Is it possible to predict the future?

For centuries, the world’s brightest minds have been trying to prove whether it’s scientifically possible to predict the future. Just answering the question involves a short history lesson in physics – as shared by Stephen Hawking in his book Brief Answers to the Big Questions.

Long ago, natural events like earthquakes and floods seemed to happen at random. Gradually, people observed certain regularities in nature (like the motion of planets and stars), which led to the first field of science: astronomy.

Over time, more natural phenomena were found to obey scientific laws. This inspired the French scientist Pierre-Simon Laplace to argue that if the position and speed of all particles were established, you could calculate their behavior at any point both in the past and future.

This idea that a freeze-frame of the universe offers a window into its state at all other times suggests that, in theory, predicting the future is possible. The problem? Chaos. Even one tiny change can have dramatic effects. This is why weather forecasts are often wrong.

Laplace’s idea of scientific determinism was challenged by German physicist Werner Heisenberg, whose Uncertainty Principle established that you can't pinpoint the position and speed of an object at the same time. This appeared to rule out the possibility of predicting the future.

The development of quantum mechanics reframed our understanding of how the physical universe works. Instead of having exact speeds and positions, particles are represented by a wave function. This is a formula that calculates the probability of a particle’s speed and position.

Although it’s still hard to predict the position and speed of a particle with certainty, quantum mechanics allows us to accurately calculate one combination of its position and speed. This isn’t what Laplace had in mind when he envisioned scientific determinism, but it’s closer.

Yet even this limited predictability gets shaky when we consider black holes. There are parts of space we can’t observe because of gravity’s ability to warp space–time. And if we can’t see what happens to particles inside a black hole, we don’t have a full picture of possibility.

So is it scientifically possible to predict the future? In theory, yes, the laws of physics allow us to predict the future to a limited degree. But in reality, the calculations involved are just too complex.

Bottom line: If we could measure the position and speed of a particle simultaneously, we could unlock accurate predictions of the future. Unfortunately, we can only predict one combination of position and speed. Getting a picture of 100% certainty is currently impossible.