“BPAE cells” by Joseph Elsbernd is licensed under CC BY 2.0

What is the surface area of a mouse intestinal tract? What is the persistence length of DNA? What is the diameter of a typical human red blood cell?

These are the sorts of questions that arise when building physics models of biological systems, and finding answers can often involve extensive digging through the literature. One resource, that hopes to “facilitate quantitative analysis and reasoning” in biology, is the BioNumbers database, a website that catalogues numerical values of biological quantities.  The database can be browsed by category or searched by keyword, and provides a citation of the original source of every number. It’s been going since 2007 and now covers categories from algae to zinc.

(From BioNumbers: mouse intestinal tracts have a surface area of 1.41 m²; DNA has a persistence length of around 50 nm; human red blood cells have a diameter of 7.7 µm.)

We asked Ron Milo, a systems biologist and developer of BioNumbers, about the project.

Courtesy Ron Milo

How did the idea for BioNumbers come about?

I was a fellow at Harvard medical school and was trying to do some back of the envelope calculation with my bay mates Mike Springer and Paul Jorgensen and we found none of the books and internet resources could give us what we needed so we decided to start a database ourselves.

How has the project grown and developed? Do you have any goals for the future?

It took shape rapidly in the first year and has been expanding ever since. The book that came out recently with Rob Phillips helps distill key insights from the available numbers and is available freely online. In the coming year I plan to revamp the interface to make it easier to use with mobile devices, make it more intuitive etc.

In your book Cell Biology by the Numbers you accompany tables of numbers with vignettes about the topics covered – do you have a favourite you’d like to share?

I love the one where we talk about how many H+ ions are in a cell – only about 100 in a bacterial cell! I also like the one about the turnover rate of different tissues in the body and how that was inferred with the help of signals from nuclear tests.

Do you have any advice for physicists who are interested in working on biology problems?

Don’t be worried about all the jargon, it is a field where you can easily penetrate things by reading textbooks that are almost page-turners and consulting wikipedia when needed. There are low hanging fruits ready to be picked, but you have to be willing to solve the problems by making your own makeshift  biological model and not always turning things into the beloved Ising model.

Post by Gaia Donati

Philip Ball talks about his latest book “Beyond Weird” — an exploration of the meanings of quantum theory and a tale of a continued effort to make sense of it. Call it counter-intuitive, challenging or puzzling — just don’t call it weird.

How did the idea for “Beyond Weird” take shape?

Over the past several years I found myself writing various articles about aspects of quantum mechanics, such as the classical–quantum transition and decoherence, uncertainty relations, quantum computing. It began to dawn on me that many of the standard “stories” we science writers — and often scientists themselves, especially when speaking to a general audience — fall back on to convey what happens in quantum physics are incomplete, misleading or plain wrong. Partly this is due to poor metaphors used to talk about what pioneers like Bohr and Einstein said; partly it’s because conceptual and technical advances have reshaped the narrative in the past few decades, for example by realising in the laboratory what were previously considered just thought experiments. So the book is an attempt to bring the presentation of quantum mechanics up to date, and to get away from the habit of referring to a ‘weird’ kind of behaviour bound up with ‘wave–particle duality’, ‘two paths at once’ and so on.

In the book it looks like you wish to deconstruct some statements and comments associated with the theory of quantum mechanics and its interpretation(s)— noting the limitations of these statements and the confusions stemming from these — in order to usher in a more positive message taking the form of a ‘quantum reconstruction’ — finding new axioms for quantum mechanics. Do you view your book as a manifesto?

If the book is a manifesto, then it’s for ceasing to use the shaky old clichés and find better language, better images. But what are these? I’m not sure we yet know, though I tentatively suggest a few. It is definitely not a manifesto for a particular interpretation of quantum mechanics, although I do think that the informational perspective has brought a fresh and fruitful view — literally so, given the technologies which it spawns. In this respect, I also wanted to point out that these ‘quantum technologies’ are not merely applications of quantum mechanics: they bind practical potential very closely to the fundamentals. Then even so, regarding quantum mechanics as ‘all about information’ is not without its problems either.

One big point I wanted to make is that we need to try harder to get away from ‘explaining’ quantum mechanics with classical stories. The idea that a particle ‘takes both paths at once’ through the double slit is a prime example: we think in terms of classical paths that happen to be weirdly simultaneous. I don’t think that helps. The same applies to ‘spooky action at a distance’: quantum nonlocality isn’t the technical term to that, it’s the alternative.

What do you hope the readers to take away from the book? What reactions do you expect?

I hope the readers will take away a fresh perspective on how to think about the counter-intuitive aspects of quantum mechanics, and feel dissatisfied with articles that merely say ‘quantum is weird’. I would be very happy if we could hear less about Schrödinger’s cat in the future too.

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Post by Giulia Pacchioni

Juan Knaster, project leader of IFMIF/EVEDA, answers our questions.
What made you want to be a physicist?

Since childhood I have been obsessed with nature around me. Watching insect life, flowers, clouds moving, stars, moon, sunsets… Certainly Sagan’s television documentaries ‘Cosmos’ in the early 80s made a breakthrough in my spirit, but possibly the reading a few years later of the Spanish translation of Gamow’s Biography of Physics led me to be interested in nuclear fusion.

Gamow is the γ of the revolutionary αβγ-paper that unravelled nucleosynthesis in stars; possibly this led me unconsciously to my professional drive towards nuclear fusion from my teenage years, concurrently with the 80s Reagan–Gorbachov political move towards the research world’s adventure of ITER. I dreamt since I was a teenager to work for ITER. As soon as I finished my studies, I joined nuclear fusion research in CIEMAT in the last phases of design and start of construction of the TJ-II, the successful Spanish stellarator which remains in operation. After few years in CERN, where I matured professionally in the best possible environment I could have dreamt of, I re-joined the world’s fusion program through ITER.

