Cowley and Jonathan Flint.

A take-home message from Blundell was that it took 50 years from the discovery of superconductivity until we got to the point of commercializing the science – something that funding bodies and policy-makers should keep in mind. But as well as such sensible opinions, there were some unusual goings-on that I won’t forget in a hurry.

One such highlight was the video below. Lythgoe showcased what we’ve learned about the human brain through magnetic resonance imaging (MRI), which only has such high resolution due to superconducting magnets. Lythgoe challenged the audience to watch the following video and count how many times the people in white T-shirts pass the ball between each other. Have a go yourself, but try not to be distracted by the people in black T-shirts, who will try to confuse you by running around and throwing a second ball.

So, how many times did the white ball get passed? The answer is 15. Well done if you got that right – it shows you have good attention. However, this was an example of a selective attention test. Did you see the gorilla?

In a particularly curious moment, a group of people stood up and made their way to the front of the room; in hindsight they were conspicuously young and gender-balanced compared with the rest of the crowd. It was explained that we were in for a musical treat – a music/art performance called Brainwaves, one of the composers having been inspired by an MRI scan. The experience was immersive, with visual effects from design studio loop.Ph, and Mira Calix and Anna Meredith’s electronic music sounding menacing and grating next to the more soothing tones of the Aurora string quartet. I’ve never been in an MRI scanner, but watch for yourself and see what you think.

None of the evening’s events would have taken place were it not for that serendipitous discovery of superconductivity 100 years ago. This April, Physics World produced a special issue to celebrate the centenary, a free PDF of which can be downloaded by following this link.

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Zero resistance to cake


By Louise Mayor

We had a good chuckle in the Physics World office when we saw how Ted Forgan and his condensed-matter group at Birmingham University in the UK are celebrating the centenary of superconductivity.

As Forgan explained, “According to my info, today is the actual day, so in our group we celebrated with a cake.” He does, however, acknowledge his “amateur icing skills”.

Apparently, comments about the cake have included “Does it contain super currants?”, “Does it contain pears?”, and the less obvious “Is it a Butter–Chocolate–Sugar supercake? (maybe this depends on Tc, the cooking temperature)”.

I had to get this last one explained to me; if you need a clue too, it refers to the Bardeen–Cooper–Schrieffer (BCS) theory of superconductivity.

Once the pun-groans have subsided, if you want to know more about what superconductivity is all about and what’s hot in superconductivity right now, then look no further than this free PDF download of our April special issue. In fact, we’re in touch with Forgan because he contributed a piece about high-temperature superconductivity called “Resistance is futile”.

You might also want to check out this video feature about superconductivity by Paul Michael Grant called “Down the path of least resistance”.

Clearly, superconductivity brings out the puns in everyone.

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The flip-flop world of research


By Louise Mayor

Life in research involves a turbulent rollercoaster of emotions. But often the only glimpse we see is the success and jubilation of when things work out and results get published.

This new video report (below) offers a behind-the-scenes look into the whole research process, from the long hours spent working in the lab to that day when the results finally get accepted for publication in a journal. It features researchers at Nottingham University achieving a breakthrough in part of their broader aim: to construct 3D objects on surfaces, atom by atom, using scanning probes. “The novel aspect of this video is not so much the science but the fact that we’ve filmed the entire research process over the course of a year or so,” says Philip Moriarty, the main protagonist in this adventure.

The joy that results when experiments go well comes across nicely when, while being filmed in the lab, Moriarty breaks off mid-sentence to throw his fists in the air and exclaim “yes!” However, he reveals that the groundwork preceding what looks so effortless has been 18-months-plus in the making and has sometimes involved 24- and even 36-hour shifts.

But research is rarely over once you’ve got that crucial result: there are then the highs and lows of trying to get the work published in as prestigious a journal as possible. Moriarty highlights that there’s a definite hierarchy of journals to which physicists submit papers. In this case their work was rejected from both Nature and Science before finally being accepted in Physical Review Letters.

