Question

On the popular TV show LOST, the passengers on an airplane experience rapid decompression (i.e. going from high pressure to low pressure) when the plane breaks in half. The plane then rapidly descends (crashes), putting the people through a rapid change from low pressure to high pressure. Explain in detail how going rapidly from high pressure to low pressure and then from low pressure to high pressure would kill most people before they impacted the ground.

Answer 1

When a plane flies above 3 km, it is mandatory to pressurize the plane properly so that it can maintain a high enough oxygen level for everyone onboard to function. The excessive air from the compressors is cooled and pumped into the cabin and that's how the pressure inside the cabin is gradually adjusted while going higher altitude or descending down. Therefore, planes are pressurized to simulate lower (or ground level ) pressure inside the plane. As the plane climbs to a high altitude, the plane is pressurised and as it descends to the ground, it is gradually depressurised

When a plane is flying at higher altitude it has to maintain the higher pressure inside the plane because thin air and less oxygen outside the plane in the atmosphere can't let people to get enough oxygen in the body and additionally low pressure in the atmosphere and high pressure inside the body create dangerous pressure differences.

When the plane is experiencing the decompression going from high pressure to low pressure rapidly while the plane breaks in half within a few moments, it creates a pressure difference between the human body and atmosphere. This pressure difference. Since the human body is so custom and evolved to function at ground level atmospheric pressure, it cannot function at the low pressure at higher altitude. Since atmospheric pressure is a closed system at higher altitude, it tries to lower the pressure inside the human body which causes ruptures of the blood vessels and eardrum that leads to bleeding from people's noses and ears. For minutes of time, this situation causes hypoxia and ultimately kills the people.

In the case of LOST, while passengers' bodies are adjusting the pressure difference rapidly from higher pressure to lower pressure, they are experiencing the opposite situation within a moment because the plane breaks and descends toward ground. This higher pressure to lower pressure and within a moment from lower pressure to higher pressure kills the human body instantly because the human body takes time to adjust the outside pressure difference. Due to unbearable pressure difference leads to death of passengers.