Why does a normal fountain pen oozes ink in a flying jet plane?
1) May be because of sudden change in its (pen body) position. The inertia of the ink inside makes it stay in its original position. So the overall effect will be that of jerking the pen which makes ink splash out. 2) Low Pressure. That’s the short answer. Back when people used fountain pens as a matter of course, aeroplane cabins had variable pressure throughout the flight. Pens, shampoos, potato chip bags, etc. expand, pop, or leak at high altitudes is because of low air pressure. The air inside a sealed container holds the pressure of the environment when it was closed. If this container travels up, to Denver or up in an aeroplane, the air pressure –barometric pressure– of the environment becomes lower than it was closer to sea level. The container expands in dimensions or leaks in an attempt to equalize the pressure. These days people use ball point pens and they’re pens don’t leak. 😉 Actually, these days commercial aeroplanes have better seals and climate control systems. Howev
