Backyard and Beyond

Here at Backyard and Beyond, we spare no wonder for our natural and unnatural world. In the Bergen St. F/G subway station in Brooklyn, these stalactites descend from both platforms. They’re classic soda straw formations, hollow through the center. They are also, obviously, not exactly like the ones you’d find in a cave. (Frankly, you should be staying out of caves these days, since cavers are suspected in transporting White Nose Syndrome). Here it’s the calcium oxide in concrete that interacts with leaking water to form calcium hydroxide. This reacts with carbon dioxide in the atmosphere to precipitate as calcium carbonate. Voila!
Subway stalactites. Drip, drip, drip.