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WHAT IF BOOK PDF RANDALL MUNROE

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Humor, Science |12 February,February 12, by pdf origin | 2 Comments About the Book: What If?: Serious Scientific Author: Randall Munroe The charm of What If? Lies in the ease Munroe are jumping past intensely interesting . Wife Book · Обсуждения. Просмотр темы1. DOWNLOAD What If?: Serious Scientific By Randall Munroe [PDF EBOOK EPUB KINDLE] DOWNLOAD What If?. on orders over $25—or get FREE Two-Day Shipping with Amazon Prime . Randall Munroe is the author of the #1 New York Times bestseller What If?, the.


What If Book Pdf Randall Munroe

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cittadelmonte.info Pages INTRODUCTIO THIS BOOK IS A collection of answers to hypothetical questions. RANDALL MUNROE what if?. RANDALL MUNROE. HOUGHTON from the What If? Inbox, #8. If you're going to wait it out, one of the best places to do it might be Helsinki,. Finland. [PDF] What If?: Serious Scientific Answers to Absurd Hypothetical Questions I' m a Car each week to read Randall Munroe's iconic webcomic.

What If? Is a fast, engaging read. Read on and you will learn how. Thither is a kind of joy in getting actual answers to the admittedly ridiculous questions Munroe is sent every day. For example, yes, you could swim in a pool of spent nuclear fuel rods.

But even if a bunch of us spent years on SoulMateRoulette, another bunch of us managed to hold jobs that offered constant eye contact with strangers, and the rest of us just hoped for luck, only a small minority of us would ever find true love.

The rest of us would be out of luck.

Given all the stress and pressure, some people would fake it. A world of random soul mates would be a lonely one. The first thing to consider is that not everyone can see the Moon at once.

We could try to illuminate either a new moon or a full moon. The new moon is darker, making it easier to see our lasers. The atmosphere would distort the beam a bit, and absorb some of it, but most of the light would make it. Half an hour after midnight GMT , everyone aims and presses the button.

This is what happened: It makes sense, though. Sunlight bathes the Moon in a bit over a kilowatt of energy per square meter. Just kidding! Memo to presidential candidates: This policy would win my vote. In addition to being more powerful, green laser light is nearer to the middle of the visible spectrum, so the eye is more sensitive to it and it seems brighter. The beam is several degrees wide, so we would want some focusing lenses to get it down to the half-degree needed to hit the Moon. The beam is providing 20 lux of illumination, outshining the ambient light on the night half by a factor of two!

Still barely visible. Good job, team. The Department of Defense has developed megawatt lasers, designed for destroying incoming missiles in mid-flight. The Boeing YAL-1 was a megawatt-class chemical oxygen iodine laser mounted in a The Moon would shine as brightly as the midmorning sun, and by the end of the two minutes, the lunar regolith would be heated to a glow.

The most powerful laser on Earth is the confinement beam at the National Ignition Facility, a fusion research laboratory. Under those circumstances, it turns out Earth would still catch fire.

The reflected light from the Moon would be four thousand times brighter than the noonday sun. But forget the Earth—what would happen to the Moon? The laser itself would exert enough radiation pressure to accelerate the Moon at about one ten millionth of a gee. Forty megajoules of energy is enough to vaporize a kilogram of rock. Our laser would keep pouring more and more energy into the plasma, and the plasma would keep getting hotter and hotter.

The particles would bounce off each other, slam into the surface of the Moon, and eventually blast into space at a terrific speed. This flow of material effectively turns the entire surface of the Moon into a rocket engine—and a surprisingly efficient one, too. Using lasers to blast off surface material like this is called laser ablation, and it turns out to be a promising method for spacecraft propulsion.

But if we make the wild guess that the particles in the plasma exit at an average speed of kilometers per second, then it will take a few months for the Moon to be pushed out of range of our laser.

This Earth-crossing orbit would lead to periodic unpredictable orbital perturbation. And that, at last, would be enough power. These collectors try to gather physical samples of as many of the elements as possible into periodic-table-shaped display cases. Another few dozen can be scavenged by taking things apart you can find tiny americium samples in smoke detectors.

