over the past month news of LK 99 a
potential room temperature
superconductor set the internet allies
superconductivity means lossless power
transfer it means electrons travel
freely through a material without losing
power to resistance we already have
superconductors but we need to cool them
down to very low temperatures to achieve
the effect MRI machines use them to
generate a magnetic field so strong that
we can manipulate hydrogens in our flesh
in order to look inside our bodies
maglev trains use them to levitate a
train full of passengers off the ground
and propel them forward faster than any
other train technology the need to cool
these coils to extremely cold
temperatures makes it impractical at
larger scales room temperature
superconductors would open the
technology to incredible new
applications we could build a global
lossless energy grid power from solar
farms in Africa and Europe could send
power to the Americas during their night
and then in return they could send that
power back across the ocean during
Europe and Africa's night the
intermittency of Renewables would be a
minor problem with a Global Network of
lossless interconnecting power cables we
could pass electricity not just across
the Earth's night and day zones but our
summer and winter zones too cheap clean
energy for the entire planet room
temperature superconductors are a Holy
Grail technology and over the past two
decades numerous teams have claimed room
temperature superconductivity but each
time they turned out to be false and
often are clouded in allegations of
academic dishonesty the latest claim of
a room temperature superconductor set
researchers Around the World Racing to
replicate the findings but yet again the
claims appear to be false so how do
superconductors work and why are we
struggling to unlock the next stepping
stone in human technological progress
let's delve deeper into what
superconductors are their current
applications and what x citing prospects
the future may hold for these remarkable
materials
temperature affects all metallic
conductors with resistance gradually
lowering with temperature but
superconducting materials are special in
that their resistance drops to zero at
temperatures close to minus 273 degrees
Celsius the critical temperature in
theory when this happens an electric
current could travel in a loop of
superconducting material indefinitely
never needing a power source while we
can't truly measure indefinitely there
have been practical instances where
superconducting currents have flowed
uninterrupted for decades here in
Belgium a superconducting sensor is
being used to measure gravitational
forces and has been in operation for
over 28 years without any loss of
current it works by levitating a
superconducting sphere in a
superconducting coil in a stable
position then we can track its position
which changes with gravitational forces
superconductivity is more common than
you'd think a little under half of the
elements on the periodic table exhibit
superconductivity at low temperatures
and when combining elements together or
increasing their pressure even more
materials exhibit the phenomenon
initially the underlying mechanism
behind superconductivity was a mystery
however in 1957 three scientists
explained it in this groundbreaking
paper at any temperature above absolute
zero all molecules shake a little this
means that electrons in a conductor slow
down as they bump into the shaking
Crystal molecules this is why conductors
have some resistance but at ultra low
temperatures crystal lattices in
superconductors vibrate less slow enough
to allow one electron to draw nearby
atoms together creating a positively
charged region that attracts another
electron this enables electrons which
usually repel each other to interact and
form pairs over nanometer scale
distances known as Cooper pairs electron
pairs in superconductors behave as a
single cohesive particle that occur
according to Quantum Mechanics can only
absorb energy at specific intervals this
cohesion creates an energy gap only
particles with the right energy can
interact with Cooper pairs this is why
the crystals need to be cooled down to
such low temperatures below 40 Kelvin
they don't have enough energy to
interact with the Cooper pairs so
electrons just Glide along without
interacting with the material leading to
no energy loss due to resistance however
in 1986 a new discovery blasted this
explanation out of the water introducing
the world to a new material that
couldn't be explained IBM researchers
identified a class of ceramic materials
that could display high temperature
superconductivity based on their
research another material with a
critical temperature of 93 Kelvin was
found a year later high temperature
being relative this is just over the
boiling point of liquid nitrogen of 77
Kelvin still cold but critically liquid
nitrogen is a affordable to create one
liter of liquid nitrogen it can cost as
little as 15 cents these materials have
more intricate Crystal structures
involving layers of different elements
like copper oxide which contribute to
their High critical temperatures because
these materials couldn't be explained
through conventional Cooper pair Theory
a new category of materials was created
called unconventional superconductors
and we still do not fully understand how
these materials work but a lack of a
full theory has not stopped us from
using them we have created some
unconventional superconducting
transmission cables like this one just
south of Seoul in South Korea it
connects two substations that power a
growing residential Zone they were
already connected by two high voltage
conventional lines that were struggling
to meet the increasing power demand and
adding another conventional cable would
have required new Transformers at each
station to convert the high transmission
voltage into the medium distribution
voltage and there was no space for
another Transformer so the engineers
turned to superconductors to solve the
problem we transfer power over longer
