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Imagine a dragonfly the size of a seagull! You would have seen them 300 million years ago, as well as other B-movie sized insects. Why did they grow so large back then? A new theory says it’s because of oxygen, which insects absorb through their surface area. Wilco Verberk of Plymouth University found that insect larvae are very sensitive to oxygen levels compared to adult insects -and there was a lot more oxygen present in the Carboniferous period.
It’s likely the larvae of many ancient insects also passively absorbed oxygen from water and were not able to regulate their oxygen intake very well—a big danger when oxygen levels were so high.
One way to decrease the risk of oxygen toxicity would have been to grow bigger, since large larvae would absorb lower percentages of the gas, relative to their body sizes, than small larvae.
“If you grow larger, your surface area decreases relative to your volume,” Verberk explained.
Read more about the study at National geographic News. Link
(Image credit: Ned M. Seidler, National Geographic)
Engineering students in Palwal City, India, built a motorcycle that runs on a tank of compressed oxygen:
“This bike is different from others because the engine doesn’t burn fuel, nor does the temperature rise. The air is compressed and transferred to the engine without any combustion. The piston reciprocates from the air pressure leading to an up-down movement, making the flywheel run and the bike move.”
Students say the basic concept behind the invention is to achieve an equivalent thrust of blast inside the engine without using any combustion.
The bike can run at a speed of six to 12 miles an hour for up to 370 miles using 100 liters of 300 PSI oxygen.
Video at the link.
Medical researchers went to Mount Everest and took samples of their own blood while near the peak. What they found was shocking!
An average person at sea level has about 13-14 kilopascals (kPa) of oxygen in their bloodstream, University College of London medical researcher Dan Martin says. When his intensive care patients drop to around 8 kPa he gets very worried, and a normal person with 6 kPa of oxygen faces almost certain death. Imagine his shock, then, when he and three colleagues on the top of Mount Everest measured their own blood oxygen level to be between 2.5 and 4 kPa, the lowest ever measured in live people.
Martin and his colleagues -all experienced climbers- also took muscle biopsies while on the mountain. They hope their findings may lead to knowledge that will help patients in intensive care, where sudden oxygen drops can lead to death. Link -via Digg
(image credit: Pavel Novak)
