Chan,+Amanda

This article was about how scientists would soon try to redefine the kilogram so it is defined by "an unvarying physical property nature." Right now, the universal kilogram scientists use everywhere is defined by a lump. The kilogram is the last SI base unit to be defined by some type of lump, which should definitely change. When scientists first needed measurements and weights, sticks and lumps worked just fine for roughly measuring things out, but today is 2011, and we are a smart species completely capable of measuring correctly. The kilogram should be redefined by the "unvarying" property, because it does not change; it would provide stability for the kilogram and scientists. Also, people would not have to guard with the lump, which the fear a low life wanted to disrupt nationwide measurements. I certainly believe the kilogram should be redefined soon, because that lump is no longer reliable and "unvarying physical" properties of nature are.
 * Redefining the Kilogram**

Amanda, Funny and to the point! Well written post! 5 stars. MW

I read an article titled, "Could Cell Phone Radiation Damage Our Brains?" One question often raised in the science community is the effects of cell phones on people's brains. According to Regis and Barbara, high school science teachers, there are no real conclusive studies on the effects of cell phone on the brain. Though the radiation of cell phones are not as strong as other radiation waves, such as microwaves, they still release some energy. It could be of special concern, because, not only is the cell phone used so closely to the brain, but the amount of people using cellphones is growing. Also, younger people are getting more cell phones, and their skulls are still thin and developing. The studies that have been conducted varied widely, some saying "people who use cell phones have an increased risk of brain cancer, while others show no such link." In addition studies are difficult to conduct with the constantly changing cell phone industry. People cannot keep track of their cell phone usage for extended periods of time. The core question is, "Do cell phones cause damage to our brains?" The answer is, "Who knows?" No studies are conclusive, but the article challenges people to send in what they think. In my opinion, cell phone usage for long periods of time are no doubt bad for humans, and if one uses it to the extent where one develops cancer, they need to lay off the chatting on the phone.
 * Cell Phones and Brain Damage**

Amanda, I guess the old motto "everything in moderation" applies here. Probably there is a greater danger of hearing loss than cancer. Great post! 5 stars. MW

I read "Keepers of the Gate" by Mitch Jacoby, which discusses the various techniques the TSA may try to tighten airport security. With explosives and bombs evolving and changing, the job of detecting is a difficult task. In addition, there are many step-by-step instructions listed online on how to make different types of explosives. Items used to create these explosives can range from common household items to stuff one could buy at the store. When I go through the airport, I see the long lines and heavy machinery and expect that I am safe, but now people are terrified that terrorists, or crazy people, can hop on the plane and pop their bomb hidden in their clothing, luggage, and anywhere else somebody might be willing to hide a bomb. The TSA is working to develop advanced forms of technology to detect all the new types of explosives, but until then, frequent flyers and travelers will just have to cross their fingers.
 * Airline Security**

Amanda, It is a bit scary if you think about it too much. In the end however flying in a plane is much safer than driving in a car.

I realize that I have walked through automatic doors all my life without really ever giving a second thought as to how they worked. I guess I thought they worked just Disney showed us in Toy Story...the black mat on the floor signaled the doors to open when something heavy enough got on. Maybe that's how they used to work, but according to the article, three ways motion-detected devices work is when a light source is blocked. It seems that a light is shot at a sensor, and when the sensor no longer sense light, because something is blocking the way (like a human) then the sensor sends out a signal to say that something is there. Also, there is an echo technique, which I already knew bats use. "Pulses" or waves are sent out and when they bounce back, they vary according to what they bounced back off of. The most interesting, I think, is the motion detector that detects heat. Heat at its simplest is motion, and when the detector can sense you are there just by the temperature of your body, you will have a hard time eluding that. Something else that was intriguing were the rattlesnake's receptors they used to sense heat. I had always believed they had super nice sight, but it's because they can sense heat that allows them to capture their prey so well. Something that really surprised me was the fact that milk jugs can transmit IR light. How could a milk jug be used in an experiment to see what conditions are best to transmit the light? These things are all important to the department of chemistry. Who knew walking through the door at the grocery store was a result of chemists?
 * Motion Detectors**

Amanda, Good reflections! You exceeded the assignment and asked some great questions. We'll address some of these items during this unit. 5 huge stars! MW