## 太空家的野心：Metropolis 与 Cosmopolis

At the edge of Dubai, where Emirates airline has forged a massive global crossroads for air travelers out of once empty desert, an entirely new and even more colossal airport under construction is being billed as the world’s first “cosmotropolis”. Authorities say it will be capable of handling rocket ships and hyper-and supersonic aircraft as well as conventional jet airliners.

## 利用 GDP 数据理解「到 2050 年中国争取要达到中等发达国家水平，基本实现现代化」

Comparisons of national wealth are frequently made on the basis of nominal GDP and savings (not just income), which do not reflect differences in the cost of living in different countries (see List of countries by GDP (nominal) per capita); hence, using a PPP basis is arguably more useful when comparing generalized differences in living standards between nations because PPP takes into account the relative cost of living and the inflation rates of the countries, rather than using only exchange rates, which may distort the real differences in income. This is why GDP (PPP) per capita is often considered one of the indicators of a country’s standard of living,[3][4] although this can be problematic because GDP per capita is not a measure of personal income. (See Standard of living and GDP.)

$$\log_{\frac{1.06}{1.02}}\frac{57467}{15535} = 34~\text{years}\tag{1}$$