An illustration of jellyfish swimming in the ocean by Rebecca Konte. The jellyfish are wearing cones on their "heads" to streamline their swimming that contain some sort of electronics inside.

The Six Million Dollar Jellyfish

March 1, 2024 by Navarre Bartz 14 Comments

What if you could rebuild a jellyfish: better, stronger, faster than it was before? Caltech now has the technology to build bionic jellyfish.

Studying the ocean given its influence on the rest of the climate is an important scientific task, but the wild pressure differences as you descend into the eternal darkness make it a non-trivial engineering problem. While we’ve sent people to the the deepest parts of the ocean, submersibles are much too expensive and risky to use for widespread data acquisition.

The researchers found in previous work that making a cyborg jellyfish was more effective than biomimetic jellyfish robots, and have now given the “biohybrid robotic jellyfish” a 3D-printed, neutrally buoyant, swimming cap. In combination with the previously-developed “pacemaker,” these cyborg jellyfish can explore the ocean (in a straight line) at 4.5x the speed of a conventional moon jelly while carrying a scientific payload. Future work hopes to make them steerable like the well-known robo-cockroaches.

If you’re interested in some other attempts to explore Earth’s oceans, how about drift buoys, an Open CTD, or an Open ROV? Just don’t forget to keep the noise down!

Continue reading “The Six Million Dollar Jellyfish” →

NASA Found Another Super Earth With Tantalizing Possibilities

February 29, 2024 by Lewin Day 57 Comments

Earth is a rather special place, quite unlike the other planets in the solar system. It’s nestled at the perfect distance from the sun to allow our water to remain liquid and for life to flourish in turn. It’s a rare thing; most planets are either too close and scorching hot, or too far and freezing cold.

NASA is always on the hunt for planets like our own, and recently found a new super-Earth by the name of TOI-715b. The planet is larger than our own, but it’s position and makeup mean that it’s a prime candidate for further study. Let’s take a look at how NASA discovered this planet, and why it’s special.

Continue reading “NASA Found Another Super Earth With Tantalizing Possibilities” →

The Strange Metal Phase And Its Implications For Superconductivity

February 28, 2024 by Maya Posch 1 Comment

The behavior of electrons and the exact fundamentals underlying the phenomenon we call ‘electricity’ are still the subject of many competing theories and heated debates. This is most apparent in the area of superconducting research, where the Fermi liquid theory — which has has formed the foundation of much of what we thought we knew about interacting fermions and by extension electrons in a metal — was found to break down in cuprates as well as in other metals which feature a state that is a non-Fermi liquid, also called a ‘strange metal phase’.

This phase was the subject of a 2023 research article by [Liyang Chen] and colleagues in Science titled Shot Noise in a Strange Metal. As summarized in a Quanta Magazine article, the term ‘shot noise’ refers hereby to the quasiparticles that are postulated by the Fermi liquid theory to form part of the electrical current as electrons interact and ‘clump’ together, creating discrete ‘particles’ that can be measured like rain drops falling on a roof. [Liyang Chen] and colleagues created a 200 nm thin nanowire (pictured, top) out of ytterbium, rhodium and silicon, followed by cooling it down to a few Kelvin and measuring the current.

What the team found was no sign of these discrete quasiparticles, but rather non-Fermi liquid continuous current. Yet what is exactly the nature of this measured current? Quite a few attempts at explaining this phenomenon have been undertaken, e.g. Jianfan Wang et al. (2022) in rare-earth intermetallic compounds. More recently [Riccardo Arpaia] and colleagues explore charge density fluctuations (CDF) as a signature of the quantum critical point (QCP), which is a point in the phase diagram where a continuous phase transition takes place at absolute zero.

They studied the CDF using X-ray scattering in cuprate superconductors with a wide doping range, using the measured CDF as an indication of the QCP, indicating that the former may be a result of the latter. With these results mostly inspiring more discussion and research, it’ll probably be a while still before we risk replacing the Fermi liquid theory, or apply strange metal findings to produce high-temperature superconductors.

Ask Hackaday: What If You Did Have A Room Temperature Superconductor?

