This result could be very big news, and overnight revolutionize all of electronics and energy. It might not.
Here's a mental model for the non-expert to understand what's going on.
RTAPS: The good, the bad, and the ugly: 🧵
Summary
The good: There's some plausibility here, and if so, it's game-changing
The bad: Reasonable chance this is a similar but different physical property
The ugly: Their plots, and engineering usefulness
Let me explain:
The Good:
Lee-Kim-Kwon (LKK) use familiar materials, Cuprates, and measures some key metrics of a room-temp superconductivity (SC):
- Zero-resistivity
- Critical current
- Critical magnetic field
- Meissner effect
For context, past progress was measured by successively higher temperatures using new kinds of materials. LKK result does fit the rough trend of increasing temperatures, but, they do it at ambient pressure.
The highest-temperature results before were at >1 million atmospheres
To understand, think of electrons normally bouncing off everything as they fall, plinko-style; in SC they glide smoothly. To make electrons glide, either you cool them down a lot, or squeeze them together.
Therefore you can sort of just trade pressure for temperature
The key difference in LKK paper is this: the channel for letting electrons glide doesn't come from low temp, or by squeezing together.
It comes from an internal tension that forms as the material forms, just like the tempered glass of a car windshield.
LKK hypothesis that copper atoms are percolating into the crystal and replacing lead atoms, and this creates a structural shrinkage of ~0.5% and produces internal strains, creating this smooth-electron-channel
Good: Plausible materials, fits an overall trend, easy to reproduce
The bad:
Normally the superconducting transition temperature is predicted by measuring heat capacity versus temperature. This is the Debye Temp.
TKK say they can't measure this, because the usual theories of SC don't explain their sample: a lil bit sus
There's two two papers published, which present results in different ways, using different scalings. One result seems almost unphysical altogether.
Normally SC's perfectly repel magnetic field, or have a diamagnetism of -1. These guys report it as -154
A 'super diamagnetic' could also weakly levitate itself above a large permanent magnet, like what the authors video shows.
There's some reason for caution here, but this could also boil down to non-standard presentation of results and genuine impurities in the sample
The ugly:
Some of their plots.
More seriously, there's really three numbers that are relevant for superconductors in engineering practice:
Current density, magnetic field, and temperature.
You can think of it as your 'magnet budget' that you get to spend on either high current density, high magnetic fields, or high temperature. There are limits too - you need to stay well below Tc, and, pushing the limits will burn out your magnets by 'quenching' them
If you want to design a magnetic confinement fusion reactor, you need a balance of all three: magnets that can withstand their own high field, be compact, and not require too much cooling
LKK haven't put out a full set of numbers on critical current density, just total current, so its hard to compare. However, magnets for fusion have to withstand fields of ~10 Tesla or more, or about 300x the fields that kill off SC in their samples
That being said, the temperatures these operate at are enormous by comparison. In Fusion, the magnet-killer is the neutron heat flux that escapes through the reactor walls and heats up your coils.
Heat-resistant coils would still make my job 10x easier
The net-net:
No champagne yet, but watch closely - this would be a serious game changer in things like power transmission, energy storage, and future-tech like quantum computers, fusion energy, mag-lev trains.
The Manhattan project didn't just invent the nuclear bomb, destroyer of worlds.
It forever changed the scale and scope of our collective scientific ambitions
It began what I call "Civilization-Scale Science" - and there's no greater force for progress today
Let me explain 🧵
2/ Before WW2 science was a cottage industry.
The best research groups in the world were often teams of 4-5 people, or like the Curies, husband-and-wife, working with tools they made themselves, with shoestring budget
This is the room where radioactivity was discovered
3/ Neutron capture is the principle behind both nuclear bombs and nuclear energy.
Fermi discovered it while working in his lab in Rome, with the "via Panisperna boys" - his research team.
Here's them in a team photo, and here's Fermi working in his lab
Fusion energy is the ultimate power source, but it's a complete zoo of different reactor designs.
Here's how each one works, the companies building them, explained in chronological order 🧵 1/N
0.1/
What is Fusion?
When you take hydrogen (or other fuel) and compress it for sufficient density, temperature, and time, the atomic nuclei 'fuse' together to form a heavier element.
This releases energy.
Deuterium-Tritium is the easiest to 'burn', but other fuels exist
0.2/
Many devices have been designed and built to achieve nuclear fusion, all striving for the "Lawson criterion" - when the fusion reaction becomes self-sustaining
Generations of scientists and engineers and their struggles for 'confinement' of plasma, in a single plot
There's no better analogue to cathedrals in the modern world than our mega-scale physics experiments.
Thousands of individual careers dedicated to constructing colossal works of cutting-edge engineering.
To better know the mind of god.
Here's six of my favorites:
#1
@ATLASexperiment is one of the main detectors along the LHC beam line at CERN and the largest particle detector ever created.
The experiment is a collaboration involving 6,003 members, out of which 3,822 are physicists from 257 institutions in 42 countries
#2
@LIGO is a project of more than 1,000 scientists from the US and other countries to detect gravitational waves emitted by events like the merger of black holes.
It measures changes in distance smaller than 1/10,000th the width of a proton. There are two exact copies of LIGO
A technology quietly maturing over the last 10 years that few people talk about.
But it's at the bottleneck of current limitations on GPU performance and compute.
A 🧵 on how Silicon Photonics will enable the next computing hardware revolution, starting with interconnect
2/ Mega-scale data centers and cloud computing business models have demanded computing architectures become disaggregated.
Specialized resources for video acceleration, AI/ML training and inference, HPC, and data storage are connected by petabytes-per-second bandwidth
2/ In the last 10 years, GPU power has grown by 8x, but interconnect power - how things talk to each other - has grown 25x. This heat is a major limitation on data center scale
Interconnect now consumes almost 25% of total system power in many state of the art systems.
SpaceX has reduced the cost to get to orbit by 100x.
This has quadrupled the space industry which is now on track to $1 trillion in size by 2030.
What if we could reduce this cost by another 100x, and put a kilogram in orbit for $10?
How To Get To Space: Rail-Gun Edition
2/ A railgun is able to accelerate metal projectiles to tens of kilometers per second - well within the range of velocities needed to escape a planets gravity well.
This isn't new - Robert Heinlein proposed a rail-gun on the moon for launching valuable minerals to Earth in 1966
3/
Physicist Gerard K. O'Neill held the first conference on Space Manufacturing at Princeton in 1975 (🛠️ @zebulgar).
O'Neill reached celebrity-like status. Rail guns, he argued, would become integral to supply rotating cylindrical space cities of the future: O'Neill Cylinders.
Every company builds products using the same limited set of available foundational technologies.
Every few decades Physics produces a fundamentally new 'thing' that changes what's physically possible.
High-temperature superconductors are coming, and they'll change everything.
2/ Superconductivity is a quantum-mechanical phenomenon at a macroscopic scale, leading to something that seems impossible - zero electrical resistance.
Barely out of the research laboratory, they already enable things like particle accelerators, quantum computers, and fusion.
3/ The physical effect of superconductivity is subtle - inside a metal is a 3D lattice of metal atoms, and a sea of electrons.
If the temperature is low enough, two electrons of opposite 'spin' can come together to form a Cooper pair.