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This is Big Bear Lake in California, USA.
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An observatory stands in
the middle of the lake.
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00:00:17,121 --> 00:00:20,373
It houses the largest solar
telescope in the world,
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00:00:20,561 --> 00:00:22,913
completed in 2011.
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00:00:25,373 --> 00:00:28,779
When the sun surface is observed
through this telescope,
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00:00:31,046 --> 00:00:33,616
a strange pattern can be seen.
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The heat generated within is making the gas
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on the surface bubble up and boil.
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This is the sun as seen
from space by a satellite.
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With surface temperatures
exceeding 6,000 degrees Celsius,
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the sun glows red hot.
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00:01:00,178 --> 00:01:03,897
The dark shadows that can be
seen are called sunspots.
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00:01:04,061 --> 00:01:06,543
Violent explosions occur around these spots
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from time to time.
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00:01:14,444 --> 00:01:18,178
This erupting loop of gas
is known as a prominence.
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At 15 times the size of the Earth,
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it is of a magnitude hard to fathom.
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It's thanks to the light and
heat emitted by the sun
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that life on Earth can thrive.
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However, experts believe
the sun is undergoing
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some unusual changes.
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Up to now, changes in the
intensity of the suns activity
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have occurred in regular cycles.
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However, the cycles are beginning to lose
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their clockwork regularity.
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00:02:05,736 --> 00:02:09,290
This change comes at a golden
age for solar observation,
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with several satellites
currently watching the sun
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00:02:11,899 --> 00:02:13,383
from space.
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00:02:17,958 --> 00:02:21,317
Now scientists have reached
a surprising conclusion.
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They say that some time in the near future,
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the temperature of the Earth may drop.
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What is now happening to the sun
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and how will this effect life on Earth?
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Cosmic Front delves into the mystery
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of how our sun is changing.
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Coming up, going into close
loop control in LSPU.
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The field of solar observation
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is entering an unprecedented golden age.
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In the last decade,
countries around the world
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have launched solar observation satellites
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00:04:13,060 --> 00:04:14,854
one after another.
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There are now more satellites
than ever observing the sun
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00:04:26,146 --> 00:04:29,943
from space, with six
currently in orbit.
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The footage captured by the
satellites is sent here
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to the Solar and Astrophysics
laboratory in California.
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The laboratory has been
developing solar observation
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satellites since the 1970s.
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This is the laborites imaging server room.
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The images captured by
five of the satellites
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are collated here, and then
sent out to researchers
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00:05:03,891 --> 00:05:05,840
around the world.
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00:05:14,301 --> 00:05:17,672
Dr. Ted Tarbell has spent the
last 30 years researching
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00:05:17,673 --> 00:05:20,723
the sun using satellite observations.
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Today we have SDO, Hinode,
Stereo, and SOHO.
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As the fixed star closest to the Earth
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the sun has always been
of particular interest
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to astronomers.
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Of the satellites currently
observing the sun,
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the newest is SDO, which was launched
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in February 2010.
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The satellite can observe
the sun in its entirety
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in both visible and ultraviolet light.
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00:06:02,934 --> 00:06:05,118
When observed in various types of light,
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the sun appears in totally
different guises.
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In normal light, the sunspots
appear as small dots,
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but when seen in ultraviolet light,
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in stark contrast to the
quiet, still image,
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the sun appears as a glowing
orb of swirling activity.
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Sunspots are where the
activity on the sun's surface
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is at the most intense.
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It follows, therefore, that
the more sunspots there are,
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the more active the sun is.
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Hinode was launched in 2006.
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Its on board telescope boasts images
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00:07:02,880 --> 00:07:05,414
of unprecedented resolution.
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00:07:11,717 --> 00:07:14,950
What do sunspots look
like under Hinode's gaze?
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What looks simply like a dot
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now looks like a moving, living organism.
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This sunspot is known among
researchers as Nippon,
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as it resembles the islands of Japan.
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Thanks to the clarity of Hinode's images,
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various phenomenon have been
revealed to be occurring
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around the sunspots.
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This sunspot is 20,000 kilometers wide.
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Flames reaching 10,000 degrees
Celsius erupt and flicker
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00:08:04,130 --> 00:08:05,621
around the sunspot.
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00:08:12,005 --> 00:08:15,950
The dark ring that frames the
sunspot is called a penumbra.
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00:08:22,979 --> 00:08:25,917
When closely examined, the
stripes of the penumbra
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00:08:25,918 --> 00:08:29,853
can be seen to flow alternately
in opposite directions.
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The lighter stripes flow
towards the sunspot center,
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00:08:33,934 --> 00:08:36,516
while the darker parts flow out.
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Professor Saku Tsuneta heads
up an observation project
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that uses Hinode.
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He spent 11 years developing the satellite.
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He says he will never
forget the first image
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sent from Hinode.
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00:09:24,245 --> 00:09:26,248
In April 2008,
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Hinode captured the greatest
explosion in the solar system.
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Between the two black sunspots
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small sparks of light start to appear until
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a band of white light suddenly erupts.
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This is a massive explosion
known as a solar flare.
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00:09:49,179 --> 00:09:51,533
The phenomenal amount of energy it emits
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is equivalent to 100
million hydrogen bombs.
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00:10:00,412 --> 00:10:03,748
Furthermore, a strange
phenomenon was also observed
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where swirls of gas were
sucked into the sunspots.
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Sunspots do not necessarily
stay in the same place.
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They can appear and disappear
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and are constantly changing.
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00:10:32,689 --> 00:10:34,699
This footage shows the surface of the sun
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captured repeatedly over a
period of more than 10 years.
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The lighter, glowing
patches are the sunspots.
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When observed over several years,
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00:10:48,919 --> 00:10:51,055
it becomes evident that
the number of sunspots
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varies with time.
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This is proof that the sun's
activity changes in intensity.
