Despite their variety and complexity, living organisms obey simple scaling laws due to the universality of the laws of physics. In the present paper, we study the scaling between maximum speed and size, from bacteria to the largest mammals. While the preferred speed has been widely studied in the framework of Newtonian mechanics, the maximum speed has rarely attracted the interest of physicists, despite its remarkable scaling property; it is roughly proportional to length throughout nearly the whole range of running and swimming organisms. We propose a simple order-of-magnitude interpretation of this ubiquitous relationship, based on physical properties shared by life forms of very different body structure and varying by more than 20 orders of magnitude in body mass.
Jacopo.bertolotti
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How fast do living organisms move: Maximum speeds from bacteria to elephants and whales
Scalable Integration of Long-Lived Quantum Memories into a Photonic Circuit
Author(s): Sara L. Mouradian, Tim Schröder, Carl B. Poitras, Luozhou Li, Jordan Goldstein, Edward H. Chen, Michael Walsh, Jaime Cardenas, Matthew L. Markham, Daniel J. Twitchen, Michal Lipson, and Dirk Englund
Quantum networks built out of distinct quantum bits (qubits) connected via photons may enable quantum computation and long-distance communication. The high yield integration of high-quality solid-state qubits into an on-chip photonic circuit could provide a stable and scalable architecture to build such a network.

[Phys. Rev. X 5, 031009] Published Tue Jul 21, 2015
Mathematicians vs scientists
Jacopo.bertolottiROTFL!
Gian-Carlo Rota explained, in 1997, a difference between mathematicians and scientists:
To a scientist, nature is a primeval forest to be explored, rich in surprising and unpredictable fauna, endowed with mysterious laws that scientists bravely wrest from the jungle. Once discovered, the laws of nature are written up by scientists for the benefit of posterity, in a language that sometimes – but not always – happens to be the language of mathematics. A scientist need not be fluent in that peculiar language that is called mathematics, just as he or she need not be fluent in Urdu or Gaelic.
Mathematicians do not agree with this view.
Big tech companies back Samsung in court case against Apple
Focus: Understanding a Spreading Puddle
Author(s): Michael Schirber
Classical fluid theory can't explain a puddle that spreads and then stops. A new theory solves the problem by incorporating intermolecular forces between the liquid and the solid underneath.
[Physics 8, 69] Published Fri Jul 17, 2015
Why isn’t this working?!
Professor Povey’s Puzzling Problems
Jacopo.bertolottiOk, you got me curious. Now I have to read this book.
What happens when a 747 collides with a mallard duck? That’s one of the puzzles in the book Professor Povey’s Puzzling Problems. I have not yet read the book, but the promotional video (which you see here) is possibly perfect:
Professor Povey practices from a perch, and teaches tutorials, at Oxford University. Fluid dynamics is his game of choice.
BONUS: What happens when a mallard duck collides at a slower, but still potent, speed. See it re-enacted as an opera, in London, on August 8 and 9.
Saturday Morning Breakfast Cereal - Quantum Gravity
Il futuro dell'euro e dell'Unione Europea; la lezione greca
Considerazioni, in forma di dialogo, sulle questioni di fondo che l'eterna "crisi greca" sembra sollevare alla luce dell'accordo di lunedì mattina. Son lunghe e forse più convergenti di quanto potrebbe divertire il lettore ma, a nostro avviso, queste sono, sino a ora, le lezioni da apprendere.
Tralasciamo i dettagli e le scaramucce del momento e diamo per scontato che il lettore conosca la sostanza dell'accordo e di come si è arrivati ad esso.
[In Depth] Torture report prompts APA apology
Space junk collision scare forced ISS crew to evacuate
mi hai fatto piangere
Per quello che può valere la mia opinione, io sto con Alberto Biraghi, che nella vicenda di Angela Merkel e della ragazza palestinese piangente fa notare che la cancelliera ha scelto di seguire le regole ben conscia che da un lato se avesse detto “ghe pensi mi” avrebbe sicuramente migliorato la propria immagine, ma dall’altro avrebbe commesso un’ingiustizia nei confronti di tutti gli altri profughi che non sono sufficientemente telegenici da far parte del pubblico di una trasmissione televisiva.
