How to Survive a Grenade Blast

The Backyard Scientist and I recently had the opportunity to film a video together, where we took two live grenades and attempted to determine which one would provide better protection for survival. We set up our experiment with a simple yet effective design: Kevin, also known as The Backyard Scientist, would be standing on land with a grenade, while I would be wading into the pool with another grenade. The question at hand was which of us had a better chance of survival.

Before we began, it was essential to understand how a grenade works and its mechanics. Once you pull the pin, as long as you keep the handle pushed down, you're perfectly safe. However, as soon as you let go of the grenade, this handle springs off, releasing a spring-loaded striker that hits a percussion cap, starting a five-second fuse that cannot be stopped. I never really thought about it until I made this video, but the reason grenades have a waffle pattern is to create weak points in the shell, where it will break first.

Grenades are designed to be lethal, and their effectiveness can be attributed to their ability to shoot 40 bullets in all directions. Warfare often utilizes grenades as a means of creating chaos and destruction, making them an essential component of modern warfare. The best strategy for survival when faced with a grenade is to get as far away from it as possible within a few seconds and hit the deck with your feet facing towards the grenade. This presents the smallest possible target for a flying grenade chunk to hit.

When we conducted our experiment, I calculated that my chances of getting hit by a grenade fragment were less than 1%. However, Kevin had an even better chance due to the properties of water. It has been well-documented that bullets do not travel far in water at all, as the drag force is so high they disintegrate after a few feet. This means that Kevin would have zero percent chance of getting injured by a grenade fragment in the water.

Despite our thorough approach and rigorous scientific method, we wanted more information and decided to design an experiment where we filled three balloons with air half and with water to mimic the human body, which is mostly water but also has pockets of air. We then subjected them to identical explosions at various distances apart on both land and in water. The results were striking.

On land, there was little effect from the explosion, as air is compressible and helps dissipate energy, plus the blast wave reflects around objects. However, in water, the story changed dramatically. Water is incompressible, which means that not only is the blast wave not dissipated but it passes right through your mostly water body. The air cavities in our balloons represented the air in our bodies, such as lungs and sinuses. What was happening was the blast wave pushing against you, while the air cavities could not push back with the same force since they were filled with compressible air.

This meant that these air-filled areas moved a lot very quickly, causing permanent damage to your body. As a control, we had a balloon filled only with water, which remained perfectly fine and was similar to how arms and legs would function without air in them, being virtually incompressible like water. The effect of an explosion underwater is akin to the sound of a silver ball hitting a surface.

The initial energy of the blast represented by this balloon then came down and passed through the incompressible water before coming out without losing any energy at the water's surface. However, when our balloons with air were surrounded by incompressible water on the path of the blast wave, there was a lot of relative motion. This is bad if you like your lungs in their current state.

Sadly, our experiment verified this effect in real life. We witnessed firsthand how devastating an explosion can be underwater when it hits something solid, as in the video where they threw an M80 into the water and showed the damage that could happen. On land, a bird would likely be startled by the proximity of such an explosive device but would be perfectly fine if not nearby.

In conclusion to our experiment, while there is a small chance you might get unlucky with the grenade chunk if you chose to dive next to me, choosing to join Kevin in the pool meant being in that pool for the rest of one's life. Huge thanks go out to The Backyard Scientist for sacrificing himself in the name of science.

For those who have never seen his work before, it is a must-check-out. His channel is full of this type of fascinating content, and I highly recommend subscribing and watching some of his other videos as well.

"WEBVTTKind: captionsLanguage: en(water splashing)- So I'm here today inFlorida filming with Kevin,more commonly known asThe Backyard Scientist.- That's right.- And today we're gonna takethese two live grenades,and we're gonna be dipping 'emin this tub of liquid nitrogen.So go ahead and hand 'em to me.And then dude, baby alligator.(grenades bouncing)(water splashes)(classical uplifting music)So now we're both about 15 feet away,except I'm on land with a grenade on land,and Kevin is in the waterwith a grenade in the water.So the question is, which oneof us has a better chance of survival?Take a moment to decide, do you diveon the pool deck or jump in the pool?We both had very differenttheories for survival.So as firm believers inthe scientific method,we decided to test out our hypotheses.So we devised some experiments.But before I get to those,I think it's importantto understand how agrenade actually works.So once you pull the pin, as longas you keep this handle pusheddown, you're perfectly safe.But as soonas you let go of the grenade,this handle springs offwhich releases a springloaded striker that hitsa percussion cap thatstarts a five second fusethat you can't do anything to stop.And I never really thoughtabout it until I made this videobut the reason you see a waffle patternin grenades is to createweak points in the shell.So that's where it's going to break first.And since there are 40 bumps,this grenade is basicallyan explosion that shoots 40bullets in all directions.In warfare, that's what makes them lethal.So the best strategy is to get as faras possible in a few seconds,and then hit the deckwith your feet facing towards the grenade.This presents the smallest possible targetfor a flying grenade chunk to hit.So 15 feet away.Mathematically, that puts my chancesof getting hit at less than 1%.But things are even betterfor Kevin in the pool.It's been well documentedthat bullets do not travelfar in water at all.The drag force is so high,they just disintegrate after a few feet.So he has a 0% chanceof getting injured by agrenade fragment in the water.But we are thorough men of scienceand we wanted more information.So we designed an experimentwhere we filled three balloons,half with water and halfwith air to roughly mimic the human body,which is mostly water, but we have pocketsof air in our lungs, intestines,in our sinuses, in our ears,and then we subjected themto identical explosions,identical distances apart in both air(shot fires)and water.(shot fires)As you can see, thereisn't much effect on land,because air is compressible,which helps dissipate energy,plus the blast wavereflects around objects.But in water, the story is different.Water is incompressible,which means not only is theblast wave not dissipated,but it passes right throughyour mostly water body.So the air in theseballoons represents the airin your body, like yourlungs and your sinuses.So basically what'shappening is the blast waveis pushing in on you,but the air cavities can'tpush back with the same force,since they're filledwith compressible air,that means they move a lot really quickly,which causes permanent damage.As a control,you could see this balloonthat is filled with just water.It is perfectly fine.That would be like your armsand legs, which have no airin them, and they arebasically incompressiblelike water, and would be fine.An explosion underwater is sort of likethe silver ball things.So this represents theinitial energy of the blast,which then comes down and passes throughthe incompressible water,and then comes outwithout losing any energyat the water surface.But now your squishablelungs are surroundedby incompressible water inthe path of the blast wave.And so when the blasthappens, there's a lotof relative motion, which isbad if you like your lungsthe way they are right now.And sadly, our experimentis verified in real life.So these jerks throwan M80 into the water,and you can see thedevastating effect it has.On land, if a bird werethat close to an M80,it would be startled,but it would be perfectly fine.So now that you know, thinkback, which did you choose?While it's true, there is asmall chance you would getunlucky with the grenadechunk if you choseto dive next to me.If you chose to join Kevin,you will be in that poolfor the rest of your life.(upbeat video game music)So huge thanks to the backyard scientistfor dying in the name of science.If you've never seenhis stuff, you just haveto check it out.Here's a video we just finished filming.- It's a bunch of whichis a non-Newtonian fluid,and we destroyed it inevery way imaginable.- It's incredible footage.His channel is full of this type of junk.So check it out, subscribe,and as always, thanks for watching.\n"