L’énergie, en poésie

Et si je prenais le Français
Cette fois pour te parler
D’une chose que je tiens à cœur
Et qui se trouve dans un réacteur
Se trouve aussi dans l’eau
Dans les choses tombées en bas
Et celles qui partent du haut

Cela s’appelle l’énergie
Et je sais que t’as envie
De ses mystères connaître
Car tout le temps ça semble paraître
Dans les news et les discours
que les gens te font autourEnergy_Types_ImageÉlectrique, thermique, chimique,
Solaire, nucléaire, éolien,
C’est quoi tous ces machins?
Et ben c’est pas si lourd que ça
Une chose qui n’est pas là
Du coup elle y est bien
C’est pas qu’on l’ait crée
Elle a juste un peu changé
D’une forme à un autre type
et comme ça ainsi de suite

On dirait de la monnaie,
T’achètes ce que tu veux:
T’as envie de mouvement?
Maintiens fixe ton volant
Tu fonces à fond sur la pédale
Et ta vitesse n’est plus égale
Avec l’essence dans ton moteur
On fait un peu comme dans le réacteur
T’empruntes quelque chose, elle se transforme
T’obtiens une autre, ce qui est énorme
Le bilan est respecté
C’est pas que t’as triché
Tout en fait est conservé

En fin j’ai pris le Français
Encore une fois pour te parler
de la Nature et son charme infini
duquel nous aussi on fait partie
Cela devrait nous rappeler
Qu’est bien plus riche la réalité
Continuons ensemble à en parler
Toi et moi, tous les deux
Moi je veux bien et toi, tu veux?

Cutting funds to scientific research: whose problem is it?

European Commission reveals details of proposed cuts to science. This is not new, unfortunately. However, what is worse is that the answer to these cuts from the scientific community is the same as always: it’s an inevitable fatality of the crisis and the lack of understanding of our representatives in government.

In the article, dated January 15, we read:

Research advocacy organizations lobbied last month to protect Horizon 2020, but their response this week has been muted. “I’m surprised that there isn’t a louder outcry and no clearer opposition from the scientific community,” Hans-Olaf Henkel, a member of the European Parliament, told Science|Business. “What are these ministers for research, presidents of science organisations, and scientists themselves doing? Where is the outcry by all European Nobel laureates?”

It would seem a few scientific organizations have protested just recently: it’s been through a letter addressed to the European Commission, the same who have proposed the cuts, so I cannot help finding it funny. You wanna change the minds of political representatives? You gotta change the minds of their constituency! If the public is not onboard with science as a mission for society we will continue to witnees this sad game of letters exchanged by higher-ups, that delivers absolutely nothing.

I believe the problem is in thinking it is up to Nobel Laureates to efficiently lobby and save the day for science. Defunding research, at this point, is clearly not a matter of technical merit, it is rather due to how the public perceives the social utility of research. The scientific community should undertake a serious campaing for engaging the public, for example through the many activities I propose here: http://arxiv.org/abs/1210.0082. A trademark of my strategy is to adopt the audience’s language and appeal to its own interests. Just like what is done in marketing. Therefore it is not a heresy to mix scientific content with languages that are either non-scientific or even non-verbal, including theatre, dance, video-games, comics or rap music.

A key element is to look at communications as something that concerns a whole university instead of just a single scientific group or department. Notably by building collaborations among them, university departments will be able to take full advantage of the multi-disciplinary nature of an education institution. Numerous, ready-to-use examples are presented in my white paper, that do not necessarily cost more money than the existing budget available to departments. Initiatives range from a dance show about black holes to translating existing material and citizen science. In so doing a university turns the necessity of reaching out into an investment for itself: it could establish itself as unique in the education panorama, providing its students with a diverse portfolio of work experiences and educating them toward creativity. If, and only if, the Ivory Tower of knowledge opens its doors, it becomes a better known and more attractive place, whose usefulness and proximity to the public are shared concepts. Only at this point it will be possible to efficiently lobby for science at political assemblies because it will be the public to require it as a right to its wellbeing, in the present and the future.

 

Questa è la scienza, lor signori

Prendo la penna, la poggio sul foglio
penso un po’ e poi scrivo ciò che voglio
Anzi no, non è un’opinione:
È solo il frutto della ragione
Prende forma da un rivolo nero
Descrive una mela che cade, un buco nero
Succede lì, lo affermo qui,
Così vicino, così lontano
Eppure è vero, lo tocco con mano.

