Speculation on the fate of Earth and humanity
Rich
http://www.washington.edu/newsroom/news/2003archive/01-03archive/k011...
In its 4.5 billion years, Earth has evolved from its hot, violent
birth to the celebrated watery blue planet that stands out in pictures
from space. But in a new book, two noted University of Washington
astrobiologists say the planet already has begun the long process of
devolving into a burned-out cinder, eventually to be swallowed by the
sun.
By their reckoning, Earth's "day in the sun" has reached 4:30 a.m.,
corresponding to its 4.5 billion-year age. By 5 a.m., the 1
billion-year reign of animals and plants will come to an end. At 8
a.m. the oceans will vaporize. At noon - after 12 billion years -
the
ever-expanding sun, transformed into a red giant, will engulf the
planet, melting away any evidence it ever existed and sending
molecules and atoms that once were Earth floating off into space.
"The disappearance of our planet is still 7.5 billion years away, but
people really should consider the fate of our world and have a
realistic understanding of where we are going," said UW astrophysicist
Donald Brownlee. "We live in a fabulous place at a fabulous time. It's
a healthy thing for people to realize what a treasure this is in space
and time, and fully appreciate and protect their environment as much
as possible."
In "The Life and Death of Planet Earth," Brownlee and UW
paleontologist Peter Ward use current scientific understanding of
planets and stars, as well as the parameters of life, to provide a
glimpse of the second half of life on Earth and what comes after.
The book, a sort of biography of our planet, is being published today
by Times Books, a division of Henry Holt and Co. It is a sequel to
Ward and Brownlee's best-selling and much-discussed book "Rare Earth,"
in which they put forth the hypothesis that simple life is relatively
common in the universe but complex, Earth-like life is exceedingly
rare.
"The Life and Death of Planet Earth" explains how the myriad life on
Earth today was preceded by a long period of microbial dominance, and
the authors contend that complex life eventually will disappear and be
succeeded again by a period of only microbial life. They say that
higher life will be removed much as it came into being, ecosystem by
ecosystem. Aspects of the planet's past, such as numbingly cold ice
ages, will be relived in the period of devolution.
"If we do begin to slide into the next glacial cycle, there probably
are grand, planetary-scale engineering projects that might stop or
lessen the effects," Ward said.
"The big unknowns are whether we can afford to do such projects and
would we really know what to do. If the planet was cooling, we could,
in principle, begin painting the surface black to collect more heat.
Could we afford it? And what would be the many possible ramifications
of a planet suddenly covered in black paint? Any planetary remediation
project would always run the risk of making things worse."
Eventually, though, scorching heat will drive land creatures to the
sea for respite. Those that can adapt will survive for a time, but
eventually the oceans will warm too much for the complex life forms to
continue.
"The last life may look much like the first life - a single-celled
bacterium, survivor and descendant of all that came before," the
authors write. Finally, even the surviving microbes "will be seared
out of existence."
The prospects of humans surviving by moving to some other habitable
planet or moon aren't good, Brownlee and Ward contend, because even if
such a place were found, getting there would be a huge obstacle.
Various probes sent into space could survive Earth's demise, and just
a few grams of material could arguably carry a DNA sample from every
human, they say, but it's not likely the human species itself will
survive. Long before the planet's final end, life will become quite
challenging, and finally impossible, for humans.
As the sun gets hotter and grows in size, it will envelop Mercury and
Venus. It is possible it will stop just short of Earth, the authors
say, but the conditions still would make this a most-inhospitable
planet. More likely, though, the sun will consume Earth as well,
severing all the chemical bonds between molecules and sending its
individual atoms out into space, perhaps eventually to form new
planets. That would leave Mars as the nearest planet to the sun, and
on Mars the fading sun's glow would be like that of Earth's moon.
That end is still some 7.5 billion years distant, but by then Earth
will have faced a variety of "ends" along the way, the authors say.
The last dinosaur perished long ago. Still to come are the last
elephant, the last tree, the last flower, the last glacier, the last
snowflake, the last ocean, the last life.
"The Life and Death of Planet Earth" is like its predecessor, "Rare
Earth," in that the authors collected and distilled some of the latest
scientific ideas about the Earth's place in the universe, Brownlee
said. He hopes the new book, like "Rare Earth," will spark widespread
discussion, and give people a fundamental and realistic view of the
past and future of their planet.
