Let’s all just be glad that Earth keeps rotating.
In his new book, What If?: Serious Scientific Answers to Absurd Hypothetical Situations, xkcd author Randall Munroe illustrates some of life’s most bizarre questions and conundrums. Munroe recently joined Mashable‘s social book club MashableReads with the #WhatIfChallenge, and is encouraging readers to submit their own one-panel comics depicting outrageous hypothetical situations on Tumblr, Twitter, Instagram and Vine.
What If? debuts on Sept. 2, but to help get your creative juices flowing for the #WhatIfChallenge, here is a sneak peek at a chapter from Randall Munroe’s latest title, below:
Q. What would happen if
the Earth and all terrestrial
objects suddenly stopped
spinning, but the atmosphere
retained its velocity?
— Andrew Brown
A. NEARLY EVERYONE WOULD DIE. Then things would get interesting.
At the equator, the Earth’s surface is moving at about 470 meters per second — a little over a thousand miles per hour — relative to its axis. If the Earth stopped and the air didn’t, the result would be a sudden thousand-mile-per-hour wind.
The wind would be highest at the equator, but everyone and everything living between 42 degrees north and 42 degrees south — which includes about 85 percent of the world’s population — would suddenly experience supersonic winds.
The highest winds would last for only a few minutes near the surface; friction with the ground would slow them down. However, those few minutes would be long enough to reduce virtually all human structures to ruins.
My home in Boston is far enough north to be just barely outside the supersonic wind zone, but the winds there would still be twice as strong as those in the most powerful tornadoes. Buildings, from sheds to skyscrapers, would be smashed flat, torn from their foundations, and sent tumbling across the landscape.
Winds would be lower near the poles, but no human cities are far enough from the equator to escape devastation. Longyearbyen, on the island of Svalbard in Norway — the highest-latitude city on the planet — would be devastated by winds equal to those in the planet’s strongest tropical cyclones.
If you’re going to wait it out, one of the best places to do it might be Helsinki, Finland. While its high latitude — above 60°N — wouldn’t be enough to keep it from being scoured clean by the winds, the bedrock below Helsinki contains a sophisticated network of tunnels, along with a subterranean shopping mall, hockey rink, swimming complex, and more.
No buildings would be safe; even structures strong enough to survive the winds would be in trouble. As comedian Ron White said about hurricanes, “It’s not that the wind is blowing, it’s what the wind is blowing.”
Say you’re in a massive bunker made out of some material that can withstand thousand-mile-per-hour winds.
That’s good, and you’d be fine . . . if you were the only one with a bunker. Unfortunately, you probably have neighbors, and if the neighbor upwind of you has a less-well-anchored bunker, your bunker will have to withstand a thousand mile-per-hour impact by their bunker.
The human race wouldn’t go extinct. In general, very few people above the surface would survive; the flying debris would pulverize anything that wasn’t nuclear-hardened. However, a lot of people below the surface of the ground would survive just fine. If you were in a deep basement (or, better yet, a subway tunnel) when it happened, you would stand a good chance of surviving.
There would be other lucky survivors. The dozens of scientists and staff at the Amundsen–Scott research station at the South Pole would be safe from the winds. For them, the first sign of trouble would be that the outside world had suddenly gone silent.
The mysterious silence would probably distract them for a while, but eventually someone would notice something even stranger:
As the surface winds died down, things would get weirder.
The wind blast would translate to a heat blast. Normally, the kinetic energy of rushing wind is small enough to be negligible, but this would not be normal wind. As it tumbled to a turbulent stop, the air would heat up.
Over land, this would lead to scorching temperature increases and — in areas where the air is moist — global thunderstorms.
At the same time, wind sweeping over the oceans would churn up and atomize the surface layer of the water. For a while, the ocean would cease to have a surface at all; it would be impossible to tell where the spray ended and the sea began.
Oceans are cold. Below the thin surface layer, they’re a fairly uniform 4°C. The tempest would churn up cold water from the depths. The influx of cold spray into superheated air would create a type of weather never before seen on Earth — a roiling mix of wind, spray, fog, and rapid temperature changes.
This upwelling would lead to blooms of life, as fresh nutrients flooded the upper layers. At the same time, it would lead to huge die-offs of fish, crabs, sea turtles, and animals unable to cope with the influx of low-oxygen water from the depths. Any animal that needs to breathe — such as whales and dolphins — would be hard-pressed to survive in the turbulent sea-air interface.
The waves would sweep around the globe, east to west, and every east-facing shore would encounter the largest storm surge in world history. A blinding cloud of sea spray would sweep inland, and behind it, a turbulent, roiling wall of water would advance like a tsunami. In some places, the waves would reach many miles inland.
The windstorms would inject huge amounts of dust and debris into the atmosphere. At the same time, a dense blanket of fog would form over the cold ocean surfaces. Normally, this would cause global temperatures to plummet. And they would.
At least, on one side of the Earth.
If the Earth stopped spinning, the normal cycle of day and night would end. The Sun wouldn’t completely stop moving across the sky, but instead of rising and setting once a day, it would rise and set once a year.