Others can be ordered over the Internet. But what if you did? The periodic table of the elements has seven rows. The third row would burn you with fire. The fourth row would kill you with toxic smoke. The sixth row would explode violently, destroying the building in a cloud of radioactive, poisonous fire and dust. Do not build the seventh row. The first row is simple, if boring: The cube of hydrogen would rise upward and disperse, like a balloon without a balloon. The same goes for helium. The second row is trickier.

The lithium would immediately tarnish. The beryllium is pretty toxic, so you should handle it carefully and avoid getting any dust in the air. The neon floats away. Fluorine is the most reactive, corrosive element in the periodic table. Almost any substance exposed to pure fluorine will spontaneously catch fire. You would definitely need a gas mask.

Keep in mind that fluorine eats through a lot of potential mask materials, so you would want to test it first. Have fun! On to the third row! The big troublemaker here is phosphorus. Pure phosphorus comes in several forms. Red phosphorus is reasonably safe to handle. White phosphorus spontaneously ignites on contact with air.

It burns with hot, hard-to-extinguish flames and is, in addition, quite poisonous. When exposed to pure fluorine gas, sulfur—like many substances—catches fire. The inert argon is heavier than air, so it would just spread out and cover the ground.

You have bigger problems. The fire would produce all kinds of terrifying chemicals with names like sulfur hexafluoride. On to row four! The reason it sounds scary is a good one: This is not one of those times. The burning phosphorus now joined by burning potassium, which is similarly prone to spontaneous combustion could ignite the arsenic, releasing large amounts of arsenic trioxide.

That stuff is pretty toxic. This row would also produce hideous odors. Bromine is liquid at room temperature, a property it shares with only one other element—mercury. However, if you did this experiment from a safe distance, you might survive. The fifth row contains something interesting: If you spent all day wearing it as a hat—or breathed it in as dust —it could definitely kill you.

Techneteium aside, the fifth row would be a lot like the fourth. On to the sixth row! No matter how careful you are, the sixth row would definitely kill you.

These elements are normally shown separately from the main table to avoid making it too wide. Astatine is the bad one. Our cube would, briefly, contain more astatine than has ever been synthesized.

The heat alone would give third-degree burns to anyone nearby, and the building would be demolished. The cloud of hot gas would rise rapidly into the sky, pouring out heat and radiation.

The explosion would be just the right size to maximize the amount of paperwork your lab would face. If it were larger, there would be no one left in the city to submit paperwork to. Dust and debris coated in astatine, polonium, and other radioactive products would rain from the cloud, rendering the downwind neighborhood completely uninhabitable. The radiation levels would be incredibly high. Given that it takes a few hundred milliseconds to blink, you would literally get a lethal dose of radiation in the blink of an eye.

The seventh row would be much worse. There are a whole bunch of weird elements along the bottom of the periodic table called transuranic elements. They decay radioactively. And most of them decay into things that also decay.

It would all happen at once. The flood of energy would instantly turn you—and the rest of the periodic table—to plasma. A mushroom cloud would rise over the city. The top of the plume would reach up through the stratosphere, buoyed by its own heat. Entire regions would be devastated; the cleanup would stretch on for centuries.

While collecting things is certainly fun, when it comes to chemical elements, you do not want to collect them all. O2 and N2. They cover the kinematics pretty well. This crowd takes up an area the size of Rhode Island. At the stroke of noon, everyone jumps. Earth outweighs us by a factor of over ten trillion. On average, we humans can vertically jump maybe half a meter on a good day.

Next, everyone falls back to the ground. A slight pulse of pressure spreads through the North American continental crust and dissipates with little effect. The sound of all those feet hitting the ground creates a loud, drawn-out roar lasting many seconds. Eventually, the air grows quiet. Seconds pass. Everyone looks around. There are a lot of uncomfortable glances. Someone coughs. A cell phone comes out of a pocket. Outside Rhode Island, abandoned machinery begins grinding to a halt.