"It's a healthy thing to think of the place of Earth among the other
planets, and its place in the sun. The sun gave life and ultimately it
will bring death."
Tim Killian
> Rich wrote:
[...]
Soggy Bottom Boys
George
"Tim Killian" <T...@notmyrealemail.com> wrote in message
news:F8CdnUBy2ZUA8UXe...@bresnan.com...
Actually, if you include algae, plants have been here appreciably longer
than one billion years.
George
Davoud
> 'The end of the world' has already begun, UW scientists say
> http://www.washington.edu/newsroom/news/2003archive/01-03archive/k011...
> ... "The disappearance of our planet is still 7.5 billion years away, but
> people really should consider the fate of our world and have a
> realistic understanding of where we are going," said UW astrophysicist
> Donald Brownlee...
It was, in part, my interest in the origin and geological history of
the Earth and my interest in cosmology that brought me into astronomy.
I'm not going to let the fate of our planet 7.5 Gy from now interfere
with my weekend plans, however. Actuarial data available to me
indicates there is an excellent chance that I won't be alive after 7.5
Gy.
Meanwhile, laissez les bontemps rouler!
> By 5 a.m., the 1billion-year reign of animals and plants will come to
> an end.
As Stephen Jay Gould pointed out <http://tinyurl.com/boqzc>, macro
animals and plants have never reigned; it is the bacteria that have
been ruled the Earth for the past 3.5 Gy or so.
Davoud
Blessed are the meek: for they shall inherit the earth.
Matthew 5:5
*****
I apologize for being so dense. Would you please explain once more how
directing klieg lights at /my/ house improves security at /your/
house!?
--
usenet *at* davidillig dawt com
Chris L Peterson
>I'm not going to let the fate of our planet 7.5 Gy from now interfere
>with my weekend plans, however. Actuarial data available to me
>indicates there is an excellent chance that I won't be alive after 7.5
>Gy.
The ultimate fate of the planet may be 7.5 Gy away, but it may be
incapable of sustaining human life in as little as 1 Gy! Don't put off
worrying about this until it's too late! <g>
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
George
"Chris L Peterson" <c...@alumni.caltech.edu> wrote in message
news:1n5it1p4ft6pbf2fk...@4ax.com...
Of course, if all hell breaks loose in the Middle East, which is looking
more and more likely, all bets are off.
George
Shawn
> Of course, if all hell breaks loose in the Middle East, which is looking
> more and more likely, all bets are off.
You kidding? Life will go on almost unchanged as it has for most of the
last 3.? Gy. You may not fare so well. What new hell is this BTW?
Shawn
Davoud
> >I'm not going to let the fate of our planet 7.5 Gy from now interfere
> >with my weekend plans, however. Actuarial data available to me
> >indicates there is an excellent chance that I won't be alive after 7.5
> >Gy.
Chris L Peterson replied:
> The ultimate fate of the planet may be 7.5 Gy away, but it may be
> incapable of sustaining human life in as little as 1 Gy! Don't put off
> worrying about this until it's too late! <g>
OK, OK! I'll go around wearing a sign that reads "The End is
(relatively) Near!"
Seriously, this puts the issue in a different light. I might not live
until CE 7,500,000,006, but I have plans for the last weekend in
January of CE 1,000,000,006.
Davoud
George
"Davoud" <st...@sky.net> wrote in message
news:260120061728368940%st...@sky.net...
LOL! Good one.
George
Mij Adyaw
"George" <geo...@wtfiswrongwithyou.com> wrote in message
news:sNcCf.734847$_o.519504@attbi_s71...
Nick Theodorakis
<c...@alumni.caltech.edu> wrote:
[...]
>The ultimate fate of the planet may be 7.5 Gy away, but it may be
>incapable of sustaining human life in as little as 1 Gy! Don't put off
>worrying about this until it's too late! <g>
Aaaahhhhh!!! End of life as we know it on only 1Gy!
Oh wait, for a minute there I thought you said 1My. <whew> Wotta
relief!
Nick
--
Nick Theodorakis
nick_the...@hotmail.com
contact form:
http://theodorakis.net/contact.html
Mipho Hip
is not
the world I was born into 65 years ago.
Counselors are fond of saying "you must adapt to change". My reply ahs
always been: "But I gave you a five dollar bill. What's the dime for?"