Posted in Science & Nature


When asked “name a bird you see often”, most city-dwellers would name a pigeon or a sparrow. These two birds are the most famous urban birds that are closely associated to humans. The sparrow, being very opportunistic and adaptable, have easily taken over environments around the globe, especially those where European settlements were made. Nowadays, they are regarded as a pest due to their foraging of agricultural crop and the spread of disease. However, citizens still view them in a positive light, especially in parks or gardens where the sparrows appear to be a “symbol of nature” (ironically, they are likely an invading species driving away native birds).

One interesting fact regarding sparrows that most people do not seem to know is how to differentiate a male and female sparrow.
A female sparrow has very soft, brown feathers, with no marked features.
A male sparrow has areas of dark brown or black feathers, especially on the head and eyes. Its beak is also darker than the female.
If one observes carefully at sparrows, they can notice that the two behave slightly differently as well.

Posted in Science & Nature

Urban Paradox

A few years ago, a theoretical physicist studied population growth in cities to find the mechanism of how cities operate. What he found was an astonishing law.
Wherever the city, as the population doubled in size, the average income, number of patents, number of educational and research facilities and other important numbers all increased around 15 percent. Although it is normal for such statistics to increase as a city grows, it is interesting to see that almost all of them increasing at a similar rate, despite being so different sometimes.
More fascinating is the fact that not only do the above “good” statistics increase equally, but so do crime rates, pollution, smog occurrence, stomach flu and AIDS prevalence all increase approximately 15 percent.
Therefore, a city can be seen as a double-edge sword that is both the source of fast growth, wealth and ideas, but also waste, pollution, stress and disease.

Biologically speaking, an organism has a tendency to have slower growth and pace of life as it gets larger. For instance, an elephant’s heart beats slower than a mouse, and its cells do less work on average too. However, a city exhibits a snowball effect where it grows faster as it gets larger. To achieve this extremely high rate of growth, it must consume an immense amount of resources, which ultimately ends up as large quantities of waste and pollution. Also, as people get busier, the overall “quality” of the society falls, leading to increased stress and disease prevalence.

If so, should we abandon our current productivity and live a slow, village life and ignore our potential as a species? Or should we continue our exponential growth at the cost of using up nature’s well-maintained resources like no tomorrow?