Is Fire Conductive Enough To Power A Lamp?

February 2, 2025 by Maya Posch 17 Comments

Is fire conductive? As ridiculous that may sound at first glance, from a physics perspective the rapid oxidation process we call ‘fire’ produces a lot of substances that can reduce the electrical insulating (dielectric) properties of air. Is this change enough to allow for significant current to pass? To test this, [The Action Lab] on YouTube ran some experiments after being called out on this apparent fact in the comments to an earlier video.

Ultimately what you need to make ‘fire’ conductive is to have an appreciable amount of plasma to reduce the dielectric constant, which means that you cannot just use any rapid oxidation process. In the demonstration with lights and what appears to be a (relatively clean-burning) butane torch, the current conducted is not enough to light up an incandescent or LED light bulb, but can light up a 5 mm LED. When using his arm as a de-facto sensor, it does not conduct enough current to be noticeable.

The more interesting experiment here demonstrates the difference in dielectric breakdown of air at different temperatures. As the dielectric constant for hot air is much lower than for room temperature air, even a clean burning torch is enough to register on a multimeter. Ultimately this seems to be the biggest hazard with fire around exposed (HV) electrical systems, as the ionic density of most types of fire just isn’t high enough.

To reliably strike a conductive plasma arc, you’d need something like explosive (copper) wire and a few thousand joules to pump through it.

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Patching Up Failing Hearts With Engineered Muscle Tissue

January 30, 2025 by Maya Posch 3 Comments

As the most important muscle in our body, any serious issues with our heart are considered critical and reason for replacement with a donor heart. Unfortunately donor hearts are rather rare, making alternatives absolutely necessary, or at the very least a way to coax the old heart along for longer. A new method here seems to be literally patching up a patient’s heart with healthy heart tissue, per the first human study results by [Ahmad-Fawad Jebran] et al. as published in Nature (as well as a partially paywalled accompanying article).

Currently, simple artificial hearts are a popular bridging method, which provide a patient with effectively a supporting pump. This new method is more refined, in that it uses induced pluripotent stem cells (iPS) from an existing hiPSC cell line (TC1133) which are then coaxed into forming cardiomyocytes and stromal cells, effectively engineered heart muscle (EHM). After first testing this procedure on rhesus macaque monkeys, a human trial was started involving a 46-year old woman with heart failure after a heart attack a few years prior.

During an operation in 2021, 10 patches of EHMs containing about 400 million cells each were grafted onto the failing heart. When this patient received a donor heart three months later, the removed old heart was examined and the newly grafted sections found to be healthy, including the development of blood vessels.

Although currently purely intended to be a way to keep people alive until they can get a donor heart, this research opens the tantalizing possibility of repairing a patient’s heart using their own cells, which would be significantly easier than growing (or bioprinting) an entire heart from scratch, while providing the benefit of such tissue patches grown from one’s own iPS cells not evoking an immune response and thus mitigating the need for life-long immune system suppressant drugs.

Featured image: Explanted heart obtained 3 months after EHM implantation, showing the healthy grafts. (Credit: Jebran et al., 2025, Nature)

Crystal structure of a monolayer of transition metal dichalcogenide.(Credit: 3113Ian, Wikimedia)

Transition-Metal Dichalcogenides: Super-Conducting, Super-Capacitor Semiconductors

January 28, 2025 by Maya Posch 3 Comments

Transition-metal dichalcogenides (TMDs) are the subject of an emerging field in semiconductor research, with these materials offering a range of useful properties that include not only semiconductor applications, but also in superconducting material research and in supercapacitors. A recent number of papers have been published on these latter two applications, with [Rui] et al. demonstrating superconductivity in (InSe₂)_xNbSe₂. The superconducting transition occurred at 11.6 K with ambient pressure.

Two review papers on transition metal sulfide TMDs as supercapacitor electrodes were also recently published by [Mohammad Shariq] et al. and [Can Zhang] et al. showing it to be a highly promising material owing to strong redox properties. As usual there are plenty of challenges to bring something like TMDs from the laboratory to a production line, but TMDs (really TMD monolayers) have already seen structures like field effect transistors (FETs) made with them, and used in sensing applications.

TMDs consist of a transition-metal (M, e.g. molybdenum, tungsten) and a chalcogen atom (X, e.g. sulfur) in a monolayer with two X atoms (yellow in the above image) encapsulating a single M atom (black). Much like with other monolayers like graphene, molybdenene and goldene, it is this configuration that gives rise to unexpected properties. In the case of TMDs, some have a direct band gap, making them very suitable for transistors and perhaps most interestingly also for directly growing 3D semiconductor structures.

