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Friday, January 28, 2011

Young Again







Scientist may have found the way of slowing the age of humans. Firstly, we will look into why humans age.

1. Chromosones in cells are capped by telomeres, which looks like shoelace tips.
2. Each time a cell divides to create new skin blood or bone, it uses a bit of telomeret to create the new cells.
3. After 50 to 70 divisions, the telomere runs out
4. Cells die because there is not enough telomere to create new cells.
5. Cells without telomeres may also fuse with each other, creating dangerous mutations, so cells usually kill themselves when the telomere is used up.
6. Telomeres get shorter and shorter as more cells die. As human body ages, the body becomes more prone to diseases and eventually dies.

Harvard scientists have genetically enginered mice without telomerase, an enzyme used to create telomeres. These mice became prematurely aged and diseases-ridden. But after they injected the mice with a drug that stimulates telomerase production, the mice became younger, less diseased and more active.If a similar drug is found for humans, cells may divide indefinitely, slowing age indefinitely.

Objections: 1.Some scientists question the comparison between engineered mice and normal human growth.
2. Others believe telomere erosion is not the dominant cause for human ageing.
3. Also, mutations in telomerase may cause cancer and help tumors grow faster

Why mouse? 1.Mouse have 70-90% of human's dna. 2. Because of their small body size, large numbers can be housed together in relatively small places. 3. They reproduce quickly and in large numbers.

Friday, January 21, 2011

Vanishing Act

Invisible World

Do you believe things can be made invinsible? If you don't, I am now going to to introduce you into a world of invisibility. There are a few types of invisibility cloaks. Firstly, I will be talking about the radar cloak. The radar cloaks purpose is to minimise detection by radar, which uses radio waves to detect objects. How? The cloak is created using materials and paint which absorb radar waves. It is only used on stealth planes, such as the F-22 Raptor and some Navy ships, such as the Singapore Navy. However, there are some limitations-- 1. Bad weather can increase chances of detection. 2. No radar-absorbent materials is effective for all radar bandwidths. Next, I will be talking on the Sonar Cloak, which basically absorbs sound so that ships and submarines are "hidden". There is one limitation-- 1. Active sonar can be absorbed at near distances. Lastly, I will be talking on the optical cloak, which can hide tanks and planes in plain sight! With the optical cloak, you can hide pipes and protrusions and hide the observer observing wildlife. However, the optical cloak can only currently work on micro and nano metre objects. The good news is that the optical cloak can start to cover bigger and bigger objects. What fun would we have playing with Harry Potter's "Invisibilty Cloak!" For now, it is only a dream, but someday, we will be able to.

Saturday, January 15, 2011


Mercury

Mercury is the first and nearest planet from the sun. It has no moons and orbits the sun every 87.969 days. It is called Mercury( the winged messanger from roman mythology) as it is orbital rate is faster than all of the plantets. Its surface is about the same as the moon- rocky and lots of craters. Do you know why? During Mercury's formation, it was bombarded with many comets. Mercury has a thin but unstable atmosphere. It has a magnetic field unlike the moon that is approxinately 1% of Earth's. Its average speed is 47.87 km/s. Its ditance from the sun is 57, 910,000 km or 38 AU.( AU=Astronomical Unit)(1AU is the distance from the sun to the earth) Its diamter is 4880km.