## The Art of Science: The Not-Quite-3D Christmas Tree

Little plastic Christmas trees don’t really count as art, but the science and math behind this one is pretty interesting, so we’ll let the deeper questions of aesthetics and meaning slide just this once.

Computer Science researcher Richard Zhang of Canada’s Simon Fraser University printed the tree as a demonstration of a newly developed 3D printing algorithm that has potential applications far beyond seasonal tchotchkes.

Michael Byrne at Motherboard explains:

“Zhang is solving a real-life problem: saving waste. Printing an object with overhanging parts, like a tree branch, requires the deposition of extra material below to support the top part through the printing process. At the end, this material is cut away and trashed. The answer, according to Zhang, is in using pyramidal components.”

“Decomposing a complex shape into simpler primitives is one of the most fundamental geometry problems,” Zhang and his team write in a recent paper. “The main motivation is that most computation and manipulation tasks can be more efficiently executed when the shapes are simple.”

And pyramids offer an elegant solution, because, Zhang says, pyramids are 2.5D.  (I’ll give you a second to collect your brain cells from the floor)

Byrne explains:  “Two-and-a-half dimensions is a concept used in machining (and computer graphics, with a different meaning) to describe an object with no overhangs. It only has a top, and can be viewed as a projection of 2D flatness into the third dimension.”

There’s lots more info about the science and math behind the printable pyramids in Byrne’s article and in Zhang’s paper.

## The Red Nose Gene [Repost]

Originally posted on 24 December 2012 when my now 5 year old was 4.

Tis the season…for my 4 year old to ask me to sing Rudolph the Red-Nosed Reindeer repeatedly during any car trip longer than 30 seconds. My apologies to anyone who gets caught in the crossfire. My singing does not get better with repetition.

My kids also love the Rankin/Bass stop animation classic film Rudolph the Red-Nosed Reindeer. As you probably have come to expect, I have had a lot of time to wonder about how two seemingly normal reindeer could have a child with a glowing nose. Classic genetics is well-equipped to deal with this problem.

Both Santa and we should be very concerned about the genetics of red reindeer noses. According to Wikipedia, the Rudolph story dates back to 1939. There have probably been quite a few foggy Christmas Eves in the intervening years. According to the Pittsburgh Zoo, reindeer typically live for 10 years in the wild. While we can expect that Santa’s reindeer do a bit better than those in the wild, it is clear that Rudolph alone would not be able to “guide Santa’s sleigh” today. Given their success breeding flying reindeer, it is not hard to imagine that Santa’s elves could generate a stable of red-nosed reindeer. How they would go about doing so would depend on how, genetically, Rudolph wound up with that first Red Nose. Continue reading “The Red Nose Gene [Repost]”

## Eggnog – Alcohol & raw eggs make the season bright [Repost]

Originally posted on 21 December 2012, the Traditional Egg Nog recipe has passed independent replication by Josh Witten.

My father is a very clever man. Long ago, as a Christmas Eve was coming to a close and we were preparing to plate up our milk and cookie offering to Santa, my dad stopped us with a suggestion. Arguing that, because our name was near the end of the alphabet, we were going to be one of the last houses Santa visited. Therefore, the jolly old elf would be very cold and tired of milk. Instead, we should leave him some bourbon to warm him up. It didn’t take long for our young minds to realize that a warmed up and happy Santa was much more likely to leave us better loot. As it happened, Dad had some of Santa’s favorite bourbon (parents know these things), which by amazing coincidence was also my dad’s favorite. I would hazard to say that this was the creation of our family’s traditional Christmas drink: alcohol.

In the spirit (or spirits) of my family’s holiday tradition, this post is going to celebrate my personal favorite Christmasy holiday drink: eggnog. Continue reading “Eggnog – Alcohol & raw eggs make the season bright [Repost]”

## Christmas Shuffle [Repost]

Originally posted on 20 December 2012.

Last year our eldest daughter (then 3, now 4), The Frogger, fell in love with the song “Rudolph the Red-Nosed Reindeer”. This year she is obsessed with “A Holly Jolly Christmas”. It is no coincidence that both songs are performed by Burl Ives in the Rankin/Bass classic Rudolph the Red-Nosed Reindeer.

Cut to me, in the car, frantically pushing buttons to cycle through CDs and play Burl Ives singing “A Holly Jolly Christmas” in order to fulfill the heartfelt request of my child. Experienced parents will know that there are a variety of potential motivations for such behavior beyond simply avoiding a tantrum, for example cutting short a half-hour of repeatedly yelling the same three lines of the song with 73.21% accuracy.

Having found the correct CD and as I pushed buttons to get to the right track, I began to wonder if I was taking the shortest route to my song of choice. There are three possible routes to any given track on my car’s CD player. Continue reading “Christmas Shuffle [Repost]”