Tag: materials science

  • Room-Temperature Superconductors: What Happened After LK-99 and Where the Search Stands

    In July 2023, a small Korean lab called Q-Centre posted two preprints claiming a material called LK-99 — a copper-doped lead apatite — was a room-temperature, ambient-pressure superconductor. The internet lost its mind. Stock markets moved. Twitch streamers watched replication attempts live. A Chinese researcher uploaded a levitation video to Bilibili that got 4.5 million views in nine hours. For approximately two weeks, it felt like humanity might have stumbled into the most transformative materials discovery of the century — a substance that conducts electricity with zero resistance at room temperature and normal pressure, which would transform power grids, computing, transportation, medical imaging, and essentially every system that moves electrons through wire.

    It wasn’t real. Within a month, labs worldwide had synthesized LK-99 and found no superconductivity. No zero resistance. No Meissner effect. No flux pinning. The partial levitation in the original Korean video turned out to be a ferromagnetic impurity — copper sulfide — not a superconducting phenomenon. A comprehensive rebuttal by Georgescu and colleagues, updated in early 2025 and published in Chemistry of Materials, dismantled the original claims point by point. LK-99 was a semiconductor with interesting magnetic properties. It was not a superconductor at any temperature.

    But LK-99 was only the most public failure. The field’s deeper wound came from Ranga Dias.

    The Dias fraud

    Ranga Dias, a physicist at the University of Rochester, published a paper in Nature in October 2020 claiming room-temperature superconductivity in a carbonaceous sulfur hydride under extreme pressure — roughly 267 gigapascals, the kind of pressure found near Earth’s core. Nature had actually ignored the majority opinion of its peer reviewers, who expressed serious concerns. The paper launched Dias to fame. Rochester doubled his salary. Venture capitalists courted his startup, Unearthly Materials, which raised $17 million to commercialize the discovery. Nobody could reproduce the results.

    In 2022, physicist James Hamlin at the University of Florida discovered that a section of the magnetic susceptibility data in Dias’s paper appeared to have been copied and pasted from one temperature range to another. Hamlin also found that Dias had plagiarized portions of his PhD thesis from Hamlin’s own earlier thesis. Nature retracted the 2020 paper in September 2022.

    Dias responded by publishing another room-temperature superconductor claim in Nature in March 2023 — nitrogen-doped lutetium hydride, this time at near-ambient pressure. The paper went through extra review. It didn’t matter. Other labs couldn’t replicate the results. Dias’s own graduate students contacted Nature with concerns about data validity. That paper was retracted in November 2023. A third retraction followed in Physical Review Letters. Then a fourth, then a fifth.

    In March 2024, a University of Rochester investigation — conducted by external physicists at the National Science Foundation’s request — concluded that Dias had engaged in “falsification, fabrication, and/or plagiarism of data, images, and text.” He was stripped of his students and laboratories. As of November 2024, he is no longer employed at Rochester. Five papers retracted. Millions in grants. A $17 million startup. And not a single reproducible result. As Lilia Boeri at Sapienza University of Rome put it, Dias’s “inconsiderate behaviour has harmed the reputation of the field.” James Hamlin, the physicist who caught the fraud, was more direct: the saga is “damaging to science in general, and superconductivity research more so.”

    Where the field actually stands

    Strip away LK-99 and Dias, and the legitimate science of superconductivity is in a more interesting place than the fraud cycle suggests. The highest confirmed superconducting temperature at ambient pressure remains around 135 Kelvin (-138°C), achieved in cuprate superconductors — the copper-containing ceramics discovered in 1986 that earned Bednorz and Müller the Nobel Prize. Under extreme pressure, lanthanum decahydride superconducts at 250 Kelvin (-23°C) at 150 gigapascals — genuinely close to room temperature, but at pressures that require diamond anvil cells and have no practical application.

    The real action is in nickelates. In February 2025, researchers at SLAC National Accelerator Laboratory and Stanford achieved a breakthrough that got far less public attention than LK-99 but matters considerably more: they stabilized a nickelate superconductor at room pressure for the first time. Nickelates are chemically similar to cuprates — the same class that holds the ambient-pressure temperature record — and had previously shown superconducting behavior only under extreme pressure. The SLAC team demonstrated that lateral compression from a substrate could stabilize the material without the diamond anvil cells that make high-pressure experiments impractical. This doesn’t mean nickelates superconduct at room temperature. They don’t, not yet. But it means researchers can now study them using advanced techniques like X-ray scattering that were impossible when the materials only existed under crushing pressure. The constraint has shifted from “can we make it at all” to “can we understand it well enough to improve it.”