The T. Assuming they got things organized including sending out scouting missions to retrieve fuel , they could run at percent capacity for years without making a dent in the crowd. Moments later, I, I, and I become the sites of the largest traffic jam in the history of the planet.

Some make it past New York or Boston before running out of fuel. All the cops are in Rhode Island. The edge of the crowd spreads outward into southern Massachusetts and Connecticut. Any two people who meet are unlikely to have a language in common, and almost nobody knows the area.

Violence is common. Everybody is hungry and thirsty. Grocery stores are emptied. Within weeks, Rhode Island is a graveyard of billions. Our species staggers on, but our population has been greatly reduced. But at least now we know. First, some definitions. A mole is a unit.

A mole is also a type of burrowing mammal. A mole the animal is small enough for me to pick up and throw. One pound is 1 kilogram. I happen to remember that a trillion trillion kilograms is how much a planet weighs. An eastern mole Scalopus aquaticus weighs about 75 grams, which means a mole of moles weighs: Mammals are largely water.

A kilogram of water takes up a liter of volume, so if the moles weigh 4. The cube root of 4. So doing this on Earth is definitely not an option. Gravitational attraction would pull them into a sphere. But this is where it gets weird.

What If?: Serious Scientific Answers to Absurd Hypothetical Questions

The mole planet would be a giant sphere of meat. Normally, when organic matter decomposes, it releases much of that energy as heat. Closer to the surface, where the pressure would be lower, there would be another obstacle to decomposition— the interior of a mole planet would be low in oxygen. While inefficient, this anaerobic decomposition can unlock quite a bit of heat.

If continued unchecked, it would heat the planet to a boil. But the decomposition would be self-limiting. Throughout the planet, the mole bodies would gradually break down into kerogen, a mush of organic matter that would—if the planet were hotter—eventually form oil.

Because the moles form a literal fur coat, when frozen they would insulate the interior of the planet and slow the loss of heat to space. However, the flow of heat in the liquid interior would be dominated by convection. Eventually, after centuries or millennia of turmoil, the planet would calm and cool enough that it would begin to freeze all the way through.

The deep interior would be under such high pressure that as it cooled, the water would crystallize out into exotic forms of ice such as ice III and ice V, and eventually ice II and ice IX. There might be a billion habitable planets in our galaxy. If you want a mole of moles, build a spaceship. All watts have to go somewhere. This is true of any device that uses power, which is a handy thing to know. Are they right? This is true of almost any powered device.

At that temperature, the box will be losing heat to the outside as fast as the hair dryer is adding it inside, and the system will be in equilibrium. If the box is made of metal, it will be hot enough to burn your hand if you touch it for more than five seconds. The temperature it reaches will depend on the thickness of the box wall; the thicker and more insulating the wall, the higher the temperature.

I wonder how high this dial goes. Two megawatts pumped into a laser is enough to destroy missiles. One more notch. Now 18 megawatts are flowing into the box. If it were steel, it would have melted by now. The floor is made of lava. Before it can burn its way through the floor, someone throws a water balloon under it. The burst of steam launches the box out the front door and onto the sidewalk. According to Back to the Future, the hair dryer is now drawing enough power to travel back in time.

It sits in the middle of a growing pool of lava. Anything within 50— meters bursts into flame. A column of heat and smoke rise high into the air. Periodic explosions of gas beneath the box launch it into the air, and it starts fires and forms a new lava pool where it lands. We keep turning the dial. At In , H. Wells imagined devices like this in his book The World Set Free. The story eerily foreshadowed the development, 30 years later, of nuclear weapons.

The box is now soaring through the air. Each time it nears the ground, it superheats the surface, and the plume of expanding air hurls it back into the sky. The outpouring of 1. A trail of firestorms —massive conflagrations that sustain themselves by creating their own wind systems —winds its way across the landscape.

