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A former Harvard physics lecturer and science communicator has said that heaven could have a physical location.While he draws on foundational ideas, such as Hubble’s law and the cosmic horizon, the claim fuses modern cosmology with biblical imagery.Other scientists have rejected his claim, but some point out that certain scientific musings have slipped into ideas that sound at least partially religious, spiritual, or metaphysical.
In an opinion essay published on Fox News in late January 2026, Michael Guillén, PhD, a former Harvard physics lecturer and science communicator, took the internet by storm with a provocative claim: that paradise might have a physical address.
Drawing on basic cosmological ideas—such as Hubble’s law, which holds that distant galaxies recede faster than nearby ones as space expands, and the cosmic horizon, the theoretical limit of what we can ever observe—Guillén extended that relationship to the edge of the observable universe. Pushing that reasoning outward, he wrote that what many religious traditions call “heaven” could lie roughly 273 billion trillion miles away (about 439 billion trillion kilometers), beyond the cosmic horizon.
The claim fused modern cosmology with biblical imagery—and set off a rapid scientific backlash. Multiple outlets published follow-up pieces quoting astronomers who expressed disbelief at efforts to drape the observable boundary with physical or theological significance. Alex Gianninas, PhD, an associate teaching professor of astronomy at Connecticut College, is one of the scientists pushing back.
“The cosmic horizon is not a physical place, but a finite boundary beyond which we simply cannot see or communicate,” Gianninas says. That limit exists not because the universe ends there, but because light takes time to travel and the universe has a finite age, he explains. The universe is about 13.8 billion years old, and light moves at roughly 300,000 kilometers per second—meaning we can only observe regions whose light has had enough time to reach Earth. Some regions are simply too far away: their light hasn’t arrived yet—or never will.
Then, something intriguing happened very early in the universe’s history. During a brief phase known as cosmic inflation—fractions of a second after the Big Bang—space itself expanded so rapidly that some regions were pushed permanently out of causal contact with one another. That early phase matters, Gianninas says, because it effectively set the rules for how space and matter behave on cosmic scales: while matter is bound by the speed of light, space itself can stretch faster than that limit, steadily carrying already disconnected regions farther out of reach.
Guillén treats the cosmological limit as a natural stopping point for the physical universe—after which a “divine realm” may begin.
Gianninas says precisely the opposite: that space almost certainly continues beyond it. “Likely as a continuation of the universe filled with planets, stars, and galaxies, but there is no scientific basis to claim that it is the realm of God, the gods, or the peak of Mount Olympus.”
Yet, Guillén’s claim didn’t just pop out of nowhere—it fits into a broader moment in which some scientists, and science-informed thinkers, are publicly flirting with ideas that sound at least partially religious, spiritual, or metaphysical. Last year, cosmologist Niayesh Afshordi and co-author Phil Halper suggested that treating the Big Bang as the end-all, be-all beginning can sometimes slip into creation-story language, even within the scientific community itself.
Gianninas believes the moment has less to do with new science than with the new ways ideas now spread. “In an era shaped by social media and instant publishing,” he says, “someone who once might have kept a controversial metaphysical belief to themselves can now share it widely—and quickly find validation from like-minded voices around the globe.”
This does not mean we live in a unique moment in history. Physics, Gianninas notes, has long ventured into territory that could not immediately be tested. Einstein published his paper about general relativity in 1915, but experimental confirmation didn’t arrive until years later, when Arthur Eddington observed gravitational lensing during a 1919 solar eclipse. More recently, theories like string theory have proposed extra dimensions and deep mathematical structures that remain experimentally unverified decades after their introduction. The nature of physics is to push deeper into the structure of reality. It’s inevitable that some ideas will run ahead of our ability to verify them.
In a recent Popular Mechanics feature, University of Nevada physicist Michael Pravica, PhD, imagined concepts like heaven or hell—and even religious figures such as Jesus—as potentially hyperdimensional or liminal, emphasizing that he was speaking in metaphysical, not testable, terms. When I asked him about attempts to locate heaven beyond the farthest visible limit for this article, Pravica “had a little bit of a chuckle.”
“Not that I reject the idea of heaven—I do believe there is a heaven—but the way it was framed was intellectually limiting,” he says.
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Imagine a two-dimensional circle representing our universe. Guillén’s claim, Pravica says, places “the hereafter” outside the horizon of that circle. But the universe is expanding, which already complicates the geometry. And once you start treating heaven as something spatially “outside,” he adds, the logic quickly breaks down. “If the universe is expanding, does that mean heaven is expanding? Or is heaven being pushed out of that circle?” Still, that doesn’t mean paradise has to be “out there.” If reality includes additional dimensions beyond the familiar three, it could just as easily exist “inside the circle, in a different dimension.”
Pravica is explicit that ideas about hyperdimensional spiritual realms belong not to physics but to metaphysics, a philosophical branch that deals with concepts so abstract they may have no foundation in reality, such as identity and the nature of being. “In the future, perhaps, if we develop techniques for accessing hyperdimensional tunnels or connections—absolutely, perhaps [we could measure heaven], ” he says.
But not at the present time. “I cannot measure an energy that exists outside our spacetime bubble. We live inside the bubble. We’re talking about what’s outside it.” It would be great to pinpoint the postal code of the great hereafter using cosmological tools, but such attempts are destined to fail, because “heaven wouldn’t be tethered to normal energy or matter at all,” Pravica says. It wouldn’t obey gravity or ordinary physical interactions, because “it’s a different energy, one that exists outside the universe we know,” he says.
Gianninas says that a scientist cannot approach claims of heaven having a physical reality or dimension “without verifiable predictions and observational or experimental evidence to back up those claims,” and that they cannot be a part of scientific discourse.
“Extraordinary claims require extraordinary proof,” Gianninas says.
Others, however, believe inspiration comes first—Pravica is one of them. Proof, if it comes at all, follows later. For this camp, many of science’s biggest breakthroughs began as unprovable ideas, born in an “aha” moment. Newton was once called a heretic for proposing gravity—an invisible field no one could see. String theory imagines extra dimensions without experimental proof.
“Why is hyperdimensionality unacceptable as a starting point?” Pravica asks. Even quantum entanglement—Einstein’s “spooky action at a distance”—becomes easier to imagine, he argues, if particles remain connected through unseen dimensions, like folding a sheet of paper so distant points suddenly touch. Occam’s razor, the rule of thumb that the simplest explanation is often the best, may bring us closer to the truth, he thinks.
And there’s another reason to embrace inspiration as a starting point for approaching the unknown, he believes. After the Popular Mechanics article about his thoughts on heaven being potentially hyperdimensional or liminal ran, Pravica says he received hundreds of emails—mostly supportive—from engineers, scientists, and other readers who said they shared similar views but rarely voiced them publicly.
“I’m a physicist, but I’m also a human being,” he says [and so are they]. “I have the right to imagine what’s beyond the bubble.” Gianninas disagrees. “As scientists, personal or religious beliefs have to be kept separate from science itself,” he says.
Pravica articulates the tension differently. “When you just study physics, it’s kind of cold,” he says. It can describe particles and forces with extraordinary precision—but not the reason we are here.
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Stav Dimitropoulos is a Gold and Community Anthem Award–winning journalist, and writes about consciousness, science, and culture for Popular Mechanics, Nature, and the BBC. Her work often explores mind-stretching angles where science meets philosophy. Her debut nonfiction book, Slow, Lazy, Gluttons (Greystone Books, 2026) asks: What if the traits society shames — laziness, darkness, nostalgia, and more — are actually survival superpowers?