Warp Speed Inches Closer to Reality with New Research

We may take the concept of light for granted in our daily lives, but the notion of quantifying its properties and overcoming its barriers has tantalized us for generations. Scientists once thought it was impossible to measure or simply infinite; it was Danish astronomer Ole Rosemer in 1676 who first determined that the speed of light was finite. Other scientists built upon this to determine the arithmetic and find that light travels at the very measurable speed of about 299,792 kilometers per second—now an easily googleable fact. Fast-forward a couple hundred years to 1916, when Albert Einstein famously published his theory of general relativity, which (among many other things) states that no known object can travel faster than the speed of light. Since then, the notion of challenging this and finding a way to move faster than that barrier has fascinated us, eluded us, and inspired countless imaginations to take up the challenge.

For years, science-fiction writers have toyed with the question of how we can travel faster than light in order to satiate our appetite for reaching for the stars, bringing us stories of far-flung worlds, alien beings and creatures, and expansive interstellar societies. We’ve seen concepts such as jump drives, powered by fictional elements; Einstein–Rosen bridges (or wormholes) allowing for interstellar travel across vast amounts of space; and hyperdrives that create subregions of space where physics as we know it doesn’t apply. And then there’s the warp drive, a concept Trekkies like me are plenty familiar with, which uses immense amounts of energy to physically manipulate the space around a vessel in order to propel it forward. On screen, operating a warp drive might seem as simplistic as dramatically saying “Engage” on the bridge of the Enterprise, but in reality there has been quite a bit of thought put into how this concept could actually come to fruition.

Wormhole travel as envisioned by Les Bossinas for NASA. Les Bossinas/NASA/Wikimedia Commons

There are numerous scientists working on how exactly humans could reach faster-than-light (FTL) speeds, and the concept of the warp drive is one that deserves some serious consideration. Just recently, two papers—one by Alexey Bobrick and Gianni Martire and another by Erik Lentz—have been making some waves in the field of warp theory. The physics of warp drive is still quite theoretical and can sometimes be difficult to comprehend, so I reached out to Dr. Ethan Siegel, author of Treknology: The Science of Star Trek from Tricorders to Warp Drive, to help break it down a bit.

Being both a Star Trek fan and an astrophysicist, Dr. Siegel has closely followed the research and progress into the different theories of FTL travel. Unsurprisingly, he’s well versed in the base concepts—from general relativity to Einstein–Rosen Bridges, black holes, and wormholes—as well as the more recent works, among them Miguel Alcubierre’s theories on warp drive, follow-up research involving negative mass and energy, and of course these latest papers. Needless to say, there’s a whole lot of ground to cover.

Alcubierre—a name that will inevitably come up when discussing real-world FTL travel theories—is one of the pioneers of warp drive research. A theoretical physicist from Mexico, he first proposed his idea for a faster-than-light propulsion system, the Alcubierre drive, that would be consistent with Einstein’s theory of relativity. Essentially, the drive would somehow create a wave in the fabric of spacetime that would expand space behind an object while contracting the space ahead of it. The object caught within it would then be able to ride this wave at immense speeds in a protected “warp bubble.” But how realistic is that idea?

“The big problem with Alcubierre’s original solution and the notion that we want to fold or bend space in this particular way is that space is very hard to curve, according to Einstein. It requires enormous amounts of mass in very compact volumes,” Dr. Siegel explains. This is where the idea of negative energy or negative mass has since come into play.”

Warp field according to the Alcubierre drive. AllenMcC/Wikimedia Commons

“[With] negative energy, think about electric chargers, where you have positive and negative,” he continues. “And in electromagnetism, the like charges repel, but the opposite charges attract. In gravity, we only have one type of charge that we know of: you have positive mass, and it’s always attracted, so what would happen if you had negative mass?

“The way I like to think about imagining negative mass—because we don’t really have negative mass—is [if we] filled space uniformly with matter. Whether it’s a fluid or a bunch of dust or whatever, there’s matter everywhere. And what we’re going to do in one spot is we’re going to have an extra amount of matter, and in another spot, we’re going to take that matter away.”

From there, Dr. Siegel explains, if you cut out matter from one region of space and put it in another, you would have an overdense region with extra mass and then an underdense region with negative mass compared to the average. The second region would then attract matter around it preferentially (due to there being more gravity), but the first region would see all the matter around it less attracted to it—thus, we’d see the nearby matter moving in opposite directions. Effectively, mass would flow out from the underdense region and toward the overdense region, and an object (spaceship) between these two regions would then be propelled toward the overdense region by a field (warp bubble).

The issue, as Dr. Siegel pointed out, is that negative mass doesn’t exist as far as we know. There are experiments to try to generate and/or discover it in some capacity, but even with that, the amount of energy needed for an Alcubierre or warp drive would be exorbitant, to say the least.

This is where some of the newest research comes in. In an effort to whittle away at some of the barriers that have have plagued warp theory for years, the paper from Bobrick and Martire and the one from Lentz attempt to formulate warp drive theories that do not fundamentally rely on negative mass or negative energy.

“Previously, we were talking about giant-planet masses’ worth of energy—and so, come up with any sort of way to get that down, and that makes it more realistic to explore,” Dr. Siegel says. “It’s still all theoretical, of course, but [this new research] is saying you don’t have to reach these unfathomable energies to recreate this experience. And in particular, you might not need this fundamental negative energy. You might be able to have some clever setup or workaround where some behavior of normal matter or normal energy acts like a stand-in for this negative energy.”

Essentially, these new papers tweak Alcubierre’s model in ways that bring it just a bit closer to reality. Bobrick and Martire’s paper, published in the journal Classical and Quantum Gravity, details alterations to Alcubierre’s ideas that would allow the theoretical drive to operate using ordinary matter rather than negative energy. The catch, however, would be that a vehicle using this method wouldn’t quite exceed light speed but rather would reach incredibly fast subluminal speeds. In Lentz’s paper, published independently but also in Classical and Quantum Gravity, the idea is to replace the negative matter element with a theoretical, hyperfast particle known as a soliton. 

It’s true that a warp drive is still far from a reality, but the field is alive and robust with continued research and fresh ideas. And while this technology may not be just over the horizon for us, each new idea brings us one step closer to surpassing our imaginations and truly reaching for the stars.