Affermare per poi verificare,
Indagare, sperimentare,
progredire, ricominciare:
Questa è la scienza, lor signori
E non c’è modo di farla fuori.
Il dato s’interpreta, non si cancella
E non perché lo dice Umberto Cannella.
È valido come un mantra
Ma la religione non ci entra.

L’Universo per lo più è ancora oscuro
E a volte si sbatte contro un muro:
Tutto questo è un po’ frustrante
Ma ancor di più è stimolante.
Nessuno riesce a prevedere
Fin dove la curiosità può far volare
Ma se ci si lascia trasportare
Si è sicuri di arrivare
Da qualche parte inaspettata
Nuova, reale e inesplorata

È da lì che poi ci si gira
E il cammino si rimira;
Si pensava di aver sognato
E invece tanto si è guadagnato:
Comprensione, cognizione,
Una nuova spiegazione
Che un fenomeno descrive
Ed è qualcosa che poi vive
Applicata a destra e a manca
Rende la vita meno stanca.


[ Questa è la mia terza poesia, le precedenti sono:
– “Che ce frega der bosone?
– “Ode to the Higgs
buona lettura! ]

The Perils of NOT Romanticizing Physics

A couple of weeks ago the Wall Street Journal featured an article titled “The Perils of Romanticizing Physics“, from Dr Ira Rothstein, professor of theoretical physics at Carnegie Mellon University in Pittsburg.

I had the chance to meet Ira in my past life as a researcher, when I was working toward my PhD at the University of Geneva, in Switzerland. He agreed to let me visit him in Pittsburg for a few weeks right before Christmas 2009, in order to interact about one of his many an expertise: effective field theory. This is a very powerful and elegant tool that helps physicists discern the intricacies of a problem and work them a set at a time. So far Ira has adopted this calculation technique with success in at least three fields: particle physics, black hole encounters and molecular interactions. I indulged a bit in this technical bit of information in order to stress how much I revere Ira’s work: I think he’s a cool, smart scientist and I especially like the multi-disciplinary character of his research.

This said I’m afraid I cannot spend similarly appreciative words for his op-ed on the Wall Street Journal, which was inspired by the public success of the movies “Interstellar” and “The Theory of Everything”. The main point of his article is kind of spelt out in the title: if scientists concede that the object of their life’s work is mistreated by Hollywood, the future of science is bleak. Still according to Ira, it would seem that everything else than a seminar is misleading about science, thus undermining its value and reputation. I think Ira’s hidden conclusion is that there should not be any opening to the public about science that is not guaranteed to be a ceremony conducted by the proper priests, the researchers who worked on that topic, who would guide a few chosen disciples to knowledge.

Ira’s words are more nuanced than what I’ve just said but I do not think I twisted their meaning: I wanted to bring these words to their consequences because it is big time the scientific community say explicitly what they think about the problem of public awareness and appreciation of science and research. For the sake of having this conversation with all my former colleagues I chose to take Ira as a representative of the community and his words as voicing their attitude toward the problem.
As you’ll understand from reading on, my point is completely opposite to Ira’s: we do need to romanticize physics! Beside saying why I will also provide a possible solution; this feature is probably the greatest difference between me and many of my former colleagues: they seem to have a problem with research funds being cut but they do not take the time to say what they intend to do about it and how.

I haven’t yet been able to watch the movie “The Theory of Everything” but I could watch “Interstellar” and I loved it! I’ve compared notes about it with some friends and we often found ourselves on opposite sides. I have no problem with that: a movie is a work of art and as such you are entitled to appreciate it or not according to your personal taste. What I really can’t understand is why scientists have to evaluate the movie as if it were a seminar on the subjects of gravity and black holes: they want scientific rigor and absolute completeness. This attitude is made more explicit in other online posts than Ira’s, which I found completely missing the point of the movie.

A quote from the first teaser of the movie Interstellar : I like to look at it as if it were an international anthem for mankind.

A quote from the first teaser of the movie Interstellar: I like to look at it as if it were an international anthem for mankind.

Interstellar is the brainchild of Dr Kip Thorne, Emeritus “Richard Feynman Professor” of Theoretical Physics at Caltech. He’s recently published a book about The Science of Interstellar, which I’ve just started reading. In the introduction of the book Professor Thorne lets us in on his motivations: I report them here for you to know what drives a scientist who’s able to make bets with Stephen Hawking and to win them.

