Economy of London project is construction of 42 km (26 mi) of new tunnels connecting stations in central London including a branch to Canary Wharf in east London. It is Europe's biggest construction project with a £15 billion projected cost. An additional line, Crossrail 2, has been proposed. London is served by six international airports which are the world's busiest city airport system by passenger traffic. These are Heathrow, Gatwick, Stansted, Luton, London City, and Southend. There are a number of proposals for expanding airport capacity for London including expansion of London Heathrow Airport and expansion of Gatwick Airport. The principal argument in
What Is This Thing Called Love? (short story) with aliens and sex. According to Asimov the article was mostly based on "Marvel" since its contents had been the raciest. Cele Goldsmith Lalli, editor of "Amazing Stories", requested a satire of the "Playboy" article. Asimov set out to write a story telling how a sex-interested alien and humans might "really" interact. The story appeared in the March 1961 issue of "Amazing" as "Playboy and the Slime God", but when Asimov included it in his 1969 collection "Nightfall and Other Stories" he retitled it "What Is This Thing Called Love?" Goldsmith Lalli rewrote the story's last three paragraphs, a change