Semiconductors slow light

-
In a universe subject to the laws of evolution, it may seems open to question whether anything stays the same forever, "forever" being the sort of length of time during which evolution tends to play a trick or two. Having said this, the speed at which light likes to zip around (299,792,458 m/186,281 mi per second through empty space) is a good bet for a permanent feature of whatever the universe will be in the future.
This, of course, does not mean that light cannot travel more slowly. Researchers at Imperial College (London) have just found out how you can actually slow it down. Pass light through a layer of wafer-thin films of semiconductors, and you can make it travel at less than 1/40th of its speed in empty space. They hope to bring it to a complete standstill. This would perhaps satisfy Faust, and his desire for that unique, suspended moment when one could say "halt, you are beautiful". It also means that you can finally travel faster than (slowed down) light. Of course, being able to control the speed of light is excellent news for any future optical ICT.

Comments

Post a Comment

Popular posts from this blog

The Loebner Prize from a judge's perspective

-
Image
This year, for the first time in its history, the Loebner Prize competition was held in England, at the University of Reading to be precise. It was organised by Kevin Warwick and Huma Shah. Independently of whether Turing might have been pleased (he was not well treated in this country, recall?), there was a satisfying sense of “coming home” of the Turing Test (henceforth TT ). Expectations were high, and they very highly advertised too. The meeting was perfectly organised. Having been invited to play the role of a judge, together with several other colleagues, including two members of the IEG , Mariarosaria Taddeo and Matteo Turilli ( here are their pictures and Rosaria's interview ) , I enjoyed the opportunity to see from close-up the machinery and the TT . It was intriguing and great fun. Because there were interviews with the BBC and other things going on, and because we were also supposed to take part in the parallel AISB Symposium on the TT , I had time to test only...
Read more

Mind the app - considerations on the ethical risks of COVID-19 apps

-
[22 April update: at the Digital Ethics Lab (OII, University of Oxford) we have elaborated a list of 16 questions to check whether an app is ethically justifiable, the full article, open access, is available here ] There is a lot of talk about apps to deal with the pandemic . Some of the best solutions use the Bluetooth connection of mobile phones to determine the contact between people and therefore the probability of contagion. In theory, it may seem simple. In practice, there are several ethical problems, not only legal and  technical ones . To understand them, it is useful to distinguish between the validation and the verification of a system.  The validation of a system answers the question: "are we building the right system?". The answer is no if the app is illegal,  for example, the use of an app in the EU must comply with the GDPR; mind that this is necessary but not sufficient to make the app also ethically acceptable, see below; is unnecessar...
Read more

Onlife: Sulla morte di Corman McCarthy e "the best writers" della letteratura americana

-
Image
Corman McCarthy è stato descritto da alcuni come il più grande scrittore americano di [aggiungere qui un numero di secoli, oppure "la nostra epoca", oppure "una generazione" o semplicemente "sempre"]. Siccome sono insipiente, e lo avevo solo sentito nominare ma mai letto (ma i mie amici come mai non me lo hanno mai consigliato? che ci stanno a fare? O almeno Amazon, visto il numero di libri che compro, un "you may also like" lo poteva sputare no?), sono andato a vedere chi fosse. Ho letto un po' di cose su di lui, tutte molto interessanti. E poi mi sono chiesto chi rientra oggi in una lista più o meno accurata degli scrittori americani più importante degli ultimi 100 anni. Insomma, se uno dice, per esempio, "è morto il più grande scrittore americano del secolo" ti viene il dubbio di ricostruire la competizione gli ultimi cento anni. Le posizioni sono ovviamente e come sempre discutibili, ma mi è stato utile ricordare a chi si sta co...
Read more

"Notes to myself" available on Amazon

-
Image
"Notes to myself" are now available as a little book on Amazon: - ebook shorturl.at/crV09 free for kindle unlimited or  £2.50, lowest rounded price allowed by Amazon - paperback on Amazon: shorturl.at/ahvxY   $4, lowest, rounded prize allowed by Amazon MANY THANKS to everyone who sent suggestions and notes of encouragement.  I hope it won't disappoint you.
Read more

The fight for digital sovereignty: what it is, and why it matters, especially for the EU

