The Documentary Channel, which totally exists and occupies a space near enough Turner Classic Movies on my satellite TV that I discovered it, recently ran a show called Yoga, Inc, about the way yoga has taken off as big business in the United States the past couple decades. It enlightened me about a few topics, such as that yoga's been in the United States since at least as far back as the Columbian Exposition, and that it was modestly trendy in the 1920s and 1950s; that it got to be really big after 1970 wasn't a surprise, but still, I like the historical reviews of things.
One of the things mentioned was how, in the process of gaining relatively mainstream acceptance, yoga gets stripped of its spiritual side apart from some chanting at the open and close of class and maybe some exposition around the breathing exercises. It's easy to see how things like yoga-as-dance-exercise or hoisting small dogs around is really mutating the original thing almost unrecognizably far from the original idea and point. But, then, I remember my yoga class has pretty much eliminated any talk about the religious side of the activity, apart from sometimes mentioning locuses of energy in not really satisfying explanations of how the move could be done better, and a reading a randomly selected aphorism card at the end of class.
I suppose, given my non-religious preferences, it's just as well that the spiritual side is so damped down. I wouldn't be drawing anything from it anyway, past the benefits that the exercise and the time spent moving and breathing and acting differently from the rest of the week give me. But it left me aware that I --- and my class, for that matter --- am pretty much strip-mining a big thing for a narrow set of benefits. I don't think I'm actually doing any harm to the people who want the religious aspects of it, past the point that time my instructor spends teaching shoulder stands is not time spent teaching how to better meditate, but it did leave me looking more closely at something I'd not paid attention to before.
Trivia: The first aerial photograph appears to have been taken in 1858 by Gaspard-Félix Tournachon (1820 - 1910), making a black-and-white positive on glass from a tethered balloon at 262 feet altitude. Source: Maps and Civilization: Cartography in Culture and Society, Norman J W Thrower.
Currently Reading: Why Most Things Fail, Paul Ormerod.