Pa → bar
Evangelista Torricelli invented the barometer in 1643, discovering that air has weight and creates atmospheric pressure.
In 1648, Blaise Pascal had his brother-in-law carry a barometer up a mountain, proving that pressure decreases with altitude!
Ancient Romans built aqueducts using pressure principles, though they didn't have instruments to measure it directly.
Space suits maintain 0.3 bars of pressure - a balance between safety and mobility for astronauts.
Why did the pressure unit go to therapy? It was feeling too compressed! 😅