A new milestone: The box, soaring high above the surface, is putting out energy equivalent to three Trinity tests every second. At this point, the pattern is obvious. This thing is going to skip around the atmosphere until it destroys the planet. We turn the dial to zero as the box is passing over northern Canada. Rapidly cooling, it plummets to Earth, landing in Great Bear Lake with a plume of steam. And then. A brief story: When the 1- kiloton nuke went off below, the facility effectively became a nuclear potato cannon, giving the cap a gigantic kick.

The cap was never found. When we turn it back on, our reactivated hair dryer box, bobbing in lake water, undergoes a similar process. The heated steam below it expands outward, and as the box rises into the air, the entire surface of the lake turns to steam.

It exits the atmosphere and continues away, slowly fading from second sun to dim star. Much of the Northwest Territories is burning, but the Earth has survived. If a charger is connected to something, like a smartphone or laptop, power can be flowing from the wall through the charger into the device.

However, neither of them answered this particular question. Without people, there would be less demand for power, but our thermostats would still be running.

As coal and oil plants started shutting down in the first few hours, other plants would need to take up the slack. This kind of situation is difficult to handle even with human guidance. However, plenty of electricity comes from sources not tied to the major power grids. These can continue to operate until they run out of fuel, which in most cases could be anywhere from days to months.

Wind turbines People relying on wind power would be in better shape than most. Some windmills can run for a long time without human intervention. Modern turbines are typically rated to run for 30, hours three years without servicing, and there are no doubt some that would run for decades. One of them would no doubt have at least a status LED in it somewhere.

Their gearboxes would seize up. Hydroelectric dams Generators that convert falling water into electricity will keep working for quite a while. The dam would probably succumb to either clogged intakes or the same kind of mechanical failure that would hit the wind turbines and geothermal plants.

Even without anything using their power, batteries gradually self-discharge. Some types last longer than others, but even batteries advertised as having long shelf lives typically hold their charge only for a decade or two. There are a few exceptions.

Nobody knows exactly what kind of batteries it uses because nobody wants to take it apart to figure it out. Nuclear reactors Nuclear reactors are a little tricky. As a certain webcomic put it: As soon as something went wrong, the core would go into automatic shutdown. This would happen quickly; many things can trigger it, but the most likely culprit would be a loss of external power. Space probes Out of all human artifacts, our spacecraft might be the longest-lasting.

Within centuries, our Mars rovers will be buried by dust. GPS satellites, in distant orbits, will last longer, but in time, even the most stable orbits will be disrupted by the Moon and Sun. Many spacecraft are powered by solar panels, and others by radioactive decay. Eventually the voltage will drop too low to keep the rover operating, but other parts will probably wear out before that happens.

So Curiosity looks promising. With no human instructions, it will have no reason to turn them on. Solar power Emergency call boxes, often found along the side of the road in remote locations, are frequently solar-powered. They usually have lights on them, which provide illumination every night.

If we follow a strict definition of lighting, solar- powered lights in remote locations could conceivably be the last surviving human light source. Watch dials used to be coated in radium, which made them glow. Over the years, the paint has broken down. Although the watch dials are still radioactive, they no longer glow. Watch dials, however, are not our only radioactive light source.

In the dark, these glass blocks glow blue. And thus, we arrive at our answer: Centuries from now, deep in concrete vaults, the light from our most toxic waste will still be shining. In case something went wrong, next to the railing was stationed a distinguished physicist with an axe.

The principle here is pretty simple. If you fire a bullet forward, the recoil pushes you back. So if you fire downward, the recoil should push you up.

The Saturn V had a takeoff thrust-to-weight ratio of about 1. As it turns out, the AK has a thrust-to-weight ratio of around 2. This means if you stood it on end and somehow taped down the trigger, it would rise into the air while firing. Thrust is the product of these two amounts: If an AK fires ten 8- gram bullets per second at meters per second, its thrust is: Since the AK weighs only In practice, the actual thrust would turn out to be up to around 30 percent higher.

The amount of extra force this adds varies by gun and cartridge. The overall efficiency also depends on whether you eject the shell casings out of the vehicle or carry them with you.

