Alice

• We have built a small proof-of-concept computer that uses running water instead of a traditional logical circuitry processor, and forecasts future events via an approach called “reservoir computing”.
• In benchmark tests, our analogue computer did well at remembering input data and forecasting future events – and in some cases it even did better than a high-performance digital computer.

Throwing stones in the pond

• Imagine two kids, Alice and Bob, playing at the edge of a pond.
• Bob throws big and small stones into water one at a time, seemingly at random.
• Big and small stones create water waves of different size.

How to make predictions

• To understand how we can use a reservoir computer to make predictions, imagine you have a record of daily rainfall for the past year and a bucket full of water near you.
• We input the daily rainfall record to the bucket by means of stone.
• For a day of light rain, we throw a small stone; for a day of heavy rain, a big stone.
• This means a reservoir computer can also forecast financial markets and even certain kinds of human activity.

Longer-lasting waves

• To forecast complex processes such as climate change and population growth, we need a reservoir with more durable waves.
• The pump plays the role of falling stones in the game played by Alice and Bob, but the solitary waves correspond to the waves on the water surface.
• Solitary waves move much faster and live longer than water waves in a bucket, which lets our computer process data at a higher speed.

So, how does it perform?

• Our computer not only executed all tasks exceptionally well but also outperformed a high-performance digital computer tasked with the same problem.
• With my colleague Andrey Pototsky, we also created a mathematical model that enabled us to better understand the physical properties of the solitary waves.
• Our computer is also naturally immune to cyber attacks because it does not use digital data.