distances with high voltages to reduce
power losses due to heat but we can't
use that voltage in our homes so we need
to step it down to a lower voltage using
a Transformer however if we didn't have
to worry about losses we could just
transfer the power everywhere at the
lower voltage this is exactly what the
superconducting line allowed and in 2019
it became the first commercial high
temperature superconducting Cable in the
world it's a one kilometer AC cable
which transports energy in three
different phases they used this
configuration where three cables are run
parallel to each other to make it easier
for the liquid nitrogen traveling by
them to keep them cool approximately
half a kilogram Travels by every second
the liquid nitrogen is pumped through at
66 Kelvin to avoid losing heat the
cables are surrounded by a stainless
steel vacuum chamber of course some heat
does leak in raising the outlet
temperature by 3 Kelvin amounting to a
three kilowatt energy loss the same as
30 100 watt household fridges one of the
interesting problems facing this cable
is the material properties of the
superconducting tape which is wrapped
around a copper Center core high
temperature superconductors are more
brittle and have a lower tensile
strength than a conventional conductor
these two substations had straight empty
conduits between them allowing the cable
to be rooted without much bending which
would break it the high cost of
superconducting cables makes them hard
to justify economically as a result of
higher material costs and extra cooling
systems it costs hundreds of dollars to
transfer one kilo amp over one meter
while a traditional cable costs about
ten dollars the South Korean project was
a unique problem that needed a unique
solution that justified the extra costs
this is why a room temperature
superconductor would be game changing
when the the news of LK 99 broke images
of the levitating material spread across
the internet but levitation doesn't
necessarily mean superconducting other
materials can levitate through a
mechanism called diamagnetism water is a
little diamagnetic so we can actually
levitate small animals with this effect
diamagnetism simply means that when the
material becomes magnetic when placed in
a magnetic field its own magnetic field
is in the opposite direction magnetic
fields cannot be canceled so these
materials just redirect the lines around
themselves this results in a measurable
repulsive force between the material and
the magnetic field quantifying this
effect involves suspending the material
with a force caliper in a magnetic field
and measuring the change in weight
caused by the repulsion this is what the
graph would look like when quantifying
the diomagnetism of a superconductor a
straight line at high temperatures but a
sharp change at their critical
temperature becoming a perfect diamagnus
at this point all magnetic field lines
are expelled outside the material and
the material just levitates above the
magnet this is called the Meisner effect
but even though we have tests like this
it doesn't stop researchers from lying
in 2019 a research team reported
discovering a room temperature
superconductor and backed it up with
data showing perfect diamagnetism but
upon further examination the data was
found to have been copied from another
paper with so much world-changing
potential researchers often rush to push
their papers out as quickly as possible
this is why the skepticism was so high
for the LK 99 announcement the South
Korean team published their results on a
pre-published website and it raised some
red flags the first paper posted on
archive had three authors two hours
later a similar paper was posted but
this time it had five an odd choice that
seems to point to a fight for the
recognition of the discovery later one
of the authors said the paper was full
of errors and was posed without his
consent fortunately the team provided
clear replication instructions and 11
Labs worldwide have published
preliminary results the first and most
obvious piece of evidence are the videos
of the material levitating on top of a
Magnus LK 99 definitely has some
diamagnetic properties that have been
replicated by other teams this is the
resistivity data the South Korean team
presented a sharp drop in resistance
around 380 Kelvin the temperature at
which this happens in the replication
samples varies from 100 Kelvin to 400
Kelvin and in all the samples resistance
never truly drops to zero the range of
results points to an impure material so
a German team created a sample of LK 99
using a different process one that uses
inert gases in a tube to remove the
sample's exposure to impurities creating
a pure lk99 sample is was transparent
rather than gray and actually turned out
to be an insulator with some diamagnetic
property
all this evidence points to lk99 having
some interesting properties but it is
not a superconductor the world
understandably got a little excited
about the potential of this discovery
being able to harness the power of
superconductivity is a literal
superpower and we are still learning how
exactly it works it's astounding that we
already have functional Technologies
like these high temperature
superconductors in South Korea that make
the technology vastly more accessible
for now high temperature superconducting
cables have some good use cases intense
Urban centers like Seoul where limited
space and ever increasing power demand
opens the door to futuristic
Technologies and hopefully with its
success prices can begin to lower as we
figure out ways to lower the material
and Manufacturing costs while increasing
efficiency the world-changing effects of
being able to transport a large amount
of electricity with no losses across
further and further distances cannot be
overstated the enthusiasm of science
artists who believe they made a
world-changing discovery is perfectly
understandable it would be a discovery
that would mark their names in history
forever
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