Hundreds sign letter criticizing Science for reinforcing “damaging stereotypes”
After an advice columnist for Science Careers suggested a postdoc “put up with” an adviser’s wandering gaze in June, and an author of a piece in Science partly credited his success to his wife (a Ph.D. scientist) who assumed “the bulk of the domestic responsibilities” in July, some readers have gotten fed up. These examples are two of four […]
The post Hundreds sign letter criticizing Science for reinforcing “damaging stereotypes” appeared first on Retraction Watch.
First robust genetic links to depression emerge
First robust genetic links to depression emerge
Nature 523, 7560 (2015). http://www.nature.com/doifinder/10.1038/523268a
Author: Heidi Ledford
Discoveries energize hunt for genes connected to mental illness.
Don’t distort policy in the name of national pride
Don’t distort policy in the name of national pride
Nature 523, 7560 (2015). http://www.nature.com/doifinder/10.1038/523257a
Author: Dyna Rochmyaningsih
Dyna Rochmyaningsih offers a lesson from Indonesia on what can go wrong when governments use research to make a country look good.
Austerity bites
Austerity bites
Nature 523, 7560 (2015). doi:10.1038/523255b
If the UK government is serious about science, now is the time to prove it.
Sexism: Mind the gap in Hunt responses
Jacopo.bertolottiA sad example of feminism gone bad.
Sexism: Mind the gap in Hunt responses
Nature 523, 7560 (2015). doi:10.1038/523290b
Author: Rebecca Williams Jackson
In my view, you use your publishing might irresponsibly in presenting Alessia Errico's article 'Judge by actions, not words' as the sole female riposte to Nobel laureate Tim Hunt's misogynistic remarks (Nature522, 393;10.1038/522393a2015).Besides running contrary to the
Why we are teaching science wrong, and how to make it right
Jacopo.bertolottiThe idea looks shiny and nice, but I can see so many problems with it I don't know where to start.
(Maybe I can start from the fact that, afaik, there is not data-based evidence that these gimmicks really improve student's understanding)
Why we are teaching science wrong, and how to make it right
Nature 523, 7560 (2015). http://www.nature.com/doifinder/10.1038/523272a
Author: M. Mitchell Waldrop
Active problem-solving confers a deeper understanding of science than does a standard lecture. But some university lecturers are reluctant to change tack.
L'UE è un'enorme Padania
Lo è almeno per molti della mia generazione, che guardavano all'Europa come all'orizzonte di fuga dal bassissimo livello della politica italiana. Per anni abbiamo invocato un'Europa che ci salvasse dalla grettezza dei parvenus leghisti, e oggi scopriamo che a nord della Padania non c'è necessariamente più welfare e libertà, ma una Padania altrettanto gretta e parvenue, moltiplicata per venti. La retorica contro il sud fannullone e parassita la conosciamo bene; l'ansia dei popoli appena approdati al benessere occidentale, che sospettano di poterlo perdere da un momento all'altro, non dovremmo faticare molto a capirla. A non volere un'Europa unita nella buona e nella cattiva sorte non sono tecnocrati e banchieri - ai quali anzi si può rimproverare di aver fatto un passo più lungo della gamba, mandando avanti una moneta unica nella speranza che creasse le premesse per qualcosa di più solido - ma gli europei. Non tutti, no, ma la maggioranza. Quella che in democrazia decide, ahinoi.
Anomalous self-diffusion in a freely evolving granular gas near the shearing instability
Author(s): J. Javier Brey and M. J. Ruiz-Montero
The self-diffusion coefficient of a granular gas in the homogeneous cooling state is analyzed near the shearing instability. Using mode-coupling theory, it is shown that the coefficient diverges logarithmically as the instability is approached, due to the coupling of the diffusion process with the s…
[Phys. Rev. E 92, 010201(R)] Published Mon Jul 13, 2015
Storage and retrieval of vector beams of light in a multiple-degree-of-freedom quantum memory
Article
Exploiting the full structuration of light fields for storing multiple degrees of freedom holds great promise for applications in classical and quantum optics. Here, the authors demonstrate the storage of spatio-polarization-patterned beams into an optical memory, and its retrieval at the single-photon level.