<< As a child and later as a teenager, I was motivated to become a scientist by reading science fiction by Isaac Asimov, Robert Heinlein, and others, and popular science books by Asimov and the physicist George Gamow.

To them I owe so much. I’ve long wanted to repay that debt by passing their message on to the next generation; by enthusing youth and adults alike into the world of science, real science; by explaining to nonscientists how science works, and what great power it brings to us as individuals, to our civilization, and to the human race.

I hope that at least once you find yourself, in the dead of night, half asleep, puzzling over something I have written, as I puzzled at night over questions that Christopher Nolan asked me when he was perfecting his screenplay. And I especially hope that, at least once in the dead of night, as you puzzle, you experience a Eureka moment, as I often did with Nolan’s questions. >>

I believe this is the preferred way out of a bleak future where laymen cannot appreciate science because they simply ignore what it is and what its benefits are for us as a species.

Since I left research I’ve probably gone back to the pool of normal or simple people, so it won’t surprise my former colleagues to hear what I say next. Up until last Summer I vaguely knew what the Manhattan Project was about; then the tv series Manhattan was released and I fell in love with it. All of a sudden I found myself to want to know more about the whole Manhattan Project because I could see the human side of characters and their struggles. I am perfectly aware that most of them are fictitious but they are very relatable as humans and they tell a story I am eager to follow. This has only become possible for me after I’ve been able to interact with the Manhattan Project in a non-rigorous way. I don’t think my brain is peculiar from this point of view. Mankind’s brain is hard-wired like that. Ever since before we invented writing thousands of years ago, we’ve loved telling stories: they made part of our culture in the past and contributed to shape our present the way it is now.

Only by enthusing people, especially youth, by the means of a good story can we hope to have them feel the thirst for more good and sound science: the same thirst that keeps scientists like Ira up and running toward producing beautiful results.
It is not enough for scientists to preach to the converted. For this very reason I elaborated a holistic strategy to overcome the issue at stake. A trademark of my strategy is to look at science communications as something that concerns a whole university instead of just a single scientific group or department. Notably, by building collaborations among them, university departments will be able to take full advantage of the multi-disciplinary nature of an education institution. Numerous, ready-to-use examples are presented in my white paper that do not necessarily cost more money than the existing budget available to departments. Initiatives range from a dance show about black holes to rapping about science and scientific comics. In so doing a university turns the necessity of reaching out into an investment for itself: such a new paradigm could establish a university as unique in the education panorama, providing its students with a diverse portfolio of work experiences and educating them toward creativity.

Within this context and mindset finest scientists like Ira and science communicators like me will find themselves working together toward a common goal, the same goal professed by Kip Thorne: “how do I share my deepest love for science to everyone who’d listen”? coz that’s what you want to do when you’re in love: tell everyone. Just as a shy lover who’s lost for words turns to a poet to seduce his loved one, someone like Ira, whose work deserves to be properly supported and advertised, will benefit from interaction with a scientific poet such as myself.

I speak these words not in the hope of attracting more researchers to science: far from me to contribute to academic unemployment! What I’m aiming at is to have scientists on board with the mission of engaging the masses and involving them in the process of creating well-being for society, first and foremost through science. A few current job categories where I can see a career being positively inspired and uniquely impacted by science are:
– molecular gastronomy chefs and bartenders;
– programmers and tech entrepreneurs;
– radiography and oncology technicians;
– designers of special graphical effects for movies and video-games;
musicians, dancers, stylists and other artists working at the interface of their domain and science;
– last but not least, future science and math teachers.

You can't possibly have such a beautiful idea for a dress if you don't love science.

Lunar dress: you can’t possibly have such a beautiful idea for a dress if you don’t love science.

More than a single academic seminar, opening the scientific discourse to a Hollywood-type of conversation with the masses is poised to impact society. That’s why I say we do need to romanticize physics (as well as other sciences). I hope this discourse will move out misunderstandings about the aims of reaching out: physicists like Ira and science communicators such as myself have to get our hands dirty to change things for good and improve society, one outreach event at a time.

