On the surface it looks like a dullish gray rock, something you might scrape off your boot after a day of hiking. But the rock, known as LK-99, may hold the keys to a future barely imaginable today: the ability to transmit electrical power with no resistance at all.
Unfortunately, this little gray rock is sitting in a storm of controversy, with competing claims and counter-claims arguing about whether it has the magical properties necessary to make it a superconductor. While the superconducting nature of LK-99 seemed to be largely discredited last year, a new team of researchers just presented evidence that suggests it does fit the bill for a room-temperature superconductor, resurrecting the promise of this material.
Here’s a rundown of what LK-99 is, what it’s supposed to be, and why it matters.
Superconductors Are Already Indispensable
Any bit of material that allows electricity to pass through it relatively easily is called a conductor, and conductors run our lives: they are the wires in everything from the inside of your walls to the inside of your phone’s microprocessors. Conductors are how we get electricity from place to place, but nothing in this world is perfect: every time we transmit electricity, there’s a little bit of resistance in the conductor that we have to work through. That resistance adds up, causing some of the electrical energy to be lost as heat, which is a major pain in the neck.
Enter the magic trick of physics: superconductors. When the conditions are just right—usually when the temperatures drop greatly or the pressures ramp up incredibly high—all electrical resistance within a superconductor vanishes, and along with that, any magnetic fields get pushed outside of it (an important part that we’ll come back to later). This allows it to conduct electricity with no energy loss at all. We already use superconductors in a wide variety of situations, especially when we need a whole lot of electricity in a relatively confined space, because otherwise our equipment would melt in the heat of electrical resistance.
One catch: all existing superconducting materials only work at extremely cold temperatures—over 100 degrees Fahrenheit below zero.
For decades, researchers have been attempting to create a superconductor that works at normal temperatures and pressures, known as room-temperature superconductors. In other words, a superconducting material that would work pretty much the same way as a copper wire would: you could just stick it where you needed it to go, and boom, you’re conducting electricity with absolutely no resistance.
Is LK-99 Too Good to Be True?
This is where LK-99 comes in. Last year, a team of researchers based in South Korea released preliminary results that they had identified such a room-temperature superconducting material, which they named LK-99. Their claims were based in part on the material’s response to magnetic fields. They reported that their sample levitated when placed over a magnet, an effect caused when a material pushes magnetic fields away from it. It’s something that superconductors like to do.
Here’s the problem: some other, non-superconducting materials also levitate when placed over a magnet (in one famous experiment, researchers were able to make a living frog float above a magnet). So the claims of the LK-99 team depended on the precise, detailed response of their material to magnetic fields, and the stipulation that their sample behaved in ways that other non-magnetic materials would not.
Cue a flurry of research (and news) over the last few months. Some simulation work suggested that LK-99 could work, but attempts to replicate the Korean team’s findings fell flat. The Korean team argued that the other samples weren’t pure enough. Materials like LK-99 need precise amounts of copper added, and one tiny bit of contamination from other elements could throw the whole thing off. The details of the material’s construction mattered, the Korean team claimed, because if you didn’t have the right geometry, then you wouldn’t achieve superconductivity.
This past winter, the scientific community largely moved past LK-99 and on to other projects. But a Chinese team’s paper, published on the preprint server arXiv on January 2 of this year, claims to have made a replica of LK-99. Though the work has not yet been peer-reviewed, the researchers observed a loss of the magnetic field within their sample—not a slam-dunk, but their experiment provided much stronger evidence than the original Korean team had.
There’s nothing novel about the chemical makeup of the sample in this new research, which is encouraging. If the Chinese team’s work is substantiated, then we could indeed have found a room-temperature superconductor—and it could mean that other teams couldn’t replicate it because it really is hard to get the chemical properties just right.
What we’re seeing with all this back-and-forth is the scientific process playing out in real time. Researchers make claims and discoveries all the time, and it’s up to their peers and colleagues to scrutinize those results and attempt to replicate them. Most ideas in science are wrong—that is what we get for searching beyond the horizons of the known.
But no matter what, research into LK-99 will strengthen our understanding of superconductors. One scenario is that enough groups successfully replicate the original results, which brings us many steps closer to a practical room-temperature superconductor. Or, on the other hand, research into LK-99 specifically stalls out, and scientists around the world learn not to look too closely in that direction, or along similar lines. While it’s not as big of a step as a discovery, it’s still useful knowledge that guides and informs us … and brings us ever closer to cracking the case.
Why We Need a Room-Temperature Superconductor
Even if LK-99 doesn’t hold up, there’s a reason that hundreds of scientists around the globe are pursuing room-temperature superconductivity research. Put simply, the ability to transmit electrical energy without any loss of resistance would transform modern society.
We could have power stations anywhere we wanted: solar panels floating in equatorial oceans, nuclear power plants in Antarctica, wind farms miles off coastlines, wherever. We could transmit their power directly to our homes and business as if they were right next door. This would cause an explosion in green, sustainable power generation; right now, we have to balance the optimal locations for generating such power with our ability to transmit electricity over long distances.
We could accelerate computing speeds, as we wouldn’t have to deal with the huge microprocessor design problem of cooling all those circuits.
We could have much cheaper, more prolific, and extremely accurate medical diagnostic equipment. Imagine getting an MRI from a machine that sits on a tabletop and is as easy and cheap to use as a doctor’s office X-ray machine.
💡Did You Know? One of the reasons MRI machines are so costly to operate is that they use superconductors to power super-strong flows of electricity, but the guts of the machine need to be cooled down to operate.
Superconductors could be used to control fusion reactions, bringing a brand-new source of renewable power with it. They can be used to levitate trains, allowing them to travel with as little friction as possible (something that we already do, but superconductors would allow them to be much cheaper).
Finally, we could go BIG. Superconducting wires can transmit more than 200 times more electricity than traditional copper wire. Wherever we needed a lot of electricity, for homes and business, work and pleasure, we could have it.
That’s why we keep searching, and that’s why news like LK-99 makes such a big splash. We are always dreaming, always striving for a future that’s better than our present. Room-temperature superconductors are one way to make that kind of future possible.
Got burning questions about astronomy, physics, or cosmology? Send them to [email protected], and we may address your query in a future story.
Paul M. Sutter is a science educator and a theoretical cosmologist at the Institute for Advanced Computational Science at Stony Brook University and the author of How to Die in Space: A Journey Through Dangerous Astrophysical Phenomena and Your Place in the Universe: Understanding Our Big, Messy Existence. Sutter is also the host of various science programs, and he’s on social media. Check out his Ask a Spaceman podcast and his YouTube page.