    A separate advance came from Penn State in October 2025, where researchers used a framework called zentropy theory — merging statistical mechanics with quantum physics and computational modeling — to predict superconducting behavior from a material’s electronic structure. The approach correctly identified known superconductors and offered a method for screening candidate materials computationally rather than synthesizing thousands of compounds by trial and error.

    Then in March 2026, a programmatic research agenda published in the Proceedings of the National Academy of Sciences by a multi-institutional team laid out the case for a coordinated global push toward room-temperature superconductivity. The paper noted that no fundamental physical laws prevent it — the barrier is engineering and materials science, not physics. Recent advances in pressure quenching of the cuprate Hg-1223 achieved a record critical temperature of 151 Kelvin at ambient pressure. The authors argued that combining ab-initio computational simulations — now capable of modeling materials at the nanometer scale, a tenfold improvement over capabilities just a few years ago — with machine learning and AI-driven materials screening could systematically push critical temperatures higher. The paper reads less like a research summary and more like a call to arms: join forces worldwide, use modern computational tools, and treat room-temperature superconductivity as an engineering program rather than a lottery ticket.

    Why it matters and why it’s hard

    A room-temperature, ambient-pressure superconductor would eliminate the roughly 5 percent of electricity lost in transmission across the U.S. grid alone — a figure worth tens of billions of dollars annually and a meaningful reduction in carbon emissions without building a single new power plant. MRI machines, which currently require expensive liquid helium cooling for their superconducting magnets, could operate without cryogenics — relevant to anyone who’s read about the helium shortage and the supply chain fragility that makes every MRI refill a logistics problem. Maglev trains, which already use superconducting technology in Japan’s SCMaglev system, could become economically viable for mass transit instead of remaining engineering showcases. Particle accelerators, fusion reactors — where superconducting magnets are the enabling technology for plasma confinement — and quantum computers that currently require millikelvin temperatures to maintain superconducting qubits could all be transformed.

    The difficulty is that we don’t fully understand how high-temperature superconductivity works. In conventional superconductors, the mechanism — electrons forming Cooper pairs through interaction with the crystal lattice — is well understood and was described by Bardeen, Cooper, and Schrieffer in 1957. But the cuprate superconductors that hold the temperature record don’t follow this mechanism. Something else is creating the electron pairing, and after nearly four decades of research, there’s no consensus on what it is. You can’t engineer your way to a higher critical temperature when you don’t have a complete theory for why the current record holders work. The nickelate breakthrough matters precisely because it gives researchers a new family of materials to study alongside cuprates — same neighborhood of the periodic table, different structure, potentially different mechanism — which means more data points for the theorists to work with.

    The fraud problem is also a structural problem

    LK-99 and Dias didn’t happen in a vacuum. The incentive structure of academic science — where a single Nature paper can double a salary, launch a startup, and generate millions in grant funding — creates enormous pressure to produce extraordinary results. Room-temperature superconductivity is the most sought-after prize in condensed matter physics. The gap between “promising measurement” and “confirmed superconductor” requires demonstrating zero resistance, the Meissner effect, flux pinning, a temperature-dependent critical field and current, and a specific heat anomaly. LK-99’s original papers demonstrated none of these. Nature published Dias’s first claim over reviewer objections. The field’s quality-control mechanisms failed at every level, from peer review to institutional investigation — Rochester cleared Dias three times before external reviewers found the fraud.

    The March 2026 PNAS roadmap addresses this implicitly by calling for tighter integration between theory, computation, and experiment — essentially arguing that the field needs to stop waiting for someone to stumble onto a miracle material and start engineering candidates systematically. The AI-driven materials screening approach treats the problem the same way pharmaceutical companies treat drug discovery: model the candidates computationally, screen for promising properties, synthesize the top candidates, test rigorously, iterate. It’s less romantic than a eureka moment. It’s also less susceptible to fraud, because the computational predictions are independently verifiable before anyone walks into a lab.

    Room-temperature superconductivity occupies a strange position: it’s the moonshot where the physics explicitly permits success, the engineering hasn’t delivered it, and the most famous recent claims turned out to be fabricated. The legitimate science — nickelate stabilization at SLAC, zentropy theory at Penn State, AI-accelerated materials screening, the 151 K ambient-pressure record in Hg-1223 — is advancing on a timeline measured in decades, not press cycles. We cover it alongside solid-state batteries, fusion energy, and space-based solar power in our Moonshot 2169 course — where each technology gets the same treatment: define what “done” actually means, name the constraints that prevent it, separate the press releases from the physics, and be honest about how far the gap between laboratory demonstration and deployable technology really is.