Further reading

On the Science of Interstellar
– An infographic about the Science of Interstellar

UPDATE 1

As soon as I published this article I sent an email to Ira to inform him I felt like answering his op-ed and, because I referred to him in person, I wanted to make him aware. In the spirit of my post I was hoping for a reply by him and I haven’t been disappointed. Truth be told I am not surprised he has gotten back to me: Ira’s a cool person, as I said in the introduction. His answer is:

I understand your note, but I think you exaggerated my conclusions.
I emphasized the importance of communication several times in the article and I also (multiple times in the article) talk about how wonderful it is that the public is entranced by modern physics. My point was more that we should not take the metaphors too literally, which I’m sure you agree with.
I also don’t think Hollywood mistreats science, as I note how great a job Interstellar did with the physics (at least till the end).
Perhaps the article was not clear enough on this point, and I certainly don’t think that EVERYTHING beyond a seminar is misleading.

I am thankful to Ira for taking the time to acknowledge my very long post. His op-ed article was much more synthetic than mine, which is probably why I haven’t been able to completely discern his main and only point: “that we should not take the metaphors too literally”.
What set me off in the direction I took is two-fold. I had honestly thought that his point on the proper imagery to convey science was more fundamental like, as I say in my article, “no imagery at all, coz that’s where problems come”. On this basis I thought I had recognized the repeated denial I’ve heard time and again by many of my former colleagues: “there should not be any opening to the public about science that is not guaranteed to be a ceremony conducted by the proper priests, the researchers who worked on that topic, who would guide a few chosen disciples to knowledge.”
Though I have had this feedback more than once by my former colleagues I cannot say I have had it from Ira, too. Being aware of this possibly risky generalization I specified that “For the sake of having this conversation with all my former colleagues I chose to take Ira as a representative of the community and his words as voicing their attitude toward the problem.” Let me stress once again that the negative feedback I got in the past from my former colleagues is real and, because it had not been explicitly justified, I felt an op-ed such as the one I thought Ira had written represented a timely occasion to have a deeper and more productive exchange of ideas.

Now that we’ve moved out misunderstandings about respective motivations we can deepen the conversation toward the solution of the problem I care the most: what shall we do about the lack of appreciation by the general public toward science in general and physics in particular? shall we adopt CERN’s strategy with Angels and Demons and take advantage of waves of public notoriety of physical concepts/figures to establish a dialogue with laymen? if not, what else and how/why?

UPDATE 2

These last 24 hours or so I’ve received interesting feedback about my article: some comments were against my interpretation of Ira’s op-ed on the Wall Street Journal, others in support. I have to conclude that it was indeed possible to read between the lines of Ira’s article and interpret them as farther reaching than what their author later told me.
As I said in my update, the hidden message I saw in the op-ed resonated with many previous instances of negative feedback against romanticizing physics that I had got in the past. It would seem I’m not the only one who’s had to listen to dry no’s in the face of viable and concrete avenues to be taken toward actually doing something about the lack of public appreciation of science, instead of just complaining. These avenues share something with movies of the like of Interstellar: they are light ways of enticing people toward wanting to get quantitative and deep about the physical sciences. Light avenues, not false ones. Such a delicate courting is unique in seducing toward science the unchosen ones, those who will not get to it no matter what, because they haven’t always had the penchant for math and physics. These are what I call the masses. These are the unconverted that scientists should preach to. Why? Because these are tax-payers, voters, parents or youth. These people might never fall in love with science unless we go look for them, instead of waiting for them to show up at the door of the Ivory Tower. In the case of youth this need is especially urgent: they might need science as a decisive turn in their lives, either to find a job or to fall in love with something and thus give meaning to their whole existence. This is why I care so much about having an honest and quantitative conversation about outreach with practicing scientists and people working in formal education: it is a matter for the future of a country, what’s more urgent than that?

How drawing a penguin can help cure cancer: physics diagrams as modern hieroglyphs and their applications

If you are a fan of The Big Bang Theory tv series you are used to laugh at Penny and Sheldon’s interactions, especially those when Doctor Cooper tries to explain physics to his blond friend.

 Sheldon and Penny during a discussion about particle physics; drawn on the blackboard, besides formulae, are pictograms known as Feynman diagrams, after their inventor Richard Feynman, physicist and Nobel Prize winner in 1965.

Sheldon and Penny during a discussion about particle physics; drawn on the blackboard, besides formulae, are pictograms known as Feynman diagrams, after their inventor Richard Feynman, physicist and Nobel Prize winner in 1965.

One such instance is captured in the picture above. If you look at it you can easily figure Sheldon say something like: “see, Penny: this equation accounts for the branching ratio of a top quark decaying into a W boson and a bottom quark, as depicted by the upper-left diagram”. Do you think Sheldon got into drawing to put himself in Penny’s shoes? Not at all: the pictograms on the blackboard are some serious piece of physics! They are known under the name of Feynman diagrams, after their inventor Richard Feynman, who first proposed their adoption in 1948 and later won the Nobel Prize thanks to, among other things, this visual handle on particle physics.

