This installment of Retrotechtacular looks at a video lecture that is much more substantive than the usual fare. [Dr. J.N. Shive] was a researcher at Bell Labs at a time when just about every technological breakthrough was coming from that singular collection of minds.
This video, called Similarities of Wave Behavior, was made to help bring students up to speed on the principles of waves. To aid in the experience he invented the apparatus seen in front of him. It’s called a Shive Wave Machine (in the prelude to the video they call it the Shive Wave Generator). Having not taken any physics classes at University we hadn’t seen one of these devices before. It uses a series of horizontal rods connected to each other with torsion wire. When you upset the balance of one of the rods the wire conducts that energy to its neighbors as an energy wave. This turns out to be a perfect representation of wave action whether it be mechanical, electrical, or acoustic. The 28-minute video after the break makes extensive use of the device, and explains concepts in a way that is easy to understand for just about anyone.
[via Reddit]
You don’t necessarily need to take university physics to see one of these. Many science museums have them on display too. I’m pretty sure the MoS in Boston, MA should still have one, at least they used to when I was a kid. :-)
Nowadays you’re lucky if they demo this in a university, or anything else for that matter.
I’d wish my electronics teatcher had this setup, took me quite a while to “visualise” this while a 20 minute video explains it all.
I HAVE to build one of these and post a video on Hack A week!
The challenging part of this project will be precisely drilling the holes in the rods and anchoring the rods to the wire. The spacing of the rods will also be important as this will have an influence on the wave amplitude and propagation. I’m looking forward to the challenge!
Just use duct tape, skewers, and flask stoppers. :)
http://www.dailybits.com/duct-tape-wave-machine/
It looks like the rods are spot-welded to the central wire (which is a much easier construction method than glue or drilling!).
Indeed they are! I hadn’t noticed that the first time. Thanks for pointing that out. MUCH easier being that I have a MIG welder. :)
Thank you Dino. I look forward to seeing it. I’d love to build one, too.
OH the heady days of science when people used just their minds. Computers are a boon, no doubt. But they’ve made us all all a little lax in the mental visualization department.
This video is *not* an example of using just one’s mind to visualize. Instead, it’s an example of using *sticks and wires* to visualize. As for me, I’m don’t feel lax when I use Mathematica instead of sticks and wires. Tools is tools.
Oh man, I spent weeks coding up simulations of this stuff just to see it in a simple manner. Would have saved a lot of time and headache to have a device like that around.
My community college has one, but I haven’t taken the class which demonstrates it. I’m going to send the vid to my GROL professor though, it explains some things we didn’t cover well.
We had one of these in my high school physics class.
Get a copy of the old PSCC course from the 70s….. Lots of material like this.
Teachers for my kids had nothing of this old material since they knew nothing of what they were “teaching”. Just following books as drones…..
what does pscc stand for?
This is one case where adding controllable LEDs would be amazing. I’d love to see interfering wave flashes being sent down LEDs that are attached to each end.
90% of my electrical engineering teachers couldn’t teach this in a semester, what this guy explains in 30 mins.
They need to consolidate this type of teaching styles and knowledge and teach everyone the same way. Today we have a convoluted mess of teachers, half of whom can’t get the simplest ideas across. Only the students lose. When I taught in college, I felt ashamed if at least 90% of my students didn’t understand the concept being taught.
That is friggin’ awesome. That just made a whole lot of theoretical math jump over to practically visible for me. Plus, Professor Cupcakez at the beginning made me crack up.
Very nice, but he has the acoustic case backwards … it’s an open end that gives an inverted reflection and a closed end that gives a right-side-up one.
nice lecture. i think i learned something.
Wait, so the bones in my ear, the lens on my camera, the gearbox in my robot, and the thing attaching a microphone to a speaker all impedance matching buffers?! I feel like my head just imploded.
A portable Shive Wave Machine I built for sale on Ebay: