Light blogging alert...

Light blogging alert...  I'm traveling to Virginia this morning, to visit with my mom and siblings.  I'll be lugging my computer along, but I probably won't be blogging very much...

The return of the analog computer?

The return of the analog computer?  Sort of.  I worked on (as a maintenance tech) electro-mechanical analog fire control computers in the Navy.  Those computers did integration and differentiation with gears, and arbitrary functions with cams.  They were computers that could give you the wrong answer if you didn't keep them clean and lubricated.  They were also far more interesting to watch work than a modern digital computer :)

How to guarantee the continued inferiority of U.S. broadband access?

How to guarantee the continued inferiority of U.S. broadband access?  Simple.  Just get the federal government involved.  That will put us into North Korean territory.

There's a solution already proven to work: completely deregulate the industry, and eliminate all government-granted monopolies (especially the cable company monopolies).  This is the approach Estonia took, and the result of competition unleashed is crazy high broadband speeds, access everywhere, and prices lower than our current crap broadband...

Twisted string actuators...

Twisted string actuators...  I had this idea about 15 years ago, after using an old-fashioned twisted wire-and-stick to straighten up a fence gate.  I did some investigation of it, never realizing that anyone else had done so already.  I came to the same conclusion others did: that the problems outweighed the benefits:

We spent a fair bit of time evaluating twisted string actuators to build low-cost robots. Unfortunately, they have some major problems that are tough to overcome for our specific application(s). For one, their lifecycle is measured in the many thousands instead of millions -- despite our best efforts at material engineering. For another, they are highly nonlinear in response (twists vs displacement), which requires very precise calibration for precision movements. Plus, they're inherently linear motors; for rotary motion, you need two opposing motors or spring-return mechanisms. That said.... there are probably a lot of applications that could benefit from this type of actuator!

It's a pity, because these actuators are ridiculously easy to build.  The non-linear part was especially frustrating to me.

Analyzing these things was surprisingly easy – it turns out that it breaks down into a simple trigonometry problem, with the key variable being the diameter of the string or wire.  I had the most success with graphite-lubricated mono-filament fishing line, and silicone grease lubricated mono-filament line came close...

Just plain stupid...

Just plain stupid...  And probably coming to a federal government near you...

Banning encryption is a bit like banning safes because they might stop the police from looking at the contents.  Let's make everybody unsafe because your “leaders” can't spy on you!

Things like this help me understand how revolutions get started...