You don't get a postal stamp after you unless you've done something notable.

You don’t get a postal stamp after you unless you’ve done something notable.

Feynman was as much of an eccentric as his fictional colleague of The Big Bang Theory tv series: do you remember the episode “The Werewolf Transformation”, when Sheldon goes nuts and wakes up Leonard by playing bongos in the middle of the night? Well, Feynman used to play bongos, too (in fact, that’s probably where the authors of the series have taken inspiration from). However, quite differently from Doctor Cooper, Professor Feynman could drive a vehicle: this allowed him to have his van decorated with his own diagrams … how bloody cool!

Professor Feynman poses with his family in front of his van, which he decorated with instances of his very own visual handle on particle physics.

Professor Feynman poses with his family in front of his van, which he decorated with instances of his very own visual handle on particle physics.

But why would a scientist propose drawings to his colleagues? did they all get bored with their minds wandering? On the contrary: in the late 1940’s physicists were kind of stuck in their path to gain a better understanding of how the natural world works at an ever deeper level. Roughly speaking, they needed to know where to go next and how to reach their destination. That’s where the novelty of Feynman’s genius proved to be crucial: his diagrams provided the tools of a new language to formulate a new discourse.

Owing to their graphical character, Feynman diagrams bear resemblance to Egyptian hieroglyphs: just like that ancient pictogram system encoded a wealth of information in a single sign, a Feynman diagram encapsulates the description of an interaction among particles in a very clear and economic fashion; by means of this virtue, it is possible to streamline the computation of the measurable effect that a certain physical process has. Knowing what to compute and how were very much needed features at the time Feynman introduced his idea: the non-trivial advantage of adopting a common vocabulary lies in the univocal and universal standard of the naming this vocabulary provides; those who speak the same language are able to understand each other and, then, to communicate among themselves, sharing meaningful information.

Egypt Hieroglyphe4.jpg
Example of an Egyptian Hieroglyphe ” (licensed under CC BY-SA 3.0 via Wikimedia Commons).

As time passed, something very down-to-earth happened with Feynman diagrams and their adopters: when pondering about physical interactions, physicists began dubbing the configurations that particles assumed once arranged in a diagram, just like what we all do when we search for images of animals in the clouds. There are indeed particle interaction processes whose Feynman diagram resembles a bell, a sunrise, a tadpole, a seagull or even a penguin!

The Feynman diagram resembling a penguin.

The Feynman diagram resembling a penguin.

All this theoretical fun has brought physicists down the path recently crowned by the discovery of the Higgs boson, a.k.a. the God particle. Besides invaluable ideas, this endeavor was also made possible by the Large Hadron Collider, a machine whose name is inextricably linked to hadron-therapy, a branch of medicine that can accurately cure tumors lying deep in the human body.

A picture worth a thousand words. Radio-therapy employs X-ray photons, that is to say the same particles that make up visible light but with endowed higher energy. In their path to the tumor, X-rays deposit a non-negligible fraction of their radiation dose to healthy tissues. On the contrary, we can see from the picture that protons, the positively-charged constituents of atomic nuclei, are much more effective in reaching the deep-lying tumor, without damaging other body parts.

A picture worth a thousand words. Radio-therapy employs X-ray photons, that is to say the same particles that make up visible light but with endowed higher energy. In their path to the tumor, X-rays deposit a non-negligible fraction of their radiation dose to healthy tissues. On the contrary, we can see from the picture that protons, the positively-charged constituents of atomic nuclei, are much more effective in reaching the deep-lying tumor, without damaging other body parts.

More than sixty years after their proposal, Feynman diagrams are still largely employed in particle physics but not only: for example they are allowing new insight and better precision in calculating both the astrophysical signal to be expected when black holes collide and the modeling of molecular dynamics. Next time you see Penny trying to interpret some murky hieroglyph on Sheldon’s blackboard, think about these deep connections … after you have laughed, of course.

FURTHER READING

If you would like to know more about how the machinery of Feynman diagrams works you can take a look at the following references:
let’s draw Feynman diagams;
Physics and Feynman Diagrams.

