Would aliens do physics, or is science a human invention?

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Modern physics offers a remarkable perspective on reality. In just over a century, he has decoded the architecture of atoms, traced the beginnings of the history of the universe and produced laws that seem to apply everywhere, from the earth’s crust to distant galaxies. It is tempting to believe that these theories are not only correct, but inevitable – that any sufficiently intelligent civilization would eventually discover the same truths.

I believed it too. But lately I’ve begun to wonder whether physics is less a window onto universal reality than a mirror, reflecting the particular type of mind we have.

This unsettling thought emerges when you ask a deceptively simple question: Would extraterrestrial scientists, shaped by a different biology or culture, achieve the same physics as ours? Or could they develop something that works just as well, but seems completely foreign – built on concepts and assumptions that we would struggle to recognize?

This question is at the heart of my book, Do aliens talk physics?which imagines different first contact scenarios, each designed to probe a fundamental hypothesis of modern physics. As I developed it—often in conversations with philosophers of science—I realized something surprising: many pillars of physics that seem hardwired may actually be contingent. But recognizing this does not weaken science. Maybe this is how we will improve it.

I have spent my life doing physics. When I’m not teaching at the University of California, Irvine, I work at the CERN Particle Physics Laboratory near Geneva, Switzerland, where I analyze data from the Large Hadron Collider. But a few years ago, conversations with philosophers forced me to return to a question I hadn’t seriously thought about since my student days: What exactly is physics?

At its core, physics aims to explain how the universe works – not just what we observe, but also what lies behind those observations. It looks for patterns, builds models that expose the hidden structure, and ideally boils it all down to a small set of rules from which the rest follows. In this regard, the success has been spectacular.

However, physics never describes the universe in its entirety. He describes carefully chosen versions of it.

Consider predicting the path of a comet. In principle, we could explain each gravitational tug, the slow loss of material as the ice sublimates, and even the way an irregular shape causes the comet to fall. In practice, we have to decide what to include and what to ignore. There is no single correct model – only models good enough to answer the question at hand.

This is true throughout physics. Even our most precise theories rely on approximations and assumptions that make the mathematics tractable. And it is not certain that the theories we consider fundamental really are. They may simply be effective descriptions operating on a human scale. There is no guarantee that by probing nature ever more finely we will eventually reach bedrock.

If physics depends on choices – about simplification, representation and emphasis – then extraterrestrial physicists could reasonably make different ones.

What if extraterrestrials didn’t experience time like us?

Imagine that aliens arrive on Earth. They perfectly master interstellar travel and land near Paris. We send linguists and scientists to greet them, hoping for a technological boon. The delegation returns empty-handed.

“They can’t share their technology,” says the lead physicist. “Because of what happens in 74 years. »

The implication is disturbing. These aliens experience time not as a fluid sequence, but as a complete structure, something navigable rather than endured. Human physics, on the other hand, is based on the idea that the present generates the future. Causes precede effects. The universe is calculated forward, moment by moment.

But what if this image is a human convenience rather than a cosmic necessity?

We know that any viable physics must obey certain constraints. A universe that allows unlimited messages from the future quickly collapses into a paradox. But within these limits, the structure of time can be more flexible than is usually admitted.

Clues to this already exist in our own theories. Quantum entanglement connects distant particles so that the measurement of one appears to instantly fix the state of the other, despite the fact that there can be no exchange of information between them. This alone puts our intuitions to the test. But things get stranger when relativity comes into play. Observers moving at different speeds disagree on the order of events. In some frames of reference, one measurement appears to influence another before it occurs.

The standard response is to insist that no physical problem has occurred: no faster-than-light signals, no causal contradictions. But this assurance relies on clinging firmly to a classical notion of causality that quantum mechanics has never fully respected.

Some physicists have taken a more radical approach. In so-called retrocausal interpretations of quantum mechanics, future events can help shape the present. Measurements don’t just reveal results; they help define them, even backwards in time. The universe is no longer calculated strictly step by step.

If aliens had a radically different concept of time, they might adopt these ideas naturally, rather than treating them as troubling exceptions. And maybe we’ll eventually have to do the same.

What if aliens didn’t insist on a single theory of nature?

Now imagine that aliens invite us aboard their ship for a scientific conference. Earth sends its brightest minds. We present our best theories. The aliens listen politely, then respond.

One group describes a framework that reproduces all known experiments using unknown concepts. A second presents another incompatible approach. Then a third. Each one works. Each is internally consistent. None can be reduced to the others.

Finally, someone asks the obvious question: Which one is true?

The aliens seem perplexed. All of them, they say. Why choose?

Human science assumes that competing theories must ultimately confront each other, and that only one survives as the correct description of reality. When multiple explanations fit the data, we design experiments to eliminate all but one winner.

This strategy is powerful and often effective. But this is a preference and not a logical necessity. Today, science often tolerates pluralism more than it admits. Weather forecasts are a prime example. Modern meteorology relies on a series of models, each adapted to different hypotheses and scales. These models generally disagree and experts decide who to trust based on context. No model is considered unique and correct.

Another example comes from classical mechanics. In school, we learn Newton’s laws in story form about the forces that push and pull objects in space. But the same movements can be calculated in very different ways, by tracking how energy flows through a system or by assuming that nature somehow “chooses” the path that minimizes a quantity called “action.” For most physicists, these are just alternative ways of performing the same calculations.

Philosophers of science point out, however, that each framework elevates a different concept to center stage – force, energy, optimization – and offers a different view of what, ultimately, is causing motion. The fact that these images cannot be differentiated experimentally shows that empirical success alone may not be enough to tell us which account, if any, deserves to be called “true.”

This suggests an alternative vision of science – not a march toward a single, definitive theory, but a toolbox of frameworks, each useful in different situations. Aliens could take such an approach from the start, without ever feeling the need to crown a single description as the truth.

What if aliens never felt the need to do physics?

Finally, imagine that aliens arrive by opening a wormhole. The technology is amazing. Surely they must have extensive knowledge of gravity, perhaps even quantum gravity.

But what happens if they don’t?

What if their spacebending technology was the result of millions of years of trial and error rather than theoretical understanding? They know how to build it and how to use it, but they don’t know why it works – and they may not care.

This seems implausible only because we are accustomed to thinking of technology as the fruit of science. Historically, the relationship has often gone the other way. Humans were making steel, glass, and antibiotics long before we understood the chemistry or biology behind them. Cathedrals were built before calculus.

The close coupling between science and technology, which we take for granted, is a recent and culturally specific achievement.

It is tempting to assume that any intelligent species would ask “why”. But this urge may reflect human psychology rather than a universal characteristic of intelligence. Other species might value reliability over explanation, or usefulness over understanding. They were able to build extraordinary technologies without ever developing anything recognizable as physical – not because they failed to take the next step, but because that step never seemed necessary.

These scenarios are speculative. But they point out something easy to forget. Physics is the cumulative result of many human choices: about what counts as an explanation, what inconsistencies matter, and what questions are worth asking. It reflects our history, our tools and our values ​​as much as it reflects the structure of the universe.

Recognizing this does not diminish physics in any way. It does the opposite. The more we are aware of the assumptions contained in our theories and methods – about time, causality, truth and explanation – the more freedom we gain to rethink them.