Apocalypse How? Ways the world may end analyzed

Published 9:25 am Friday, December 21, 2012

We’ll go out on a limb and predict that the world will not end, Friday, Dec. 21, also known as the last date of the Maya Long Count Calendar.

If we’re wrong, we’ll gladly refund the cost of this newspaper.

But that’s not saying the world will never end. There are some things that do pose existential threats to the world, civilization or life as we know it, however remote or far in the future.

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But sorting out the cataclysmic from the claptrap can be a bit confusing. Which is why we consulted with some experts to ask them about a variety of potential catastrophes being tossed about lately to help you decide which should keep you up at night, which will be extremely annoying and which will be apocalypse never.

Alien invasion: Astrophysicist Stephen Hawking once said an alien encounter with humans would resemble contact between Christopher Columbus and the people of the New World. In the end, it didn’t work out so well for the natives.

But Joel Weisberg, a physics and astronomy professor at Carleton College isn’t too worried. In a universe where nothing travels faster than light, “the distances are too great,” so he doesn’t expect a close encounter anytime soon.

And University of Minnesota physics professor Joseph Kapusta argues, “Any beings so advanced to be able to travel between the stars would most likely want to communicate with us and to study the history of our planet, not conquer it. All the probes sent to the surface of Mars are sanitized to prevent contamination of Mars by Earthly organisms. I would expect that aliens would do no less for Earth.”

Rogue planets or rogue black holes: Doomsday predictors have said Earth is due for a disastrous date with something called Planet X or Niburu. And it would be curtains if Earth got hit by a planet or a black hole wandering through the neighborhood. But Weisberg said in reality, runaway planets or wandering black holes are so rare they’re not worth worrying about.

Asteroid impact: Now we’re talking about something a little more bothersome. “A very good possibility over long-time scales,” is the way Weisberg describes it. There are thousands of asteroids in our solar system, and it would take only one really big one, say 10 kilometers wide, to do us in. It’s happened before. A big rock that hit us 65 million years ago was credited with doing in the dinosaurs. “They come in fast. They carry more energy than a nuclear war,” Kapusta said.

“The chances of it happening at any one time are very small,” Weisberg said.

But, “the probability that one hits earth every 100 million years is not unreasonable,” Kapusta said.

Weisberg said scientists have telescopes dedicated to discovering any asteroid that gets really close, and potential solutions have been discussed, such as trying to send a rocket out there to blow up an asteroid with nuclear bombs, or painting the asteroid white and letting pressure from sunlight bouncing off push the object off course, or just trying to park another object near the asteroid and letting gravitational forces give it a nudge.

“You only need to move it a tiny bit,” Weisberg said.

But we’d need to act years in advance of impact, and we’d really want to make sure our math is right. According to Weisberg, blowing up an asteroid and subjecting the Earth to a rain of small chunks of rock could be as bad as being hit by one big rock. And Weisberg notes you’d hate to mess with the course of an asteroid that was going to be a near miss and turn it into something that actually hits us.

Ice age: The last ice age ended about 10,000 years ago, according to Kapusta, but it could happen again. “We know these things will happen because they have happened,” he said. If the ice sheets creep down to Iowa again, it could happen in as short a time as 100 years, he said. In that case, half of the population of China will have to relocated to India, Kapusta said.

And all of our homes in Minnesota will be under (frozen) water. “My property values will be zero,” Kapusta said.

Runaway physics experiment: When the Manhattan Project scientists were getting ready to test the first atomic bomb during World War II, they actually considered and took bets on the possibility that the blast might ignite the atmosphere and destroy the Earth, or maybe just New Mexico.

Kapusta, who has given a colloquium called “Accelerator Disaster Scenarios, the Unabomber and Scientific Risks,” said researchers running nuclear accelerator experiments considered similar questions, including whether a particle-smashing session could generate a mini black hole with disastrous consequences.

Biotech disaster: It would take a lot of smart people working pretty hard to engineer a virus that has just the right combination of deadliness and transmissibility to kill off a big part of the human population, according to Jennifer Kuzma, who specializes in science and technology policy as a professor at the U’s Humphrey School of Public Affairs.

But the biotech field is advancing so rapidly that, maybe in 30 or 50 years, it would take only one really smart ill-intentioned person to create some real mischief, Kuzma said.

“People are doing synthetic biology in their garages,” Kuzma said. “It doesn’t keep me up at night, but it’s something we need to be aware of.”

Kuzma said she’s less worried about a biotech disaster killing us all off than seeing ill-planned advances creating a future that we may not want, like a society in which only the wealthy have access to human enhancements in intelligence or physical features.

