Lyons,+Alexis

2/25/11
 * Motion Detectors**

This article on motion detectors was very interesting for many reasons. One thing that I found interesting was that there are different types of motion detectors, such as a light beam sensor, pulse sensor, and heat sensor. I always thought that motion detectors were all the same. A second thing that I found to be interesting was the fact that snakes and bats use motion detectors. I knew that bats use sonar to catch their food and snakes use infrared, but I didn’t know that it was classified as motion detection. A final interesting piece of information is that the amount of energy in particles of light depends on frequency, not intensity.

Alexis, That last bit was a good observation. We will definitely be talking about frequency and the like. 5 stars. MW

2/8/11 I find this article interesting because I never knew that measurements were taken so seriously in the world. I didn't know that there are standards for weights, let alone that all but the kilogram are defined by a physical property of nature. It's quite humbling to think that people spend their day figuring out how to better the known standard that is already in place. Also, it is interesting that the standard for the kilogram in Paris, France has actually lost 50 ug over time compared to its copies. This does not seem to be a positive thing, since every other weight is based on it. Finally, I think it's strange how big of a deal is being made over what the kilogram standard should be changed to. It seems that the current standard is working out perfectly fine.
 * Redefining the Kilogram**

Alexis, I guess they are trying to avoid the risk of it losing more mass! Just think somebody will be out of job. They won't need anyone to guard the artifact anymore. 5 stars. MW

1/23/11 This article discussed the possibility that serious brain damage could stem from cell phone over-usage. When I first heard of this hypothesis, I was concerned because I am an avid cell phone user. But from this article I can see that there is no harm from using cell phones. It is not possible for any damage to be caused because skin is only heated by a fraction of a degree because of cell phones. The radiation is also 1/15,000,000 of the energy from X-Rays. For a cell phone to actually do damage to the neurons of one's brain, it would have to be continuously against one's head.
 * Could Cell Phone Radiation Damage Our Brains**

Alexis, Good points. I think I can safely assume that you will continue using your cell phone. 5 stars! MW