Brown,+Hunter

I have just read the article __Lead Poisoning,__ and I learned a few things. I learned that lead poisoning can cause learning disabilities, mental retardation, stunted growth, impaired hearing and kidney damage in children. I also learned that some Mexican candies contain high levels of lead which can cause lead poisoning. They put iron and scrap metal into the guajillos sacks to increase the weight. The workers are lazy and removing them from the sacks and that is why there is such a high level of lead in the candies. Also, lead paint was banned in houses in 1978 because it was too lethal in the house.

Hunter, Yes that mexican candy thing makes you want to be careful when you eat stuff that comes from other countries! 5 stars. MW

I have just read the article __Redefining the Kilogram,__ and I learned a few things. One interesting thing I learned is that there is more than one standard physical artifact used to describe the kilogram. The article said there is ninety copies of the artifact that have been discovered on Earth. Another interesting thing that I found out is that the kilogram is the last SI that is described as a physical artifact and not a universal property of nature. The platinum iridium alloy is the artifact used to describe the kilogram. The most interesting thing about the article is that the unit has lost weight over time and scientist want to change the kilogram unit. I'm amazed that an item can lose weight over time when it's locked up in a room with guards protecting it! I wonder what they're going to do with the kilogram? I guess were going to have to wait and find out what happens.

Hunter, You can't really say that the artifacts were discovered. Good summary. I think we will see the kilogram redefined! 5 stars. MW

I have just watched __Crude Oil__ and I think that it's very interesting. I read about distillation, but I never knew that they used it to collect crude oil. I didn't know you could light oil with a very small flame without making it ignite. I never knew that they collected oil from heating it. I never knew that big companies used the same process for collecting oil, and I'm shocked that they can do it on such a large scale. Also I never knew that oil has different amounts of atoms. I wonder how long it would take them to collect one gallons worth of oil in the smaller version of collecting the oil.

Hunter, I think your question is the difference between a lab sized vs industrial sized process. All processes begin in the lab; scaling them up to the big time is a major job! 5 stars. MW

I have just read the article __Motion Detectors__ and I learned a few new things. I already knew that the detector used a beam of light that stays constant and sets the alarm off when an object passes through it. I also knew that some also use infrared to detect when warm blooded living beings pass through the sensor. I knew that the sensor used electrons to detect objects but I never knew that it had so many chemical reactions that go off when you pass by the sensor. I also never knew that this kind of work was started in 1887 by German physicist Heinrich Hertz. The final thing I learned today was that a police officers radar gun uses very low frequency radio waves that pick up what speed the car is going.

Hunter, Good job! I like the fact that you mentioned Hertz! 5 stars. MW

Elements come from suns that exploded and they're scattered through out the universe. Also they're created in this explosion, some are formed while in space.

Hunter, OK. 5 stars. MW

I have just read __Sugar An Unusual Explosive__ and i learned a few interesting things. First off, I learned that most dust particles can explode when combined with oxygen and when the surface area is right. Even wood,metal and plastic particles can burn! I also learned that the reason why sugar dose not explode in our stomach is because the reaction occurs at a slower rate and the energy is stored so no explosion occurs. The finally thing I thought was interesting was that over 30,000 facilities in the U.S. are in danger for explosive dust.

Hunter, Looks good but can you relate any info to class? 4 stars. MW

I have just read the article __Helium Balloons__ and I learned some new interesting facts. I first learned about the buoyant force. This is a force that acts on every object in the room. This causes a ballon to rise when it's filled with a gas like helium. I also learned that force is a rather small force because it can only lift .0028 pounds for every liter of air the object displaces. I was shocked to learn that it affected everything in the room as well, except it only has a minor effect on bigger objects like a desk of a human being. The second thing I learned was where this buoyant force comes from. It comes from the evening out of the particles pressure on the left and right, but not on the top and bottom. This force is added up together and moved upward, and that is a buoyant force. The final and most important thing I learned was how density affects everything. A ballon is less dense than the air around it, so if floats upwards. A human being is more dense than air and so we don't float. This article relates to class because it's explaining some of the forces that gasses have and we are in the gasses unit.

Hunter, Good points! I like your comment on humans not floating! :) 5 stars. MW