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00:11:04,466 --> 00:11:08,188
For a long time, the fluctuations
in the number of sunspots
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and therefore the level of solar activity,
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occurred in fixed 11 year cycles.
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The sun, however, is now facing a change
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in its patterns of activity.
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Having hither two marked regular cycles
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of 11 years, the sun was
due for a peak in activity
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in 2011.
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00:12:18,642 --> 00:12:20,662
However, the number of sunspots is yet
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00:12:20,663 --> 00:12:23,104
to noticeably increase.
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00:12:23,284 --> 00:12:27,373
In short, the suns regular
cycles have started to go awry.
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00:12:33,078 --> 00:12:35,152
And it's believed this sudden change
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may have a major impact on Earth.
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The first person to ever record sunspots
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was Galileo Galilei.
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These are sunspots sketched by Galileo.
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In the 400 years since,
the number of sunspots
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00:12:51,775 --> 00:12:53,929
has continued to be observed.
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00:12:57,541 --> 00:13:00,807
Looking at the records,
there's a period of 70 years
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when there were no sunspots.
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This period is known as
the Maunder Minimum,
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00:13:09,139 --> 00:13:11,871
named after the man who made the discovery.
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00:13:13,841 --> 00:13:17,214
How did this period of no
sunspots and low solar activity
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effect life on Earth?
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00:13:24,651 --> 00:13:27,266
It's impossible to know at
first hand how things were
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at the time, but clues can be
found in an unexpected place.
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This is Kyoto, the ancient
capital of Japan.
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Dr. Yasuyuki Aono is an associate professor
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at Osaka Prefecture University.
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He has come to the Yomei Bunko Library.
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It is here that he read some ancient texts
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passed down through the Konoe
family of court nobility.
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00:14:22,463 --> 00:14:24,572
The timing of when cherry trees bloom
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is determined by the temperatures
at the start of Spring.
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00:14:31,447 --> 00:14:34,609
With this in mind, Aono
looked for diary entries
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that would provide clues to
the temperatures at the time.
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The research showed that in the early 1600s
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cherry trees were in full
bloom about 100 days
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after January 1st.
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00:15:11,272 --> 00:15:13,323
But by the late 1600s,
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the day of full bloom came
more than 10 days later
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than this.
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00:15:21,156 --> 00:15:24,731
Using this data, Aono was able
to compute the temperatures
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00:15:24,732 --> 00:15:25,928
at the time.
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00:15:29,292 --> 00:15:31,956
This showed that during the
70 year Maunder Minimum
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period, the average
temperatures were nearly
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two degrees lower.
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During the period of low solar
activity and fewer sunspots,
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it is thought that Kyoto went
through a cooling phase.
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00:15:52,079 --> 00:15:55,149
In fact, Japan was not the
only place that experienced
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cooling.
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00:15:59,441 --> 00:16:02,471
The River Thames flows through
the center of London.
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This painting from the late 1600s
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shows a frozen Thames.
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During this time, poor crop
harvests were recorded
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across Europe.
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00:16:24,301 --> 00:16:27,171
The Maunder Minimum, when
sunspots disappeared
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and solar activity plummeted,
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was a period of global cooling.
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The Earth is warmed by the sun's light.
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When sunspots were scarce
and activity levels low,
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how much weaker was the sun's light?
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An American solar observation satellite
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has been making accurate measurements
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00:16:57,024 --> 00:16:59,594
of the levels of light given off by the sun
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for more then 40 years.
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These are the results.
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What is surprising is
that whether the sun is
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at its most active with lots of sunspots
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or whether its activity
levels and number of sunspots
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are low,
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the level of light it emits
varies by a mere 0.15%.
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It is practically constant.
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00:17:30,595 --> 00:17:33,572
But if the levels of light
from the sun did not decrease
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during this period of fewer sunspots,
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why then did the Earth's temperature drop?
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The answer lies not in the
sun's light, but elsewhere.
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Big Bear Lake in California, USA.
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A narrow road stretches out into the lake.
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A white dome stands at the end of it
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as if it's floating on the water.
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This is Big Bear Solar Observatory,
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operated by the New Jersey
Institute of Technology.
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00:18:32,413 --> 00:18:36,314
The observatory was
rebuilt in February 2010.
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00:18:41,367 --> 00:18:44,472
It houses the world's
largest solar telescope.
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00:18:54,575 --> 00:18:58,123
Professor Phil Goode is the
director of the observatory.
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He has spent the past 40
years studying the sun.
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Good, good.
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00:19:11,107 --> 00:19:12,982
This is the observatory's state of the art
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telescope.
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00:19:16,259 --> 00:19:18,664
It stands eight meters high.
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00:19:19,790 --> 00:19:21,552
It is painted white all over
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so as not to absorb the sun's heat.
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00:19:26,885 --> 00:19:30,162
This mirror is the largest aperture mirror
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for any solar telescope in the world
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and makes it the most
powerful solar telescope.
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00:19:36,455 --> 00:19:39,180
Collecting the light coming
in from the dome window
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is a 1.5 meter wide reflecting mirror.
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Compared to artificial satellites,
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00:19:56,147 --> 00:19:58,584
the advantage of ground-based observation
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00:19:58,585 --> 00:20:02,011
is that large telescopes
like this can be used.
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00:20:06,451 --> 00:20:08,333
The major disadvantage, however,
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00:20:08,334 --> 00:20:10,519
is the presence of air.
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00:20:15,851 --> 00:20:17,821
The turbulence in the heated up air
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00:20:17,822 --> 00:20:20,535
causes the images to be blurred.
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00:20:22,534 --> 00:20:25,065
There are two ways in which
the observatory combats
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this problem.
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Three kilometers of open water to the West
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00:20:29,821 --> 00:20:32,168
and so we have nice, smooth air
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00:20:32,169 --> 00:20:35,460
coming in and that enables
us to correct our images
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with adaptive optics all day long.
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00:20:40,505 --> 00:20:42,611
By placing the telescope on water,
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00:20:42,612 --> 00:20:45,429
which is less likely to
warm up than the ground,
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00:20:45,430 --> 00:20:49,030
there is less turbulence in the
air around the observatory.
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00:20:53,249 --> 00:20:56,080
The second way to solve the
problem can be found in the room
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where the light gathered by
the telescope is analyzed.
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00:21:03,035 --> 00:21:06,528
An observation room lies
directly under the telescope.
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00:21:07,179 --> 00:21:09,635
The light from the sun
captured by the telescope
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00:21:09,636 --> 00:21:12,054
is guided down from the ceiling.
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00:21:13,650 --> 00:21:16,635
The light passes through
several mirrors and lenses
237
00:21:16,636 --> 00:21:18,871
into the observation equipment.
238
00:21:22,182 --> 00:21:24,343
The mirror in the middle
is specially designed
239
00:21:24,344 --> 00:21:26,945
to minimize the atmospheric distortion.
240
00:21:30,067 --> 00:21:33,515
Amazingly, it can change
shape in an instant.
241
00:21:36,987 --> 00:21:39,968
A high speed camera detects
turbulence in the air
242
00:21:39,969 --> 00:21:41,883
which prompts the mirror to change shape
243
00:21:41,884 --> 00:21:44,292
in order to correct any distortion,
244
00:21:44,293 --> 00:21:46,866
producing a pristine image.
245
00:21:47,167 --> 00:21:51,199
This special technology is
called adaptive optics.
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00:21:55,314 --> 00:21:57,502
Here is how the technology works.
247
00:22:02,874 --> 00:22:06,257
A 30,000 kilometer square
area of the sun's surface
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00:22:06,258 --> 00:22:07,804
is magnified.
249
00:22:11,885 --> 00:22:15,114
It shows hot gas bubbling
up from the interior.
250
00:22:15,555 --> 00:22:17,127
The image is in focus,
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00:22:17,128 --> 00:22:20,274
but because of the turbulence
in the air, it is blurred.
252
00:22:22,339 --> 00:22:25,881
This is where the adaptive optics
equipment comes into play.
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00:22:29,704 --> 00:22:33,093
At once, a crystal clear image is revealed.
254
00:22:41,316 --> 00:22:43,915
The telescope can be
employed to observe the sun
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00:22:43,916 --> 00:22:47,751
using a special type of
light known as H-Alpha.
256
00:22:52,455 --> 00:22:54,892
Several curved lines can be seen.
257
00:22:58,815 --> 00:23:01,851
This in fact shows the source
of the sun's activity.
258
00:23:04,285 --> 00:23:07,248
These curved lines may
look strangely familiar.
259
00:23:10,298 --> 00:23:13,092
They are identical to the
magnetic field lines
260
00:23:13,093 --> 00:23:16,604
that appear when iron filings
are poured over a magnet.
261
00:23:19,443 --> 00:23:22,444
The curved lines show that
there is magnetism everywhere
262
00:23:22,445 --> 00:23:24,400
around the sun.
263
00:23:25,575 --> 00:23:31,412
Those jets are plasma
that's excited and sent up
264
00:23:31,413 --> 00:23:33,753
and attracts along magnetic field lines,
265
00:23:33,754 --> 00:23:35,595
so you can see an outline
266
00:23:35,596 --> 00:23:37,651
of the magnetic field of the sun
267
00:23:37,652 --> 00:23:40,984
and on the smallest scale, it's everywhere.
268
00:23:41,252 --> 00:23:43,114
So that's a surprise.
269
00:23:43,115 --> 00:23:45,899
The sun is truly a magnetic star.
270
00:23:47,206 --> 00:23:50,172
The sun is covered in magnetism.
271
00:23:50,619 --> 00:23:53,242
The surface may appear quiet and still,
272
00:23:53,243 --> 00:23:56,760
yet it's 100 times more
magnetic than the Earth.
273
00:23:57,446 --> 00:23:59,949
Where the intensely active sunspots lie,
274
00:23:59,950 --> 00:24:02,912
it can be as much as 10,000 times more.
275
00:24:07,066 --> 00:24:09,608
The sun is covered all
over by distinctive loops
276
00:24:09,609 --> 00:24:13,531
of magnetic field lines produced
by the strong magnetism.
277
00:24:16,820 --> 00:24:20,040
This magnetism is generated
in the sun's interior.
278
00:24:25,034 --> 00:24:27,682
There is a 400,000 kilometer deep layer
279
00:24:27,683 --> 00:24:29,627
under the surface of the sun
280
00:24:29,628 --> 00:24:33,110
where hot gases circulate
in convection currents.
281
00:24:35,814 --> 00:24:37,451
It is thought that the sun's magnetism
282
00:24:37,452 --> 00:24:40,733
is generated by the energy
of the moving gases
283
00:24:40,734 --> 00:24:42,611
at the bottom of this layer.
284
00:24:48,624 --> 00:24:51,775
The sun's magnetism can
be seen in its full glory
285
00:24:51,776 --> 00:24:54,043
during a total solar eclipse.
286
00:24:58,048 --> 00:25:00,570
The sun's atmosphere, called the corona,
287
00:25:00,571 --> 00:25:03,017
only appears at the
moment the moon obscures
288
00:25:03,018 --> 00:25:05,520
the intensely bright sun.
289
00:25:06,876 --> 00:25:10,424
Examined closely, a streaky
pattern can be seen.
290
00:25:11,151 --> 00:25:14,444
These streaks are the magnetic
field lines that the sun,
291
00:25:14,445 --> 00:25:17,832
the magnetic star,
emits into space.
292
00:25:21,890 --> 00:25:24,997
It is this magnetism that
causes the various phenomena
293
00:25:24,998 --> 00:25:26,464
on the sun.
294
00:25:28,537 --> 00:25:30,875
The flames that flicker
on the surface of the sun
295
00:25:30,876 --> 00:25:32,732
are prominences.
296
00:25:36,743 --> 00:25:39,400
These prominences are eruptions of gas
297
00:25:39,401 --> 00:25:41,387
caused by magnetism.
298
00:25:46,628 --> 00:25:50,616
This phenomenon can be recreated
using a magnetic toy.
299
00:25:52,490 --> 00:25:55,461
When a magnetic top is
spun on top of a stand,
300
00:25:55,462 --> 00:25:58,552
the magnetism causes the
top to float in the air.
301
00:26:03,587 --> 00:26:06,413
Similarly, prominences are plasma gases
302
00:26:06,414 --> 00:26:10,021
that float up through the power
of the sun's magnetic force.
303
00:26:19,618 --> 00:26:22,680
Solar flares are the
largest explosive events
304
00:26:22,681 --> 00:26:24,829
in our solar system.
305
00:26:26,247 --> 00:26:30,133
They are also caused by the
sun's strong magnetic force.
306
00:26:31,789 --> 00:26:34,674
Magnetic field lines shoot
out from inside the sun
307
00:26:34,675 --> 00:26:36,711
onto the surface.
308
00:26:36,712 --> 00:26:38,903
When the lines are pulled
together at their base
309
00:26:38,904 --> 00:26:40,743
by convection currents,
310
00:26:40,744 --> 00:26:43,312
the two sets of lines connect.
311
00:26:43,845 --> 00:26:47,506
At this point, the magnetic
field lines recombine.
312
00:26:48,532 --> 00:26:50,827
The newly reconnected lines contract
313
00:26:50,828 --> 00:26:52,667
like an elastic band.
314
00:26:55,240 --> 00:26:58,718
They snap back and force
gas down onto the surface
315
00:26:58,719 --> 00:27:02,726
of the sun, leading to
a violent explosion.
316
00:27:05,776 --> 00:27:08,042
The intense activity seen on the sun
317
00:27:08,043 --> 00:27:10,559
is the product of the
massive magnetic energy
318
00:27:10,560 --> 00:27:13,802
that is constantly
generated inside the star.
319
00:27:17,740 --> 00:27:22,330
In fact, the sun's strong
magnetic field extends so far
320
00:27:22,331 --> 00:27:25,036
that it envelopes the whole solar system.
321
00:27:31,887 --> 00:27:35,172
This magnetism lies at the
root of the various activities
322
00:27:35,173 --> 00:27:37,278
seen on the sun's surface.
323
00:27:47,021 --> 00:27:49,832
The Earth, too, has a magnetic field.
324
00:27:50,092 --> 00:27:53,273
It's field lines extend
neatly from North to South.
325
00:27:56,535 --> 00:27:59,390
In the sun's case, however,
the magnetic field lines
326
00:27:59,391 --> 00:28:01,988
are arranged in a complex tangle.
327
00:28:06,187 --> 00:28:08,562
The sun's secret lies here.
328
00:28:12,662 --> 00:28:14,899
The sun rotates on its own axis
329
00:28:14,900 --> 00:28:17,589
once every 27 days or so.
330
00:28:18,102 --> 00:28:19,742
Being made up of gas,
331
00:28:19,743 --> 00:28:22,196
it's rotational speed can vary.
332
00:28:22,474 --> 00:28:24,896
It rotates faster near the equator
333
00:28:24,897 --> 00:28:27,338
and more slowly at its poles.
334
00:28:31,466 --> 00:28:33,356
This means that the magnetic field lines
335
00:28:33,357 --> 00:28:36,410
that run from North to
South in its interior
336
00:28:36,411 --> 00:28:38,792
are gradually pulled sideways
337
00:28:38,793 --> 00:28:41,151
and end up wrapped around the sun.
338
00:28:49,664 --> 00:28:52,679
The magnetic field lines vary in density
339
00:28:52,680 --> 00:28:56,089
and where they are lighter,
they float up to the surface.
340
00:28:58,174 --> 00:29:00,235
When these field lines break through,
341
00:29:00,236 --> 00:29:02,512
they form sunspots.
342
00:29:04,611 --> 00:29:07,361
Sunspots are areas where
the strong magnetic force
343
00:29:07,362 --> 00:29:11,084
created inside the sun
shoots out of the surface.
344
00:29:16,956 --> 00:29:20,177
What happens then to the
strength of the magnetic force
345
00:29:20,178 --> 00:29:22,981
when there are changes
in the suns activity?
346
00:29:25,959 --> 00:29:29,718
As previously seen, light
levels stay fairly constant
347
00:29:29,719 --> 00:29:32,163
even with changes in number of sunspots
348
00:29:32,164 --> 00:29:34,544
and levels of solar activity.
349
00:29:35,789 --> 00:29:38,531
Here, the strength of
the suns magnetic force
350
00:29:38,532 --> 00:29:40,958
is added to the graph.
351
00:29:41,720 --> 00:29:44,640
The magnetic force varies greatly.
352
00:29:45,306 --> 00:29:47,793
Furthermore, the changes
correlate perfectly
353
00:29:47,794 --> 00:29:50,313
with the levels of solar activity.
354
00:29:55,815 --> 00:29:58,364
The sun's magnetic force fluctuates wildly
355
00:29:58,365 --> 00:30:01,442
with the changes in solar activity levels.
356
00:30:02,940 --> 00:30:06,310
A hitherto unimagined
possibility has emerged
357
00:30:06,311 --> 00:30:08,910
that it is in fact this magnetic force
358
00:30:08,911 --> 00:30:10,642
that has a major influence
359
00:30:10,643 --> 00:30:13,037
on the Earth's changing temperature.
360
00:30:17,591 --> 00:30:19,383
In the late 1600s.
361
00:30:19,384 --> 00:30:22,865
When sunspots disappeared
and solar activity dropped,
362
00:30:22,976 --> 00:30:25,844
the Earth experienced global cooling.