Day and night would each be six months long, even at the equator. On the day side, the surface would bake under the constant sunlight, while on the night side the temperature would plummet. Convection on the day side would lead to massive storms in the area directly beneath the Sun. 
In some ways, this Earth would resemble one of the tidally locked exoplanets commonly found in a red dwarf star’s habitable zone, but a better comparison might be a very early Venus. Due to its rotation, Venus — like our stopped Earth — keeps the same face pointed toward the Sun for months at a time. However, its thick atmosphere circulates quite quickly, which results in the day and the night side having about the same temperature.
Although the length of the day would change, the length of the month would not! The Moon hasn’t stopped rotating around the Earth. However, without the Earth’s rotation feeding it tidal energy, the Moon would stop drifting away from the Earth (as it is doing currently) and would start to slowly drift back toward us.
In fact, the Moon — our faithful companion — would act to undo the damage Andrew’s scenario caused. Right now, the Earth spins faster than the Moon, and our tides slow down the Earth’s rotation while pushing the Moon away from us. If we stopped rotating, the Moon would stop drifting away from us. Instead of slowing us down, its tides would accelerate our spin. Quietly, gently, the Moon’s gravity would tug on our planet . . .
. . . and Earth would start turning again.
 I mean, not right away.
 Although without the Coriolis force, it’s anyone’s guess which way they would spin.
 See “Leap Seconds,” http://what-if.xkcd.com/26, for an explanation of why this happens.
Excerpted from WHAT IF?: Serious Scientific Answers to Absurd Hypothetical Questions by Randall Munroe to be published by Houghton Mifflin Harcourt on September 2nd, 2014. Copyright © 2014 by xkcd Inc. Used by permission of the author. All rights reserved.
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More U.S. military service members have died from suicide than enemy fire, roadside bombs and injuries sustained during combat this year.
As 2.4 million Americans who fought in the wars in Iraq and Afghanistan prepare to return from combat, U.S. military entities are struggling to tackle the rising number of suicides, according to an NPR report. After experiencing war-related trauma, active-duty service members and veterans often face debilitating mental-health issues — including post-traumatic stress disorder, anxiety, depression and suicide ideation.
Suicide remains a top cause of death among active-duty personnel and veterans. For years, the Department of Defense has tried to find a solution to the problem plaguing troops.
Dr. Nigel Bush, a clinical psychologist with the DOD’s The National Center for Telehealth and Technology, or T2, believes reforming a classic suicide-prevention tactic could be the solution.
One strategy medical health practitioners use to redirect a distressed individual’s attention towards wanting to live is by creating a “hope box.” Doctors and patients work together to fill a shoe box with reminders of reasons to live. It becomes a repository of images and important items that reminds patients of loved ones, accomplishments and future aspirations.
Patients with suicidal thoughts can feel hopeless, like there’s no way out. Dr. Bush tells Mashable that one of the distinguishing characteristics of suicidal patients is being able to recite more reasons to die than to live. Clinical therapy and dialectical behavioral therapy are both effective ways to counter this state of mind, according to Dr. Bush.
“It tries to teach patients to identify positive outcomes and to try to modify their thoughts and behaviors to increase the likelihood of thinking and perceiving positive events,” Dr. Bush says.
Dr. Bush believes creating a Virtual Hope Box app could make the “hope box” portable for service members in Defense hospitals as well as veterans in V.A. hospitals.
Getting help to those who need it in time is pertinent to saving lives, according to researchers. Since providers are “somewhat clustered in locations,” help isn’t always available in moments of crisis, T2’s public affairs officer Joe Jimenez tells Mashable.
“People either don’t want to go into the office or they physically can’t because they are hundreds of miles away,” Jimenez says. “If they are in treatment that requires them to go back at least once a week, that could be very difficult to do, which causes a high dropout.”
It would be ideal for active-duty service members to undergo counseling or diagnosis testing while still deployed on combat missions. T2 hopes mobile technology can reach soldiers around the world.
“We were looking at a broad community that’s worldwide and very active, deployed a lot of the time for combat missions as well as missions around the world,” Jimenez says. “We had to look at everything to try to develop products and services to help this very large diverse community.”
T2 has about 12 health-related mobile apps in the works or already available on Apple and Android markets for U.S. military, National Guard and Reserve members.
The Virtual Hope Box app is designed to help active service members and veterans struggling with suicidal thoughts. The app mimics physical hope boxes used currently in suicide-prevention treatments.
“It’s tailor-made for a military population of patients — active duty and veterans,” Dr. Bush says. Smartphone penetration within the U.S. Military community mirrors the rate civilians are using them (more than 60%).
Unlike a physical shoe box, the app is portable and unlimited in space. The Virtual Hope Box app includes important contact information and connections to suicide hotlines for emergencies. The app will also provide “distraction” games, coping cards designed by licensed psychologists, inspirational quotes and guides to relaxation exercises (breathing exercises). It’s built to discourage hopelessness and thoughts of suicide.
The app prototype is still going under review and extensive testing. The technology research center comprised of clinical psychologists, researchers, designers and specialists will work with the U.S. Department of Veterans Affairs (V.A.) to test the app with military patients. It’s projected to be on the market at the end of next summer or, at the latest, October 2013.
Images courtesy of Flickr, DVIDSHUB