Heading image: Crystal structure of a monolayer of transition metal dichalcogenide.(Credit: 3113Ian, Wikimedia)

Big Chemistry: Catalysts

January 28, 2025 by Dan Maloney 19 Comments

I was fascinated by the idea of jet packs when I was a kid. They were sci-fi magic, and the idea that you could strap into an oversized backpack wrapped in tinfoil and fly around was very enticing. Better still was when I learned that these things weren’t powered by complicated rockets but by plain hydrogen peroxide, which violently decomposes into water and oxygen when it comes in contact with a metal like silver or platinum. Of course I ran right to the medicine cabinet to fetch a bottle of peroxide to drip on a spoon from my mother’s good silverware set. Needless to say, I was sorely disappointed by the results.

My little impromptu experiment went wrong in many ways, not least because the old bottle of peroxide I used probably had little of the reactive compound left in it. Given enough time, the decomposition of peroxide will happen all by itself. To be useful in a jet pack, this reaction has to proceed much, much faster, which was what the silver was for. The silver (or rather, a coating of samarium nitrate on the silver) acted as a catalyst that vastly increased the rate of peroxide decomposition, enough to produce jets of steam and oxygen with enough thrust to propel the wearer into the air. Using 90% pure peroxide would have helped too.

As it is for jet packs, so it is with industrial chemistry. Bulk chemical processes can rarely be left to their own devices, as some reactions proceed so slowly that they’d be commercially infeasible. Catalysts are the key to the chemistry we need to keep the world running, and reactors full of them are a major feature of many of the processes of Big Chemistry.

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Contrails Are A Hot Topic, But What Is To Be Done?

January 27, 2025 by Lewin Day 75 Comments

Most of us first spot them as children—the white lines in the blue sky that are the telltale sign of a flight overhead. Contrails are an instant visual reminder of air travel, and a source of much controversy in recent decades. Put aside the overblown conspiracies, though, and there are some genuine scientific concerns to explore.

See, those white streaks planes leave in the sky aren’t just eye-catching. It seems they may also be having a notable impact on our climate. Recent research shows their warming effect is comparable to the impact of aviation’s CO₂ emissions. The question is then simple—how do we stop these icy lines from heating our precious Earth?

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Schematic of quantum measurement basis on whiteboard

Shedding Light On Quantum Measurement With Calcite

January 26, 2025 by Heidi Ulrich 19 Comments

Have you ever struggled with the concept of quantum measurement, feeling it’s unnecessarily abstract? You’re not alone. Enter this guide by [Mithuna] from Looking Glass Universe, where she circles back on the concept of measurement basis in quantum mechanics using a rather simple piece of calcite crystal. We wrote about similar endeavours in reflection on Shanni Prutchi’s talk at the Hackaday SuperConference in 2015. If that memory got a bit dusty in your mind, here’s a quick course to make things click again.

In essence, calcite splits a beam of light into two dots based on polarization. By aligning filters and rotating angles, you can observe how light behaves when forced into ‘choices’. The dots you see are a direct representation of the light’s polarization states. Now this isn’t just a neat trick for photons; it’s a practical window into the probability-driven nature of quantum systems.

Even with just one photon passing through per second, the calcite setup demonstrates how light ‘chooses’ a path, revealing the probabilistic essence of quantum mechanics. Using common materials (laser pointers, polarizing filters, and calcite), anyone can reproduce this experiment at home.

If this sparks curiosity, explore Hackaday’s archives for quantum mechanics. Or just find yourself a good slice of calcite online, steal the laser pointer from your cat’s toy bin, and get going!

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Making Wire Explode With 4,000 Joules Of Energy

January 21, 2025 by Maya Posch 80 Comments

The piece of copper wire moments before getting vaporized by 4,000 joules. (Credit: Hyperspace Pirate, Youtube)

In lieu of high-explosives, an exploding wire circuit can make for an interesting substitute. As [Hyperspace Pirate] demonstrates in a recent video, the act of pumping a lot of current very fast through a thin piece of metal can make for a rather violent detonation. The basic idea is that by having the metal wire (or equivalent) being subjected to a sufficiently large amount of power, it will not just burn through, but effectively vaporize, creating a very localized stream of plasma for the current to keep travelling through and create a major shockwave in the process.

This makes the exploding wire method (EWM) an ideal circuit for any application where you need to have a very fast, very precise generating of plasma and an easy to synchronize detonation. EWM was first demonstrated in the 18th century in the Netherlands by [Martin van Marum]. These days it finds use for creating metal nanoparticles, brief momentary light sources and detonators in explosives, including for nuclear (implosion type) weapons.

While it sounds easy enough to just strap a honkin’ big battery of capacitors to a switch and a piece of wire, [Hyperspace Pirate]’s video demonstrates that it’s a bit more involved than that. Switching so much current at high voltages ended up destroying a solid-state (SCR) switch, and factors like resistance and capacitance can turn an exploding wire into merely a heated one that breaks before any plasma or arcing can take place, or waste a lot of potential energy.

As for whether it’s ‘try at home’ safe, note that he had to move to an abandoned industrial site due to the noise levels, and the resulting machine he cobbled together involves a lot of high-voltage wiring. Hearing protection and extreme caution are more than warranted.

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