Supervolcano: One estimate by scientists suggests that a supereruption that could blanket much of the world with ash happens less than once every 500,000 years, according to a NASA website.

“Supereruptions, though they occur, are exceedingly rare, and the odds that one will occur in the lifetime of anybody reading this article are vanishingly small,” NASA assures us.

Supernovae: “Supernovae are a bit like fireworks,” according to U physics and astronomy professor Larry Rudnick. “You want to be close enough to see how beautiful they are, but not so close that it makes the kids cry.”

Rudnick said at the range of about 50 light years, a stellar explosion would start to destroy our ozone layer. But nothing that close seems ready to burst.

“One of the closest stars likely to go supernova somewhere between tomorrow and a million years from now is Betelguese, the bright red star on Orion’s right shoulder,” according to Rudnick. “At 640 million light years away, it will put on a spectacular but safe show for Earthlings.”

Magnetic field reversal: Despite some prophesies that this will be a game changer, Rudnick said don’t sweat it: “Yes, it will happen. No, we don’t know when, but it could be sometime in the next few hundred thousand years. It will take thousands of years to actually make the reversal, and certainly doesn’t keep me up at night because it has happened many times before and life seems to have come through just fine.”

Peak oil: Another end-time favorite is the notion that an inevitable decline in fossil fuel production will trigger catastrophes like World War III or global famines. John Watkins, an English and history professor at the U who has taught a seminar called “The Apocalypse: A Cultural History,” said we’ll probably muddle through somehow.

“I think that’s about economics. I don’t think it’s about an inevitable-death-of-the-world scenario,” he said.

Destructive vacuum: This highly speculative Earth-crushing whammy would come so out of the blue that we wouldn’t know what hit us. According to Kapusta, because 70 percent of the energy in the universe consists of unknown dark energy, there’s this notion that unstable or false vacuums exist in space, which could collapse into a true vacuum in a sort of random galactic burp, sending an energy front hurtling toward us at the speed of light.

According to Kapusta, there’s nothing we could do about it, and we wouldn’t realize what happened anyway.

“The Earth would be gone in a 100th of a second,” he said. “You would never know it.”

Nuclear war: After the Cold War ended, maybe you stopped worrying about an all-out nuclear exchange between the United States and the Soviet Union wiping out humanity. Back in the bad old nuke-rattling days, the Bulletin of Atomic Scientists set their venerable Doomsday Clock — a measure of nuclear annihilation risk — as close as two minutes to midnight. After the collapse of the Soviet Union and cuts in nuclear arsenals, the risk was backed off to a whole 17 minutes to midnight in 1991.

But right now, the risk is back to five minutes to midnight. The Bulletin cites the potential nuclear weapons use in regional conflicts as well as global warming as current risks to humanity.

Robotic overlords, zombie apocalypse, rapture, rise of intelligent apes … Watkins uses one word to rate the risk of most of these things happening: “Hollywood.” Although he notes of intelligent apes, “Well, it happened once before!”

One thing he is worried about: a global pandemic. “We’ve certainly had pandemics that have wiped out a third of the world’s population before,” according to Watkins. “I’m occasionally up at night on this one. Asthmatics don’t like weird flu things appearing on the six o’clock news.”

That old sun: If we survive all that, there is one thing that is guaranteed to get us. Eventually our sun will reach the end of its life and start swelling up into a red giant, expanding toward us until we’re toast. The oceans will boil off, everything on Earth’s surface will be incinerated and the globe itself may just be turned into puffs of hot gas. It should happen in about 5 billion years.

But until then, Watkins said humanity will no doubt continue to frighten itself with elaborate end-of-the-world scenarios.

“We’ve been at this for 3,500 years,” he said. Watkins said doomsday forecasts are particularly prevalent during times of social distress or cultural crisis. People who feel oppressed especially like to conjure satisfying judgment day predictions in which the wicked — or just people who disagree with them — get their comeuppance.

“The nice thing about traditional apocalypse is we get to see all our enemies fry,” Watkins said.

Plus, an armageddon lurking just around the corner also has proven to be an “amazingly effective” community-building tool, according to Watkins. History has shown that that sometimes has resulted in communities of wackos, but it also has motivated people to work for virtuous goals, such as abolition.

Finally, contemplating our doom is just entertaining in a scary-movie kind of way, Watkins said.

“It’s a wonderful distraction from little petty worries. It’s a little vacation. There’s a huge pleasure being afraid,” he said.