For more fun, less mainstream uses of Feynman diagrams see:
– the ParticleZoo Feynman Diagram magnet set;
– the PhDComics’ Feynman Diagrams on Academic Interactions;
– the result of a Google search
art inspired by Feynman diagrams;
and much more …

A very passionate follower of Feynman diagrams chose to have one tattoed on his arm.

A very passionate follower of Feynman diagrams chose to have one tattoed on his arm.

Essere o non essere, vita da gatti (di Schroedinger)

Essere o non essere, questo è il problema, giusto? No, c’è di peggio, perlomeno per un fisico. Il problema è essere e non essere allo stesso tempo.
“Ok, allora smetto di leggere questo articolo perché non sono un fisico e non sto capendo niente.”
Un momento, please: posso spiegare, non è (complicato) come sembra. Ripartiamo con un altro incipit, uno un po’ più facile. C’era una volta un gatto, che non sapeva se era vivo oppure no; pardon, lui lo sapeva benissimo, erano gli altri a non saperlo.
“E meno male che ricominciavi facile!”
Un attimo ancora di pazienza, che fretta c’è? Tanto il gatto non scappa: non può andare da nessuna parte perché è stato chiuso in una scatola con del plutonio.
“Ok, adesso basta sul serio: chiamo la protezione animali!”
Ah perché, non l’ho detto?
“Che cosa?”
Che è un esperimento fittizio.
“fi’ che?”
Fittizio, immaginato, teorico, uno di quei “che succederebbe se …?” che i fisici teorici usano per ovviare alle ristrettezze dei fondi alla ricerca ;-)
“Cioè? non solo voi fisici sprecate soldi con delle elucubrazioni ma in più ve la cantate e ve la suonate?”
Primo: non so cantare. Secondo: teoria non vuol dire fantasia. In fisica, come nelle altre scienze sperimentali, una teoria dei fenomeni naturali rappresenta l’insieme delle spiegazioni di quei fenomeni, in particolare le spiegazioni più accurate delle quali si dispone fino a prova contraria.
“Va bene ma che ne è del gatto? L’avevamo lasciato da solo, chiuso dentro a una scatola: se non è morto per il plutonio sarà schiattato per mancanza d’aria. Non possiamo andare a controllare?”
E qui casca l’asino, anzi il gatto. Che intendi per “andare a controllare”?
“eh, che … si va e si vede.”
Cioè, spiegati meglio?
“Ma come, non sei uno scienziato? Mi pari un po’ lento.”
Preferisco rigoroso: “x” sta a “y” come io sto a me, come ama dileggiarmi mio cugino. Se non chiarisci cosa intendi, come fai ad essere smentito? In fisica chiarire vuol dire definire. Quando tu dici “si va e si vede”, quel vedere implica una tua interazione col sistema.
“Abbasso il sistema!”
Il sistema fisico è quello che stai osservando: la scatola con dentro il gatto.
“Io non sto osservando proprio niente”
Proprio niente niente no: stai osservando me mentre parliamo. In questo caso però non interferisci con quello che sono e come mi comporto: sei un osservatore passivo. Se invece vai dove abbiamo riposto il gatto, che fai per vedere se è vivo o morto?
“Vado e scuoto la scatola”
Mo la chiamo io la protezione animali!
“Allora lo chiamo: micio, micio, micio?”
Non ti sente.
“Perché, è un gatto sordo? Non potevi pensare un gatto standard?”
Veramente non l’ho pensato io ma un certo Schroedinger.
“Chi è, un ministro della Merkel?”
No, è un fisico del ‘900.
“Lo conosco: aveva mica un gatto?”