I asked my Texan acquaintances if they could weigh some shell casings for my calculations. We can try using multiple guns. If you fire two guns at the ground, it creates twice the thrust. If each gun can lift 5 pounds more than its own weight, two can lift You will not go to space today. An AK magazine holds 30 rounds. We can improve this with a larger magazine—but only up to a point.

The reason for this is a fundamental and central problem in rocket science: Fuel makes you heavier. If we added more than about rounds, the AK would be too heavy to take off.

The largest versions of this craft could accelerate upward to vertical speeds approaching meters per second, climbing over half a kilometer into the air. With enough machine guns, you could fly. Can we do better? My Texas friends suggested a series of machine guns, and I ran the numbers on each one. Some did pretty well; the MG, a heavier machine gun, had a marginally higher thrust-to-weight ratio than the AK Then we went bigger. To put it another way: If I mounted a GAU-8 on my car, put the car in neutral, and started firing backward from a standstill, I would be breaking the interstate speed limit in less than three seconds.

Its thrust-to- weight ratio approaches 40, which means if you pointed one at the ground and fired, not only would it take off in a rapidly expanding spray of deadly metal fragments, but you would experience 40 gees of acceleration. This is way too much. Landing lights almost always broke after firing.

Or something else? Fortunately, your body handles air pressure changes like that all the time. Air pressure changes quickly with height. If your phone has a barometer in it, as a lot of modern phones do, you can download an app and actually see the pressure difference between your head and your feet. At about two hours and two kilometers, the temperature would drop below freezing.

The wind would also, most likely, be picking up. If you have any exposed skin, this is where frostbite would start to become a concern. However, unless you had a warm coat, the temperature would be a bigger problem. Over the next two hours, the air would drop to below- zero temperatures. But when? The scholarly authorities on freezing to death seem to be, unsurprisingly, Canadians.

According to their model, the main factor in the cause of death would be your clothes. Above meters—above the tops of all but the highest mountains—the oxygen content in the air is too low to support human life.

Near this zone, you would experience a range of symptoms, possibly including confusion, dizziness, clumsiness, impaired vision, and nausea. Your veins are supposed to bring low-oxygen blood back to your lungs to be refilled with oxygen. This would happen around the seven-hour mark; the chances are very slim that you would make it to eight. She died as she lived—rising at a foot per second. I mean, as she lived for the last few hours.

And two million years later, your frozen body, still moving along steadily at a foot per second, would pass through the heliopause into interstellar space. Clyde Tombaugh, the astronomer who discovered Pluto, died in It can, of course, vary quite a bit. The hull would likely be airtight.

There may be a few specialized one- way valves that would let air out, but in all likelihood, the submarine would remain sealed. The big problem the crew would face would be the obvious one: Everyone knows that space is very cold. The ocean is colder than space. Interstellar space is very cold, but space near the Sun —and near Earth—is actually incredibly hot! When I was a kid, my dad had a machine shop in our basement, and I remember watching him use a metal grinder.

Without a warm environment around you radiating heat back to you, you lose heat by radiation much faster than normal. Without rockets, it has no way to do this. Okay—technically, a submarine does have rockets. Unfortunately, the rockets are pointing the wrong way to give the submarine a push. Rockets are self-propelling, which means they have very little recoil.

With a rocket, you just light it and let go. But not launching them could. Remember to disable the detonators on the missiles.

It means the warmth of sunlight in winter. Since there are 7. Your extra two million bills a year would barely be enough to notice. Would the storm cell be immediately vaporized? It turns out the National Oceanic and Atmospheric Administration—the agency that runs the National Hurricane Center—gets it a lot, too.

I recommend you read the whole thing,1 but I think the last sentence of the first paragraph says it all: Water turbines can be pretty efficient. For those 42 minutes, our hypothetical house could generate up to watts of electricity, which might be enough to power everything inside it.

The stars are named Joe Biden. It works, but it feels so wrong. I bike to class sometimes. To increase the temperature of the air layer in front of your body by 20 degrees Celsius enough to go from freezing to room temperature , you would need to be biking at meters per second. Since drag increases with the square of the speed, this limit would be pretty hard to push any further.

