Introduction
Welcome to the first post in our series exploring the deep roots of computing. Before we can talk about silicon chips and programming languages, we need to ask a much more fundamental question: What even is computation?
Most of us think of computers - laptops, phones, servers. But the idea of computation is much older, simpler, and more human than that. At its core, computation is just a fancy word for following a set of steps to solve a problem.
The Original Calculator: An Abacus
Let’s travel back thousands of years. There are no power outlets, no screens, no keyboards. But you still need to add up your goods at the market. How do you do it? You might use an abacus.
An abacus is a tool for calculation. It has beads on rods, and by moving them according to a set of rules, you can perform arithmetic. If you want to add 5 and 7, you don’t just “know” the answer is 12. You follow a physical process:
- Represent the number 5 by moving five beads.
- Represent the number 7 by moving seven more beads.
- Follow the rules for “carrying over” when a rod fills up.
- Read the final position of the beads to get your answer: 12.
This is computation. It’s not magic; it’s a structured process. You’re not using a brain, you’re using a tool and a method. The abacus doesn’t understand numbers, but it can manipulate them correctly because it’s built to follow the rules of arithmetic.
From a Tool to a Recipe
Now, let’s strip away the tool itself. What’s the most important part of using the abacus? The rules. The step-by-step method you follow.
This set of rules, this recipe for solving a problem, has a special name: an algorithm.
Think about baking a cake. You have a recipe that tells you exactly what to do:
- Preheat the oven to 350°F (175°C).
- Mix flour, sugar, and cocoa powder in a bowl.
- Add eggs, milk, and oil.
- Stir until smooth.
- Pour into a pan and bake for 30 minutes.
If you follow these steps precisely, you’ll get a cake. The recipe is the algorithm. It’s a finite sequence of unambiguous instructions that, when followed, accomplishes a task. You don’t need to understand the chemistry of baking to make the cake; you just need to follow the instructions.
Computation, therefore, is the act of executing an algorithm.
Whether it’s a person moving beads on an abacus, a baker following a recipe, or a modern computer processing billions of instructions per second, the fundamental idea is the same. It’s about taking an input (numbers, ingredients), following a clear set of steps (the algorithm), and producing an output (an answer, a cake).
This simple but powerful idea - that we can create recipes to solve problems - is the foundation of everything we’ll explore. But as we’ll see in our next post, just because you can write a recipe for something doesn’t mean all problems are solvable. A mathematician named Gödel was about to show the world that some things are fundamentally unknowable, breaking math wide open before computers were even a dream.