National boundaries are not evident when we view the Earth from space. Fanatical ethnic or religious or national chauvinisms are a little difficult to maintain when we see our planet as a fragile blue crescent fading to become an inconspicuous point of light against the bastion and citadel of the stars. Travel is broadening.

Sagan, C., Druyan, A. and Tyson, N. deGrasse (2013) Cosmos. New York: Ballantine Books.

Longevity is perhaps the best single measure of the physical quality of life. (If you're dead, there's little you can do to be happy.) This is a precious offering from science to humanity -nothing less than the gift of life.

Sagan, C. and Druyan, A. (1997) The Demon-Haunted World: Science as a Candle in the Dark. Reprint edition. Westminster: Ballantine Books.

In most real cities, such as London or Rome or Shanghai, the tiniest alleyway is hijacked and then utilized for public space, the smallest nook becomes a store, the dampest arch under a bridge is filled in with a home. Over centuries, this constant infilling, ceaseless replacement, renewal, and complexification—in other words, evolution—creates a deeply satisfying aesthetic. The places most renowned for their beauty (Venice, Kyoto, Esfahan) are those that reveal intersecting deep layers of time. Every corner carries the long history of the city embedded in it like a hologram, glimpses of which unfold as we stroll by.

Kelly, Kevin. 2010. What Technology Wants. Penguin Books. WorldCat.