363
00:30:30,975 --> 00:30:33,044
Why did the Earth's temperature fall
364
00:30:33,045 --> 00:30:35,406
when solar activity levels decreased
365
00:30:35,407 --> 00:30:38,562
and the sun's magnetic force weakened?
366
00:30:43,493 --> 00:30:46,844
In 1997, a paper written in Denmark
367
00:30:46,845 --> 00:30:49,289
caused shockwaves around the world.
368
00:30:54,652 --> 00:30:57,494
It claimed that the sun's magnetic force
369
00:30:57,495 --> 00:30:59,561
effects the Earth's clouds.
370
00:31:06,548 --> 00:31:09,808
The author of the paper lives in Denmark.
371
00:31:15,033 --> 00:31:16,850
Yes, hello.
372
00:31:16,851 --> 00:31:18,667
Professor Henrik Svensmark
373
00:31:18,668 --> 00:31:21,091
is based at the National Space Institute,
374
00:31:21,092 --> 00:31:24,351
otherwise known as DTU Space.
375
00:31:25,738 --> 00:31:27,212
Since publishing his paper
376
00:31:27,213 --> 00:31:30,153
Svensmark has continued to
research the relationship
377
00:31:30,154 --> 00:31:32,913
between the sun and the Earth's climate.
378
00:31:35,762 --> 00:31:37,391
This is
379
00:31:37,871 --> 00:31:40,633
what we call our sky experiment.
380
00:31:40,883 --> 00:31:42,633
We are testing
381
00:31:43,063 --> 00:31:45,356
how clouds are
382
00:31:45,725 --> 00:31:47,965
forming or some of the
processes that are important
383
00:31:47,966 --> 00:31:50,019
for cloud formation.
384
00:31:50,842 --> 00:31:52,976
Svensmark noticed a strong correlation
385
00:31:52,977 --> 00:31:56,592
between cloud cover and
something rather unexpected.
386
00:32:00,274 --> 00:32:02,455
This graph shows levels of cloud cover
387
00:32:02,456 --> 00:32:04,310
as measured by satellites.
388
00:32:06,766 --> 00:32:08,637
Svensmark discovered something else
389
00:32:08,638 --> 00:32:12,446
that fluctuates in the same
way as levels of cloud cover.
390
00:32:13,004 --> 00:32:15,040
It was cosmic rays,
391
00:32:15,041 --> 00:32:18,075
the radiation that showers down from space.
392
00:32:21,841 --> 00:32:25,793
Cosmic rays are a type of radiation
generated in outer space
393
00:32:25,794 --> 00:32:29,410
when a star reaches the end
of its life and explodes.
394
00:32:32,944 --> 00:32:35,892
Some of the rays travel across
space over a long period
395
00:32:35,893 --> 00:32:38,342
of time and reach Earth.
396
00:32:40,931 --> 00:32:44,068
Svensmark noticed that when
there are more cosmic rays,
397
00:32:44,069 --> 00:32:46,888
the Earth's cloud cover increases
398
00:32:46,889 --> 00:32:51,159
and when cosmic rays
decrease, cloud cover falls.
399
00:32:54,676 --> 00:32:56,235
That is
400
00:32:56,723 --> 00:32:58,773
you know, it's a big surprise,
401
00:32:58,774 --> 00:33:01,855
and the agreement was
402
00:33:02,512 --> 00:33:05,650
fairly good even though it
was very a short period
403
00:33:05,651 --> 00:33:06,819
that we had data.
404
00:33:06,820 --> 00:33:08,054
The agreement was very good,
405
00:33:08,055 --> 00:33:11,654
but the mere idea that there
could be such a connection
406
00:33:11,812 --> 00:33:13,832
I thought was very
407
00:33:14,557 --> 00:33:16,002
exciting.
408
00:33:17,972 --> 00:33:19,168
Up until then,
409
00:33:19,169 --> 00:33:21,425
no one had ever imagined a relationship
410
00:33:21,426 --> 00:33:24,789
between cloud formation and cosmic rays.
411
00:33:29,433 --> 00:33:31,729
This idea first occurred to Svensmark
412
00:33:31,730 --> 00:33:33,729
when he thought of an
experiment he had seen
413
00:33:33,730 --> 00:33:35,642
at high school.
414
00:33:38,517 --> 00:33:40,104
Of course, the cloud chamber at that time
415
00:33:40,105 --> 00:33:41,531
was much, much smaller,
416
00:33:41,532 --> 00:33:43,367
but it's the same principle.
417
00:33:43,368 --> 00:33:44,939
It works fine.
418
00:33:46,414 --> 00:33:48,294
This is a cloud chamber,
419
00:33:48,295 --> 00:33:50,550
an apparatus filled with vapor.
420
00:33:53,265 --> 00:33:55,090
There's one there.
421
00:33:55,091 --> 00:33:57,928
But it lasts only maybe a second
422
00:33:58,520 --> 00:34:00,439
and then it's gone.
423
00:34:01,548 --> 00:34:04,798
From time to time, white streaks appear.
424
00:34:05,149 --> 00:34:08,174
These streaks are the
tracks of the cosmic rays
425
00:34:08,175 --> 00:34:10,865
that fall onto Earth from space.
426
00:34:13,778 --> 00:34:16,349
When cosmic rays pass through the vapor,
427
00:34:16,350 --> 00:34:18,535
cloud-like forms appear.
428
00:34:26,058 --> 00:34:27,742
I thought immediately that
429
00:34:27,743 --> 00:34:30,270
if cosmic rays are important,
430
00:34:31,995 --> 00:34:33,436
it might be clouds.
431
00:34:33,437 --> 00:34:36,476
Sorry, yes, it might be
clouds that they are
432
00:34:36,477 --> 00:34:38,726
effecting, so that was the basic idea.
