Science

1209 Articles

A 3D-printed case encloses a number of electronic components. In the top left of the case, a laser diode is mounted. In the top right, the laser beam is shining into a cuvette, which is glowing red from scattered light. In the bottom right, a small breadboard has an integrated circuit and a few parts mounted. In the bottom left is a large red circuit board marked “Rich UNO R3.”

Measuring Nanoparticles By Scattering A Laser

August 30, 2025 by 6 Comments

A fundamental difficulty of working with nanoparticles is that your objects of study are too small for an optical microscope to resolve, and thus measuring their size can be quite a challenge. Of course, if you have a scanning electron microscope, measuring particle size is straightforward. But for less well-equipped labs, a dynamic light scattering system, such as [Etienne]’s OpenDLS, fits the bill.

Dynamic light scattering works by shining a laser beam into a suspension of fine particles, then using a light sensor to measure the intensity of light scattered onto a certain point. As the particles undergo Brownian motion, the intensity of the scattered light changes. Based on the speed with which the scattered light varies, it’s possible to calculate the speed of the moving particles, and thus their size.

The OpenDLS uses a 3D printed and laser-cut frame to hold a small laser diode, which shines into a cuvette, on the side of which is the light sensor. [Etienne] tried a few different options, including a photoresistor and a light sensor designed for Arduino, but eventually chose a photodiode with a two-stage transimpedance amplifier. An Arduino samples the data at 67 kHz, then sends it over serial to a host computer, which uses SciPy and NumPy to analyse the data. Unfortunately, we were about six years late in getting to this story, and the Python program is a bit out of date by now (it was written in Python 2). It shouldn’t, however, be too hard for a motivated hacker to update.

With a standard 188 nm polystyrene dispersion, the OpenDLS calculated a size of 167 nm. Such underestimation seemed to be a persistent issue, probably caused by light being scattered multiple times. More dilution of the suspension would help, but it would also make the signal harder to measure, and the system’s already running near the limits of the hardware.

This isn’t the only creative way to measure the size of small particles, nor even the only way to investigate small particles optically. Of course, if you do have an electron microscope, nanoparticles make a good test target.

An image of a pigeon on the left and a breakdown of six of the different kind of feathers on the bird. The bird's right wing is white with black dots and has an arrow pointing to it saying, "Developing wing with feather buds." The left wing is grey with one feather highlighted in pink with the text "Adult wing with feathers" at the end of an arrow pointing to it. The six feather types on the right side of the image are flight feathers, illustrated in pink with the text "enable flight, support aerodynamic loads, morph depending on flying style, building blocks for wing planaform." In green, we have tail feathers and the text "Maneuverability and controlability." In blue are the contour feathers, accompanied by the text, "streamline, camouflage, and sexual display. Found above filoplumes and semiplumes." A black floofy branched structure shows us the downy feathers next to the text "thermal insulation." Filoplumes and semiplumes look to be both thin and bushy feathers in black with the text "Sense underlying feathers, found above downy feathers." Finally, we have a black, stick-like bristle feather with the text "Protect face and eyes, sense surroundings."

Feathers Are Fantastic, But Flummoxing For Engineers

August 29, 2025 by 7 Comments

Birds are pretty amazing creatures, and one of the most amazing things about them and their non-avian predecessors are feathers. Engineers and scientists are finding inspiration from them in surprising ways.

The light weight and high strength of feathers has inspired those who look to soar the skies, dating back at least as far as Ancient Greece, but the multifunctional nature of these marvels has led to advancements in photonics, thermal regulation, and acoustics. The water repellency of feathers has also led to interesting new applications in both food safety and water desalination beyond the obvious water repellent clothing.

Sebastian Hendrickx-Rodriguez, the lead researcher on a new paper about the structure of bird feathers states, “Our first instinct as engineers is often to change the material chemistry,” but feathers are made in thousands of varieties to achieve different advantageous outcomes from a single material, keratin. Being biological in nature also means feathers have a degree of self repair that human-made materials can only dream of. For now, some researchers are building biohybrid devices with real bird feathers, but as we continue our march toward manufacturing at smaller and smaller scales, perhaps our robots will sprout wings of their own. Evolution has a several billion year head start, so we may need to be a little patient with researchers.

Some birds really don’t appreciate Big Brother any more than we do. If you’re looking for some feathery inspiration for your next flying machine, how about covert feathers. And we’d be remiss not to look back at the Take Flight With Feather Contest that focused on the Adafruit board with the same name.

