Let me start with a fact that might make you see the universe differently.
Wormholes weren’t invented by science fiction writers. They’re written into Einstein’s equations of general relativity.
In 1935, Einstein and physicist Nathan Rosen were studying the mathematics of black holes when they found something strange — a “bridge” connecting two different regions of space-time. It later became known as the Einstein-Rosen bridge, the origin of what we now call wormholes.
But “in the equations” doesn’t mean “in the universe.”
Today, I’ll show you what wormholes actually are in physics, what they need to be “traversable,” why physicists say they “probably don’t exist” — and why they’re still studying them anyway.
Part 1: The Einstein-Rosen Bridge — The First “Wormhole”
The core idea of general relativity is that mass bends space-time. Put a heavy object on a rubber sheet, and it creates a dent. The heavier the object, the deeper the dent.
If the mass is large enough — say, a star collapsing into a black hole — space-time gets bent so extremely that it creates something called a “singularity.” In 1935, Einstein and Rosen discovered that if you transform the mathematical description of a black hole, you get a “bridge” connecting two different regions of space-time.
This bridge is the Einstein-Rosen bridge.
Here’s its structure: it connects two “asymptotically flat” regions through a “throat” — the point where the radius is smallest. Think of it as a tunnel with an entrance near Earth and an exit somewhere in a distant galaxy.
But here’s the problem: you can’t travel through it.
The throat of an Einstein-Rosen bridge collapses at the speed of light. Before anything could pass through, the tunnel would close. Worse, it requires you to cross a black hole’s event horizon — and once inside, you’re not facing a tunnel, you’re facing a singularity whose tidal forces would tear you apart.
As Vanderbilt University physics professor Robert Scherrer put it: wormholes are at the “edge of speculative physics” — even more speculative than black holes.
Part 2: Traversable Wormholes — You Need “Exotic Matter”
If the Einstein-Rosen bridge won’t work, is there a way to stabilize one?
In the 1980s, theoretical physicist Kip Thorne (the scientific consultant for Interstellar) and Michael Morris worked out the mathematics of “traversable wormholes.” Their conclusion: to keep a wormhole’s throat open, you need something called exotic matter.
The key feature of exotic matter is negative energy density.
Normal matter pulls space-time inward. Exotic matter does the opposite — it pushes outward, creating a repulsive gravitational effect that counteracts the tendency of the throat to collapse.
The problem? We’ve never observed this stuff. Christopher Smeenk, a professor of philosophy of physics at Western University, put it bluntly: “If you ask me whether this kind of matter could exist — I doubt it.”
Yes, negative energy exists in quantum physics — the Casimir effect is a real example. But that’s at microscopic scales, producing tiny amounts. To hold open a wormhole large enough for a human to pass through, you’d need astronomical amounts of exotic matter — far beyond anything we could create or control in the foreseeable future.
There’s also a logical catch: even if you built a wormhole, if you flew a ship made of normal matter through it, the ship’s positive energy alone might trigger collapse.
Part 3: A New Life in Quantum Physics
At this point, you might think wormholes are a dead end.
But theoretical physics in the last two decades has given them a new life — not in the macroscopic universe, but as theoretical tools in quantum physics.
Physicists Juan Maldacena and Leonard Susskind proposed a conjecture called ER = EPR. In simple terms: quantum entanglement (EPR) and wormholes (ER) might be the same thing. Two entangled particles might be connected by a microscopic “wormhole.”
If this conjecture is right, wormholes aren’t physical tunnels connecting galaxies — they’re geometric representations of quantum connections. They won’t take you from Earth to Proxima Centauri, but they might help us understand how space-time emerges from quantum entanglement.
This sounds abstract, but it’s among the most cutting-edge topics in theoretical physics today. It connects two previously unrelated fields — general relativity (describing the macro-scale) and quantum mechanics (describing particles) — and pushes us closer to the ultimate goal of “quantum gravity.”
Part 4: How Would We “Find” a Wormhole?
If wormholes do exist, what would they look like?
The answer might surprise you: a wormhole would look like a sphere, not a hole.
In terms of light propagation, wormholes and black holes are remarkably similar. Photons bend around a wormhole the same way they do around a black hole, creating a “shadow.” Alexandru Lupsasca, assistant professor of physics at Vanderbilt, described passing through a wormhole as “being sucked into a ball and then spit out of another ball.”
But the question is: how do you tell if you’re looking at a black hole or a wormhole?
One method is through gravitational waves. The “ringdown” phase of a black hole merger produces specific “quasinormal modes” — signals that oscillate over time and space. In theory, a wormhole would produce similar but slightly different signals. A 2025 paper that received an honorable mention from the Gravity Research Foundation noted that precise measurements of these signal differences might allow us to distinguish black holes from wormholes using gravitational waves.
Another method is observing gravitational lensing — how light bends around the object — or looking for “anomalous energy distributions” that don’t match black hole models.
But so far — zero observational evidence.
Part 5: What Did Hawking Think About Wormholes?
Stephen Hawking studied wormholes extensively. In the late 1980s, he wrote several papers on them, trying to answer a core question: where does information go when it falls into a black hole?
His idea was: if black holes are the entrance to wormholes, maybe information doesn’t really “disappear” — it comes out the other end. That would preserve quantum mechanics’ principle that “information is never destroyed.”
But by the early 1990s, Hawking changed his mind. After studying the non-locality of wormholes, he concluded that the object entering a wormhole and the object exiting might not be the same. He famously wrote that wormholes are “not suitable for astro-navigation!”
He also proposed his famous chronology protection conjecture: physics itself prevents time machines from being built, protecting causality from being broken.
Wormholes don’t violate relativity directly — no particle travels faster than light locally — but they do allow “effective” faster-than-light travel and the possibility of going back in time. That’s exactly what Hawking wanted to rule out.
Part 6: So — Real or Not?
Let me come back to the original question: could wormholes actually exist?
My own answer has changed three times.
When I first read science fiction: of course wormholes exist. That’s cool.
Then I read the physics: Einstein-Rosen bridges are mathematically valid, but not traversable. You need exotic matter that “almost certainly doesn’t exist.” Wormholes are probably mathematical illusions.
Then I read about ER = EPR and more recent papers: at the macroscopic scale, wormholes probably don’t exist. But in the microscopic world of theoretical physics, wormholes have become a surprisingly useful concept — helping us understand quantum entanglement, space-time structure, and the black hole information paradox.
Christopher Smeenk from Vanderbilt put it best: “We consider these ideas not because we genuinely expect to find wormholes in real astrophysical systems, but because they help us see how the pieces of the puzzle fit together.”
Wormholes are one piece of the cosmic puzzle. Not the whole picture — but a piece that helps us rethink the “shape” of the universe.
Do you think wormholes will ever be discovered? Or will they remain forever in the calculations of theoretical physicists? Let me know in the comments.
