The unbearable heaviness of buildings: Another episode in the series “Useless units”

Apparently, Manhattan is sinking by 1-2mm per year, due to the weight of its skyscrapers. The Guardian reports on the research led by Tom Parsons, of the US Geological Survey, saying that New York City’s buildings “weigh a total of 1.68tn lbs”.

What’s that, you say? You don’t have any intuition for how much 1.68 tn lbs is? The Guardian feels you. They’ve helpfully translated it into easy-to-grasp terms. This, they go on to say, “is roughly equivalent to the weight of 140 million elephants”.