You might think that anything to do with a soap bubble is for kids. But it turns out that observing light scattering through a soap bubble produces unexpected results that may lead to insights into concepts as complex as space-time curvature. That’s what [stoppi] says in his latest experiment — generating “light whiskers” using a laser and a soap bubble. You can watch the video, below, but fair warning: if videos with only music annoy you, you might want to mute your speakers before you watch. On the other hand, it almost seems like a laser light show set to music.
The setup is simple and follows a 2020 Israeli-American research paper’s methodology. A relatively strong laser pointer couples to a fiber-optic cable through a focusing lens. The other end of the fiber delivers the light to the soap bubble, where it separates into strands that exhibit something called branched flow.
Our physics knowledge isn’t deep enough to explain what’s going on here. However, if you have an interest in reproducing this experiment, it doesn’t look like it takes anything exotic. The original paper has a lot to say on the topic and if that’s too heavy for you, there’s always the Sunday supplement version.
Bubble lights are mesmerizing things to watch, up there with lava lamps as one of the nicer aesthetic creations of the mid-20th century. [Tech Ingredients] decided to head into the lab to whip up some of their own design, taking things up a notch beyond what you’d typically find in a store.
Bubble lights have a liquid inside glass that is held under a vacuum. This reduces the boiling point of the fluid, allowing a small heat input to easily create bubbles that float to the top of the chamber inside. The fluid used inside is also chosen for its low boiling point, with [Tech Ingredients] choosing dichloromethane for safety when using flames to work the glass.
The video shows off the basic glass working techniques required to make the glass bubble tubes, as well as how to build the bases of the bubble lamps that light the fluid up and provide the heat to create bubbles. The use of different materials to create nucleation points for the boiling fluid is also discussed, giving different visual effects in the final result. It’s a great primer on getting started building these beautiful decorations yourself.
Bubbles are pretty things, and with different techniques, we’ve even seen them used to make displays. Video after the break.
While working towards his Computing and Information Systems degree at the University of London, [Jason Fenech] submitted an interesting proposal for generating random numbers using nothing more exotic than an aquarium and a sufficiently high resolution camera. Not only does his BubbleRNG make a rather relaxing sound while in operation, but according to tools such as ENT, NIST-STS, and DieHard, appears to be a source of true randomness.
If you want to build your own BubbleRNG, all you need is a tank of water and some air pumps to generate the bubbles. A webcam looking down on the surface of the water captures the chaos that ensues when the columns of bubbles generated by each pump collide. In the video after the break [Jason] uses two pumps, but considering they’re cheaper than lava lamps, we’d probably chuck a few more into the mix. To be on the safe side, he mentions that the placement and number of pumps should be arbitrary and not repeated on subsequent installations.
To turn this tiny maelstrom into a source of random numbers, OpenCV is first used to identify the bubbles in the video stream that are between a user-supplied minimum and maximum radius. The software then captures the X and Y coordinates of each bubble, and the resulting values are shuffled around and XOR’d until a stream of random numbers comes out the other end. What you do with this cheap source of infinite improbability is, of course, up to you.
While this project has been floating around (no pun intended) the Internet for a few years now, it seems to have gone largely overlooked, and was only just brought to our attention thanks to a tip from one of our illustrious readers. An excellent reminder that if you see something interesting out there, we’d love to hear about it.
We’ve seen a lot of unique large-format scrolling message boards on these pages, but most of them use some sort of established technology – LEDs, electromechanical flip-dots, and the like – in new and unusual ways. We’re pretty sure this air-bubble dot matrix display is a first, though.
While it may not be destined for the front of a bus or a train station arrivals and departures board, [jellmeister]’s bubble display shows some pretty creative thinking. It started with a scrap of multiwall polycarbonate roofing – Corotherm is the brand name – of the type to glaze greenhouses and other structures. The parallel tubes are perfect for the display, although individual tubes could certainly be substituted. A plastic end cap was fabricated; air nozzles in each channel were plumbed to an air supply through solenoid valves. An Arduino with a couple of motor driver hats allows pulses of air into each channel to create reasonably legible characters that float up the tube. The video below shows it in use at a Maker Faire, where visitors could bubble up their own messages.
It took some tweaking to get it looking as good as it does, but there’s plenty of room for improvement. We wonder whether colored liquid might help, or perhaps adding a Neopixel or even a laser to each channel to add some contrast. Maybe something to cloud the water slightly would help; increasing the surface tension with a salt solution might make the bubbles more distinct. We doubt it’ll ever have the contrast ratio of a flip-dot display, but it certainly has a charm all its own.
Because nothing says “fun for kids” like barbed wire and hypodermic needles, here’s an interactive real-world game that everyone can enjoy. Think of it as a kinder, gentler version of Robot Wars, where the object of the game is to pop the balloon on the other player’s robot before yours get popped. Sounds simple, but the simple games are often the most engaging, and that sure seems to be the case here.
The current incarnation of “Bubble Blast” stems from a project [Niklas Roy] undertook for a festival in Tunisia in 2017. That first version used heavily hacked toy RC cars controlled with arcade joysticks. It was a big hit with the crowd, so [Niklas] built a second version for another festival, and incorporated lessons learned from version 1.0. The new robots are built from scratch from 3D-printed parts. Two motors drive each bot, with remote control provided by a 433-MHz transceiver module. The UI was greatly improved with big trackballs, also scratch built. The game field was expanded and extra obstacles were added, including a barbed wire border as a hazard to the festooned bots. And just for fun, [Niklas] added a bubble machine, also built from scratch.
The game looks like a ton of fun, and seems like one of those things you’ve got to shoo the adults away from so the kids can enjoy it too. But if you need more gore from your robot deathmatch than a limp balloon, here’s a tabletop robot war that’s sure to please.
Post an animation on Reddit of a workable machine that looks neat and does something cool and the next day someone will have built it. That’s what happened when [The-Big-Ship] uploaded an animation of a clever bubble making machine — though we had to look twice to convince ourselves that it wasn’t real. The next day [Over_Engineered_2] posted a video of his working one.
We often hear that you need precision CAD software such as Solidworks and AutoCAD to design a functional machine but the animation was done using Cinema 4D, used for films such as Iron Man 3 and Tron: Legacy. This shows that you can at least get a reassurance that the basic mechanics will fit and move together without having to design precision parts.
That’s not to say that reality didn’t interfere with implementing it though. In [Over_Engineered_2]’s video below he points out that the bigger ring of the original animation didn’t work with his small motor and propeller, and had to switch to the smaller ring. Also, note that the ring needed guide rails on the sides to keep it from twisting, something a real world ignoring animation can get away without. Check out the videos below to see the two in action.
If you ever wanted to make an occasion festive with bubbles, [Sandeep_UNO] may have the project for you. As you can see in the video below (and, yes, it should have the phone rotated and it doesn’t), his Arduino uses a servo motor to dip a bubble wand into soap solution and then pulls it in front of a fan. The entire operation repeats over and over again.
There’s not a lot of detail and no code that we could find, but honestly, if you know how to drive a servo motor from an Arduino, the rest is pretty easy to figure out. Look closely at the motion of the robot. What is often accomplished with a spinning wheel of bubble wands and a constant fan becomes much more interesting when applied intermittently. The lazy cadence is what you expect to see from human operation and that adds something to the effect.