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Movie "Knowing"

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Glen Watson

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Aug 12, 2009, 6:16:09 PM8/12/09
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The end of the 2009 movie "Knowing" shows Earth destroyed by a solar flare.

http://www.youtube.com/watch?v=KQEh5_pSbd4

Is this even remotely possible?


[[Mod. note -- No. Contrary to how Holywood portrays them, actual
solar flares involve only very small changes in the Sun's overall
energy output, and are many orders of magnitude too weak to destroy
buildings, boil oceans, etc. Solar flares do involve large increases
in the Sun's ultraviolet and X-ray emission... but these are only a
minute fraction of the Sun's total energy output, and are
deflected/absorbed by the Earth's ionosphere & atmosphere.

In practice, the main effects of solar flares are
* disruptions to some types of radio communications
(which depend on reflecting signals from the Earth's ionosphere)
* sometimes disruptions to long-distance power lines
* dangerous radiation doses to some spacecraft (& crew, if any)

See
http://en.wikipedia.org/wiki/Solar_flare
for more information.
-- jt]]

Robert Clark

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Aug 30, 2009, 4:09:01 PM8/30/09
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It is probably unlikely but it can't be ruled out entirely because
some sun-like stars have been found to emit such "superflares":

Distant SuperFlares Found On Stars Disturbingly Similar To Our Own
Sun.
By Kathy Sawyer
Washington Post Staff Writer
Thursday, January 7, 1999
"In a worst-case scenario, the most powerful category of "superflare"
would create "a complete global ozone hole that would last a couple of
years," exposing Earth to the sun's ultraviolet radiation and "you'd
basically kill the food chain from the bottom up," Schaefer said at
the annual winter meeting of the American Astronomical Society.
"Schaefer's team found this pattern of superflares on sunlike stars by
analyzing historical records accumulated by others. The superflares,
all at least 100 light-years away, Schaefer said, have been detected
using a wide range of astronomical techniques.
"The superflares range from roughly 100 to 10 million times the
energies of the largest flare ever detected on the surface of the sun,
Schaefer said. Unlike the relatively familiar solar eruptions on
Earth's star, the newly identified superflares affect not just a given
point on the surface but the entire star and then some."
http://www.tmgnow.com/repository/solar/superflares.html

Sci/Tech
Sterilisation of planets.
By BBC News Online's Science Editor Dr David Whitehouse
Thursday, September 23, 1999 Published at 10:04 GMT 11:04 UK
"If a superflare occurred on our Sun, then the Earth would be subject
to rapid heating, aurorae would ripple in every sky, the ionosphere
would break up and the ozone layer would be destroyed.
"This would allow lethal radiation and charged particles from the Sun
to reach the ground, destroying all life-forms except those protected
in the deep oceans.
"However, all geological data, suggests our Sun has never experienced
a superflare. Although researchers cannot rule out the possibility
entirely.
"So what is going on? How can stars like our Sun exhibit such
superflares but our own Sun seem well-behaved?"
http://news.bbc.co.uk/2/hi/science/nature/454265.stm

Are superflares on solar analogues caused by extra-solar planets?
http://xxx.lanl.gov/abs/astro-ph/9909187

Superflares on Ordinary Solar-Type Stars
http://xxx.lanl.gov/abs/astro-ph/9909188


Bob Clark

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