How much physical space does the Internet take up? The storage industry produces in the neighborhood of million hard drives per year. If most of them are 3. So, by that measure, the Internet is smaller than an oil tanker. I am not an authority on lightning safety. I am a guy who draws pictures on the Internet.

With that out of the way. To answer the questions that follow, we need to get an idea of where lightning is likely to go. Roll an imaginary meter sphere across the landscape and look at where it touches. They say lightning strikes the tallest thing around. I mean, not all lightning hits Mount Everest. But does it find the tallest person in a crowd?

The tallest person I know is probably Ryan North. What about other reasons? So how does lightning pick its targets? The leader carries comparatively little current —on the order of amps. This is the blinding flash you see.

It races back up the channel at a significant fraction of the speed of light, covering the distance in under a millisecond. This is where the meter sphere comes in. To figure out where lightning is likely to hit, you roll the imaginary meter sphere across the landscape.

Places the surface makes contact —treetops, fence posts, and golfers in fields—are potential lightning targets.

The shadow is the area where the leader is likely to hit the tall object instead of the ground around it: After the current hits the tall object, it flows out into the ground. Of the 28 people killed by lightning in the US in , 13 were standing under or near trees. But lightning striking the water near you would still be bad. The 20, amps spread outward—mostly over the surface—but how much of a jolt it will give you at what distance is hard to calculate.

What would happen if you were taking a shower when you were struck by lightning? Or standing under a waterfall? Or a submarine?

A boat with a closed cabin and a lightning protection system is about as safe as a car. Or what if you were doing a backflip? Or looking straight up at the bolt? The core of a lightning bolt is a few centimeters in diameter. A bullet fired from an AK is about 26 mm long and moves at about millimeters every millisecond. Copper is a fantastically good conductor of electricity, and much of the 20, amps could easily take a shortcut through the bullet.

Surprisingly, the bullet would handle it pretty well. If it were sitting still, the current would quickly heat and melt the metal. It would continue on to its target relatively unaffected. This effect is similar to how when a traffic light turns green, the cars in front start moving, then the cars in back, so the movement appears to spread backward. On the other hand, apples are better. Humans, for example, are probably still far better at looking at a picture of a scene and guessing what just happened: To test this theory, I sent this picture to my mother and asked her what she thought had happened.

The cat knocked over the vase. The cat jumped out of the vase at the kid. The cat was mummified in the vase, but arose when the kid touched it with a magic rope. The vase exploded, attracting a child and a cat. The child put on the hat for protection from future explosions. The kid and cat are running around trying to catch a snake.

According to computer scientist Hans Moravec, a human running through computer chip benchmark calculations by hand, using pencil and paper, can carry out the equivalent of one full instruction every minute and a half. A new high-end desktop PC chip would increase that ratio to So, what year did a single typical desktop computer surpass the combined processing power of humanity?

After all, these comparisons are one computer against all humans. How do all humans stack up against all computers? This is tough to calculate. It turns out that processors from the s and processors from today have a roughly similar ratio of transistors to MIPS —about 30 transistors per instruction per second, give or take an order of magnitude.

It looks something like this: This tells us that a typical modern laptop, which has a benchmark score in the tens of thousands of MIPS, has more computing power than existed in the entire world in The complexity of neurons Again, making people do pencil-and-paper CPU benchmarks is a phenomenally silly way to measure human computing power. There are projects that attempt to use supercomputers to fully simulate a brain at the level of individual synapses.

The numbers from a run of the Japanese K supercomputer suggest a figure of transistors per human brain. One, the pencil-and-paper Dhrystone benchmark, asks humans to manually simulate individual operations on a computer chip, and finds humans perform about 0.

A slightly better approach might be to combine the two estimates. This actually makes a strange sort of sense. If we assume our computer programs are about as inefficient at simulating human brain activity as human brains are at simulating computer chip activity, then maybe a more fair brain power rating would be the geometric mean of the two numbers. Wilson, there are to ants in the world. By comparison, in there were about transistors in the world, or tens of thousands of transistors per ant.

