Big numbers. Big numbers.
According to http://en.wikipedia.org/wiki/Galaxy, a typical galaxy contains ten million to one trillion stars.
There are probably more than a hundred billion galaxies in our observable universe.
According to http://www.kokogiak.com/megapenny/seven.asp, ten million pennies would stack in a cube 6 x 6 x 6 feet.
A trillion pennies would stack in a cube measuring 273 x 273 x 273 feet, about a football field on a side.
One hundred billion trillion pennies would stack in a cube, oh, forget it.
According to https://www.cia.gov/cia/publications/factbook/geos/ch.html, as of July 2006, there are an estimated 1,313,973,713 people living in China. About 15 million of them live in Beijing.
And according to Katie Melua, there are nine million bicycles in Beijing.