Bergamo 2013-2014 Lectures. 3a. Digital is our context - part 1

Our context is digital - part 1.The digital revolution,the Web, Tim Berners-Lee, standards, ISO, technologies, languages, protocols, channels

UniBg 44111 2013-2014 .:. IT for Tourism ManagersLecture #3a. Wednesday, November 27, 2013

Roberto Peretta

Università degli Studi di BergamoArea didattica di Lingue e Letterature straniereProgettazione e gestione dei sistemi turistici /Planning and Management of Tourism SystemsCentro Studi per il Turismo e l'Interpretazione del Territorio (CeSTIT)

What are we talking about?

UniBg 44111 2013-2014 .:. IT for Tourism Managers .:. Roberto Peretta .:. #3a 2

1. What does “digital” mean?2. “Being digital” as a 1995 book3. Is digital richer or poorer than analogue?4. Standards5. Technologies, languages, protocols, channels

Our context is digital - part 1

<html><head><title>The webpages’s title,on the top in the browser</title></head><body>The webpage’s content:what we’re telling the world,and the browser shows.</body></html>

What does “digital” mean?


Digital derives from the Latin word Digitus, meaning finger.In short, digital is what can be represented with numbers, which can be counted with fingers.Digital is opposed to analogue, which is related to what is not countable: what cannot be considered within a discrete set of elements.Digital refers therefore to discrete mathematics, working with a finite set of elements,while what is analogue is modeled by the continuum, that is mathematics dealing with infinite elements (countable or uncountable).


A real wave, and a digital wave



Mechanical vs. digital watches



A mechanical watch is analogue inasmuch as the position of each of its three hands (hours, minutes and seconds) can represent any of the infinite points forming the circle of the watch itself – points that cannot be numbered.In a digital watch, instead, only the figures which make up hours, minutes and seconds are usually represented – only the 86,400 moments (24 hours x 60 minutes x 60 seconds) making up the seconds of a day.

Photographs and pixels



A traditional photograph (a photograph based on a chemical film) consists of an infinite number of points in an infinite range of colours.A chemical photograph can be digitized (scanned, for instance) and then translated into a digital photo when its surface is represented as divided into a discrete number of “points” (usually small squares or rectangles called pixels),each of which reproduces onlyone colour in an available rangeof 16,777,216 (a combinationof 256 shades of red, 256 of greenand 256 of blue – according to thewidely used RGB colour model).

Waves and bits



Many technologies rely on digital to reproduce a wave (a sound or a light wave) that was originally analog.A modem – as those now currently used for fast ADSL connections – converts an analog sound signal that can be sent through telephone wires into a digital signal, of the sort requested by computers or other electronic devices working by bits (0/1).

Bits and bytes



A bit (a contraction of binary digit) is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states.These may be the two stable states of a flip-flop, two positions of an electrical switch, two distinct voltage or current levels allowed by a circuit, two distinct levels of light intensity, two directions of magnetization or polarization, etc.

The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits.Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer architectures.

“Being digital” as a 1995 book



“I am optimistic by nature. However, every technology or gift of science has a dark side. Being digital is no exception.The next decade will see cases of intellectual-property abuse and invasion of our privacy. We will experience digital vandalism, software piracy, and data thievery.Worst of all, we will witness the loss of many jobs.”

“We are not waiting on any invention. It is here. It is now. It is almost genetic in its nature, in that each generation will become more digital than the preceding one.The control bits of that digital future are more than ever before in the hands of the young. Nothing could make me happier.”— Nicholas Negroponte [MIT]

Is digital richer or poorer than analogue?



A few socially relevant consequences: Communication Technologies (modems, broad band, wireless...) Information sharing (the Internet, the Web, mobile phones...) Email (sent and received through the Internet) Music (Mp3, iTunes...) Photography (Kodak no longer manufactures chemical films) Satellite televisionIs digital a revolution?Yes!Digital has changed our lives.Nonetheless, digital is innerly poorer than analogueinasmuch as it conveys a simplified message.(This, by the way, may imply that digital communication is invariably poorer than personal communication.Let’s not forget it, when communicating through the Internet.)

The real thing is better…



The best way to communicate is meeting someone in person. When you call her/him through a videophone (or Skype) you miss at least the physical context around her/him. When you call her/him on the phone, you miss the physical context, and you don’t see her/him. When you send her/him an e-mail message, you miss the physical context, you don’t see her/him, and you don’t know when and where she/he will get your message. When you send her/him a text message, you miss the physical context, you don’t see her/him, you don’t know when and where she/he will get your message, and you must keep it short. When post something on the Web, you miss the physical context, you don’t see your audience, you don’t know when and where your audience will get your message, you must keep it short, and you don’t know – or know little of – your audience.Let’s not forget all this, when communicating through the Internet!

