Floating Buoy Measures Ocean Conditions

July 22, 2025 by Lewin Day 11 Comments

Out on Maui, [rabbitcreek] desired to keep track of local ocean conditions. The easiest way to do that was by having something out there in the water to measure them. Thus, they created a floating ocean sensor that could report back on what’s going on in the water.

The build uses a Xiao ESP32-S3 as the brains of the operation. It’s paired with a Wio-SX1262 radio kit, which sends LoRa signals over longer distances than is practical with the ESP32’s onboard WiFi and Bluetooth connections. The microcontroller is hooked up with a one-wire temperature sensor, a DF Robot turbidity sensor, and an MPU6050 gyroscope and accelerometer, which allow it to measure the water’s condition and the motion of the waves. The whole sensor package is wrapped up inside a 3D printed housing, with the rest of the electronics in a waterproof Pelican case.

It’s a neat project that combines a bunch of off-the-shelf components to do something useful. [rabbitcreek] notes that the data would be even more useful with a grid of such sensors all contributing to a larger dataset for further analysis. We’ve seen similar citizen science projects executed nicely before, too. If you’ve been doing your own ocean science, don’t hesitate to let us know what you’re up to on the tipsline!

Could Space Radiation Mutate Seeds For The Benefit Of Humanity?

July 8, 2025 by Lewin Day 32 Comments

Humans have forever been using all manner of techniques to better secure the food we need to sustain our lives. The practice of agriculture is intimately tied to the development of society, while techniques like selective breeding and animal husbandry have seen our plants and livestock deliver greater and more nourishing bounty as the millennia have gone by. More recently, more direct tools of genetic engineering have risen to prominence, further allowing us to tinker with our crops to make them do more of what we want.

Recently, however, scientists have been pursuing a bold new technique. Researchers have explored using radiation from space to potentially create greater crops to feed more of us than ever.

Continue reading “Could Space Radiation Mutate Seeds For The Benefit Of Humanity?” →

Measurement Is Science

June 21, 2025 by Elliot Williams 22 Comments

I was watching Ben Krasnow making iron nitride permanent magnets and was struck by the fact that about half of the video was about making a magnetometer – a device for measuring and characterizing the magnet that he’d just made. This is really the difference between doing science and just messing around: if you want to test or improve on a procedure, you have to be able to measure how well it works.

When he puts his home-made magnet into the device, Ben finds out that he’s made a basically mediocre magnet, compared with samples out of his amply stocked magnet drawer. But that’s a great first data point, and more importantly, the magnetometer build gives him a way of gauging future improvements.

Of course there’s a time and a place for “good enough is good enough”, and you can easily spend more time building the measurement apparatus for a particular project than simply running the experiment, but that’s not science. Have you ever gone down the measurement rabbit hole, spending more time validating or characterizing the effect than you do on producing it in the first place?

Disarming A Nuke… Twice

May 31, 2025 by Bryan Cockfield 26 Comments

Since the tail end of World War II, humanity has struggled to deal with its newfound ability to harness the tremendous energy in the nucleus of the atom. Of course there have been some positive developments like nuclear power which can produce tremendous amounts of electricity without the greenhouse gas emissions of fossil fuels. But largely humanity decided to build a tremendous nuclear weapons arsenal instead, which has not only cause general consternation worldwide but caused specific problems for one scientist in particular.

[Steve Weintz] takes us through the tale of [Dr. John C. Clark] who was working with the Atomic Energy Commission in the United States and found himself first at a misfire of a nuclear weapons test in the early 1950s. As the person in charge of the explosive device, it was his responsibility to safely disarm the weapon after it failed to detonate. He would find himself again in this position a year later when a second nuclear device sat on the test pad after the command to detonate it was given. Armed with only a hacksaw and some test equipment he was eventually able to disarm both devices safely.

