World's worst day

When thinking about the dinosaurs, I tend to image a rain of asteroids falling down to the Earth, which bring down the dinosaurs. Last week, I learned from a science seminar that after three decades of research, the consensus of the scientific community is now believe that it just took 1 single, asteroid to cause that destruction which ended the 161-million year reign of the dinosaurs. According to computer models, it goes something like this ....
without warning some 65 million years ago, an unnamed and unwelcome visitor from deep in space. By the time it plowed into the Earth (at Yucatan Peninsula), this six-mile-wide mass of rock and mineral was traveling as fast as 20 kilometers per second, more than 50 times the speed of sound. The asteroid's energy at touchdown would have equaled the force of 300 million nuclear weapons. This wasn't the first time the Earth had absorbed a major asteroid impact. But our planet had never experienced anything quite like this. This was the world's worst day.

How long it takes for plastic bag to decompose ?

For everyday consumers, plastic shopping bag are cheap and easy to use, but ugly to look at when they stuck on tall trees or being littered to the street. I still remember a local news (of late 80's) profiling a young business star; he was on the news because the big profits earned from the plastic bag plant he owned. There is a social revolt going on lately to stop people using traditional plastic shopping bag due to enviromental concerns. Some want to make it "as fashionable to carry plastic as it is to wear fur", others simply baned them.
The most common type of plastic shopping bag is made of polyethylene, a man-made polymer that microorganisms don't recognize as food. In another word, they are not biodegradable like newspaper and banana peel
However, plastic bag do photodegrade. When exposed to ultraviolet radiation from sunlight, polyethylene's polymer chains become brittle and start to crack, and plastic bags will eventually fragment into microscopic granules. As of yet, however, scientists aren't sure how many centuries it takes for the sun to work its magic due to many variables. That's why certain news sources cite a 500-year estimate while others prefer a more conservative 1,000-year lifespan. It feels like these figures are just another way of saying "a really, really long time."
For me, the quickest way to solve the problem is to develop plastic bags sensitive to photodegradation and biodegradation. Consumer are willing to spend a bit more money on these new bags, instead of stop using them.

Injustice, heart disease, and bacterial transfer rate

1) a recent research confirmed the more unfair treatment people received, the greater their risk of suffering a heart attack or angina. Those with a strong sense of being treated unfairly had a 55% higher chance of suffering serious heart disease;

2)when you drop food on the floor, you have only 5 seconds to pick it up before it's contaminated. Yes, a research show that is how fast the bacterial can transfer from surface to food.

How many of us live in the city ?

Here is one of the city picture I took last weekend. Spring is great time for my beloved city, slush are gone, cherry blossoms.
Like majority of people in US, I am a city person all my life. Since 2000, according the US census, 79.22% of people live in cities. That number is similar for all other developed countries. In France, about 78% of population live in Paris. In developing countries like China, although majority of people still live in the country side, city population is increasing very rapidly.

Here is an interesting research explained economically, why more and more people move to the city. According to researchers, as the city grew in size it required less energy/resources to sustain it (in a proportion called sub-linear scaling). But as cities grew, the scaling of creative output (jobs, wealth generated, innovation) is super-linear, meaning as the city grew its creative output grew faster and faster. In summary, "the increase you get in wealth creation is greater than the increase in size of the city".

Today a little more than 50% of the world's population live in large urban areas. By 2030, it is estimated to be 2/3 of the world's population will be living in urban areas.

Brain damages can damage moral thinking

Current scientific theories tell us there are two parts of brain responsible for human moral judgement. One part of our brain gives us calculations (example: do what's necessary to save people from a fire), and another part gives us emotions (don't kill women and babies), and we balance the two inputs .... unless brain damage wipes out the emotional input.

Commen sense says brain damage can change moral thinking, now I have found a scientific research to support this commen sense. In a recent small-scale study, when presented with moral dilemmas, people with damage to a specific part of the brain were 2-3 times more willing to kill than were normal people.

Play video games can improve eye vision

According to a recent study out of the University of Rochester, playing video game improves your bottom line on a standard eye chart. People who play action-packed video games can boost their visual acuity by about 20% a month.

The researchers took on the nigh-impossible task of digging up a subject pool of Rochester students who never played video games. They gave the students a visual test where they identified the orientation of letters in a clutter. Students then spent a month playing either the action game Unreal Tournament or the less visually exhilarating (but still wonderful) Tetris for one hour a day. After a month, the Tetris players were still their average old selves, but the Unreal Tournament players gained unreal vision. Research concluded that "games push the human visual system to the limits and the brain adapts to it. That learning carries over into other activities and possibly everyday life."