Mere Machine to Transcendent Mind. Biology is tricky. I hope things are better in the future. Please figure out a way to come get us. It was written in Even in our best telescopes, the largest asteroids were visible only as points of light. The Little Prince took this a step further, imagining an asteroid as a tiny planet with gravity, air, and a rose.

If there really were a superdense asteroid with enough surface gravity to walk around on, it would have some pretty remarkable properties. If the asteroid had a radius of 1. This is roughly equal to the combined mass of every human on Earth. It would feel like you were stretched out on a curved rubber ball, or were lying on a merry-go-round with your head near the center.

The escape velocity at the surface would be about 5 meters per second. That means you might be able to leave our asteroid by running horizontally and jumping off the end of a ramp. Your orbital speed would be roughly 3 meters per second, which is a typical jogging speed. But this would be a weird orbit. Tidal forces would act on you in several ways. If you stretched your arm down toward the planet, it would be pulled much harder than the rest of you.

And when you reach down with one arm, the rest of you gets pushed upward, which means other parts of your body feel even less gravity. A large orbiting object under these kinds of tidal forces—say, a moon—will generally break apart into rings.

However, your orbit would become chaotic and unstable. Rugescu and Daniele Mortari. Their simulations showed that large, elongated objects follow strange paths around their central bodies. This type of analysis could actually have practical applications.

There have been various proposals over the years to use long, whirling tethers to move cargo in and out of gravity wells—a sort of free-floating space elevator. The inherent instability of many tether orbits poses a challenge for such a project. Mallory Ortberg, writing on the-toast. And you may need to defrost it after you pick it up. Things get really hot when they come back from space.

When skydiver Felix Baumgartner jumped from 39 kilometers, he hit Mach 1 at around 30 kilometers. There was no clear conclusion. To try to get a better answer, I decided to run a series of simulations of a steak falling from various heights. Apparently, the US government was shoveling tons of money at anything even loosely related to weapons research. It took me a while to realize there was a much easier way to learn what combinations of time and temperature will effectively heat the various layers of a steak: Check a cookbook.

No matter how fast it was going when it reached the lower layers of the atmosphere, it would quickly slow down to terminal velocity. For much of those 25 kilometers, the air temperature is below freezing —which means the steak will spend six or seven minutes subjected to a relentless blast of subzero, hurricane-force winds.

When the steak does finally hit the ground, it will be traveling at terminal velocity —about 30 meters per second. To get an idea of what this means, imagine a steak flung at the ground by a major-league pitcher. If the steak is even partially frozen, it could easily shatter. However, if it lands in the water, mud, or leaves, it will probably be fine.

Steaks can probably survive breaking the sound barrier. In addition to Felix, pilots have ejected at supersonic speeds and lived to tell about it. We need to go higher. At supersonic and hypersonic speeds, a shockwave forms around the steak that helps protect it from the faster and faster winds.

I searched the literature, but was unable to find any research on this. However, this is little more than a wild guess. If anyone puts a steak in a hypersonic wind tunnel to get better data on this, please, send me the video.

In this scenario, the steak reaches a top speed of Mach 6, and the outer surface may even get pleasantly seared. The inside, unfortunately, is still uncooked. From higher altitudes, the heat starts to get really substantial. That is, it becomes charred. Charring is a normal consequence of dropping meat in a fire.

If the heat is high enough, it will simply blast the surface layer off as it flash-cooks it. If most of the steak makes it to the ground, the inside will still be raw. Which is why we should drop the steak over Pittsburgh. And the Andromeda Strain. Not necessarily fine to eat. The problem, in a nutshell, is that hockey players are heavy and pucks are not.

A goalie in full gear outweighs a puck by a factor of about Even the fastest slap shot has less momentum than a ten- year-old skating along at a mile per hour. It also suggests that if you started to slowly rotate a hockey rink, it could tilt up to 50 degrees before the players would all slide to one end. Clearly, experiments are needed to confirm this. Firing an object at Mach 8 is not, in itself, very hard.

