by Cody Cassidy
Grape
A grape’s terminal velocity is 65 miles per hour—not enough momentum to do any damage even if it hit your head. However, the world record for catching a grape in your mouth is 788 feet, set by Paul Tavilla in 1988.
Conclusion: If you see a grape falling, first make sure it’s a grape and not something more solid, and then open wide!
Soccer Ball
A soccer ball is relatively large and light, a slow combination for falling objects. It would max out at 54 miles per hour if someone threw one from the top of the Empire State Building. Soccer players regularly kick them faster than that—the record is 132 miles per hour—and go to enormous effort to place their heads in front of them, suffering nothing more than a headache and the loss of a few brain cells as a consequence.
How high would the ball bounce? A soccer ball’s coefficient of restitution (COR) (how much energy an object retains after it bounces off a given material, in this case your head) is 0.85. If it hit your head, it would bounce back to the fourth story.
Conclusion: Bouncy, but not lethal. (If you’re looking for even bouncier, try dropping a Super Ball. It has a terminal velocity of 70 miles per hour—also not lethal, but with a COR of 0.90 it would bounce 80 feet high if you dropped it from the skyscraper.)
Ballpoint Pen
It depends on the pen. A ballpoint pen without a shirt clip will tumble as it falls and go too slowly to do any damage. If, on the other hand, it’s a steel pen with a shirt clip, it would drill that hole in your head that the penny was supposed to. Why?
The shirt clip would act like the feather fletching on an arrow and keep the pen pointed down. Not only would it accelerate to 190 miles per hour, it would hit your head as a rod—and rods are great for puncturing because they carry extra momentum without adding drag (which is why antitank ammunition is rod shaped).
Conclusion: Thanks to its “fletching” and its rod-momentum bonus, a falling pen with a shirt clip will puncture your skull and pierce your brain. Result? If falling from the top of a skyscraper, a pen is as mighty as the sword.
Blue Whale
A blue whale holds the world’s free-fall speed record for all life forms. Or at least it would if it could find a ride to the top of the atmosphere. Weighing in at 420,000 pounds, a blue whale has the highest falling terminal velocity of any animal that has ever lived. From any elevation greater than 4 miles, a falling whale would break the sound barrier at sea level. From the top of the Empire State Building, a whale would reach 190 miles per hour.*
That spells trouble if you were to try to catch it. You would be flattened. But it’s actually worse than that.
If a whale struck the ground it would “splash,” meaning its skin would not be able to contain the outward expansion of its guts. The same thing would happen to your body underneath the falling whale. Your skin would fail to contain its contents. So after smashing (and splashing), the whale’s insides would mix up with yours.
Conclusion: messy.
This Book
If someone should discard this book from the top of the Empire State Building—we know, probably the most unlikely scenario here—it would max out at 25 miles per hour and take more than thirty seconds to complete its fall.
Conclusion: If you have ever angered a strong-armed librarian, you might have been hit by a book traveling faster than 25 miles per hour. Startling, but not deadly.
What Would Happen If . . .
You Actually Shook Someone’s Hand?
ONE OF THE worst things you can do for your health is to shake someone’s hand. Hands are our primary disease transmitters, which is why the Centers for Disease Control is a big proponent of the fist pound. Disease alone, though, does not begin to take into account how dangerous your next handshake could be.
That’s because you have never actually touched another person’s hand—even if you’re one of those firm shakers—because of something called atomic repulsion. If you actually touched the hand of the next person you shook with, the results would be disastrous.
Every atom that makes up your palm (and everything else) has negatively charged electrons that circle their nuclei. These electrons repel one another just like the north poles of your fridge magnets, except that, unlike your fridge magnets, electrons really don’t like to touch one another.
They repel with such force that you have not actually touched anything in your life. Right now your butt is not actually touching your chair, but hovering above it. Smash a nail with a hammer, and the hammer and nail won’t actually touch each other either.
To force two atoms together, you need more pressure than your hand, a hammer, or your butt can provide.
In nature, this kind of pressure is found in the center of stars. Our sun generates heat by pushing hydrogen nuclei together in a process called nuclear fusion.
The only way to create that kind of pressure here on Earth is through explosives.
To truly shake your friend’s hand, to truly touch your atoms to his, you would have to bake your hands into a nuclear bomb and set it off. (Note: This is potentially risky. Make sure you have adult supervision.)
Unfortunately for you, your friend, and the city you happen to be located in, the most common molecule in human skin is hydrogen, and when hydrogen nuclei fuse, they release an enormous amount of energy.
In getting your two hands to actually shake, you have just detonated a medium-size hydrogen bomb.*
Everyone within twenty miles would suffer third-degree radiation burns and nerve damage. People within six miles would get that plus their houses blown down. People within three miles would get that plus an air blast powerful enough to destroy skyscrapers, and everyone within two miles would get all that plus they would be engulfed in a gigantic fireball.
For you and your friend it would be over quickly. The first thing you would see would also be the last. That’s because the flash of the bomb is blinding. Literally. The light would burn out your retinas like an overexposed photo, then vaporize your eyeballs and optic nerves.
