December 2011

Posted December 19, 2011

Crazy clouds:

I've been a fan of Phil Plait and Bad Astronomy for some time, and this video from his blog is an example of how hard he will work to find an explanation. The short version is that electric fields between the clouds are causing ice crystals to line up in various ways, and sunlight reflecting off those ice crystals is causing the changing glare. Check out Plait's longer explanation here. YouTube link

Posted December 12, 2011

Reboosting the ISS:

Sometimes it is difficult to demonstrate that a force is needed to change the motion of an object. This video from the International Space Station during a "reboost" burn shows astronaut Jeff Williams taking advantage of the free fall environment to do just that. When the rockets are firing, there is a net unbalanced force on the space station, but not on Jeff. The station starts to accelerate, but until he comes in contact with the wall, he does not. YouTube link

Posted December 5, 2011

Hard candy chemistry:

As I noted in a recent column on the science of the cooking show Good Eats, there is a lot of chemistry in the kitchen. This video shows how hard candy is made, and notes the link between temperature and the final condition of the sugar syrup. One other important piece of the puzzle is including two types of sugar (both granulated sugar and corn syrup) to inhibit the formation of crystals when the syrup cools. YouTube link

Jacob Clark Blickenstaff is Assistant Professor of Physics and Assistant Director of the Center for Science and Mathematics Education at the University of Southern Mississippi.