Schrödinger

Spiritoso. Comunque mi pare di sì ma non gli ha fatto niente di male. Se n’è servito solo a livello teorico, per dare un’idea concreta di un problema, un’immagine che ci parlasse in maniera chiara.
“Ma se non ho capito ancora niente!”
Ok, arriviamo al sodo. Per verificare lo stato di vita del gatto devi aprire la scatola: così facendo, agisci sul sistema diventandone parte: non sei più un osservatore passivo. Questa tua azione determina una conseguenza: è come se il sistema “scegliesse” la condizione nella quale manifestarsi a te solo nel momento in cui interagisci con esso. Prima di allora il gatto potrebbe essere sia morto …
“Io non ho fatto niente, giuro!”
che vivo …
“Sono riuscito a salvarlo!”
Non ti agitare, parliamo solo di probabilità: ed è qui che casca il gatto.
“Non era già caduto prima? avrà pure nove vite ma il tuo parte svantaggiato.”
Stai buonino, ché ora ti rispondo.
“Veramente io non ti ho chiesto niente.”
Lo so ma io te lo voglio dire lo stesso. Quando ami qualcuno vuoi dirlo a tutti, giusto?
“Ti sei innamorato di un gatto? protezioneeeeeeeee”
Stolto! Volevo solo spiegarti perché ti dico tutte queste cose; poi giuro che concludo. Dicevo: quando sei innamorato di qualcuno o profondamente appassionato di qualcosa, ne parli senza che te lo si chieda, perché è una cosa bella da condividere e può servire da invito allo sperimentare altrettanto. Tornando all’esperimento, l’esimio signor Schroedinger si era posto il problema del gatto per capire meglio il mondo delle particelle: in particolare, se la natura probabilistica della realtà microscopica confligga o no con quella deterministica del mondo macroscopico.
“Ahhhh, ora sì che è chiaro!”
Ci sto arrivando. Il nodo della questione è appunto che per noi un gatto è vivo oppure morto: si può trovare nell’una o nell’altra delle due condizioni in maniera mutualmente esclusiva. Per le particelle microscopiche invece la vita è incerta: possono sia “essere” che “non essere” qualcosa, con diversi gradi di probabilità per ognuna delle condizioni. Quale sia effettivamente lo stato di una particella lo si sa, in parte, solo osservandola, il che implica una interazione con essa. Solo in parte perché questa interazione rende sì apparente una condizione della particella ma ne modifica altre. Si riesce quindi a conoscere una caratteristica della particella a scapito di un’altra, che resta indeterminata. Questo costituisce il principio d’indeterminazione di Schroedinger, uno dei pilastri della fisica nel micro-mondo dei quanti di energia e materia, dove regna la probabilità. In questo nuovo mondo, il gatto, in quanto insieme di particelle quantistiche, dovrebbe mostrare delle caratteristiche di indeterminazione: ne consegue, quindi, che prima di venire osservato, il gatto è sia un po’ vivo che anche un po’ morto, allo stesso tempo. Non è che il gatto abbia fatto indigestione di pesce andato a male: è solo che sia la vita che la morte sono equiprobabili, fifty-fifty.

Schroedinger_Ket

Ecco allora perché è famoso il gatto di Schroedinger: perché incarna un paradosso. Dall’esperienza quotidiana sappiamo bene che lo stato del gatto non è per niente incerto o ambiguo: o è vivo (essere) oppure è morto (non essere). Dal canto suo, il plutonio o, meglio, i suoi atomi possono essere e non essere allo stesso tempo: finché non si va a vedere non lo si può sapere. Nella fattispecie dell’esperimento a scatola chiusa del gatto, una sostanza radioattiva, non necessariamente il plutonio, si trova nel contenitore insieme all’animale; completa il tutto un dispositivo che, se rileva radioattività, fa scattare un martelletto che rompe una fiala di veleno che uccide il gatto …
“Che alla fiera dell’est mio padre comprò”

Schroedinger_Cat

Eh eh eh, vedo che stavi seguendo. Guarda, mi è venuto in mente un esempio che fa al caso nostro. Hai presente quei biscotti al burro tipici del nord Europa?
“Quelli nelle scatole di metallo tonde?”
Proprio loro; ti ricordi che ci si faceva con quelle scatole una volta finiti i biscotti?
“Mia nonna ci metteva gli attrezzi per cucire”
Pure a casa mia. Ecco, se ti trovi davanti una di queste scatole chiusa, fino a che non la apri non puoi sapere cosa ci sia dentro: conterrà ancora i biscotti oppure sarà già stata riconvertita a un altro uso”
“Ah, mo ho capito; giuro!”

Biscotti_Schroedinger

Va be’, allora annamo a inzuppa’ i biscotti in un po’ di caffè ché te vedo provato; poi semmai riprendiamo il discorso.
“No guarda, non c’è bisogno: mi compro un cane.”
Va be’, mi rifaccio su chi legge, che ringrazio per la paziente attenzione e per i commenti. Vi propongo di guardare il video qui di seguito in cui Sheldon, pardon, il Dottor Sheldon Cooper spiega a Penny cosa è il gatto di Schroedinger.
Se voleste saperne di più, non esitate a chiedere ché vi rispondo … oppure no … oppure tutt’e due? chi vivrà vedrà (e saprà).