Nature Communications doi: 10.1038/ncomms8706
Authors: Valentina Parigi, Vincenzo D’Ambrosio, Christophe Arnold, Lorenzo Marrucci, Fabio Sciarrino, Julien Laurat
Diagrammatic and asymptotic approaches to the origins of radiative transport theory: tutorial
Jacopo.bertolottiStrange to find a tutorial on JosaA. But it might be a useful tutorial.
The radiative transport equation (RTE) is used widely to describe the propagation of multiply scattered light in disordered media. In this tutorial, we present two derivations of the RTE for scalar wave fields. The first derivation is based on diagrammatic perturbation theory, while the second ... [J. Opt. Soc. Am. A 32, 1475-1484 (2015)]
07/13/15 PHD comic: 'Dante's Inferno, Academic Edition'
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title:
"Dante's Inferno, Academic Edition" - originally published
7/13/2015
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OGM, una battaglia già persa
Per puro caso mi sono imbattuto in questo video sugli OGM di Scihow, un ottimo canale Youtube che spiega la scienza in modo semplice e diretto. Il titolo del video, Why are GMOs bad?, è volutamente provocatorio, e il presentatore lo mette subito in chiaro fin dall’inizio. Gli OGM infatti non sono intrinsecamente “malvagi” e ci spiega in modo efficace perchè semplicemente spiegandoci cosa sono gli OGM. Perchè per capire la questione scottante degli OGM non ci vuole molto: basta sapere cosa sia un OGM. Sfortunamente per sapere cosa sia un OGM bisogna sapere cosa sono: una proteina, un gene e in definitiva l’evoluzione. Ma non basta, bisogna anche sapere cosa è l’agricoltura e la sua storia. Una volta compreso tutto questo parole come “contaminazione OGM” diventano vuote, senza senso. E si comprende che perfino la definizione di OGM non sia altro che una tautologia: tutti gli organismi sono modificati geneticamente. Ma se non si comprende tutto questo, si rimane in balia dei ciarlatani di turno e si diventa schiavi della paura dettata dall’ignoranza. Si incomincia perfino a criticare chi cerca di spiegare che gli OGM non sono intrinsecamente malvagi accusandoli di essere al soldo della Monsanto, come molti commenti al video dimostrano. Se pensate che gli OGM vi facciano male per il semplice fatto che sono OGM sarebbe inutile da parte mia dirvi che vi sbagliate o che ignoriate le basi della biologia: mi direste che sono saccente, mi accusereste di essere pagato dalla Monsanto o peggio. E, ironia della sorte, mentre lo fate vi mangiate una bistecca di manzo nutrito con mais OGM.
Comments off.
Rare breed: Linux Mint 17.2 offers desktop familiarity and responds to user wants
Jacopo.bertolottiSooner or later I will have to try Mint
These days, the desktop OSes grabbing headlines have, for the most part, left the traditional desktop behind in favor of what's often referred to as a "shell." Typically, such an arrangement offers a search-based interface. In the Linux world, the GNOME project and Ubuntu's Unity desktop interfaces both take this approach.
This is not a sea change that's limited to Linux, however. For example, the upheaval of the desktop is also happening in Windows land. Windows 8 departed from the traditional desktop UI, and Windows 10 looks like it will continue that rethinking of the desktop, albeit with a few familiar elements retained. Whether it's driven by, in Ubuntu's case, a vision of "convergence" between desktop and mobile or perhaps just the need for something new (which seems to be the case for GNOME 3.x), developers would have you believe that these mobile-friendly, search-based desktops are the future of, well, everything.
There are, however, some holdouts. These desktops defiantly stick with the traditional task bar and start menu-style interface. Apple's OS X has thus far been surprisingly conservative about changing its basic metaphors, but then the company has iOS to tantalize developers.
Read 35 remaining paragraphs | Comments
Saturday Morning Breakfast Cereal - The Village and the Tower

Hovertext: This comic is an allegory for, of course, the 1896 presidential elections.
New comic!
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