Will History (Of Physics) Repeat Itself?

4 min readJun 24, 2022

End of the nineteenth century. The feeling has never been so high that we are close to having a complete understanding of the laws of physics and, dare we say, of the universe. Newton’s equations wonderfully describe particles. Maxwell’s equations wonderfully describe waves. Yet something doesn’t feel quite right: they are not compatible with each other: the former relies on a principle of relativity of, among others, speeds (as formulated by Galileo Galilei), while the latter uses a constant (that would be c) that has the unit of a speed.

Followed, as we entered the twentieth century, two unprecedented shocks. Relativity, special and general. Quantum theory. And one century of heated and passionate debates on the nature of time, on determinism and randomness, on what reality is. Probably not going to end any time soon.

Let’s go back to the present

2022. The standard theory of elementary particles was comforted with the discovery of the Higgs boson and is as strong and popular as ever. Relativity wonderfully describes gravitation and every day, new experiments support it. Quantum physics wonderfully describes waves and particles, as well as the other forces (electromagnetic, weak, strong). Yet something doesn’t feel quite right: they are not compatible with each oth… Hm. Wait. Does this not ring a bell?

Maybe rightly so.

But how did the relativity and quantum theories gain acceptance, in other words, what did they have that other theories did not have?

Science 101

Science is based on theories. A theory does not claim to be right or wrong: it provides a possible account (a model) of the universe, or of some aspects thereof, and makes predictions based on its model.

Experiments can then be carried out to validate (or invalidate) these predictions. A point of crucial importance is that a new theory must also make predictions on the outcome of experiments that have never been carried out so far — correctly predicting past experiments is not enough. These are the rules of the scientific game. And relativity and quantum theory are incredibly good at this game.

If validated (but never confirmed with 100% certainty), a theory is reinforced in its credibility. If invalidated, it provides new avenues for designing future theories. Yet a theory may be technically invalidated, yet still provide a fairly good and useful approximation of reality. For example, Newton’s theory on classical mechanics, even though it got superseded by relativity theory, is still in use today for classical speeds.

The above process is a fundamental principle of science. Relativity and quantum theory acquired their credibility and relevance this way. The new, upcoming theories, will have to go through the same pipeline.

A thought experiment

Imagine somebody coming to us from the future, such as from the twenty-second century, with books full of a newer theory that is mainstream, validated by experiments not accessible to us yet, and widely accepted in the future. And this someone distributes the books without giving any context. It is likely that most scientists would not take them seriously — and I am by no way claiming that yours truly would, either.

Simply because it is likely to contradict principles that our scientific community, today, feels strong about. Like the concept that speeds add up arithmetically, or the concept that the elapsing of time is universal, which were taken for granted back in the nineteenth century.

Novelty of future theories vs. inertia of our principles

This is a tough one. So how do we overcome this apparent barrier to novelty? The above pipeline provides an objective safeguard for the temptation to discard theories only based on intuition. In the review process, we both need:

to keep a scientific rigour, so that only strong and sound theories successfully make it through the pipeline.
but also to keep an open mind on what’s next and refrain from rejecting novel theories just based on how one feels about them.

Prepare yourself to be surprised

Given the unexpected rise of twentieth-century theories, it’s very hard, today, to make any prediction on what will come next. Some say string theory may already be the key. Others even say we stumbled upon it earlier than we should have. Hard to say what will happen.

Yet, I think that one prediction can be made: whichever way it goes, we can expect to be surprised. Very surprised. Today’s mysteries (randomness, dark matter, dark energy, and so on) do not seem to be solvable with the tools and theories we have today. Some shifts of paradigm are bound to happen. Maybe even sooner than we think. And, next thing we know, we may even get used to them and find them obvious.

That is, only until the next ones come.