February 26, 2024 by Al Williams 80 Comments

The news doesn’t go long without some kind of superconductor announcement these days. Unfortunately, these come in several categories: materials that require warmer temperatures than previous materials but still require cryogenic cooling, materials that require very high pressures, or materials that, on closer examination, aren’t really superconductors. But it is clear the holy grail is a superconducting material that works at reasonable temperatures in ambient temperature. Most people call that a room-temperature superconductor, but the reality is you really want an “ordinary temperature and pressure superconductor,” but that’s a mouthful.

In the Hackaday bunker, we’ve been kicking around what we will do when the day comes that someone nails it. It isn’t like we have a bunch of unfinished projects that we need superconductors to complete. Other than making it easier to float magnets, what are we going to do with a room-temperature superconductor? Continue reading “Ask Hackaday: What If You Did Have A Room Temperature Superconductor?” →

You Got Fusion In My Coal Plant!

February 24, 2024 by Navarre Bartz 48 Comments

While coal was predominant in the past for energy generation, plants are shutting down worldwide to improve air quality and because they aren’t cost-competitive. It’s possible that idle infrastructure could be put to good use with fusion instead.

While we’ve yet to see a fusion reactor capable of generating electricity, Type One Energy, the Tennessee Valley Authority, and Oak Ridge National Lab have announced they’re evaluating the recently-closed Bull Run Fossil Plant in Oak Ridge, Tennessee as a site for a nuclear fusion reactor. One of the main advantages for siting any new generation source on top of an old one is the ability to reuse the existing transmission infrastructure to get any generated power to the grid.

Don’t get too excited as it sounds like this is yet another prototype reactor that will be the proof-of-concept before construction of a reactor that can produce commercial power for the grid. While ambitious, the amount of investment by government entities like the Department of Energy and the state of Tennessee (>$55 million) seems to indicate they aren’t just blowing smoke.

If any of this seems familiar, you might be thinking of the Department of Energy’s report on placing advanced fission reactors on old coal sites. A little fuzzy on the difference between a stellarator and a tokamak? Checkout this explainer on some of the different ways to (non-explosively) do fusion on Earth.

Mirror, Mirror, Electron Mirror…

February 23, 2024 by Al Williams 2 Comments

If you look into an electron mirror, you don’t expect to see your reflection. As [Anthony Francis-Jones] points out, what you do see is hard to explain. The key to an electron mirror is that the electric and magnetic fields are 90 degrees apart, and the electrons are 90 degrees from both.

You need a few strange items to make it all work, including an electron gun with a scintillating screen in a low-pressure tube. Once he sets an electric field going, the blue line representing the electrons goes from straight to curved.

Continue reading “Mirror, Mirror, Electron Mirror…” →

Rebuilding A $700k Refrigerator

February 21, 2024 by Bryan Cockfield 20 Comments

When cleaning out basements, garages, or storage units we often come across things long forgotten. Old clothes, toys, maybe a piece of exercise equipment, or even an old piece of furniture. [Ben] and [Hugh] were in a similar situation cleaning out an unused lab at the University of California Santa Barbara and happened upon an old refrigerator. This wasn’t just a mini fridge left over from a college dorm, though. This is a dilution refrigerator which is capable of cooling things down to near absolute zero, and these scientists are trying to get it to its former working state.

The pair are hoping to restore the equipment to perform dark matter experiments, but the refrigerator hasn’t been in use since about 2016 (and doesn’t have an instruction manual), which is a long time for a piece of specialty scientific equipment to be collecting dust. The first step is to remove wiring and clean it of all the grime it’s accumulated in the last decade. After that, the pair work to reassemble the layers of insulation around the main cooling plate and then hook up a vacuum pump to the device which also needed some repair work.

The critical step at this point is to evacuate the refrigerant lines so they can be filled with expensive Helium-3 and Helium-4. The problem is that there’s still some of this valuable gas in the lines that needs to be recovered, but the risk is that if any air gets into the cold section of the refrigerator it will freeze and clog the whole system. After chasing some other electrical and vacuum gremlins and discovering a manual from a similar refrigerator, they eventually get it up and running and ready for new scientific experiments. While most of us won’t discover a fridge like this cleaning out our attics, this refrigerator powered by rubber bands is a little more accessible to the rest of us.

Continue reading “Rebuilding A $700k Refrigerator” →