Walking on Water (with cornstarch)

In undergrad we learned about non-Newtonian fluids. Normally fluids that we’re familiar with (like water) have a constant viscosity. However, some fluids change their viscosity depending on strain rate. That is: they get thicker or thinner when you move something through them.

The quintessential example of this, often used in demonstrations, is to mix cornstarch and water in the right proportions. Then, if you put your finger in the fluid slowly, it goes right in. However, if you rapidly poke the surface of the fluid, it firms up, your finger is stopped, and leaves a dent in the surface, and if you take your finger away as rapidly as you inserted it, you typically end up with nothing on your finger.

I always wondered if it would be possible to run across a big pool of this stuff, provided one kept moving. Well, thanks to the Internets, I wonder no more. Observe:

Thanks to babayada for the initial link to YouTube (to another cornstarch and water video) via which I found this.

ADDENDUM: I just noticed that the very Wikipedia article I linked also references this video. Hah!

Early Hearty Friday



difusor

Originally uploaded by orticanoodles


I’m traveling this weekend and things will be less regular than usual. Not like my Hearty Friday posts have been regular or on Friday most of the time.

Also, most of my Hearty Friday posts from Flickr have been artistic hearts (as in, not anatomical). This one is art to be sure, but it’s more anatomically-accurate.

The enemy of the good

I came across this quote in the subversion book:

“It is important not to let the perfect become the enemy of the good, even when you can agree on what perfect is. Doubly so when you can’t. As unpleasant as it is to be trapped by past mistakes, you can’t make any progress by being afraid of your own shadow during design.” — George Hudson

Someone introduced me to this phrase in the last few weeks, “better is the enemy of good” or something like that. It’s an interesting maxim, especially for those of us who end up bent on creating the “perfect GTD system” or who are overly self-critical because we can’t do something-or-other perfectly. Sometimes working for perfect distracts us from producing or using something that’s good, and something good is better than nothing perfect. “Good enough” things are what keep us moving forward every day.

What are you striving for perfection on that’s preventing you from moving forward?