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

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Modern physics offers a remarkable lens on reality. In just over a century, it has decoded the architecture of atoms, traced the early 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 accurate but inevitable—that any sufficiently intelligent civilization will eventually uncover the same truths.

I used to think so too. But lately I’ve begun to wonder if physics is less a window onto universal reality and more a mirror, reflecting the particular kind of mind we happen to have.

The unsettling thought arises when you ask a deceptively simple question: Would alien scientists, shaped by a different biology or culture, arrive at the same physics we have? Or can they develop something that works just as well, but looks completely alien – built on concepts and assumptions we will struggle to recognize?

This question is at the heart of my book, Do aliens speak physics?which imagine different scenarios of first contact, each designed to examine a fundamental assumption of modern physics. In developing it—often in conversation with philosophers of science—I’ve come to realize something surprising: many pillars of physics that feel hardwired may actually be conditional. But acknowledging that does not weaken the science. That might be how we do it better.

I have spent my life on physics. When I’m not teaching at the University of California, Irvine, I work at the CERN particle physics laboratory near Geneva, Switzerland, analyzing data from the Large Hadron Collider. But a few years ago, conversations with philosophers forced me to return to a question I hadn’t considered seriously since my undergraduate days: what is physics, really?

At its core, physics aims to explain how the universe works – not just what we observe, but what lies behind those observations. It looks for patterns, builds models that reveal hidden structure and, ideally, distills everything down to a small set of rules that the rest follow. In that sense, it has been spectacularly successful.

Yet physics never describes the universe in its entirety. It describes carefully selected versions of it.

Consider predicting the path of a comet. In principle, we can explain every gravitational tug, the slow loss of material as the ice sublimates, even the way an irregular shape causes the comet to tumble. In practice, we have to decide what to include and what to disregard. There is no single correct model – only models that are good enough for the question.

This applies throughout physics. Even our most precise theories depend on approximations and assumptions that make mathematics tractable. And it is not clear that the theories we treat as fundamental really are. They may simply be effective descriptions that work on a human scale. There is no guarantee that, by probing nature ever more finely, we will eventually hit the bedrock.

If physics depends on choices—about simplification, representation, and emphasis—foreign physicists might reasonably make different ones.

What if aliens don’t experience time the way we do?

Imagine aliens coming to Earth. They have mastered interstellar travel and have landed near Paris. We send linguists and scientists to greet them, hoping for a technological downturn. The delegation returns empty-handed.

“They can’t share their technology,” explains the lead physicist. “Because of what will happen 74 years from today.”

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

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

We know that all usable physics must obey certain constraints. A universe that allows unlimited messages from the future quickly collapses into a paradox. But within these limits the time structure can be more flexible than we usually admit.

Hints about this already exist in our own theories. Quantum entanglement links distant particles so that measuring one appears to instantly fix the state of the other, despite the fact that no information can be exchanged between them. This alone strains our intuition. But things get weirder when relativity enters the picture. Observers moving at different speeds disagree about the order of events. In some frames of reference, one measurement appears to affect another before it occurs.

The default response is to insist that nothing physically problematic has happened: no faster-than-light signals, no causal contradictions. But that security depends on clinging 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 are allowed to help shape the present. Measurements don’t just reveal results; they help define them, even backwards in time. The universe no longer calculates itself strictly step by step.

If aliens had a radically different time construct, they might adopt such ideas naturally, rather than treat them as disturbing exceptions. And maybe we will eventually have to do the same.

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

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

One group describes a framework that reproduces all known experiments using unknown concepts. Another presents a different, incompatible approach. Then a third. Each 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 confused. All of them, they say. Why choose?

Human science assumes that competing theories must eventually fight it out, with only one surviving as the correct description of reality. When multiple explanations fit the data, we design experiments to eliminate all but one single winner.

This strategy is powerful and often effective. But that’s a preference, not a logical necessity. Science today often tolerates pluralism more than it admits. Weather forecasting is a striking example. Modern meteorology relies on series of models, each tuned to different assumptions and scales. These models routinely disagree, and experts decide which to trust depending on the context. No single model is treated as uniquely correct.

Another example comes from classical mechanics. In school, we learn Newton’s laws as a story about forces that push and pull objects through space. But the same movements can be deduced in a completely different way, by tracing 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 doing the same sums.

However, philosophers of science will point out that each framework elevates a different concept to the center – power, energy, optimization – and provides a different description of what fundamentally drives movement. The fact that these images cannot be separated by experiment shows that empirical success alone may not be enough to tell us which account, if any, deserves to be called the “true” one.

This suggests an alternative vision of science—not a march toward a single, final theory, but a toolbox of frameworks, each useful in different situations. Aliens may 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 at all?

Finally, imagine aliens arriving by opening a wormhole. The technology is astounding. They must surely have a deep understanding of gravity, perhaps even quantum gravity.

But what if they don’t?

What if their space-bending technology is the result of millions of years of trial and error rather than theoretical understanding? They know how to build it and use it, but not why it works—and they may not care.

This sounds unlikely only because we are used to thinking of technology as the offspring of science. Historically, the relationship often ran the other way. Humans made steel, glass and antibiotics long before they understood the underlying chemistry or biology. Cathedrals were built before calculus.

The tight link between science and technology that we take for granted is a recent and culturally specific achievement.

It is tempting to assume that any intelligent species would be driven to ask “why”. But that urge may reflect human psychology rather than a universal trait of intelligence. Other species may value reliability over explanation, or utility over understanding. They could build extraordinary technologies without ever developing anything recognizable as physics—not because they couldn’t take the next step, but because the step never seemed necessary.

These scenarios are speculative. But they point to something that is 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 even worth asking. It reflects our history, our tools and our values ​​as much as it reflects the structure of the universe.

Acknowledging that doesn’t diminish physics. It does the opposite. The more aware we are of the assumptions baked into our theories and methods – about time, causation, truth and explanation – the more freedom we have to think anew.