On Cloud Nine

A phrase with a specific, satisfying-sounding explanation that turns out not to hold up well. The most repeated theory ties it to the 1896 International Cloud Atlas, which classified ten types of cloud, with cloud number nine (cumulonimbus) being the tallest and puffiest. It's a nice image, but there's no documented evidence anyone was actually calling it "cloud nine" in that meteorological context before the idiom appeared. The earliest real trail instead leads through 1930s American slang, where "cloud eight" meant being drunk, later apparently drifting upward, numerically and figuratively, into "cloud nine" for blissful happiness by the 1950s, possibly popularised by jazz musicians describing a feeling of being pleasantly "high." A separate theory linking it to Buddhist stages of enlightenment has even less supporting evidence behind it.