In what ways could the hundred

Celebrate the th Day in Ways 97, 98, One hundred ideas for celebrating the th day of school!

In what ways could the hundred

Here we look at the factors that could doom humanity: In theyears Homo sapiens has roamed the land we've built cities, created complex languages, and sent robotic scouts to other planets.

It's difficult to imagine it all coming to an end. Yet 99 percent of all species that ever lived have gone extinct, including every one of our hominid ancestors. InBritish cosmologist Brandon Carter framed the " Doomsday argument ," a statistical way to judge when we might join them.

If humans were to survive a long time and spread through the galaxy, then the total number of people who will ever live might number in the trillions. By pure odds, it's unlikely that we would be among the very first hundredth of a percent of all those people. Or turn the argument around: How likely is it that this generation will be the one unlucky one?

Something like one fifth of all the people who have ever lived are alive today. The odds of being one of the people to witness doomsday are highest when there is the largest number of witnesses around—so now is not such an improbable time.

Human activity is severely disrupting almost all life on the planet, which surely doesn't help matters. The current rate of extinctions is, by some estimates, 10, times the average in the fossil record.

In what ways could the hundred

At present, we may worry about snail darters and red squirrels in abstract terms. But the next statistic on the list could be us. But there is no question that a cosmic interloper will hit Earth, and we won't have to wait millions of years for it to happen.

In a foot-wide comet fragment slammed into the atmosphere and exploded over the Tunguska region in Siberia, Russia, with nearly 1, times the energy of the atomic bomb dropped on Hiroshima.

Astronomers estimate similar-sized events occur every one to three centuries. Benny Peiser, an anthropologist-cum-pessimist at Liverpool John Moores University in England, claims that impacts have repeatedly disrupted human civilization. As an example, he says one killed 10, people in the Chinese city of Chi'ing-yang in Many scientists question his interpretations: Impacts are most likely to occur over the ocean, and small ones that happen over land are most likely to affect unpopulated areas.

But with big asteroids, it doesn't matter much where they land. Objects more than a half-mile wide—which strike Earth everyyears or so—would touch off firestorms followed by global cooling from dust kicked up by the impact.

Humans would likely survive, but civilization might not.

In what ways could the hundred

An asteroid five miles wide would cause major extinctions, like the one that may have marked the end of the age of dinosaurs.

For a real chill, look to the Kuiper belt, a zone just beyond Neptune that contains roughlyice-balls more than 50 miles in diameter. The Kuiper belt sends a steady rain of small comets earthward.

If one of the big ones headed right for us, that would be it for pretty much all higher forms of life, even cockroaches.

Celebrate the th Day in Ways | Education World

Once a day or so, you would see a bright flash appear, briefly outshine everything else, then vanish. These gamma-ray bursts, astrophysicists recently learned, originate in distant galaxies and are unfathomably powerful—as much as 10 quadrillion a one followed by 16 zeros times as energetic as the sun.

The bursts probably result from the merging of two collapsed stars. Before the cataclysmal event, such a double star might be almost completely undetectable, so we'd likely have no advance notice if one is lurking nearby.


Once the burst begins, however, there would be no missing its fury. At a distance of 1, light-years—farther than most of the stars you can see on a clear night—it would appear about as bright as the sun.

Earth's atmosphere would initially protect us from most of the burst's deadly X rays and gamma rays, but at a cost. The potent radiation would cook the atmosphere, creating nitrogen oxides that would destroy the ozone layer. Without the ozone layer, ultraviolet rays from the sun would reach the surface at nearly full force, causing skin cancer and, more seriously, killing off the tiny photosynthetic plankton in the ocean that provide oxygen to the atmosphere and bolster the bottom of the food chain.

All the gamma-ray bursts observed so far have been extremely distant, which implies the events are rare. Scientists understand so little about these explosions, however, that it's difficult to estimate the likelihood of one detonating in our galactic neighborhood.Oct 08,  · Here are four ways a shorter workweek could be tied to living better, longer.

(16 Videos)

Clocking in longer-than-average hours at work has been associated with negative outcomes related to . Because of that, there’s a growing risk that oil could once again top $ a barrel in the coming years since there are at least a dozen ways it could get there.

Oct 09,  · This feature is not available right now. Please try again later.

Milky Way could have at least billion larger brown dwarf stars -

Nov 14,  · In this Reaction Time Episode I reacted to 10 ways in which planet earth could be destroyed. For Video Submissions E-mail: [email protected] Follo.

The world isn’t necessarily going to end because Donald Trump was elected president. It’s going to end because we’ve squeezed the natural gasses out of it like a dirty sponge; it’s going. However, with several potential issues looming under the surface, crude has many possible paths that could come together and take it back above $ a barrel by

Celebrate the th Day in Ways | Education World