I’m trying to illustrate the notion that things that are conceptually simple are oftentimes extremely complex to implement for a variety of reasons. The problem is, I can’t think of a specific example. At first I was going to go with moving a pile of sand with tweezers, but then I realized that that is conceptually and practically simple–using tweezers to move sand is easy, but prohibitively tedious.
What are some examples of simple ideas that are hard to implement?
How about clicking a link on a web page. Conceptually, all you have to do is move your mouse there and click.
But in actuality[ol]
[li]The web browser needs to parse the link’s target address[/li][li]It needs to open an HTTP connection to the target host[/li][li]If the target host is unknown the operating system needs to make a DNS query to find it[/li][li]That DNS query is sent via UDP[/li][li]That UDP stream is transmitted via IP[/li][li]That IP datagram zips around on your home Ethernet to your broadband connection[/li][li](skipping a bunch of stuff)[/li][li]With the address in hand, the OS opens a connection[/li][li]The browser uses it to communicate with the host via HTTP[/li][li]That HTTP stream travels over TCP over IP over Ethernet…here we go again[/li][li]The browser checks the cookie jar to see if any cookies need to be sent[/li][li]The server parses the request[/li][li](skipping another whole bunch of crap here)[/li][li]The server sends a response via the HTTP connection[/li][li]The browser parses the response and displays the information, but wait![/li][li]The response contains links to 16 images, three CSS files and a Javascript file. Rinse and repeat our HTTP steps to get them.[/li][li]And so on.[/li][/ol]
ETA: And of course all this ignores the mouse itself, peripheral protocols like PS/2 or USB, device drivers, opposable thumbs, the neural pathways, motor skills, nerve impulses and so forth necessary for moving and clicking a mouse, the development of reason, the evolution of mankind, the origin of life on Earth, the origin of the Earth in the Universe, the Big Bang, and for some reason the Muppets.