Tattoos are an interesting technology. They’re a way of marking patterns and designs on the skin that can last for years or decades. All this, despite the fact that our skin sloughs off on a regular basis!
As it turns out, tattoos actually have a deep and complex interaction with our immune system, which hold some of the secrets regarding their longevity. New research has unveiled more insight into how the body responds when we get inked up.
Historically, nature has used trees to turn carbon dioxide back into oxygen for use by living creatures. The trees play a vital role in the carbon cycle, and have done so for millennia. Recently, humans have thrown things off a bit by getting rid of lots of trees and digging up a lot more carbon.
While great efforts are underway to replenish the world’s tree stocks, Belgrade has gone in a different direction, creating artificial “liquid trees” to capture carbon dioxide instead. This has spawned wild cries of dystopia and that the devices are an affront to nature. Let’s sidestep the hysteria and look at what’s actually going on.
Continue reading “The Liquid Trees Of Belgrade: The Facts Behind The Furore”
In the automotive world, batteries are quickly becoming the energy source of the future. For heavier-duty tasks, though, they simply don’t cut the mustard. Their energy density, being a small fraction of that of liquid fuels, just can’t get the job done. In areas like these, hydrogen holds some promise as a cleaner fuel of the future.
Universal Hydrogen hopes that hydrogen will do for aviation what batteries can’t. The company has been developing flight-ready fuel cells for this exact purpose, and has begun test flights towards that very goal.
Continue reading “Largest Ever Hydrogen Fuel Cell Plane Takes Flight”
Pneumatic tires provide a great ride, great grip, and yet have one fatal flaw — they’re always getting punctured and leaving you stranded. [The Q] decided to solve this problem with a unique design: tires that use tennis balls as the cushioning medium instead.
The build begins with small cut sections of plastic water pipe. These are used as housings to hold tennis balls, which are pressed in with a unique tool of [The Q]’s own construction. The individual ball assemblies are then bolted into a standard bicycle wheel, and a tread from a regular bike tire is stretched around the outside for grip.
It goes without saying that these tires won’t offer the same quality of ride as regular pneumatic bike tires. Nor will the performance be as good, due to the significant extra unsprung weight. They are eye-catching and fun, however. Plus, if you live in an area with tons of nails or prickles, you might find these are just the ticket. Maybe.
We’ve seen some other great bike hacks before, too.
Continue reading “Tennis Balls Serve As Decent Bicycle Tires That Don’t Easily Puncture”
Here at Hackaday, we love a good art piece, whether that involves light or sound. Combining both is a sure-fire way to get our attention, and [Eirik Brandal] did just that with his Void Extrusion piece.
The project is built around the Daisy Seed from Electrosmith. It’s an embedded platform designed for musical purposes, which made it perfect for [Eirik]’s project. Based on an STM32 chip, it’s very capable when it comes to DSP tasks. In this role, it’s charged with algorithmic music composition, providing the captivating soundtrack that emanates from the sculpture.
The sculpture itself looks almost like a fancy mid-century home from the Hollywood Hills, but it’s fundamentally a little more abstract than that. [Eirik] built it as an opportunity to experiment with using 3D printed forms in his work. To that end, it features a beautiful diffused LED wall and a speaker enclosure as an integral part of the build. The LEDs are run from an Arduino Nano Every.
[Eirik’s] work shows us that “generative” music can be intoxicating and compelling with a real sense of feeling and mood. The sculpture is a visually-capable pairing that works with the soundscape. It recalls us of some other great artworks we’ve featured from [Eirik] before, too.
Continue reading “Sound Sculpture Uses Daisy Seed To Generate Audio”
The cochlea is key to human hearing, and it plays an important role in our understanding of complex frequency content. The Visual Ear project aims to illustrate the cochlear mechanism as an educational tool.
The cochlea itself is the part of the ear that converts the pressure waves of sound into electrical signals for the brain. Different auditory frequencies excite different parts of the cochlea. The cells in the different parts of the cochlea then send signals to the brain corresponding to the sound it has picked up.
The Visual Ear demonstrates similar behavior on a strip of addressable LEDs. Lower LEDs coded in the red part of the color spectrum respond to low frequency audio. Higher LEDs step through yellow, green, and up to blue, and respond to the higher frequencies in turn. This is achieved at a high response rate with the use of a Teensy 4.0 running a Fast Fourier Transform on incoming audio, and then outputting signals to run a string of WS2812B LEDs. The result is a visual band display of 104 bands spanning 43 Hz up to 16,744 Hz, which covers most but not all of the human range of hearing.
It’s an impressive display, and one that makes a great music visualizer, too. When teaching the physics of human hearing and the cochlea, we can imagine such a tool would be quite useful.
Continue reading “Visual Ear Demonstrates How The Cochlea Works”
It’s always great fun to build your own robot. Sometimes, though, if you’re doing various projects or research, it’s easier to buy an existing robot and then use it to get down to business. That was very much the role of the Willow Garage PR2, but unfortunately, it’s no longer in production. However, as covered by The Robot Report, the design files have now been released for others to use.
The PR2 was built as an advanced platform with wide-ranging capabilities. It was able to manipulate objects with its 7-degrees-of-freedom end effectors, as well as visualize the real world with a variety of complex sensor packages. Researchers put it to work on a variety of tasks, from playing pool to fetching beers and even folding laundry. The latter one is still considered an unsolved problem that challenges even the best robots.
Rights to the PR2 robot landed in the hands of Clearpath Robotics, after Willow Garage was shut down in 2014. Clearpath is now providing access to the robot’s design files on its website. This includes everything from wiring diagrams and schematics, to assembly drawings, cable specs, and other background details. You’ll have to provide some personal information to get access, but the documentation you desire is all there.
We actually got our first look at the PR2 robot many years ago, way back in 2009. If you decide to build your own from scratch, be sure to hit us up on the tipsline.