-
This article is forthcoming in Philosophy & Technology 33.3 (September) 2020,  as Editor Letter. Digital sovereignty seems to be something very important, given the popularity of the topic these days. True. But it also sounds like a technical issue, which concerns only specialists. False. Digital sovereignty, and the fight for it, touch everyone, even those who do not have a mobile phone or have never used an online service. To understand why, let me start with four episodes. I shall add a fifth shortly. 18 June 2020: the British government, after having failed to develop a centralised, coronavirus app not based on the API provided by Google-Apple,  gave up, ditched the whole project (Burgess 19 June 2020), and accepted to start developing a new app in the future that would be fully compatible with the decentralised solution supported by the two American companies. This U-turn was not the first: Italy (Longo 22 April 2020) and Germany (Busvine and Rinke 26 April 2020, Lom...
Read more

Le tre funzioni del linguaggio digitale e le loro conseguenze

-
Image
(Questo testo è la Prefazione al volume: Linguaggi nella società e nella tecnica, 1968-2018 - Atti della giornata di studi organizzata dall’Associazione Archivio Storico Olivetti, in occasione del centenario della nascita del fondatore Camillo Olivetti, per riprendere e attualizzare i temi del convegno internazionale sui “linguaggi nella società e nella tecnica” promosso e organizzato nel 1968 dalla Società Olivetti. Milano, Fondazione Giangiacomo Feltrinelli, 15 Ottobre 2018). * * * Nel 1988, grazie a una borsa di studio dell’Università di Roma La Sapienza, fui ammesso come visiting student all’Università di Warwick, per studiare con Susan Haack, una delle più famose docenti di filosofia della logica. Tra i tanti ricordi, c’è quello di giornate senza fine, passate tra la caffetteria e i laboratori del campus, dormendo poco e lavorando senza sosta, scrivendo la tesi di laurea e facendo girare programmi di logica su uno dei tantissimi Olivetti M24, sempre disponibili, ad ogni ora e in...
Read more

On the importance of being pedantic (series: notes to myself)

-
Image
They say that to call someone pedantic is an insult. I'm not so sure. True, someone pedantic is obsessed with minor details, small errors, or tiny imperfections. And a pedantic is also someone who cares too much about all such things not to let you know about them, advising or correcting, disagreeing or disapproving. And yes, if you are a pedant, you are more than just occasionally pedantic. This can happen to anybody, the excessive emphasis on some narrow or boring detail being a tendency we all share when it comes to matters about which we care very much. But if you are a pedant, being pedantic is your daily stance, your intrinsic nature, your way of living. You are always, consistently, reliably, systematically pedantic, from the moment you wake up, about the exact place where the slippers should be next to your bed, all the way to the moment you go to sleep, and the exact place where the phone should be placed to recharge. If you are a true pedant, no detail is too trivial, no ...
Read more

On the art of biting one's own tongue (series: notes to myself)

-
The art of biting one's own tongue consists in the ability not to engage when someone says something unpleasant, untrue, malicious, or abusive about you. Instead of answering a biased question, arguing against a ludicrous opinion, complaining about an abusive message, correcting a meaningless error, countering a fallacy, explaining a patent mistake, objecting to a groundless criticism, rectifying a willful misrepresentation, rejecting an insinuation, responding to a provocation, retorting to a nasty remark, replying to an offensive allegation, … in short, instead of engaging with your mindless interlocutors you simply ignore them and do absolutely nothing, not even acknowledging that you might have received their communication, not even sharing a “no comment”, just silence. As far as they know, you might have never got the email, read the tweet or the Facebook comment, seen the Instagram picture. If you bite your own tongue appropriately, for them their communication might have nev...
Read more

(revised on Medium) On a sachet of brown sugar (series: notes to myself)

-
Image
Mid-morning, somewhere in Italy. Seating at a bar, in an elegant square, summery weather, a kind breeze, refreshing. An espresso macchiato comes with a brown sachet of sugar, to be added if you wish. I look at it. I look around. I have time to think. How do people deal with this task? Can one divide people, the sugary kind, into types according to how they open a sachet of sugar? A student, with interesting tattoos on her left shoulder, opens it by pinching the two sides and pulling them, gently ungluing the sachet. It requires her to use four fingers, each couple pinching a side of the sachet. She is attentive and careful. She better be. I know that feat is demanding. Too much force and the sachet may give in abruptly, spreading the sugar everywhere. Too little, and the little shell will hold on to its content and won’t be convinced to release its treasure. I love the cautions determination. She puts her hands together, palms touching at the bottom as if praying, to measure the effort...
Read more