A topic came up in conversation today that I think is really important: what's so special about computers? It's often said that software is eating the world, meaning that every business, every process, every aspect of our lives seems to involve computers in some way. We talk to friends on computers, spend money with computers, and the few places where computers aren't being used much are just waiting targets for software businesses. Indeed, it seems like the dominant startup model at the moment is find an industry where they don't use enough computers and make them use more.
Okay, but why couldn't medicine be eating the world? Or insurance? Or internal combustion engines? What's so special about computers? Well, I think the best way to answer that is to look at another world-eating invention: currency. Trading existed before currency through barter and gifting, but the idea of currency fundamentally changed trading because it acted as an abstract unit of value. You don't have to trade a bushel of corn for a bunch of bananas, you trade a bushel of corn for 20 units of value, which you can turn back into a bunch of bananas.
In practice, that doesn't sound particularly special: you're still trading corn for bananas. But having an abstract unit of value involved gives rise to all the other possibilities of the modern economy. Savings, loans, interest, insurance, investment, taxation - all of these things wouldn't work well or at all without it. The reason why currency is special is because it created that abstract unit that let us connect everything else together. Of course, currency itself is based on an even more important abstraction: numbers, an abstract unit of information.
Computers create a similar abstract unit, but a much more powerful one: an abstract unit of operation. That is to say, anything that can be done can be done by a computer (with only a few fairly obscure exceptions). Of course, to begin with most of those things are pretty mundane. I could write a document already, now I type into a computer and the computer writes the document. But, in exactly the same way, having that abstract unit of operation has transformed everything we do, and will keep transforming it into the future.
So while it might be tempting to think there'll be a next big thing and computers will stop being such a big deal, it just isn't possible. They may change shape or be made from different things, but the abstract unit they embody will never stop being relevant. Computers are special because they are the abstraction of doing things, and there will always be things to do.