  • Space Elevators in 2026: Engineering Fantasy or Eventual Reality?

    The concept is simple enough to explain on a napkin and difficult enough to build that it’s been 130 years since anyone first described it and we’re still nowhere close. You put a satellite in geostationary orbit—35,786 kilometers above the equator—and you lower a tether all the way down to the surface of the Earth. Anchor it at the bottom. Attach a counterweight above geostationary altitude to keep the whole thing taut. Then you send climbers up the tether, hauling cargo to orbit without a single gram of rocket fuel. The cost per kilogram to geostationary orbit drops from roughly $20,000 on a conventional launch vehicle to an estimated $500. The environmental impact drops to essentially zero. You could, in theory, send 170,000 metric tons to orbit per year on a mature system.

    The Russian scientist Konstantin Tsiolkovsky described the basic idea in 1895 after visiting the Eiffel Tower. Arthur C. Clarke popularized it in his 1979 novel The Fountains of Paradise. A 2003 NASA Innovative Advanced Concepts study concluded that a space elevator “could be built in the near future with acceptable risk and less funding than some current space programs.” The key word in that sentence turned out to be “could,” because twenty-three years later we still cannot manufacture the tether material, and the tether material is the entire problem.

    One material, and everything depends on it

    A space elevator tether needs to be 100,000 kilometers long, roughly one meter wide, and about as thick as plastic wrap. It needs to support its own weight—which, at that length, is enormous—plus the weight of multiple climbers carrying payloads. The required specific strength (tensile strength divided by density) is approximately 50 to 60 GPa·cm³/g. For reference, the specific strength of steel is about 0.25 GPa·cm³/g. Kevlar is about 2.5. The best carbon fiber composites reach maybe 4. You need a material that is roughly 15 to 25 times stronger per unit weight than the best structural material in common industrial use.

    In 2026, there are exactly three known materials with the theoretical tensile strength to serve as a space elevator tether: carbon nanotubes, single-crystal graphene, and hexagonal boron nitride. Carbon nanotubes have been the poster child for space elevator materials since the 1990s. Their theoretical tensile strength is approximately 150 GPa—more than adequate. The problem is manufacturing them. The longest single carbon nanotube ever publicly reported is 0.5 meters. Nanotube “forests”—bundles grown on a substrate—have reached 14 centimeters at Waseda University, at a growth rate of one meter every 186 hours. The tether requires 100,000 kilometers of continuous, defect-free material. The gap between 0.5 meters and 100,000 kilometers is not a gap that incremental manufacturing improvements are going to close on any human timescale.

    This is why the International Space Elevator Consortium—yes, there is one, and they publish monthly newsletters on tether materials research—has increasingly shifted its focus to graphene. Graphene was isolated for the first time in 2004 and won the Nobel Prize in 2010. Its theoretical tensile strength is approximately 130 GPa, comparable to carbon nanotubes. But here’s the critical difference: polycrystalline graphene can already be manufactured at lengths of one kilometer and speeds of two meters per minute. Multiple industrial companies are producing it commercially. The material isn’t at tether quality yet—you need single-crystal graphene with no grain boundaries or defects, manufactured as a continuous sheet at industrial scale—but the trajectory from “lab curiosity” to “industrial product” is incomparably more advanced than the trajectory for nanotubes.

    ISEC’s current leading candidate is what they call “graphene super laminate”—multiple layers of single-crystal graphene bonded together through a process they describe as “spot welding” using covalent carbon-carbon bonds. In theory, this creates a material where each layer retains graphene’s extraordinary in-plane strength while the interlayer bonds prevent the shearing weakness that plagues regular multilayer graphene. In September 2025, ISEC reported that spot-welding layers of graphene had been demonstrated in the lab and produced a material with diamond-like properties. In February 2026, they published research on atomic oxygen corrosion resistance of graphene super laminate—addressing one of the critical environmental hazards a tether would face in low Earth orbit.

    Whether graphene super laminate can actually be manufactured at 100,000-kilometer continuous lengths, at tether-quality purity, at a speed that doesn’t require decades of production time, and at a cost that makes the project economically viable rather than merely physically possible—that remains entirely undemonstrated. The gap has narrowed. The gap is still enormous.

    Everything else that’s also impossible

    The tether material gets all the attention because it’s the most obvious bottleneck, but it’s worth cataloging the other engineering challenges that would need to be solved even if someone handed you a perfect tether tomorrow.