433
00:34:40,781 --> 00:34:42,833
Svensmark believes that the cosmic rays
434
00:34:42,834 --> 00:34:46,304
that fall from afar cause clouds to form.
435
00:34:50,705 --> 00:34:53,321
It is widely known that
the sun's magnetic force
436
00:34:53,322 --> 00:34:56,456
effects the levels of galactic cosmic rays.
437
00:35:03,824 --> 00:35:06,694
Cosmic rays fly down towards Earth.
438
00:35:07,160 --> 00:35:09,464
The suns strong magnetic field, however,
439
00:35:09,465 --> 00:35:12,399
extends all the way
across the solar system.
440
00:35:12,776 --> 00:35:16,433
This acts as a barrier, making
it difficult for cosmic rays
441
00:35:16,434 --> 00:35:17,996
to break through.
442
00:35:22,098 --> 00:35:24,476
But when solar activity levels drop,
443
00:35:24,477 --> 00:35:26,501
the magnetic shield weakens
444
00:35:26,502 --> 00:35:29,848
allowing more cosmic rays
to enter the solar system.
445
00:35:32,360 --> 00:35:35,407
The cosmic rays can then reach
the Earth's atmosphere.
446
00:35:37,841 --> 00:35:41,146
In short, the volume of cosmic
rays that reaches Earth
447
00:35:41,147 --> 00:35:44,064
is determined by solar activity levels.
448
00:35:47,059 --> 00:35:51,273
Here, solar activity levels are
added to the earlier graph.
449
00:35:53,312 --> 00:35:56,073
It is evident that when
solar activity is low
450
00:35:56,074 --> 00:35:58,090
and the magnetic shield weakened,
451
00:35:58,091 --> 00:36:00,321
more cosmic rays fall on Earth
452
00:36:00,322 --> 00:36:02,541
and there is greater cloud coverage.
453
00:36:07,875 --> 00:36:11,175
What is important is the
sun's magnetic field,
454
00:36:11,600 --> 00:36:13,357
which shields against the cosmic rays
455
00:36:13,358 --> 00:36:15,505
and when this shield changes,
456
00:36:15,681 --> 00:36:18,036
it changes the Earth's cloudiness
457
00:36:18,260 --> 00:36:21,356
and thereby the temperature of the Earth.
458
00:36:21,594 --> 00:36:24,198
So the solar activity
459
00:36:24,465 --> 00:36:26,836
and the plasma that comes from the sun
460
00:36:26,837 --> 00:36:28,363
or the magnetic field
461
00:36:28,364 --> 00:36:31,333
is really what controls the climate.
462
00:36:33,955 --> 00:36:37,159
Clouds are not formed by water vapor alone.
463
00:36:38,616 --> 00:36:41,915
They can only form with the
presence of tiny particles
464
00:36:41,916 --> 00:36:45,496
that act as seeds around
which water vapor gathers.
465
00:36:49,571 --> 00:36:52,523
In this photo taken above
the Pacific Ocean,
466
00:36:52,524 --> 00:36:54,275
white streaks can be seen.
467
00:36:57,048 --> 00:36:59,548
These are clouds created by ships
468
00:36:59,549 --> 00:37:01,872
travelling across the ocean.
469
00:37:02,243 --> 00:37:05,271
Water vapor gathers
around the tiny particles
470
00:37:05,272 --> 00:37:08,896
found in the ships
exhaust forming clouds.
471
00:37:14,166 --> 00:37:16,625
Svensmark theorizes that cosmic rays
472
00:37:16,626 --> 00:37:19,129
effect the formation of these particles.
473
00:37:21,449 --> 00:37:23,449
When cosmic rays reach Earth,
474
00:37:23,450 --> 00:37:26,275
they collide with molecules in the air.
475
00:37:26,947 --> 00:37:29,998
The molecules then become
charged with electricity
476
00:37:29,999 --> 00:37:31,833
and are drawn to each other
477
00:37:31,834 --> 00:37:34,006
growing bigger and bigger.
478
00:37:37,112 --> 00:37:39,745
This gives rise to the
tiny particles necessary
479
00:37:39,746 --> 00:37:41,798
in cloud formation.
480
00:37:43,273 --> 00:37:44,752
According to this theory,
481
00:37:44,753 --> 00:37:47,052
the particles become cloud seeds
482
00:37:47,053 --> 00:37:49,527
for water vapor to gather around
483
00:37:49,528 --> 00:37:51,860
and clouds are formed.
484
00:37:57,371 --> 00:37:59,876
Svensmark's theory of
climate change on Earth
485
00:37:59,877 --> 00:38:01,991
can be summarized thus:
486
00:38:03,133 --> 00:38:06,496
The Earth is protected by
the sun's magnetic field,
487
00:38:06,497 --> 00:38:09,576
but when this is weakened,
higher levels of cosmic rays
488
00:38:09,577 --> 00:38:11,348
can reach Earth.
489
00:38:11,349 --> 00:38:14,216
This creates more particles up in the air
490
00:38:14,494 --> 00:38:16,673
giving rise to clouds.
491
00:38:19,593 --> 00:38:22,077
As a result, sunlight is blocked,
492
00:38:22,078 --> 00:38:24,038
and the Earth cools.
493
00:38:24,938 --> 00:38:27,794
What is happening in the
space surrounding us
494
00:38:27,795 --> 00:38:32,945
is very important and the
solar activity can change
495
00:38:32,946 --> 00:38:35,552
the number of particles which
changes the cloudiness
496
00:38:35,553 --> 00:38:37,655
of the Earth, which changes the climate.
497
00:38:37,656 --> 00:38:39,352
So that is the
498
00:38:39,816 --> 00:38:42,709
connection that it's very surprising,
499
00:38:42,710 --> 00:38:46,053
but that is how things look now.
500
00:38:49,113 --> 00:38:51,237
Svensmark's claim that the Earth's climate
501
00:38:51,238 --> 00:38:55,590
is influenced by space sparked
a heated debate worldwide.
