Why Some Scientists Suggest Advanced Aliens May Exist Without Physical Bodies

Advanced aliens, if they exist, may have no physical bodies at all and could be built from materials nothing like human flesh, according to a new theory put forward by scientists in California and Portugal in 2024. Philosophers Eric Schwitzgebel of the University of California, Riverside, and Jeremy Pober of the University of Lisbon argue that truly advanced aliens might be conscious beings without bodies in any recognisable sense, challenging long‑held assumptions about what we should even be looking for in the cosmos.

Most popular images of extraterrestrials, from glossy Hollywood franchises to grainy UFO reports on social media, lean heavily on one basic idea, that if intelligent life is out there, it probably looks vaguely like us. Two arms, two legs, a head, a face, perhaps green skin for flair, but always some kind of body. Schwitzgebel and Pober think that confidence is badly misplaced and have now tried to give that intuition a more formal backbone.

In their working paper, the pair build around a concept they call ‘substrate flexibility.’ They say there is no good reason to think consciousness must always be tied to the kind of carbon‑based, neuron‑filled biology found on Earth.

If what really matters is the pattern and complexity of a system, they argue, then any sufficiently complex arrangement of matter could, in theory, support conscious experience. The ‘stuff’ does not have to be blood and tissue. It might not even be anything that behaves like a body.

Schwitzgebel and Pober point to the sheer scale of the observable universe as their starting evidence. With an estimated trillion galaxies and uncountable planets, the odds that Earth is the only place where consciousness has ever emerged look, at best, wildly optimistic.

If life has appeared under very different chemical conditions elsewhere, then the blueprint guiding its evolution would diverge radically from our own. In that case, the end result might not be a creature at all, at least not in the way biologists use the word.

Scientists Challenge ‘Terrocentric’ Alien Assumptions

The scientists have even coined a slightly mocking label for our human bias, ‘terrocentrism,’ the belief that Earth is a kind of master template for life in the universe. The term is a riff on ‘anthropocentrism,’ the habit of putting humans at the centre of the story, and it is pitched as both a warning and a provocation to astrobiologists and science fiction fans alike.

For centuries, scholars insisted the Sun revolved around the Earth. The idea that our planet circled a fairly ordinary star took time, evidence and no small amount of bruised ego to accept. For Schwitzgebel and Pober, assuming that alien minds would show up in anything even loosely humanoid, or even recognisably biological, feels like a low‑budget sequel to the same mistake.

In their account, what we call a ‘body’ is just one way consciousness has bundled itself with matter. It happens to be the way that evolved here, in one corner of one galaxy.

Elsewhere, if complex systems of a different kind have developed, conscious experience might ride on top of silicon‑like networks, clouds of interacting particles, or something that would look to us like inanimate structure. The paper does not claim to know what those systems would be, only that our ignorance is vast and our imagination, so far, fairly tame.

Advanced Aliens Without Physical Bodies Could Be ‘Much Stranger Than Fiction’

The theory also takes aim at how films and TV handle aliens. On screen, even the weirdest extra‑terrestrial usually ends up as a sexy lizard person, a rubber‑suited insect, or a slightly tweaked human face with CGI dots.

That is partly practical, it is easier and cheaper to put an actor in prosthetics than to reinvent biology from the ground up. Still, Schwitzgebel and Pober suggest reality, if we ever encounter it, is likely to be far stranger than fiction has dared.

Movie aliens tend to be ‘humanoids,’ sharing the same basic body plan as people, even if the details are rearranged. According to the working paper, this is not simply lazy design, it reflects terrocentric thinking about what minds must look like.

The authors argue that, in a universe tilted towards complexity, the most advanced minds might long ago have shed the evolutionary baggage of bodies. Instead of walking around, they could be distributed across vast structures, or manifest as processes rather than solid forms. The language gets speculative at this point, and the authors are careful to present this as possibility, not proof.

As of now there is no direct evidence for any kind of alien life, let alone bodiless civilisations with exotic substrates. All of this remains theoretical.

IBTimes UK could not independently verify these claims, so take everything lightly. The argument relies less on data and more on philosophical pressure, asking whether our assumptions about life are warranted given what little we know.

SETI researchers, who spend their careers listening for signals from the stars, increasingly wrestle with the same problem. If you secretly assume aliens are basically people with fancy gadgets, you design one kind of search strategy. If you think consciousness could reside in structures we have not even named yet, the task of finding it becomes more complicated, and perhaps more honest.

The paper does not offer a neat checklist for spotting consciousness in the wild and the authors acknowledge that our current scientific toolkit is tuned for life that looks at least a bit like terrestrial biology. Instead, their proposal functions as a kind of intellectual nudge, a reminder that our sample size, one planet with one lineage of intelligent life, is a terrible basis for cosmic generalisation.

Whether this rethinking will filter into mainstream space science is another question. Philosophers often get accused of wandering too far from solid ground and there will be plenty of researchers who prefer to focus on habitable worlds, liquid water and molecules they can actually measure.

Still, the arrogance of assuming the universe will kindly repeat our story elsewhere has been called out before. It would not be the first time we had to swallow a little pride and rethink who, or what, we share the universe with.

Originally published on IBTimes UK