Do Explosions Actually Blow You Into The Air? The Myth Debunked

Do explosions in movies accurately depict real-world physics? The common trope of heroes narrowly escaping a blast and being thrown into the air, only to dust themselves off and walk away, is a staple of action films. But how much of this is based on reality? Let's dive into the science behind explosions and debunk some common misconceptions.

What is an Explosion?

At its core, an explosion is a rapid expansion in volume. This can occur naturally, such as trees exploding during wildfires due to boiling sap, or on a massive scale, like volcanic eruptions and supernovae. However, the explosions we're most familiar with are usually artificial, caused by accidents involving volatile chemicals or the intentional use of explosives.

In movies, explosions are often portrayed as enormous, fiery events that send people flying. While these scenes can be visually impressive, they often deviate from reality.

The Science of Explosives

Chemical explosives create a rapid increase in volume through a chemical reaction that produces gas. These explosives are categorized into two main groups:

• Low Explosives: These explode at a rate slower than the speed of sound (up to 343 meters per second). The energy produced is primarily in the form of heat and light. Gunpowder is an example of a low explosive, used to propel bullets without destroying the gun.
• High Explosives: These explode faster than the speed of sound. Examples include TNT (6.9 kilometers per second) and C-4 (8 kilometers per second). Octanitrocubane (ONC) is the fastest known explosive, detonating at 10.1 kilometers per second.

Deflagration vs. Detonation

Low explosives deflagrate, meaning the explosion involves a flame front that moves rapidly but subsonically. This type of explosion is often used when a less powerful, more controlled blast is needed, such as in mining or in Hollywood films where safety and visual effects are priorities.

High explosives detonate, creating a supersonic wave of pressure known as a shockwave. This shockwave is incredibly destructive, making high explosives ideal for demolition, mining, and military applications.

The Impact on Humans: Blast Injuries

Militaries and governments have extensively researched the effects of explosions on the human body, categorizing blast injuries into four types:

• Primary Injuries: These are a direct result of the explosion's overpressure, the near-instant spike in pressure that propagates outward as a shockwave. High explosives possess brisance, the ability to shatter anything within their blast radius. Close proximity to a high explosive can result in "total body disruption," or being blown to bits.
• Secondary Injuries: These are caused by shrapnel, which can be fragments of the surroundings or deliberately included metal pieces. Shrapnel can cause penetrating trauma and severe injuries.
• Tertiary Injuries: These injuries occur from the blast wave of compressed air that follows the detonation. This wave can throw people into objects or cause serious blunt force trauma.
• Quaternary Injuries: This category includes burns, radiation exposure, and psychiatric injuries like PTSD.

Can Explosions Lift a Person? The Truth

Tertiary injuries are most relevant to the question of whether an explosion can lift a person off their feet. Under specific conditions—the right amount of the right explosives, detonated at an optimal distance—it is possible for a person to be thrown into the air, similar to what is seen in movies.

However, the movies often exaggerate the aftermath. While it's possible to be thrown by an explosion, anyone close enough to be launched into the air would likely sustain severe internal injuries, especially to the lungs and gut. The chances of walking away unscathed, as often depicted in films, are slim to none.

Movie Myths vs. Reality

Films often take liberties with the physics of explosions:

• Slow-Moving Fireballs: Explosions with large, slow-moving fireballs are likely deflagrations, which lack the power to lift a person.
• Grenade Launches: Small explosive weapons like hand grenades are often shown throwing people several meters, which is unrealistic given their design and power.
• Walking Away from Bomb Blasts: Heroes who walk away from missile or bomb blasts without injury are defying reality. The force required to throw someone would cause significant internal damage.

Conclusion

So, do explosions throw you in the air? The answer is maybe. It depends on the type and size of the explosion, as well as your proximity to it. While it's possible to be lifted by a blast, the likelihood of surviving without severe injuries is very low. The action movie trope of dusting yourself off after an explosion is largely a myth.