I studied physics wishing to work for this beautiful dream of human kind, as old as humanity, of harnessing the fire of stars, and we are now very close! ITER will make a breakthrough in human history, since we will harness fire for the 2^nd time in our history on Earth: this time the real one. Coming back to the question, before I keep on digressing… Fusion energy development led me to become a physicist.

Which historical figure would you most like to have dinner with — and why?

That’s a tricky question. I don’t think there is only one historical figure I wish to have dinner with.

I am fascinated with Neoplatonism, which was the philosophical consolidation of Gnosticism, which we could understand as the esoteric branch of a new religion, Christianity, that they attempted to eradicate following Council of Nicaea in 325 a.d. The line of thought of ‘oneness’ in the Universe, with humans  being not only observers, but very special actors in this united perception, pervades all cultures in all times, like flowers blooming in a field. Among these flowers, if I had to choose historical figures to have dinner with, possibly I would select Plotinus or Iambliqus as prominent figures of Neoplatonism, or moving east possibly the zen Chinese patriarch Huineng from the 7^th century, whom I adore for his deeply Neoplatonic views; or the 11^th century Persian Sufist Suhrawardi; or Pico della Mirandola, one of the fathers of the Rennaissance; or Boehme in 18^th century; or Hegel in the 19^th century; or Husserl or Jung in the 20^th century.

Eating is one of my private pleasures, so possibly ascetic individuals like most of those previously mentioned would not be good company for a dinner; then, if I had to choose someone to really have a good time with, possibly I would choose Jung, with whom I know I would get along very well because of so many common interests in life. I am certainly persuaded that we would enjoy more than one dinner together, addressing topics of common interests combining my physics background with his studies on Hermetism, accompanied with a nice glass of red wine. He was interested in modern physics, and he collaborated with Pauli; some of the dreams he analyses in his Psychology and Alchemy are Pauli’s.

What are you working on, and what do you hope will be the impact of your research?

I am leading a European-Japanese research project, IFMIF/EVEDA, that aims to overcome the pending technological challenges to construct a fusion-relevant neutron source. The project is framed by the Broader Approach Agreement between Europe and Japan in the field of Fusion energy research. IFMIF, the International Fusion Materials Irradiation Facility, is a project whose concept was proposed in the mid-70s, but it demands a high-current linear accelerator, a liquid metal facility and an irradiation facility with unprecedented performances, that frankly were rather science fiction during its first serious attempt with FMIT, the Fusion Materials Irradiation Test facility, in the mid-80s in the US.

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Post by Iulia Georgescu.

Ben Still talks about his new book Particle physics brick by brick, an accessible and extremely enjoyable introduction to particle physics all LEGO fans will love – and who is not a LEGO fan?

You have been involved with various outreach activities, how did you get the idea for this book?

The idea has been with me since 2009 when I first started participating in outreach as a newly appointed postdoc. I took it to the outreach team at Queen Mary, University of London and we fleshed out the ideas into workshops. These workshops and materials covered only a small portion of particles and used similar blocks to represent quarks in one instance and nucleons in another. They were fantastically popular.  Since then, I have had in the back of my mind an attempt to use a LEGO analogy to encapsulate as much of particle physics as possible. The result is Particle physics brick by brick.

Are you a LEGO fan? Which is your favourite set?

I am a huge fan, I got hooked as a kid.  I am an avid collector of the Architecture series, but I have to say that my favourite kit is the Saturn V rocket released recently in the Creator series.

Is LEGO a good tool to teach science in general? What is the best physics/science LEGO?

Sometimes you need a hook to get those otherwise disengaged in science to get involved and LEGO certainly helps bring in a broad audience. It made sense to me to use LEGO after many utterances of fundamental particles being the building blocks of nature. I think that the best use of LEGO in any sense, whether for teaching or for leisure, is creativity. I tried to stress in the book that with just the rules I cover you can be creative and build particles and chemical elements which don’t appear in the book. I think that LEGO is a great way of linking science with creativity and showing that science is about exploration.

Technic and Mindstorm are fantastic for the advanced technical creative, but I still love good old fashioned bricks.

In the book you explain particle physics in a very accessible way, but you do not shy away from abstract concepts that might intimidate the layperson. Who is this book for?

The book was officially aimed at ‘science interested adults’, but I think that teens from 14 years with an interest in science will find the book equally exciting. I did not want to shy away from the more abstract concepts because they are important, particle physics is abstract compared with our day-to-day lives. The book is structured, however, in a way that I hope eases the reader into the abstraction. I think the earlier chapters involving the history of the universe can be used with younger readers when hands-on with the LEGO as the workshops have shown in the past.

What do you think are the biggest challenges in explaining particle physics to the general public? How to avoid the pitfalls of hype or misleading analogies?

Our everyday lives are deterministic, we know if we strike a football in a certain way it will follow a path which we can calculate. Particle physics lives in the quantum world where probability, not determinism, rules. In this world all sorts of weird wonderful and mind-bending things can happen because so much is possible if not probable. It is this separation from our daily experiences that makes particle physics a tough subject to get across sometimes. It would be much easier if we were living in the quantum world too because the goings on of particle physics would be day-to-day.

In the book I openly talk of the limitations of analogies and throughout admit to the shortcomings of the LEGO analogy I use. In a very real sense our scientific understanding is nothing but an analogy of the underlying fundamental laws of nature. New science is found at the edge of our knowledge and so understanding the limitations of any scientific analogy is the way that science progresses.

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