Online Cortex Thoughts on Science and Technology

One of the groups I belong to on LinkedIn posted an interesting problem that was published in a New Scientist article on the Gathering for Gardner meeting. The problem goes like this:

I have two children.
One is a boy born on a Tuesday.
What is the probability I have two boys?

Can the fact that you were told that one of the boys was born on a Tuesday tell you anything about whether both children are boys?
Indeed it can!

Find out more HERE:
http://kevinknuth.com/blog/2010/06/bayes-theorem-and-our-poor-sense-for-probability/

Posted under Probability

I came across a lovely video of an experiment where CO2 is used to put out flames.

I myself once performed a demonstration in my physics class where I compared a Helium filled balloon to a Carbon Dioxide filled balloon. Of course, one floats and the other falls to the ground (faster than a balloon filled with room air).

I then showed how my voice sounds higher when I inhale Helium due to the fact that the speed of sound is faster in Helium than in air, and the waves pile up as the slow down at the Helium-Air interface.

To be clever, I asked my students what happens when you breathe in Carbon Dioxide and try the same trick. Your voice should sound far lower. What I didn’t count on was that when you breathe pure Carbon Dioxide, it combines with the water in your lung membranes and forms Carbonic Acid. I almost coughed to death during the demo.

Next time Michelle Bachmann says that CO2 is harmless, have her take a breath out of a CO2 balloon!

Kevin Knuth
Albany NY

Posted under Fun, Physics, Stuff

I have recently become interested in making chain maille, and am fascinated by the possibilities of modernizing many of the weaves. I have been practicing with some of the basic weaves and have begun selling some of the jewelry I have made on Etsy at http://21stCenturyMaille.etsy.com.

I find that I love working in silver. The brilliant white color of the metal is far more beautiful than gold. I really love the Byzantine chain weave, and I feel challenged to make them as small as possible. Here is a picture of my Byzantine weave bracelet handwoven with sterling silver and blue anodized niobium rings. It is only 3/8 of an inch wide.

Blue Byzantine Bracelet made with Sterling Silver and Anodized Niobium

I also love the hexagonal patterns of the Japanese weave. I have been playing with variations that involve different sized rings. I won’t show those here quite yet. But below are two necklaces I have made with this weave.

Japanese Chainmaille Necklace

Springtime Necklace features leaves made from a Japanese-style weave

I am now working on integrating gemstones into the maille to obtain some truly unique designs.

Posted under Fun

On Robots Everywhere we see that a recent BBC show makes it clear why we really shouldn’t get physically aggressive with today’s computer systems!

Posted under Fun, Robotics

I took a look at the new iPod shuffle today and I was dismayed by Apple’s continued development of the “intuitive” control system. To help people use their products, Apple actually has to have a website devoted to instructions.

The ipod shuffle (3rd gen) requires a table of instructions

These instructions include

Play: click the center button once (status light blinks green once)

Fast-Forward: double-click an hold the center button (status light blinks green once)

Rewind: triple-click and hold the center button (status light blinks green once)

Hear song title and artist names: Click and hold the Center button (status light blinks green once)

Go to the next track: Double-click the Center button (status light blinks green once)

This reminds me of the combination of buttons I had to press to perform that triple roundhouse kick in Nintendo! And that all informative status light! Thank goodness they thought to put that in there, otherwise who would ever know that the ipod shuffle was getting your commands correct.

The problem is that to make these things slick and sleek Apple needs to minimize the number of controls on the device. This puts the burden on the user to remember precisely what pattern of button presses and holds will give the desired result. Its unfortunate that Apple couldn’t at least add some extra LEDs so that the status light actually conveyed meaningful information.

I find this a disturbing trend in consumer electronics resulting in devices that work like that darn overhead ceiling fan. You are never sure how many times you need to pull on that string to get the thing to stop. Or it reminds me of the crappy little alarm clocks where you have to press two buttons in some crazy pattern to set the alarm. I think most people have at some point in their lives overslept because of this “feature”.

A good friend of mine Asaf Degani who is a NASA research scientist wrote a book called Taming HAL: Designing Interfaces Beyond 2001 where he examines the design of effective user interfaces. I should find out what he thinks of Apple’s interfaces.

Me? I disapprove.

Kevin Knuth
Albany NY

Posted under Gadgets, Product