One of the photo-detector spheres of ARCA (Credit: KM3NeT)

Confirmation Of Record 220 PeV Cosmic Neutrino Hit On Earth

August 26, 2025 by 11 Comments

Neutrinos are exceedingly common in the Universe, with billions of them zipping around us throughout the day from a variety of sources. Due to their extremely low mass and no electric charge they barely ever interact with other particles, making these so-called ‘ghost particles’ very hard to detect. That said, when they do interact the result is rather spectacular as they impart significant kinetic energy. The resulting flash of energy is used by neutrino detectors, with most neutrinos generally pegging out at around 10 petaelectronvolt (PeV), except for a 2023 event.

This neutrino event which occurred on February 13th back in 2023 was detected by the KM3NeT/ARCA detector and has now been classified as an ultra-high energy neutrino event at 220 PeV, suggesting that it was likely a cosmogenic neutrinos. When we originally reported on this KM3-230213A event, the data was still being analyzed based on a detected muon from the neutrino interaction even, with the researchers also having to exclude the possibility of it being a sensor glitch.

By comparing the KM3-230213A event data with data from other events at other detectors, it was possible to deduce that the most likely explanation was one of these ultra-high energy neutrinos. Since these are relatively rare compared to neutrinos that originate within or near Earth’s solar system, it’ll likely take a while for more of these detection events. As the KM3NeT/ARCA detector grid is still being expanded, we may see many more of them in Earth’s oceans. After all, if a neutrino hits a particle but there’s no sensor around to detect it, we’d never know it happened.

Top image: One of the photo-detector spheres of ARCA (Credit: KM3NeT)

Food Irradiation Is Not As Bad As It Sounds

August 19, 2025 by 50 Comments

Radiation is a bad thing that we don’t want to be exposed to, or so the conventional wisdom goes. We’re most familiar with it in the context of industrial risks and the stories of nuclear disasters that threaten entire cities and contaminate local food chains. It’s certainly not something you’d want anywhere near your dinner, right?

You might then be surprised to find that a great deal of research has been conducted into the process of food irradiation. It’s actually intended to ensure food is safer for human consumption, and has become widely used around the world.

Continue reading “Food Irradiation Is Not As Bad As It Sounds” →

Antiviral PPE For The Next Pandemic

August 19, 2025 by 35 Comments

In what sounds like the plot from a sci-fi movie, scientists have isolated an incredibly rare immune mutation to create a universal antiviral treatment.

Only present in a few dozen people worldwide, ISG15 immunodeficiency causes people to be more susceptible to certain bacterial illnesses, but it also grants the people with this condition immunity to known viruses. Researchers think that the constant, mild inflammation these individuals experience is at the root of the immunoresponse.

Where things get really interesting is how the researchers have found a way to stimulate protein production of the most beneficial 10 proteins of the 60 created by the natural mutation using 10 mRNA sequences inside a lipid nanoparticle. Lead researcher [Dusan Bogunovic] says “we have yet to find a virus that can break through the therapy’s defenses.” Researchers hope the treatment can be administered to first responders as a sort of biological Personal protective equipment (PPE) against the next pandemic since it would likely work against unknown viruses before new targeted vaccines could be developed.

Hamsters and mice were given this treatment via nasal drip, but how about intranasal vaccines when it comes time for human trials? If you want a short history of viruses or to learn how smartwatches could help flatten the curve for the next pandemic, we’ve got you covered.

Gentle Processing Makes Better Rubber That Cracks Less

August 15, 2025 by 19 Comments

Rubber! It starts out as a goopy material harvested from special trees, and is then processed into a resilient, flexible material used for innumerable important purposes. In the vast majority of applications, rubber is prized for its elasticity, which eventually goes away with repeated stress cycles, exposure to heat, and time. When a rubber part starts to show cracks, it’s generally time to replace it.

Researchers at Harvard have now found a way to potentially increase rubber’s ability to withstand cracking. The paper, published in Nature Sustainability, outlines how the material can be treated to provide far greater durability and toughness.

Continue reading “Gentle Processing Makes Better Rubber That Cracks Less” →

How The Widget Revolutionized Canned Beer

August 14, 2025 by 76 Comments

Walk into any pub and order a pint of Guinness, and you’ll witness a mesmerizing ritual. The bartender pulls the tap, fills the glass two-thirds full, then sets it aside to settle before topping it off with that iconic creamy head. But crack open a can of Guinness at home, and something magical happens without any theatrical waiting period. Pour it out, and you get that same cascading foam effect that made the beer famous.

But how is it done? It’s all thanks to a tiny little device that is affectionately known as The Widget.

Continue reading “How The Widget Revolutionized Canned Beer” →