There is, of course, only one appropriate way to respond in a situation like this: with another comic.
Back in 2011, I wrote an era-appropriate semi-autobiographical rage comic, that I could use as a standard response when people sent me that comic.
Joking aside, we really do spend a lot of our time engineering— and many of our friends and colleagues are bona fide engineers. On the other hand, I love to cook, but that doesn’t make me a chef either.
Biosphere 2 is an enormous earth science laboratory, originally built as an attempt to create a closed ecosystem. The goals were to study long term viability of an isolated human habitat, such as might be needed for long term space travel or colonization.
The results of the initial experiments were a (fascinating) mixed bag. The goal of a strictly closed ecosystem was not met for a variety of reasons. However, some of the results have improved our understanding of the effects of climate change, such as how increased CO2 levels lead to acidification of the ocean habitat and coral bleaching.
The facility is now being used both for education and for research. The enormous agricultural greenhouses have been transformed by the University of Arizona into the Landscape Evolutionary Observatory, a large-scale carefully-controlled long-term study of soil processes. It serves as an experimental bridge between computer models, small-scale laboratory experiments, and the real world.
Some of the original biomes are relatively unchanged and have been growing since the project started in 1991. It is striking to have all hint of surrounding desert obscured by the vines of the rainforest.
One of the most fascinating engineering aspects of the facility are the “lungs,” which are accessed through long narrow tunnels branching off of the main facility.
The lungs were used to compensate for the changes in pressure and temperature. The two domed buildings have flexible inner liners that can expand and contract. A weight attached to the center of the liner makes them look toroidal inside of the dome.
The facility was built outside of Tucson, and is strikingly beautiful, surrounded by wildlife including lizards, snakes, tarantulas, jack rabbits, coyotes, gila monsters, and an incredible variety of birds and insects. We’ve put a few more pictures from our visit in albums on flickr here and here. Tours are available to the public daily, and it’s worth the drive and ticket price if you’re nearby.
We found a remake from our project Make your own 1952 Fraction-of-an-inch Adding Machine on display at Xerocraft, a hackerspace in Tucson. They cut and engraved the calculator out of hardboard using their laser cutter. It’s sturdier than papercraft and it looks great!
Our co-founder Windell Oskay is the guest on Cool Tools this week, and talks about some of his favorite tools, ranging from pencils to soldering irons. You can read about them or listen to the full podcast.
- 10 Cuts: How to make wooden pliers (YouTube, embedded above)
- Inside the TWA terminal at JFK, a “time capsule from 1962.”
- Emu vs Weasel Ball (YouTube)
- How does pumping a swing work?
- Historic spacecraft illustrations, CC-licensed.
- Echochamber.js — a brilliantly cynical approach to blog comments (via Scanner)
- Wintogreen Lifesaver Flash (YouTube, via @xek)
- Super-K neutrino detector news: EGADS! GADZOOKS!
- The Straight Dope on pronunciation of ancient languages
- Computer-generated handwriting: Paper (arxiv.org), online examples
- Aldrovanda vesiculos: An aquatic carnivorous plant
- Receiving weather satellite data on your computer
- A filmmaker debunks the moon landing hoax
Our two “dis-integrated circuit” kits are the Three Fives Discrete 555 Timer, and the XL741 Discrete Op-Amp. These two kits are functional, transistor-level replicas of the original NE555 and μA741 (respectively), which are two of the most popular integrated circuits of all time.
Last year, we wrote up a detailed educational supplement for the Three Fives kit, that works through its circuit diagram and discusses its principles of operation down to the transistor level. Today, we are doing the same for the XL741 kit, and releasing an educational supplement that explains how a ‘741 op-amp IC works internally, down to its bare transistors and resistors:
This ability to peek inside the circuit makes the XL741 a unique educational tool. In what follows, we’ll work through the circuit diagram, discuss the theory of operation of the ‘741 op-amp, and present some opportunities for experiments and further exploration.
You can download the supplement here: XL741 Principles of Operation (1.1 MB PDF)
- Get the XL741 kit at our store.
- Our original article here, announcing the XL741 kit
- Main XL741 documentation page at our documentation wiki
Steve W. wrote in to share his improvement on the method for making wire bundles we wrote about:
I’ve used the bend-it-over-and-stuff-it-in-the-chuck approach, but was not fully happy with it.
So I drilled a 1/8″ hole in the back of a binder clip. The drilling is easy if you clip a ~3/8 scrap of wood.
A 4-40 SHCS screw long enough to allow me to actuate the clip was not threaded all the way to the head, so I used a 1/4″ spacer between the binder clip and the 4-40 nut. (Pan head screws are usually 100% threaded, but I would have had to look in the dreaded ‘other’ box to find one of those). Having the nut up against the chuck acted as a lock-nut. I had been surprised when I first tried this that I did not have to work harder to keep it from loosening. I had expected I might need a lock washer, and/or a second nut to lock the first.
Just grabbing the wires with the binder clip (my original plan) was not secure. So I wrap the wires 180 degrees around a screwdriver bit and put that in the clip.
Works great, and it is quick to pop in and out when twisting many groups of wires.
Thanks for sharing your hack and sending the photos!