One note for how treacherous this work actually was, outside of the obvious: although there were safety devices on the bombs to ensure the nuclear explosion would only occur under specific situations, there were also high explosives on the bomb that might have exploded even without triggering the nuclear explosion following it. Nuclear bombs and nuclear power plants aren’t the only things that the atomic age ushered in, though. There have been some other unique developments as well, like the nuclear gardens of the mid 1900s.

Flow Visualization With Schlieren Photography

May 8, 2025 by Tyler August 9 Comments

The word “Schlieren” is German, and translates roughly to “streaks”. What is streaky photography, and why might you want to use it in a project? And where did this funny term come from?

Think of the heat shimmer you can see on a hot day. From the ideal gas law, we know that hot air is less dense than cold air. Because of that density difference, it has a slightly lower refractive index. A light ray passing through a density gradient faces a gradient of refractive index, so is bent, hence the shimmer. Continue reading “Flow Visualization With Schlieren Photography” →

A picture of a single water droplet on top of what appears to be a page from a chemistry text. An orange particle is attached to the right side of the droplet and blue and black tendrils diffuse through the drop from it. Under the water drop, the caption tells us the reaction we're seeing is "K2Cr2O7+ 3H2O2 + 4H2SO4 = K2SO4+Cr2(SO4)3+7H2O+3O2(gas)"

Water Drops Serve As Canvas For Microchemistry Art

May 5, 2025 by Navarre Bartz 3 Comments

If you’re like us and you’ve been wondering where those viral videos of single water drop chemical reactions are coming from, we may have an answer. [yu3375349136], a scientist from Guangdong, has been producing some high quality microchemistry videos that are worth a watch.

While some polyglots out there won’t be phased, we appreciate the captioning for Western audiences using the elemental symbols we all know and love in addition to the Simplified Chinese. Reactions featured are typically colorful, but simple with a limited number of reagents. Being able to watch diffusion of the chemicals through the water drop and the results in the center when more than one chemical is used are mesmerizing.

We do wish there was a bit more substance to the presentation, and we’re aware not all readers will be thrilled to point their devices to Douyin (known outside of China as TikTok) to view them, but we have to admit some of the reactions are beautiful.

If you’re interested in other science-meets-art projects, how about thermal camera landscapes of Iceland, and given the comments on some of these videos, how do you tell if it’s AI or real anyway?

Building The Simplest Atomic Force Microscope

March 23, 2025 by Elliot Williams 22 Comments

Doing it yourself may not get you the most precise lab equipment in the world, but it gets you a hands-on appreciation of the techniques that just can’t be beat. Today’s example of this adage: [Stoppi] built an atomic force microscope out of mostly junk parts and got pretty good results, considering. (Original is in German; read it translated here.)

The traditional AFM setup uses a piezo micromotor to raise and lower the sample into a very, very fine point. When this point deflects, it reads the height from the piezo setup and a motor stage moves on to the next point. Resolution is essentially limited by how fine a point you can make and how precisely you can read from the motion stages. Here, [stoppi]’s motion stage follows the traditional hacker avenue of twin DVD sleds, but instead of a piezo motor, he bounces a laser off of a mirror on top of the point and reads the deflection with a line sensor. It’s a clever and much simpler solution.

A lot of the learnings here are in the machine build. Custom nichrome and tungsten tips are abandoned in favor of a presumably steel compass tip. The first-draft spring ended up wobbling in the X and Y directions, rather than just moving in the desired Z, so that mechanism got reinforced with aluminum blocks. And finally, the line sensors were easily swamped by the laser’s brightness, so neutral density filters were added to the project.

The result? A nice side effect of the laser-bouncing-off-of-mirror setup is that the minimum resolvable height can be increased simply by moving the line sensors further and further away from the sample, multiplying the deflection by the baseline. Across his kitchen, [stoppi] is easily able to resolve the 35-um height of a PCB’s copper pour. Not bad for junk bin parts, a point from a crafts store, and a line sensor.

If you want to know how far you can push a home ~~AFM~~ microscope project, check out [Dan Berard]’s absolutely classic hack. And once you have microscope images of every individual atom in the house, you’ll, of course, want to print them out.