502
00:38:59,885 --> 00:39:03,325
His theory is now being
verified around the world.
503
00:39:09,399 --> 00:39:11,755
The most extensive
verification of the theory
504
00:39:11,756 --> 00:39:15,732
is being carried out just
outside Geneva in Switzerland
505
00:39:15,733 --> 00:39:19,025
at the European Organization
for Nuclear Research
506
00:39:19,026 --> 00:39:20,903
known as CERN.
507
00:39:21,980 --> 00:39:24,912
Large-scale research, such
as studies into the origins
508
00:39:24,913 --> 00:39:28,251
of the universe, is being
carried out using the world's
509
00:39:28,252 --> 00:39:30,513
largest particle accelerator,
510
00:39:30,514 --> 00:39:32,892
which is 27 kilometers long.
511
00:39:38,836 --> 00:39:40,932
One of the projects being carried out here
512
00:39:40,933 --> 00:39:42,720
is the cloud experiment,
513
00:39:42,721 --> 00:39:45,988
which investigates the
relationship between cosmic rays
514
00:39:45,989 --> 00:39:47,395
and clouds.
515
00:39:49,322 --> 00:39:52,643
Consisting of an airtight chamber
three meters in diameter
516
00:39:52,644 --> 00:39:56,399
and four meters high, it is the
only facility in the world
517
00:39:56,400 --> 00:39:59,094
which can recreate the
conditions of the atmosphere
518
00:39:59,095 --> 00:40:01,032
anywhere on Earth.
519
00:40:01,033 --> 00:40:04,133
Using this, scientists can
test whether cosmic rays
520
00:40:04,134 --> 00:40:06,624
really do cause clouds.
521
00:40:08,565 --> 00:40:10,434
So this is the
522
00:40:11,071 --> 00:40:13,189
cloud chamber where we
523
00:40:13,582 --> 00:40:15,187
create the atmosphere
524
00:40:15,188 --> 00:40:19,511
and investigate the effective
cosmic rays from the beam
525
00:40:20,223 --> 00:40:22,574
on the cloud processes.
526
00:40:25,259 --> 00:40:27,757
Dr. Jasper Kirkby uses this chamber
527
00:40:27,758 --> 00:40:30,173
to run the cloud experiment.
528
00:40:30,174 --> 00:40:32,429
He started the project three years ago
529
00:40:32,430 --> 00:40:35,430
as a result of Svensmark's research.
530
00:40:42,957 --> 00:40:45,467
26,000 liters of air can be trapped
531
00:40:45,468 --> 00:40:47,778
inside this airtight chamber.
532
00:40:52,320 --> 00:40:55,020
The ceiling is fitted with
lights that irradiate the same
533
00:40:55,021 --> 00:40:58,700
strong ultraviolet light that
comes down from the sky.
534
00:41:01,959 --> 00:41:05,011
The experiment simulates the
composition of the air,
535
00:41:05,012 --> 00:41:08,021
the temperatures, humidity,
and light levels
536
00:41:08,022 --> 00:41:10,592
to recreate the exact same conditions
537
00:41:10,593 --> 00:41:13,480
as the atmosphere where clouds are formed.
538
00:41:15,910 --> 00:41:18,690
The chamber is then
showered with cosmic rays
539
00:41:18,691 --> 00:41:21,318
artificially created by the accelerator.
540
00:41:24,041 --> 00:41:27,128
The researchers then carefully
check for the tiny particles
541
00:41:27,129 --> 00:41:29,675
necessary for cloud formation.
542
00:41:36,050 --> 00:41:38,512
The results can be seen here.
543
00:41:41,391 --> 00:41:44,777
When the chamber is irradiated
with artificial cosmic rays
544
00:41:44,778 --> 00:41:47,323
from the large-scale accelerator,
545
00:41:47,975 --> 00:41:50,222
the chamber quickly begins to fill up
546
00:41:50,223 --> 00:41:52,137
with tiny particles.
547
00:41:58,264 --> 00:42:00,034
When these particles grow,
548
00:42:00,035 --> 00:42:03,274
they form the seeds that
give rise to clouds.
549
00:42:04,538 --> 00:42:07,679
We've run for three so-called campaigns
550
00:42:07,680 --> 00:42:09,468
and we're finiding a very strong effect
551
00:42:09,469 --> 00:42:11,900
when the beam goes through the chamber,
552
00:42:11,901 --> 00:42:14,343
these particles, these seeds,
553
00:42:14,773 --> 00:42:17,636
for cloud droplets or at
least the embryonic form,
554
00:42:17,637 --> 00:42:22,001
the very small version
of them, do form
555
00:42:22,002 --> 00:42:25,031
much more abundantly when
the beam goes through.
556
00:42:27,169 --> 00:42:28,627
Furthermore, it has been found
557
00:42:28,628 --> 00:42:31,846
that when the number of
tiny particles increases
558
00:42:31,847 --> 00:42:34,909
the nature of the clouds
themselves changes.
559
00:42:39,472 --> 00:42:42,972
Research has been carried out
using Japan's earth simulator
560
00:42:42,973 --> 00:42:44,586
super computer.
561
00:42:53,850 --> 00:42:57,228
Professor Kanya Kusano of Nagoya University
562
00:42:57,229 --> 00:43:00,054
studied the effect the
number of tiny particles has
563
00:43:00,055 --> 00:43:01,546
on cloud formation
564
00:43:01,547 --> 00:43:04,037
when the amount of water vapor is fixed.
565
00:43:07,912 --> 00:43:09,445
In this simulation,
566
00:43:09,446 --> 00:43:12,724
air containing water vapor
is warmed up on the ground
567
00:43:12,725 --> 00:43:14,165
and rises.
568
00:43:19,779 --> 00:43:22,595
The water vapor gathers
together up in the air
569
00:43:22,596 --> 00:43:24,815
and forms clouds.