PDF Download What If?: Serious Scientific Answers to Absurd

One of the best methods for doing so is the aforementioned hypersonic gas gun, which is—at its core —the same mechanism a BB gun uses to fire BBs.

Imagine throwing a ripe tomato—as hard as you can—at a cake. After a few days, your immune system notices and destroys it,3 but not before you infect, on average, one other person.

Could our immune systems then wipe out every copy of the virus? A global quarantine brings us to another question: How far apart can we actually get from one another? A lot of us would be stuck standing in the Sahara Desert,5 or central Antarctica. That way, we could walk around and interact, even allowing some normal economic activity to continue: Would it work? To help figure out the answer, I talked to Professor Ian M. He said that rhinoviruses—and other RNA respiratory viruses —are completely eliminated from the body by the immune system; they do not linger after infection.

The remote islands of St. Kilda, far to the northwest of Scotland, for centuries hosted a population of about people. The exact cause of the outbreaks is unknown,8 but rhinoviruses were probably responsible for many of them.

Every time a boat visited, it would introduce new strains of virus. These strains would sweep the islands, infecting virtually everyone. After several weeks, all the residents would have fresh immunity to those strains, and with nowhere to go, the viruses would die out. If all humans were isolated from one another, the St. After a week or two, our colds would run their course, and healthy immune systems would have plenty of time to clear the viruses.

The story is different for those with severely weakened immune systems. In transplant patients, for example, whose immune systems have been artificially suppressed, common infections —including rhinoviruses —can linger for weeks, months, or conceivably years. This small group of immunocompromised people would serve as safe havens for rhinoviruses. The hope of eradicating them is slim; they would need to survive in only a few hosts in order to sweep out and retake the world.

While colds are no fun, their absence might be worse. On the other hand, colds suck. And in addition to being unpleasant, some research says infections by these viruses also weaken our immune systems directly and can open us up to further infections. If the average were less than one, the virus would die out.

If it were more than one, eventually everyone would have a cold all the time. Kilda correctly identified the boats as the trigger for the outbreaks.

But what if the empty half of the glass were actually empty—a vacuum? Which half is empty? For the first handful of microseconds, nothing happens.

On this timescale, even the air molecules are nearly stationary. For the most part, air molecules jiggle around at speeds of a few hundred meters per second. But at any given time, some happen to be moving faster than others. The fastest few are moving at over meters per second. These are the first to drift into the vacuum in the glass on the right. However, in the vacuum of the glasses, it does start to boil, slowly shedding water vapor into the empty space.

While the water on the surface in both glasses starts to boil away, in the glass on the right, the air rushing in stops it before it really gets going. The sides of the glass bulge slightly, but they contain the pressure and do not break. A shockwave reverberates through the water and back into the air, joining the turbulence already there.

The shockwave from the vacuum collapse takes about a millisecond to spread out through the other two glasses. The glass and water both flex slightly as the wave passes through them. Around this time, the glass on the left starts to visibly lift into the air. This is the force we think of as suction. The boiling water has filled the vacuum with a very small amount of water vapor.

However, the glass and water are now moving too fast for the vapor buildup to matter. Without a cushion of air between them —only a few wisps of vapor —the water smacks into the bottom of the glass like a hammer. The momentary force on the glass is immense, and it breaks.

In our situation, the forces would be more than enough to destroy even the heaviest drinking glasses. The bottom is carried downward by the water and thunks against the table. Do you like this book? Please share with your friends, let's read it!! Free ebook download XooBooks is the biggest community for free ebook download, audio books, tutorials download, with format pdf, epub, mobi,…and more. Randall Munroe Publisher: Houghton Mifflin Harcourt Genres: Physics Publish Date: September 2, ISBN Epub Language: English Ads.

Book Preface What If?: Serious Scientific Answers to Absurd Hypothetical Questions This book is a collection of answers to hypothetical questions. Here it is, reproduced verbatim from her year-old sheet of paper: Are there more soft things or hard things in our house? How about in the world? Well, each house has three or four pillows, right? And each house has about 15 magnets, right? I guess. So there are probably about 3 billion soft things, and. Well, which one wins?

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