Your task: measure the height of a tall building using an old-style analogue barometer and science.
Most creative solution wins. Go.
Edit: Muting the thread, it kind of got a bit of traction.
@futzle
1. Using the barometer I measure the air pressure at the top, and call it A. Then measure it at the bottom, and call it B. Assume B-A=building height.
2. Post this process and solution on social media. Wait for about two minutes until 15 mortally offended nerds have replied with the correctly derived calculations and exact resulting height.
@jannem Correct solution, extra points for outsourcing the complicated maths!