Standards

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UniBg 44111 2013-2014 .:. IT for Tourism Managers .:. Roberto Peretta .:. #3a

As every other widespread technology, digital technologies are based on standards.But what’s a standard?

As we already observed on November 12, when you think of standards you should think of different electric plugs in different countries, of electric tension (voltage), or octanes in gasoline, or …of the http, the html. International standards are standards developed by international standards organizations. International standards are available for consideration and use, worldwide. The most prominent organisation is the International Organization for Standardization, or ISO. International standards is one way of overcoming technical barriers in international commerce caused by differences among technical regulations and standards developed independently and separately by each nation, national standards organisation, or company.

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The ISOOur context is digital - part 1


As you should already know, some technology standards that are particularly relevant for our lectures – like the html, WAP, or Bluetooth – are official standards, internationally recognized.(WAP was even the result of a joint, previously planned effort among several companies, like Ericsson, Nokia, Motorola, Microsoft, Oracle, Vodafone, and Telefónica).We can consider those standards as de iure standards.Sometimes, however, standards exist de facto, although no official agreement has been reached about them.This is, for instance, the case of the portable document format, or pdf, developed by Adobe Systems Inc.Another de facto standard, for multimedia distribution on the Web, is the Flash platform, now owned by Adobe, but originally developed by Macromedia.

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De iure and de facto standardsOur context is digital - part 1


The most important language standard in our field is the html: the HyperText Markup Language, the language of the Web.It was devised by Tim Berners-Lee in 1989, while at CERN, the European Particle Physics Laboratory.From the year 2000, the HTML is an application of the International Standard ISO 8879W3C.The World Wide Web Consortium(W3C) is an international communitythat develops open standardsto ensure the long-term growthof the Web.The W3C is made up of memberorganizations, both from privatecompanies and the academy.

Html, and W3C Our context is digital - part 1



Tim Berners-Lee


http://www.w3.org/

A graduate of Oxford University, Tim Berners-Leeinvented the World Wide Web, an internet-basedhypermedia initiative for global information sharingwhile at CERN, the European Particle PhysicsLaboratory, in 1989. He wrote the first web clientand server in 1990. His specifications of URIs, HTTPand HTML were refined as Web technology spread.


The most important protocol standard in our field is the http: the HyperText Transfer Protocol.It is an application protocol for distributed, collaborative, hypermedia information systems.Http is the foundation of data communication for the World Wide Web.Just like for the html, Tim Berners-Lee and his team are credited with inventing the original HTTPand the associated technology for a webserver and a text-based web browser.Some more protocols are fairly commonon the Internet, like the e-mail protocolor the ftp, file transfer protocol.

ProtocolsOur context is digital - part 1



There’s something very important to understand – in depth.Behind all the perceived magic of the Web, Google, Facebook, Skype, the iPhones or the like, there’s technology.A lot of different technologies, frequently combined.(Ok… There’s a lot of marketing, too...)What we perceive as friendly chats, angry posts, poisonous gossip, a picture of our dog, a short message of love from our partner, a video from New York on Facebook, voice instructions on how to reach a place while driving, an instant cut-and-paste from Wikipedia to try to make a fool of a university professor, aretechnologies.They are not magic. They are chips, antennas, codes, monitors, keyboards, earphones, standards, patents, digital languages…They mimic human behaviours. Or, rather, some humans have designed them in order to let us humans communicate more.But they are technologies. Someone knows how they work.

TechnologiesOur context is digital - part 1


One last word you’re expected to become familiar with in the digital world – if you aren’t already – is channels.To put it according to Wikipedia, a “Communication channel is a transmission medium, e.g. a wire, or a multiplexed connection, e.g. a radio channel, used to convey an information signal from a sender to a receiver”.A less technical term than “languages” or “protocols”, “channels” commonly refers to the opportunity that a digital content can be distributed through different media to different audiences.If you shoot a video, for instance, your content can be delivered as a mastered CD sent through snail mail, an mpeg or wmv file attached to an e-mail message, an uploaded YouTube file, or a proper movie seen at home through a tv network or by a specific audience in a movie theater.The same digital file can be distributed through a lot of channels.

ChannelsOur context is digital - part 1


Bergamo 2013-2014 Lectures. 3a. Digital is our context - part 1

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