When will the world end?

Question

How?
When?

Answer 1

When Will the World End? New Theory Emerges
New Theory Emerges
on How the World Will End
By Lee Dye
Jan. 22


The Earth has probably already peaked as a haven for plants and animals and begun its long descent into oblivion, according to scientists at the University of Washington who have plotted out the future of our planet.

These are not prophets of doom who have mounted the podium to warn us that we are killing ourselves through bad stewardship. They are scientists who say all good things must come to an end sometime, and at best we've got no more than half a billion years left.

After that, the planet will return to its ancient past, inhabited only by bacteria and single-celled organisms, just as it was in its earliest years. But in time even those will vanish as the Earth is reduced to a lifeless chunk of rock, or swallowed entirely by an expanding Sun.

And if you believe astrophysicist Donald Brownlee and paleontologist Peter Ward, there's not a whole lot we can do about it. They have laid out the grim facts in a new book, The Life and Death of Planet Earth, published by Times Books.

Time Is Ticking

Here are the essential nuggets in their findings:

Like any star, the Sun won't last forever.

There's a short window of about 1 billion years when it's possible for plants and animals to survive on Earth, and that's probably true of any habitable planet. We're already about half way through it.

Planets like this may be quite rare in the universe, so we better take care of what we've got. (With such dire predictions, you've got to allow these guys a little time on the soapbox.)

To simplify a very complicated story about the "devolving" of planet Earth, Brownlee and Ward have reduced its 12-billion-year lifespan to 12 hours, with the end coming at high noon.

It's only 4:30 a.m. in Earth's "day in the sun," as they put it, but by 5 a.m. the 1 billion-year reign of plants and animals will come to an end. By 8 a.m. the oceans will vaporize.

By noon it will all be over, about 7.5 billion years down the road.

It's not a pretty story, the two admit, but "Mother Nature wasn't designed to make us happy," according to Brownlee.

And if you're still hoping for a happy ending, here's the worst part. This is the BEST-case scenario.

Brightening Sun

Long before the Earth dies a natural death, we could get knocked off by an asteroid, or blown away by a nearby exploding star. As the scientists themselves note, there are a couple of ways for people to die. They die of old age, or they get run over by a truck.

"Either way, the vital signs are the same," Brownlee says.

The sun is constantly growing brighter, and is about 30 percent brighter today than it was in its infancy, he says. That alone should have made life on this planet a bit difficult, but the Earth is blessed with a complex atmospheric system that has kept the climate reasonably stable, except for an occasional ice age, for 4.5 billion years.

"How is it possible that the Earth has had a reasonably constant environment in spite of the fact that the sun has gotten 30 percent brighter?" Brownlee asks. "It's amazing, but the Earth's systems have conspired to do this. As the sun has gotten brighter, the composition of the atmosphere has changed."

The key, he says, is carbon dioxide and other greenhouse gases. Early on, when the sun was much fainter, these gases kept the temperatures tolerable. As the sun warmed up, weathering processes removed carbon dioxide from the atmosphere and deposited it in the soil as carbonates.

"The warmer the Earth is, the more rapid the removal process becomes," Brownlee says.

So despite the fact that the sun has gotten much brighter, the Earth has remained fairly consistent because of a gradual reduction in carbon dioxide.

"That's the magic thing that has kept the Earth as nice as it is," he adds.

This may seem a bit confusing because of the current concern over global warming resulting from an increase in carbon dioxide in the atmosphere, but Brownlee says that's just a brief blip in the grand scale of things.

"In the short term, that's a big problem," he says. "But in the longer term, hundreds of millions of years, it's a decline of carbon dioxide that's really the major problem."

Going Down in a Blaze of Glory

Carbon dioxide is the "food of life," providing the critical nutrient that allows plants to grow, which in turn are consumed by animals.

The plants, thus, will starve to death because of a lack of carbon dioxide. And the animals won't be far behind.

He says the end won't come suddenly. Some critters will retreat into the sea in an effort to escape the rising heat, thus reversing the evolutionary process as we move back towards green slime, or wherever we came from.

But even the seas will be doomed. The sun will continue to expand, turning into something astronomers call a "red giant," and the Earth will become so hot that the oceans will gradually evaporate.

That process will take a few hundred million years.

Then, the prospects get really grim, according to Yale University solar physicist Sabatino Sofia. For awhile, the sun will contract, then expand rapidly into a red supergiant as it blasts off about a third of its mass through "thermal pulses."

That exploded material will become super hot as it expands, probably engulfing the Earth, and the sun's inner core "will settle down as a hot, nuclearly inert, dense object, a white dwarf star," according to Sofia.

The sun will be about the size of the Earth at that point, and at the end of its evolution. It will "slowly cool and darken to forever disappear from the view of our galactic neighbors.

"This dark cinder and the even darker outer planets that have not been swallowed up by the sun during its expanding stage, are all that will remain of our solar system," Sofia has written.

And our brief moment in the sun, so to speak, will be over.

Lee Dyes column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.


Copyright © 2007 ABC News Internet Ventures

Answer 2

No one knows the true end, but according to the I Ching, a Chinese divination, and the Aztec Calendar both have been correct in their predictions of remarkable events happening. The Aztec Calendar and the I Ching both foretell a major happening in August 2012. (I think in August). This is a significant year because of the way the planets will line up and cause the earths polar opposites to shift their magnetic qualities. What was the positive end of polar energy will now yeild a negative one and vice versa. The Jewish fortelling says that the messiah will come a long time after you and I die. I do not believe in Nostradamous's theory's because his theory's were broad, and after the fact of significant events, many went in and "catastrphized" what he was foretelling, giving the event and meaning after the fact. It's like someone saying that there will be a big fire between 1980 and 2005...would one think it Mt. St. Helens a volcanoe? Or the collapse of the twin towers of 9-11? You decide. Much of this nature is at your local library. I think it is fascinating reading to read stories of those whom have died and returned. Their accounts are tremendous....

Answer 3

There are many, many, many thoeries out there ranging from killer gods, to atomic bomb, to just a sudden stop. I have found that the one I must like is the Aztec's beliefe. They measure time on a 'clock' (nothing like the one we use) and this 'clock' was set to stop on the End of Days (Dec 24, 2012 on our calender). Given they don't say how it will end.To me that has been a reason to live each day to the fullest because it has given me an 'end date'. Now if I wake up on the 25th and life is still going then so be it, that will just be a reason to be happy.

Answer 4

Now

Answer 5

When the sun exhausts it's fuel of hydrogen, it'll swell & become a Red Giant, engulfing Earth, and causing it to fall out of it's orbit, and into the core of the dying sun.

And, probably 5 to 8 billion years from now.

Answer 6

I just watched a show earlier today and they said December 21, 2012. Something about things lining up and the earth will shift on its axis. History Channel

Answer 7

No one knows, even though some people claim to. 1/4 of the world's population will be wiped out at one point.

Answer 8

Either in 4.5 billion years when the sun expands and cools and grow to the orbit of Mars or when the asteroid Apophis collides with earth in 2036.

Or in probability if you croak before then .

Answer 9

Yesterday, at 4:20 pm, EST.
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Answer 10

When that one big storm arrives that's when the whole world will end.Like there will be a storm and then the earth will be no more.I guess it will be destroyed for all humans to live on!That's how.

Answer 11

when God comes. He gives examples of things that will happen towards the end of the world. These things are already been happening like wars and rumors of wars, large earthquakes, etc.

It says that Jerusalem will be surrounded by armies and that we will know that the time is very near.