crushed by the weight of Earth’s atmosphere? Despite exerting a pressure equivalent to tons, this invisible force doesn’t seem to affect us. So, how does our body handle it without any issues? The answer lies in a fascinating balance that keeps us safe.
The Earth’s atmosphere exerts a constant pressure on everything at its surface, including us. Yet, this immense weight seems to have no noticeable effect on our daily lives. How can we explain this fascinating phenomenon? To understand it better, let’s explore the mechanisms that govern atmospheric pressure and its interaction with our bodies.
Atmospheric Pressure: What Is It?
The Earth’s atmosphere, though made up of light gases, has weight. The pressure exerted on us at sea level is about 101,300 pascals (Pa), which equals one kilogram per square centimeter. This pressure is evenly distributed across our bodies. Anthony Broccoli, a professor of atmospheric sciences at Rutgers University in the United States, states that “the total mass of Earth’s atmosphere is 5.1 trillion trillion kilograms.” While this may sound overwhelming, it’s important to note that this pressure is counterbalanced by the pressure inside our bodies, preventing us from feeling its weight.
The Balance of Forces
Atmospheric pressure is evenly distributed, meaning every part of our body experiences the same force. It’s not a crushing downward force, but more of a circulation that allows our bodies to balance it. Professor Michael Wood from Canisius University in Buffalo explains that “our bodies have evolved over time to withstand these pressures,” creating an equilibrium between the internal and external pressures.
Why Don’t We Feel It?
The key to not feeling this external pressure lies in the balance between the internal pressure of our bodies and the atmospheric pressure outside. The fluids inside us exert an internal pressure equal to that of the surrounding air, which helps maintain equilibrium and prevents us from being crushed. This subtle interaction protects us, and it has evolved over time to ensure our survival.
Exceptions: When Pressure Becomes a Problem
However, there are situations where this pressure can become an issue. For example, at high altitudes or on airplanes, when external pressure decreases, our bodies take time to adjust the internal pressure, which can cause discomfort, such as the “pop” felt in our ears. This is also why astronauts need space suits: in space, where external pressure is almost non-existent, these suits create an artificial internal pressure necessary for human survival.
The following table illustrates the main effects of atmospheric pressure on the human body in different contexts:
| Situation | Pressure | Effect on the Body | Explanation |
|---|---|---|---|
| Sea level | 101,300 Pa | Perfect balance | External pressure is balanced by the internal pressure of the body, creating a sensation of comfort. |
| High altitude (air travel) | Reduced pressure | Mild ear discomfort | The body slowly adjusts internal pressure due to the decrease in external pressure. |
| Space travel | Almost zero | Need for space suits | With virtually no external pressure, spacesuits maintain artificial internal pressure for survival. |
The pressure exerted by Earth’s atmosphere, though impressive in terms of weight, doesn’t affect our well-being thanks to a subtle biological balance. Our bodies have evolved to maintain internal pressure that perfectly compensates for the external pressure. So, while the air exerts a force on us, we live in harmony with this pressure, safely shielded from the risk of being crushed.
