The core components of a mobile phone are small enough for rectal insertion, so there's really no limit to what shape a phone can take (something you can verify with your own eyes in Shenzhen, where phones are unbelievably cheap (no, cheaper than that), and come in every shape and size). Read the rest
If the novelty of holding an elaborate bearing (possibly connected to some motion-sensitive LEDs) is wearing thin, have no fear: with a 3D printer and a little ingenuity, you can make your own double-pendulum fidget spinner, a chaotic system that is intensely sensitive to initial conditions, such that it becomes very hard to predict the motion of the pendulum when you set it to swinging. Read the rest
Since fidget spinners were originally designed to help people manage their ADHD, BuzzFeed asked people with the condition to try out spinners for a week and report back on their experiences. Read the rest
Jonathan Odom -- aka Jon-a-Tron -- worked out that the fidget-spinner fad has created a world where we're all holding spinny things all the time, and that means we could all be holding amazing, awesome zoetropes! Read the rest
Just for kicks, Australian auto system manufacturer AXT Turbo put a fidget spinner in a vice and blasted it with an air compressor:
We were playing around with the fidget spinner after work, seeing how fast and what the structural integrity of the unit is. We first started with finger on it until it got a little hot. Then we put in in a vice. After it let go, we calculated it was turning 50000 plus RPM.
(via Laughing Squid)
"Engaging in fine motor activity may assist students with ADHD in resisting the pull of distraction."
Wired's Rhett Allain built a rig with a laser and light sensor to study fidget spinner physics and determine how long it will spin based on the starting angular velocity. Allain's article will make a great teachable moment for my kids, as in I'll ask them to read it and explain it to me. From Wired:
If I know the starting angular speed and I assume a final angular speed of zero radians per second, I can calculate the spin time:Read the rest
All I need is the angular acceleration—assuming it remains constant as the spinner slows. I could calculate the angular acceleration based on the change in angular velocity, but this isn’t so simple to measure. The spinner moves too quickly to get a good video of its motion, so I will use a laser in a rig I built to measure the change in the angular velocity.
Basically, the laser shines down onto a light sensor. As the spinner spins, it occasionally blocks the sensor, interrupting the laser. By measuring the values from the light sensor, I determine the spin rate. But this creates a couple of problems. First, the light change rate and the rotation rate differ because the three “lobes” in the spinner create multiple openings during each rotation. Second, the spinner will spin for a significant amount of time such that it would be difficult to analyze it all at once...
Now for the fun trick. Instead of looking at a giant plot of light vs. time (the full data is over 2 minutes), I will plot the Fourier transform of this data.