Edwards,+Nashaya

Nashaya Edwards Redefining the Kilogram:

I found it interesting that the kilogram is the last of the SI base units that is still defined by a physical artifact and not an unvarying physical property of nature. Also, I thought the fact that scientists have been discovering the truth about how the natural world works since early Enlightenment days. They’ve been determining the physical constants of the universe and establishing standards for measuring them. The last thing I found most interesting about the article is the outcome of Avogadro’s constant proposal.

Nashaya, We'll have to see about the Avogadro's constant outcome. 5 stars. MW

Nashaya Edwards

Motion Detectors

Some things I found interesting about this article is the body temperature of a human is 37.0oc, but the temperature of the skin is around 33.9oc, causing us as well as anything else at the same body temperature to radiate infrared light with a wavelength of 9-10 micrometers. Also, I found that glass will completely block out the 8-12 micrometer infrared light, the motion detectors cannot penetrate the glass, although it’s clear. This is why someone moving outside the window of won’t register on an indoor motion sensor. The last thing I found interesting was that bats send off signals similar to those set off by automatic doors, but in sound energy, not light. They use a process known as echolocation. Bats use this so well that they can locate an insect, which way it’s headed, and how fast it is going. It especially helps them in distinguishing edible moths from poisonous ones.

Nashaya, Good post! Bats are pretty amazing animals! Good comment on the skin temperature – obviously it is cooler than internal body temp. 5 stars! MW

Intro to Chem: The article I found most interesting was the invisble fire article. It was amazing that the fire could eat through the metal of a spaceship. It was interesting to learn hydroflouric acid can damage the tissue without leaving the traces on the skin due to the fact it doesn't carry a charge, making it easy for them to pass through the membrane and fatty tissues. At he worst, exposure can lead to muscle spasms, convulsions, an irregular heartbeat, and even death. Hydroflouric acid burns very rare, so much that it the advice of an expert is needed.

Nashaya, Looks interesting. The truth is that acids can't eat through spaceships - that is only in the movies. This stuff(HF) is bad news however! Pretty late on this one. MW