New hand railing by Robert Abdallah.

Recent 3d prints

Here are a variety of recent 3D prints.  All algorithmic generated.  All use openscad as the renderer.  Some use solidpython that exports to openscad.  Printed on my Makerbot 2

Introduction to Linear Algebra

I just finished a Colorful Introduction to Linear Algebra. I wrote it because I thought that most textbooks do a poor job of introducing such an important subject.  Please let me know if you find this useful.

3D Flower

Flower designed today and printed on my new MakerBot 3D printer!

Life: Expecting Mother

[The following is one of many second-person stories I've written imagining oneself as one of a variety of interesting creatures on earth. I've got lots more of these stories. If there's any interest in this post, I'll post the others.]

Expecting

So you’re about to become a mother.  Congratulations!  Here’s some important facts you need to know.  First, and I can’t stress this enough, girls, be sure to attach your babies to each other with plenty of glue; you don’t want them falling off.

Second, once some of your little ones have turned into toddlers then it’s time to leave them in a swimming pool.  Common wisdom says no more than one toddler per pool.  You can leave them unsupervised while you check back on your less-developed children.  It might stress you out a bit to leave them there alone, but it’s okay; probably no more than 9 out of 10 will die.

Meanwhile you’ll find the proud father to be very protective of your house. This is normal.  He can be expected to keep the swimming pools full and clean, but not much more than that.  Don’t even bother asking more of him -- it won’t work.

Soon your surviving toddlers will be very hungry and begging you for food as you bounce back and forth between your broods.  You’ll have no time for anything else but shuttling around, so your best bet for a quick meal to satisfy those hungry toddlers is to simply feed them your younger, less-developed children.  In fact, it’s important to do so.  You’re toddlers will not turn into healthy adults unless you feed them the complete diet provided by their younger siblings.  Don’t worry about cooking them -- babies are best served raw...

… You are a poison dart frog.

Oophaga pumilio the strawberry poison dart frog, like many other poison dart frogs, feeds its unfertilized eggs to its developing tadpoles hence its genus name “Oophaga” which means “Egg-eater” in Greek.

The mother deposits the fertilized eggs into pools of water such as might be found inside of a bromeliad in the top of a tree in the rain forest.  She then returns to these places once every few days to feed her unfertilized eggs to the growing tadpoles.  Her success rate in this endeavor is not high, it is estimated that only a few percent survive.

New couch

New built-in couch!

Don't go back to school

I was recently interviewed and featured in the book "Don't Go Back To School".  Kio Stark did a great job summarizing the case for self-directed education.