Accompanying the flash is a veritable smorgasbord of electromagnetic radiation. To get a sense of its effect on you, imagine this: If you stepped into a microwave, your water molecules would be tickled into moving faster and would heat up. Eventually your liquids would turn to steam and expand. When water expands under pressure, like the pressure of your veins, it explodes. You would coat the inside of the microwave. Except a microwave offers only a sampling of low-powered electromagnetic radiation. An H-bomb gives you the entire photon radiation buffet: infrared, visible, ultraviolet, X-ray, and gamma ray.
The photons would blast your vaporized body and destroy the atomic bonds holding your molecules together—breaking you down into your component atoms.
And then it would get worse.
Your molecules would no longer be attached, but they would still be clumped up like billiard balls. Then along comes the photon cue ball. The photons would hit your atoms and disperse you into an area the size of a high school gymnasium.
Next come the particles. These are your slower-traveling neutrons and electrons, and it’s the neutrons that should particularly concern you. They would go after your individual atoms and transmute your nuclei—turning your last remains radioactive.
The slowest traveling effect of the bomb is its supersonic shock wave. That blast of turbulence would push your transmuted, radioactive, ionized-plasma body at high speed, turbulently mixing your atoms with the expanding hot plasma cloud of everything else that used to be you. Eventually you would sprinkle back down to Earth as 10,000,000,000,000,000,000,000,000,000 separate atoms. Roughly.
What Would Happen If . . .
You Were the Ant Under the Magnifying Glass?
ANY KID KNOWS that a magnifying glass can scorch an ant. Fortunately CVS doesn’t sell magnifying glasses big enough to heat blast a person, but with enough people and a lot of mirrors you c
ould give someone a lot more than a sunburn.
In Arthur C. Clarke’s “A Slight Case of Sunstroke,” a president conceives a diabolical plan to counter a crooked referee. He gives 50,000 soldiers a free ticket to a soccer game and a two-foot reflective program. The soldiers think they’re being given a novel way to boo, but the president has deadlier intentions, and after a particularly egregious call they all use their programs to reflect sun onto the ref. The power of 50,000 reflecting mirrors burns the referee alive.
The story is fictional but the theory is surprisingly sound, and executed properly it would take a lot less than 50,000 fans.
Arthur C. Clarke is not the first person to think of using sunlight as a weapon.
According to legend, Archimedes burned enemy ships by having 129 soldiers reflect sun onto them with their brass shields. With the technology available to Archimedes it’s clear this didn’t happen, though a study by MIT showed it’s theoretically possible.
Although focused sunlight has never killed a human, it does kill thousands of birds every year. Solar farms in the Mojave Desert use garage-door-size mirrors to focus sunlight into a 1,000-degree bird-frying beam.
The biggest issue with weaponizing sunlight, which the solar farms solve with movable mirrors and computer algorithms, is focus.
Once you have more than ten or twelve squares of light on an object it becomes very difficult for each person to aim their light. Nobody knows which square they’re aiming.
The U.S. Air Force has solved this problem. Included in their survival kits is something called a signal mirror, and it’s a powerful tool for a downed pilot.
A small mirror reflecting sunlight can flash distress signals that can be seen for miles. The trick is aiming the mirror’s light, and air force signal mirrors use reflective beads to place a red dot, like a sniper’s scope, where your reflection is pointing.
The mirrors are surprisingly effective. In 1987, a father and son rafting down the Colorado River in the Grand Canyon had an accident and used a signal mirror to successfully signal SOS at an airliner passing 35,000 feet overhead. Attaching signal mirrors to each fan’s mirror solves the focus issue, and once you do that, the heat scales quickly. A standard one-foot-by-one-foot bathroom mirror receives one hundred watts of energy from the sun, and each mirror reflects exactly as much heat as it receives. So one mirror reflects the heat of that mirror, two mirrors the heat of two mirrors, and so on.
So if you were the referee in the Arthur C. Clarke story and you made a couple of bad calls, here’s what we think you could expect. If the fans brought basic mirrors, as they do in the book, you would not have much to worry about. The light would be too diffuse to do anything other than make you a bit warmer, and you would have plenty of time to scamper off the field.
If, on the other hand, it was a sunny day and 1,000 fans attached signal mirrors on top of their bathroom mirrors, you would need to be very concerned, because they could collectively direct 100,000 watts onto your chest. That’s enough heat to boil a 200-pound person in a few minutes, but you would die long before you began boiling.
A well-stoked fire is 800 degrees—if you stuck your hand close to one you would have to pull it away, and in the glare of 1,000 mirrors the temperature would be even hotter, in the neighborhood of 1,000 degrees.
Your cells work in only a narrow band of temperatures. They’re happy at 98.6 degrees, and even a 2-degree rise will make you uncomfortable. A 10-degree rise in your temperature is lethal.
Fortunately, you have developed a number of ways to keep your inner temperature cool in scorching heat. Sweating, dilating your veins, and your body’s insulation can keep you alive in rooms over 200 degrees for a few minutes.