    The climber system needs to ascend 35,786 kilometers to geostationary orbit. At reasonable speeds, that’s a multi-day journey—Obayashi Corporation’s 2012 design estimated eight days. The climber needs to be powered the entire way, and it can’t carry all its fuel because that would make it too heavy. Proposed solutions include ground-based lasers beaming power to photovoltaic cells on the climber, which introduces its own set of engineering problems including atmospheric attenuation, beam tracking accuracy across thousands of kilometers, and what happens to anything that accidentally flies through the beam path.

    Space debris. The tether passes through low Earth orbit, where thousands of tracked objects and millions of untracked fragments are traveling at orbital velocity—roughly 7.8 kilometers per second. A collision between a piece of debris the size of a marble and a tether the thickness of plastic wrap would be catastrophic. ISEC published a June 2025 analysis titled “The Space Elevator Tether and Space Debris: Irresistible Force Meets Impenetrable Object?” The paper-thin ribbon design proposed by researcher Bradley Edwards would help—a ribbon can survive small punctures because the stress redistributes across its width—but routine avoidance maneuvers for tracked debris would still be necessary, and the tether can’t exactly dodge.

    Atmospheric hazards. The bottom portion of the tether passes through the troposphere, where it encounters wind loads, lightning strikes, and weather of every variety. The portion passing through low Earth orbit encounters atomic oxygen, which corrodes most materials. The Van Allen radiation belts degrade molecular bonds over time—though studies suggest carbon nanotubes could survive radiation for over 1,000 years. Gravitational perturbations from the Moon and Sun create oscillations in the tether that need damping systems.

    The anchor station. The tether needs to be anchored at the equator, ideally on an ocean platform to allow positional adjustments and avoid geopolitical complications. Building and maintaining a floating platform capable of anchoring a structure under millions of newtons of tension, in equatorial waters, indefinitely, is itself a major engineering project.

    Where the money actually is in 2026

    A market research report published in March 2026 values the “space elevator market” at $720 million, projected to reach $1.16 billion by 2030. These numbers require some decoding, because there is no space elevator to buy or sell. What the market consists of is materials research (primarily carbon nanotubes, graphene, and boron nitride), climber system design, tether dynamics modeling, and related R&D. The major corporate names are Obayashi Corporation (which still maintains its 2050 target date for a completed space elevator), Shimizu Corporation, Tethers Unlimited, and the LiftPort Group—whose CEO admitted in 2019 that “little progress had been made” on their original space elevator ambitions despite years of effort.

    Google X investigated the concept around 2014 as part of its Rapid Evaluation R&D team. They concluded that nobody had manufactured a perfectly formed carbon nanotube strand longer than a meter and put the project in “deep freeze,” where it has remained. They reportedly keep tabs on materials science advances, which is Silicon Valley’s polite way of saying “we’ll wait.”

    The honest assessment

    The International Academy of Astronautics published feasibility assessments in 2013 and 2019, both concluding that Earth-based space elevators are feasible in principle and that the critical bottleneck is the tether material, which they projected could achieve the necessary specific strength “within 20 years.” That projection, made in 2013, would put the material breakthrough at approximately 2033. The graphene super laminate research is consistent with that timeline in the sense that the trajectory is visible, even if the destination hasn’t been reached.

    Obayashi’s 2050 target—an operational space elevator with an eight-day trip to geostationary orbit—is the most specific commitment from a credible engineering firm. Whether it’s achievable depends almost entirely on whether single-crystal graphene or an equivalent material can be manufactured at scale within the next decade, which is a materials science question that nobody can answer with confidence.

    The comparison that clarifies the situation: in 1903, the Wright brothers flew at Kitty Hawk. In 1969, Apollo 11 landed on the Moon. Sixty-six years from first powered flight to lunar landing. The space elevator concept has existed for 130 years. The materials science necessary to build it has been actively researched for roughly 30. The longest carbon nanotube is half a meter. The required tether is 100,000 kilometers. The concept is not fantasy—the physics is sound, the engineering challenges are understood, and the materials are making measurable progress. But “eventual reality” is doing a lot of work in that phrase, and “eventual” might mean 2050, or 2080, or later, depending on breakthroughs that cannot be scheduled.

    We cover space elevators alongside 23 other civilization-scale engineering challenges—from fusion reactors to ocean thermal energy to asteroid mining—across our Moonshot 2169 course. If the gap between “the physics works” and “we can actually build it” is where your brain lives, the course is 24 lectures of exactly that tension.