"You Are Not Expected to Understand This"

A fascinating book about the various way computers and coding have changed the world. Some essays are on the history of coding and others are on famous code hacks. Some essays touch on ethics, social justice, discrimination and cheats that coding has enabled. And, of course, one essay is one that infamous comment found in the Commentary on UNIX: "You are not expected to understand this."

What follows is a summary of each essay in the book.

1. The First Line of Code: a look at what may be the first lines of code written in history to control weaving looms using punch cards.

2. Monte Carlo Algorithms: Random Numbers in Computing from the H-Bomb to Today: on the history of Monte Carlo Algorithms, whose statistics and random numbers are used in many fields to estimate the future behaviours of systems in many fields.

3. Jean Sammet and the Code That Runs the World: on programmer Jean Sammet who (with Grace Hopper), pulled together early attempts at programming languages to come up with COBOL.

4. Spacewar: Collaborative Coding and the Rise of Gaming Culture: on the history of Spacewar, the first graphical computer game, and the culture (and joy) of hacking computers that came up around it.

5. BASIC and the Illusion of Coding Empowerment: on how BASIC enabled interactive programming for students on time-shared systems. But early on, this was only for entitled students, mainly the better-off white males in the US.

6. The First Email: The Code That Connected Us Online: the ability to send messages from one user to another on the same computer system was so in demand that the need to be able to send messages from one system to another was developed and became the email that we know today.

7. The Police Beat Algorithm: The Code That Launched Computational Policing and Modern Racial Profiling: the search for a technological solution to policing at a time when racial riots were rife would lead to the surveillance systems in use today.

8. "Apollo 11, Do Bailout": on the capabilities of the computer on the Apollo Lunar Lander that enabled the moon landing.

9. The Most Famous Comment in Unix History: "You Are Not Expected to Understand This": this comment, and others in source code, show the personalities and abilities of the people who wrote the code, and left such comments in the code as guidelines (or for fun) for future programmers.

10. The Accidental Felon: on the history of the Morris worm, the self-replicating code that bought down many systems in the early days of the Internet.

11. Internet Relay Chat: From Fish-Slap to LOL: on the propagation of the culture of leaving 'actions' as words on the early internet relay chat into today's social media, leading to postings of LOLs and other kinds of interactive reactions, as well as emojis.

12. Hyperlink: The Idea That Led to Another, and Another, and Another: the history of hyperlinks, which lead people from one document to another, ad infinitum.

13. JPEG: The Unsung Hero in the Digital Revolution: how JPEG works to compress digital images and how this would lead to the fingerprinting of images to individual digital cameras.

14. The Viral Internet Image You've Never Seen: refers to the notorious single pixel image file that appears (hidden) on webpages and emails to track who is fetching the information.

15. The Pop-Up Ad: The Code That Made the Internet Worse: written by the person who wrote the first pop-up ad, it talks about taking responsiblity for what you do with technology.

16. Wear This Code, Go to Jail: starting with the Perl code for the RSA algorithm printed on a shirt, it goes on to shows the problems with trying to do export controls or to restrict software.

17. Needles in the World's Biggest Haystack: The Algorithm That Ranked the Internet: on the ranking algorithm that lauched Google.

18. A Failure to Interoperate: The Lost Mars Climate Orbiter: the Mars probe was lost due to conversion bug between metric and imperial measurements. But the article points to the bigger problem of the decline in interoperability of current day software and applications due to business decisions (to restrict competition).

19. The Code That Launched a Million Cat Videos: viral videos of cats reacting to the iRobot Roomba vacuum cleaner helped to make it popular. But the software for the Roomba at the time, that controlled its somewhat random behaviour, also helped to make it beloved for the idiosyncratic way of cleaning a room.

20. Nakamoto's Prophecy: Bitcoin and the Revolution in Trust: on the development of bitcoin and the blockchain behind it that may yet revolutionize the way people trust one another and do business without a central authority.

21. The Curse of the Awesome Button: the development of Facebook's 'Like' button started off as a way to provide feedback on the social network. But it then became a way to track users as they moved from site to site.

22. The Bug No One Was Responsible For-Until Everyone Was: Heartbleed (a buffer overflow error in OpenSSH) was a programming error, but it showed the effects of using a popular piece of code but not providing proper support to the developers of the code.

23. The Volkswagen Emissions Scandal: How Digital Systems Can Be Used to Cheat: how software became a way to cheat and get around regulations.

24. The Code That Brought a Language Online: the development of software to allow users to enter text in Bangla after a terror attack in Bangladesh would have repercussions for blogging and freedom of expression in the country afterwards.

25. Telegram: The Platform That Became "the Internet" in Iran: Telegram enabled users in Iran to communicate and to broadcast messages in channels until it became Iranian's view of the Internet, for a while.

26. Encoding Gender: the issues around storing information on gender, when most databases are set up to only accept two binary gender values.