Jumping from star system to star system with the push of a spacecraft’s warp drive throttle is a kind of Star Trek-inspired future tech that has very little in common with space travel of today. Achieving this sci-fi future would require not only new technology but breaking one of nature’s most fundamental rules: the speed of light. It’s very, very unlikely — but there may be new hope on the horizon.
In a recent paper published in The European Physical Journal C, a team of engineers and physicists led by former NASA engineer Harold “Sonny” White say they have discovered the right conditions to — theoretically — create a small warp bubble in a lab. A warp bubble is like a car traveling along a warp drive highway.
While White and colleagues have experimentally evaluated part of the science behind this discovery, the warp bubble itself currently exists only in theory as computations — White and colleagues haven’t proven that experimentally. But if they do, White says it could completely revolutionize the study of warp-speed space travel.
“This has not been done before in the literature and hence is significant,” White tells Inverse. “It is a matter of precedence for the idea of a space warp analogous to the Chicago pile for nuclear reactors.”
What is warp drive?
Before we dive further into what this warp bubble could mean for space travel, let’s back up to understand a warp drive first. The key here lies in two of Einstein’s pivotal papers, published in 1905 and 1915 respectively, on special and general relativity.
Among other things, these papers lay down three fundamental theories of physics:
- The universe has a speed limit and it is the speed that light travels — 299,792,458 meters per second, or just 3x10^8 meters per second among friends
- At velocities approaching the speed of light, the passage of time will change relative to an observer. In other words, space travelers moving faster age slower relative to their less speedy counterparts — like in Interstellar when they visit the water-world planet.
- Space and time are knitted together in a fabric creatively called space-time that ebbs, flows, and bends around mass. This curvature is gravity.
White explains that “space warp” is one of two loopholes within the theory of general relativity and noted in a 1994 paper by theoretical physicist Miguel Alcubierre.
“[It] allow[s] one to cover arbitrarily long distances in arbitrarily short times without ever locally breaking the speed of light — e.g., get to Proxima Centauri in, say, a month as measured by clocks on the spacecraft and clocks in mission control.”
Similar to a wormhole — which theoretically lets you skip across space-time by “walking” through a region where the fabric is folded together like a fan —warping space-time would look like the fabric bunching up in front of the bubble and then stretching out behind it in a train.
In a 2017 lecture, Alcubierre compares the phenomenon to the experience of being on a moving walkway at the airport.
“You can imagine that the floor behind you is being created out of nothing, and in front of you it is being destroyed, so you move along.”
In theory and science fiction, a warp bubble could move along this walkway and ride the bunching space-time fabric in such a way that its relative time remained slow (meaning Kirk wouldn’t be an old man when he arrived) while simultaneously moving great distances faster than the speed of light.
But there’s a catch: The bubble must be enrobed in negative energy, the kind that might come from anti-gravity. Sadly, that’s not something you can easily whip up in a lab.
How to discover a warp bubble
The negative energy constraint might seem like a fatal blow to the notion of warp drive, but a few glimmers of hope remain. For one, we may be able to do away with this requirement altogether, according to 2021 research by physicist Erik Lentz, who pored over the problem during the lockdown.
In the case of White and colleagues, the solution could come from a fluctuating of magnetic fields in something called the Casimir effect. Put succinctly, the Casimir effect refers to the attractive force of fluctuating magnetic fields that “pull” two objects — like plates or mirrors — together when inside a vacuum.
The idea is that electromagnetic waves flow continuously even through a vacuum, but only some small waves can fit between the two objects. As a result, the total vacuum energy between the objects becomes less than the outside energy, and they are attracted to one another. During such interactions, negative energy can be created on very small scales.
It was something called “Casimir cavities” that White and colleagues were investigating for DARPA when they noticed in their calculations something that looked suspiciously like a warp bubble.
“The detailed numerical analysis of our custom Casimir cavities helped us identify a real and manufacturable nano/micro-structure that is predicted to generate a negative vacuum energy density such that it would manifest a real nanoscale warp bubble — however humble it may be,” White says.
White and colleagues write that “a toy model consisting of a 1-micron diameter sphere centrally located in a 4-micron diameter cylinder” could be used to explore the Casimir effect energy density experimentally.
Is the DARPA warp bubble fake?
So, is this a real warp bubble? It seems like it has the potential to be — if experimentally validated. However, not all scientists are convinced.
But regardless of how this latest finding ultimately shakes out, White says we are still a long way off scientists and aerospace engineers coming anywhere close to building genuine warp drive — and that’s not a problem he’s looking to solve right now.
“Currently, we are laser-focused on exploring the characteristics of our custom Casimir cavities for,” White says. “It is too early to ask questions about some type of actual flight experiment. In my mind, step one is to just explore the underlying science at the nano/micro-scale.”