Film-maker Brady Haran really digs deep with a frank set of questions that would make many less-composed subjects squirm, such as: “Why is this impressive?”; “What you’ve written…looks really hard to read and really boring – who’s this for?”; and “If only you and a select number of people in the world can understand that paper, how is it doing the world any good?”

The up-and-coming Haran highlights this video on his blog as a great example of what he hopes to achieve with science films. Haran is the mastermind behind the Test Tube project where this video is featured alongside a veritable trove of other gems, as well as The Periodic Table of Videos and Sixty Symbols.

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Four steps to success

By Louise Mayor

Today CERN announced on its Twitter feed that “the first 7 TeV LHC [proton] collisions of 2011 were recorded last night, round midnight, with low intensity beams”.

But how do particle physicists work out from the millions of detected collision events per day whether they are observing a new particle or phenomenon?

Tommaso Dorigo, a collaborator on the Compact Muon Solenoid collaboration at CERN and the Collider Detector at Fermilab, has described just what researchers are looking for and how they go about their search in a fabulous new article, “On the road to discovery”, in the March 2011 issue of Physics World. You can read it here.

In his article Dorigo breaks down the search for new physics into four general steps and to make this clear he sent us these four charming hand-drawn sketches (below).


In the sketches, Dorigo imagines looking for a particle that theory says will decay to a pair of particle jets which fly out back-to-back. But before even looking for new physics, the detector must first be checked – does it do everything we expect for particles and phenomena that we do know about already? That’s step 1.

Now we’re ready to take on the maelstrom of data – huge files where as much as possible about each collision has been recorded. To make a detailed analysis of every single file would take ridiculous amounts of computer power, so step 2 involves culling anything that’s obviously not what we’re looking for. Here we’re looking for two jets back-to-back, so anything else – no jets, three jets, or two jets not back-to-back – is scrapped.

In step 3, the remaining events are split into either “background” or “signal”, and the background events – those we already understand with the Standard Model – are discarded. These are in effect considered to be background noise, and the aim is to remove this so that any signal is easier to spot.

Events are classed as “background” if the particles produced are only at a small angle to the beam so have not undergone much momentum change – you can imagine these events to be like a truck that hits a stray goose and does not go far off course, as opposed to a head-on truck-on-truck crash where debris might fly off sideways.

In the fourth and final step, the mass of the jet pairs is plotted on a histogram along with all the other events analysed so far. The shape of this distribution is compared to the “null” hypothesis – the shape if the particle being searched for doesn’t exist – and the “alternate” hypothesis – the shape if the particle does exist. Statistics are used to say how confidently the data agrees with the new idea – usually converted into units of “standard deviations”.

You can read more about this in Dorigo’s feature article: On the road to discovery.

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Pulling power

By Louise Mayor

Love moves in mysterious ways, and try as we might to find one, there is no formula that will unlock the secrets of how to find and sustain romantic love.

So if you’re looking for foolproof tips on your love life this Valentine’s Day, I’m afraid they don’t exist. But you’ve come to the right place if you fancy watching three physicists from the University of Nottingham explain something even deeper – the four fundamental forces of attraction.

In some introductory comments to this new video, nanoscientist Philip Moriarty explains, “Generally, forces of attraction, when we’re talking about Valentine’s Day, mean people falling in love and what holds them together…Of course, I’m a physicist so I have to look into it a little bit more deeply than that.”

Ed Copeland, who is a particle cosmologist by trade, explains how three of the forces – the strong, weak and electromagnetic – can be beautifully described by quantum chromodynamics, or QCD. But he adds that gravity’s proving most difficult: “That remains the goal – to try and also bring gravity into this big picture.”

While the video might not explain the forces of love, it’s quite instructional if you fancy your chances at impressing the object of your affections with some good old-fashioned geek chic. Moriarty and Copeland, as well as Roger Bowley, are charmingly enthusiastic.

You can find plenty more videos from them, as well as other Nottingham University scientists, on the website Sixty Symbols.

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