Mark Steadman - 30-Second Coding: The 50 essential principles that instruct technology, each explained in half a minute

The 50 essential principles that instruct technology, each explained in half a minute

Editor

Mark Steadman

Contributors

Adam Juniper

Suze Shardlow

Mark Steadman

Illustrator

Nicky Ackland-Snow

Mark Steadman

Code is one of the most significant building blocks in modern society. Every time we send an emoji to a friend, were sending a tiny piece of code (a string of letters and numbers) across a virtual wire. That string of numbers and letters, called hexadecimal code, is then read by our friends phone and associated with an image. When we pick up the phone to talk to our friend, code converts our analogue voice to digital data, which is encoded at one end and then decoded at the other.

What we call code is a set of instructions, written in a particular language. That language depends on a number of things, like how easy it is for us humans to read and write it, how quickly a computer can understand it, the number of other computers that speak the same language and the features that language provides. Coding (or programming) can be as simple as adding two numbers together, or as complex as constructing a vast neural network that can perform complicated machine learning tasks. Code can enable mass change within a society, or it can help you rescue a few minutes from your busy day.

You dont need to have aced your maths exams in order to be a great coder. As long as you can think logically, putting one thought in front of the other, you can code. Nor do you need to memorize thousands of obscure commands, because most of us still turn to Google when we cant remember how a particular aspect of our programming language works!

You dont even need what you might consider a traditional computer in order to write code. A tablet or a smartphone will do, and there are apps that can help you learn, and achieve practical results. In this book well cover the key events in the evolution of computer programming, from the first-ever human computers to modern cloud infrastructures that can help scale bedroom businesses up to massive corporations.

Coding is no longer the preserve of the stereotypical basement nerd. Its everywhere, from those blocky square barcodes that we scan with our phones, to the encryption that keeps our WhatsApp conversations from being seen by prying eyes. Its the job of these pages to open your eyes to that wider world so you can use it as you choose, whether thats to build the next TikTok or just understand why its a good idea to turn the computer off and on again.

A tour of this book

In this book we present the ideas closest to the hearts of computer programmers (you can add your own joke about a well-known science-fiction franchise here). In academic circles, what you might know as programming is known as computer science, and it is a subject that isnt that old. For that reason, weve begun by devoting a whole chapter to the emergence of the computer as we understand it today, before breaking down the means by which we can instruct them. Whether its introducing the Difference Engine or face detection, each entry is broken into several parts. The centrepiece is the 30-second code the explanation itself. If youre short on time, the 3-second bit squeezes the essence of that into a single sentence, while the 3-minute byte offers a broader context.

Computing is also more about the people involved than you likely imagined the first time you saw the blue screen of death. For that reason, this book introduces many of the names behind innovations in code and computing in general. Check out the 3-second biographies and youll find a little more about many of the big names past and present. The book also features more detailed profiles of some folk who youve likely heard of even beyond the geek-o-sphere!

GLOSSARY

algorithmThe term for the mathematical aspect of a computer program; often an over-simplification. For example, Google is often described as having an algorithm in the singular, but many aspects go towards the systems ranking of websites.baseIn maths, the base is the number on which the counting scale is based. Base 10 means writing numbers using ten symbols, including zero, so 09.Bernoulli numbersNamed for mathematician Jacob Bernoulli. He described a probability the same each time being calculated over repetition of the same event, for example a coin toss or dice throw.Boolean logicIn mathematics, something that is Boolean (such as the result of a certain formula) can have only two states: true or false. The term leapfrogged into computer science not just to refer to early systems but, for example, if you encounter a checkbox on a web form itll likely be linked to an on/off or true/false field in a database.binaryLiterally means composed of two things, or having two parts. In computing, a system of counting that uses base 2, and can be depicted: 0, 1, 10, 11, 100, 101, 111, 1000 and so on.bitA bit may only have two states: on or off (usually represented as 0 or 1). The word is a portmanteau of binary digit.DOSDisk Operating System, as opposed to DoS (denial of service a cyber attack).floating pointA method of mathematical representation for real numbers that are especially large or small, which takes the form [significand] X [base] to the power of [exponent]: 2.5951 X 104 = 25951. You might also choose a limit on the number of digits in the significand to reduce the overall computational load on the computer limit it to three decimal places and we would only record 2.595*104 (in code * = multiply).general-purpose computerA computer that can be programmed to carry out different operations (traditionally arithmetic or logical). Earlier devices could perform only the operation they were designed for.loopIn programming, a section of the program repeated (either until a condition is met or, by mistake, infinitely causing the program never to end).memoryThe element of a computer that stores information for the active program, as opposed to storage.operating systemSystem software that manages the computer hardware, provides common resources for applications, and allows the launching and termination of applications.