For most of us, movies are a form of escape. And as part of the escape, many viewers are willing to give Hollywood some leeway when it comes to the accuracy of life as portrayed on the big screen. Most of us probably don't really think that stormtroopers, Jedis, Wookiees and little green men wielding light sabers chased each other around a long time ago in a galaxy far, far away. Nor do we truly believe that Abraham Lincoln slayed vampires before he delivered the Gettysburg address. Yet, for cinematic genius like "Star Wars" or the couple of hours of cheap entertainment of "Abraham Lincoln: Vampire Hunter," we're willing to suspend reality.
Nevertheless, there are certain cinematic devices used so often in film and television that many viewers are left thinking that these stunts could actually be pulled off in real life.
Take the "running away from an explosion" scene, for example. In its basic form, the device features our hero -- James Bond, John Rambo, Jason Bourne -- narrowly avoiding extinction by sprinting away from a fiery blast just in the nick of time. The explosion sequence is the hallmark of an action adventure flick. In "Die Hard," Bruce Willis didn't turn his undershirt from bright white to dirt-caked in 131 minutes by just rolling around with a machine gun. He also swung from a fire hose to escape an exploding skyscraper [source: TV Tropes].
No one seems to doubt that Willis' hard-boiled John McClane could pull off such a feat, but what about ordinary schlubs like you and me? Read on to find about whether an explosion can really be outrun.
How Explosions Happen
An explosion occurs when a large amount of energy is released into a small volume of area in a very short time. The energy released comes in many forms, including chemical (artificial explosives), nuclear and hydrothermal (volcano eruptions).
Burning very rapidly, explosive material releases concentrated gas that expands quickly to fill the surrounding air space and apply pressure to everything in it. That is, it explodes in a blast powerful enough to blow away nearby trees, cars, buildings and anything else in its path [sources: Muller, Harris].
On the set of an action flick, blasts are often cultivated using nifty camera angles, CGI and miniature explosive devices, with notable exceptions like 2009 Oscar winner "The Hurt Locker" which used actual full-sized explosives. In real life, movie-type blasts require an explosive like C-4, TNT or gasoline, which cause explosions when they burn and mix with oxygen. C-4, for example, combines combustible material with plastic, often in a block form. The explosive is ignited using a detonator, which burns and causes the block to release a number of gases, including nitrogen and carbon oxides at a very fast rate and with a whole lot of force (the explosion) [sources: Harris, Failes].
And those fiery automobile explosions that are the centerpiece of any good car chase scene? More likely caused by strategically placed C-4 than an explosion in the gas tank. These days, cars on the street are equipped with highly durable gas tanks precisely to prevent them from detonating in the event of a crash. It is also important to remember that gas burns in vapor, but not liquid form. That means that, even if a car's tank were ruptured, the liquid gas in it would have to convert to vapor, mix with the air in the proper proportion, and be ignited in order to the car to blow up.
When an explosion of big screen proportions does happen, however, it engulfs the surrounding area in a heartbeat. Think you can outrun it? Read on, and then think again.
Racing an Explosion
The simple answer is: No, you cannot outrun an explosion. But it may depend on how close you are to the explosion when you start running. And how fast you are.
A C-4 explosion, for example, is virtually instant. Gases are released from the explosive at the super speedy rate of 26,400 feet per second (8,050 meters per second), pummeling everything in its immediate wake. In other words, if you are within 26,400 feet or so of an explosive, you will get hit by the blast within one second, assuming it is powerful enough to reach you [source: Harris].
By comparison, Jamaican sprinter Usain Bolt set a world record at the Beijing Olympics by running 200 meters (656 feet) in 19.30 seconds. That's about 10.4 meters or 34 feet per second. On the set of a real-life action flick, Bolt's lightning fast pace would not have prevented him from going up in flames, so to speak [source: Olympic.org].
That's assuming that Bolt or any other explosion racer is standing in the vicinity of the blast. Of course it is possible "outrun" an explosion if you are already pretty darn close to a safe distance away.
According to the U.S. Department of Homeland Security, the minimal safe distance from a 5-pound (2.2 kilogram) pipe bomb is 1,200 feet (360 meters). "Minimum evacuation distance is the range at which a life-threatening injury from blast or fragmentation hazards is unlikely," the department explains, adding that a person within the safe zone may still suffer injuries that are not life-threatening. The evacuation distance rises with the size of the explosion, from a 50-pound (22 kilogram) briefcase bomb (1,850 feet or 564 meters) to a 1,000-pound (453 kilogram) explosive device in a van (2,400 feet, 732 meters) and a 60,000-pound (27, 180) tractor trailer bomb (9,300 feet, 2,835 meters).
In other words, should you find yourself repelling an exploding skyscraper from a dangling fire hose, you're likely to come out with more than just a crispy, interestingly-colored undershirt.
Still thirsting for some high-powered action? Check out the links on the following page for more information on C-4, bomb sniffing and even internal human "explosions."
Author's Note: Can you really outrun an explosion?
Sure, Willis' leap from the Nakatomi Plaza in "Die Hard" was as enjoyable as it was unbelievable. And who doesn't get a kick out of watching the great Nic Cage walk away from a ridiculous, over the top and completely unnecessary blast in just about any of the ridiculous, over the top and unnecessary performances he's turned in over the years. But for my money, the best cinematic portrayal of "outrunning" an explosion is the car blast scene from Martin Scorsese's Oscar-nominated mafia tale, "Goodfellas." As a young Henry Hill (later played by Ray Liotta) explains his early entry into life in the mob, his Mafioso exploits rise from running errands for the bosses to hocking stolen cigarettes and later dropping a couple Molotov cocktails in a lot full of parked cars. The impressive part of this scene is not the explosion itself, it's that Hill sprints away in a suit and a pair of expensive loafers. It's one thing to survive an explosion. It's another to do it without scuffing your Bruno Maglis.
- EasyCare. "Common Myths About Cars." (Dec. 2, 2012) http://www.easycare.com/ResourceCenter/EnjoyingYourCarMore/CommonMovieMythsaboutCars
- Failes, Ian. "Hurt Locker Special Effects: Physical Bombs." FX Guide. March 19, 2010 (Dec. 4, 2012) http://www.fxguide.com/featured/Hurt_Locker_Special_Effects_Physical_Bombs/
- Harris, Tom. "How C-4 Works." HowStuffWorks.com. (Dec. 2, 2012) https://science.howstuffworks.com/c-4.htm
- Muller, Richard. "Physics for Future Presidents." Lawrence Berkley National Laboratory. Feb. 26, 2002 (Dec. 2, 2012) http://muller.lbl.gov/teaching/physics10/old%20physics%2010/chapters%20%28old%29/1-Explosions.htm
- Olympic.org. "Usain Bolt Wins 3 Sprinting Events in WR Time." Aug. 8, 2008. http://www.olympic.org/videos/usain-bolt-wins-3-sprinting-events-in-wr-time
- TVTropes.com. "Outrun the Fireball." (Dec. 2, 2012) http://tvtropes.org/pmwiki/pmwiki.php/Main/OutrunTheFireball
- U.S. Department of Homeland Security. "Bomb Threat Standoff Chart." (Dec. 2, 2012) https://www.fbiic.gov/public/2009/june/DHS-BombThreatChart-6-5-09.pdf