Precision, Imprecision, Intellectual Honesty, And Little Green Men

October 18, 2025 by Elliot Williams 32 Comments

If you’ve been following the hubbub about 3I/ATLAS, you’re probably either in the camp that thinks it’s just a comet from ridiculously far away that’s managed to find its way into our solar system, or you’re preparing for an alien invasion. (Lukewarm take: it’s just a fast moving comet.) But that doesn’t stop it from being interesting – its relatively fast speed and odd trajectory make astronomers wonder where it’s coming from, and give us clues about how old it is likely to be.

Astronomy is the odd-man-out in the natural sciences. In most branches of physics, chemistry, and even biology, you can run experiments. Even those non-experimental corners of the above fields, like botany, for instance, you can get your hands on the objects you’re talking about. Not so astronomy. When I was studying in college, one of my professors quipped that astronomers were pretty happy when they could hammer down a value within an order of magnitude, and ecstatic when they could get a factor of two or three. The deck is simply stacked against them.

With that background, I love two recent papers about 3I/ATLAS. The first tries to figure out why it’s moving so fast by figuring out if it’s been going that fast since its sun kicked it out, or if it has picked up a gravitational boost along the way. While they can’t go all the way back in time, they’ve worked out whether it has flown by anything close enough to get a significant boost over the last 10 million years. This is impressive that we can calculate the trajectory so far back, but at the same time, 10 million years is peanuts on the cosmic timescale.

According to another paper, there is a weak relationship between interstellar objects’ age and their velocity, with faster-moving rocks being older, they can estimate the age of 3I/ATLAS at between 7.6 and 14 billion years old, assuming no gravitational boosts along the way. While an age range of 7 billion years may seem like a lot, that’s only a factor of two. A winner for astronomy!

Snarkiness aside, its old age does make a testable prediction, namely that it should be relatively full of water ice. So as 3I/ATLAS comes closer to the sun in the next few weeks, we’ll either see it spitting off lots of water vapor, and the age prediction checks out, or we won’t, and they’ll need to figure out why.

Whatever happens, I appreciate how astronomers aren’t afraid to outline what they can’t know – orbital dynamics further back than a certain date, or the precise age of rocks based solely on their velocity. Most have also been cautious about calling the comet a spaceship. On the other hand, if it is, one thing’s for sure: after a longer-than-10-million-year road trip, whoever is on board that thing is going to be hungry.

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?