But in extreme conditions, everything happens too fast for your defense mechanisms to do any good.
If 1,000 perfectly aimed mirrors reflected their beams on you, you would be dead before you took two steps. You would not combust right away because you have so much water in you that you are like a soaked log, but as soon as you took a breath, the tender skin in your throat would burn and scar, disabling it permanently. You would suffocate if you were able to last another minute or two, but, not to worry, there’s no chance of that.
Instead your inner body temperature would rocket up the required 10 degrees, your brain cells would stop working, and your proteins would denature (what physicists call cooking).
Nothing in your body works without your proteins ferrying energy, so you would be dead meat.
But your body would keep cooking until it was fully dehydrated and then you would burst into flame. The fire would gradually move through you until there was nothing left but bones and teeth.
Crematoriums heat up to 1,500 degrees and take two and a half hours to fully transform someone to ash, so unless the fans were truly dedicated, at least a few of your teeth and scorched bones would remain on the field.
Perhaps, as in “A Slight Case of Sunstroke,” your death would be followed by a short moment of silence, a “new and understandably docile referee,” and a comeback victory by the home team.
What Would Happen If . . .
You Stuck Your Hand in a Particle Accelerator?
IN JULY 1978 a Russian scientist named Anatoli Bugorski was inspecting Russia’s most powerful particle accelerator (a machine that speeds subatomic particles to near the speed of light), called the U-70, when the main particle beam hit him in the back of the head and passed through his nose. He felt no pain but reported seeing a flash “as bright as a thousand suns.” Russian doctors rushed him to the hospital expecting him to die from radiation poisoning, but, other than some facial paralysis, the occasional seizure, a touch of radiation sickness, and a small hole through his head, he was fine and went on to finish his PhD.
Does this mean you could stick your hand in Europe’s new Large Hadron Collider (LHC)? Would you get a cool scar but otherwise be unharmed? No. Unfortunately for you and your hand, the Russian U-70 accelerator had less than 1 percent of the power that the LHC does.
The LHC is the most powerful particle collider in the world. It accelerates protons around a 17-mile loop to 0.99999999 c (7 miles per hour less than the speed of light) and smashes them together in the world’s greatest demolition derby. It’s so powerful that a small but vocal community expressed concern that the smashing particles would create a black hole large enough to consume Earth (see p. 197 for what would happen if it did).
The beam is composed of 100 billion protons, which, when accelerated to near light speed, carry a huge amount of energy—similar to a 400-ton train traveling at 100 miles per hour.
The beam carries so much energy it can drill a hole through 100 feet of copper in a millisecond—which is why most accelerators are pointed into the ground, ensuring that if a malfunction occurs a killer beam is not shot through a city.
So you can see right away that there will be a few issues with sticking your hand in the beam, but let’s say you ignored the warning signs and did it anyway. The first problem? Your ears.
Carbon-fiber jaws guide the beam’s path. If the beam wanders, it strikes the carbon fiber, and for you the sound would be as loud as if you were standing in front of concert speakers. Then, when scientists are done experimenting, the beam’s energy is dumped into a graphite block used as a proton trap, which would sound like a 200-pound TNT explosion—loud enough to blow out your eardrums.
In other words, wear some earplugs. But, really, blown-out eardrums would be the least of your concerns. A bigger problem would be the power of the beam.
The protons would pass through your hand as if nothing were there at all. The beam is small, about the width of the lead in a pencil, and traveling so fast it would punch through your hand painlessly. There’s a good chance it would miss your bones and leave your hand fully functional, but that is only if you kept your hand very, very still.
The U-70 Russian reactor was
not only less powerful than the LHC, it was also only a single shot, so Bugorski had only one hole in his head. The LHC is more like a proton machine gun—in two seconds it fires nearly three thousand shots. If you pulled your hand away after the first pulse, the beam would cut your hand in half.
So don’t do that.
As the beam passed through your (hopefully) steady hand, another far more troubling process would take place. Particles traveling as fast as these, by their nature, are accompanied by intense radiation. Even if you were many yards away from the beam you would be dosed with the equivalent of a full chest X-ray.
Exactly how much radiation you would receive if the beam hit you, though, is actually difficult to say. The beam itself carries a gargantuan amount of radiation, enough to kill you quickly (and many times over), but the vast majority of the radiation would miss you because although you might think your hand is solid, at an atomic level there’s actually quite a bit of space.
If an atom in your hand were enlarged to the size of a football stadium, then a marble sitting on the fifty-yard line would be the nucleus. Because the radiation bullets fired at you are also quite small, most of them would miss, saving you from instant death. Unfortunately, only most of them would miss. You would probably be hit with just enough radiation to kill you slowly and painfully.
In the end, because Bugorski nearly died of radiation poisoning despite the accelerator being less than 1 percent as powerful, we can be confident that a beam from the LHC would kill you. The particles created when the beam struck your hand would irradiate and poison your entire body with at least 10 sieverts of radiation, and your experience would likely mimic what two workers at the Tokaimura nuclear processing plant went through after an accident in 1999.