COVID mask types compared (humor)

In this time of scarcity and uncertainty, we need reliable information more than ever.

Now that we are advised to wear masks in public, there is confusion about what kind of mask to wear and how much protection it provides, to us and to others.

Our purpose here is to provide simple, easy-to-understand answers to these vexing questions.

Continue reading “COVID mask types compared (humor)”

Sophomoric MIT student laser work

As undergrads in the late fall of 1969, John and I were both taking an optics course, six point something or other. It required a lab project. Perhaps primed by Star Trek and Mission Impossible, we ambitiously decided to build a long-distance laser communicator.

There was clear line-of-sight from the top of MIT Building 24, looking over the shoulder of the Great Dome, to my 5th-floor apartment on the other side of the Charles, on Mass Ave near Beacon St. At just over a kilometer, that seemed a long enough distance to prove the point. A safely low-milliwatt helium-neon laser (the red kind) would carry our signals. A high-voltage transistor would modulate the laser’s couple-hundred volt input power. (I think we asked first, before we tore into the laser to re-engineer our transistor into the circuit.) Continue reading “Sophomoric MIT student laser work”

H.S. robotics project

This is not a proposal, but a way to communicate just one fevered vision.


It seems a fair assumption that the Robotics Club members are interested in doing some robotics. But maybe they heard “Nope, we’re not doing robotics, not until FIRST in January. The rest of the year it’s just fundraising (collecting old shoes, selling candy bars) and leaning on parents to be mentors.”

Maybe there’s a robotics project that would help with fundraising. That would combine two problems into one solution.

Continue reading “H.S. robotics project”

Competition between scrum teams

An “agile” coach/consultant was brought into to a place where I once worked. Among other things, he said he likes to set up a little competition between scrum teams, with some (undisclosed) reward for the team with the best record of completing all tasks in the sprint, over some period of time. Here’s why I think that’s a terrible idea. Continue reading “Competition between scrum teams”

Ubuntu admin—users and groups

It seems that I do admin for Ubuntu users and groups just infrequently enough, that every time I have to go look this stuff up and decide which to use. So I collected it in one place that I should be able to find next time.  I put it here just in case it might help someone else in the meanwhile.

Continue reading “Ubuntu admin—users and groups”