570
00:43:25,379 --> 00:43:28,321
In time, rain falls from the clouds
571
00:43:28,322 --> 00:43:30,785
and the clouds disappear.
572
00:43:32,639 --> 00:43:35,619
The number of tiny particles
that form the cloud seeds
573
00:43:35,620 --> 00:43:37,245
is then varied.
574
00:43:40,860 --> 00:43:43,283
When there are fewer tiny particles,
575
00:43:43,284 --> 00:43:46,672
the water vapor that
rises does form clouds,
576
00:43:46,957 --> 00:43:50,815
but it quickly leads to rainfall
and the clouds disperse.
577
00:43:53,876 --> 00:43:56,332
With a large number of
tiny particles, however,
578
00:43:56,333 --> 00:43:58,601
there is hardly any rainfall
579
00:43:58,602 --> 00:44:00,923
and the clouds remain for longer.
580
00:44:03,823 --> 00:44:07,441
Kusano has a theory of what
causes this difference.
581
00:44:09,039 --> 00:44:11,989
The amount of water vapor is kept constant.
582
00:44:11,990 --> 00:44:14,377
When there are fewer tiny particles,
583
00:44:14,378 --> 00:44:17,330
more water is concentrated on each particle
584
00:44:17,331 --> 00:44:20,572
creating big droplets that fall as rain.
585
00:44:22,314 --> 00:44:24,572
With lots of tiny particles, however,
586
00:44:24,573 --> 00:44:27,064
each particle attracts less water
587
00:44:27,065 --> 00:44:29,770
creating droplets that
are too small and light
588
00:44:29,771 --> 00:44:31,451
to fall as rain.
589
00:44:36,547 --> 00:44:38,215
The number of tiny particles
590
00:44:38,216 --> 00:44:41,014
determines whether the
droplets turn into rain
591
00:44:41,015 --> 00:44:43,104
or stay as clouds,
592
00:44:44,511 --> 00:44:47,678
and this has major repercussions
on the amount of light
593
00:44:47,679 --> 00:44:49,723
that reaches Earth.
594
00:44:53,974 --> 00:44:55,878
When solar activity drops
595
00:44:55,879 --> 00:44:58,321
and the suns magnetic field weakens
596
00:44:58,322 --> 00:45:00,270
more clouds are formed,
597
00:45:00,271 --> 00:45:03,259
which may lead to a cooling of the Earth.
598
00:45:06,784 --> 00:45:10,398
Will the present lowering of
solar activity levels continue
599
00:45:10,855 --> 00:45:13,571
or will it return to previous levels?
600
00:45:18,849 --> 00:45:22,386
Researchers are looking to the
past for clues to the future.
601
00:45:22,815 --> 00:45:24,481
The island of Yakushima,
602
00:45:24,482 --> 00:45:27,814
a natural world heritage
site, offers an answer.
603
00:45:31,775 --> 00:45:33,480
Dr. Hiroko Miyahara from the
604
00:45:33,481 --> 00:45:37,170
University of Tokyo's Institute
for Cosmic Ray Research
605
00:45:37,171 --> 00:45:40,063
is investigating trends
in solar activity levels
606
00:45:40,064 --> 00:45:42,171
from the past thousand years.
607
00:45:44,176 --> 00:45:47,132
She's here to study the
Yakusugi cedar trees
608
00:45:47,133 --> 00:45:49,658
aged 1,000 years or more.
609
00:45:52,207 --> 00:45:55,242
A growth ring sample from
a fallen Yakusugi tree
610
00:45:55,243 --> 00:45:57,411
is carefully extracted.
611
00:46:16,498 --> 00:46:18,718
This sample contains a special substance
612
00:46:18,719 --> 00:46:20,638
that provides valuable clues
613
00:46:20,639 --> 00:46:23,171
to the sun's activity in the past.
614
00:46:23,609 --> 00:46:25,824
That substance is carbon.
615
00:46:29,285 --> 00:46:31,687
When cosmic rays hit the atmosphere,
616
00:46:31,688 --> 00:46:34,924
carbon dioxide containing
a special kind of carbon,
617
00:46:34,925 --> 00:46:38,795
called C-14, is produced in varying amounts
618
00:46:38,796 --> 00:46:41,529
depending on the number of cosmic rays.
619
00:46:41,530 --> 00:46:44,682
The Yakusugi trees absorb
this carbon dioxide
620
00:46:44,683 --> 00:46:46,958
through photosynthesis.
621
00:46:48,600 --> 00:46:51,310
As a result, in the years
when the Earth's atmosphere
622
00:46:51,311 --> 00:46:53,881
saw a high volume of cosmic rays,
623
00:46:54,103 --> 00:46:58,103
the growth rings contain a
greater quantity of C-14.
624
00:47:00,484 --> 00:47:03,338
This means that by measuring
the quantity of C-14
625
00:47:03,339 --> 00:47:06,127
in each growth ring, the
amount of cosmic rays
626
00:47:06,128 --> 00:47:09,290
that fell on Earth that
year can be ascertained.
627
00:47:13,751 --> 00:47:16,715
Miyahara carefully peeled
apart each growth ring
628
00:47:16,716 --> 00:47:20,294
of the Yakusugi and collected
around 1,000 years
629
00:47:20,295 --> 00:47:21,919
worth of samples.
630
00:47:24,220 --> 00:47:26,918
By looking at the changes
in volume of cosmic rays
631
00:47:26,919 --> 00:47:28,988
over 1,000 years,
632
00:47:28,989 --> 00:47:32,657
she can calculate the solar
activity level of each year.
633
00:47:33,390 --> 00:47:35,421
She also noticed something interesting
634
00:47:35,422 --> 00:47:37,172
before the Maunder Minimum.
635
00:47:41,627 --> 00:47:43,999
That was the period in the 1600s
636
00:47:44,000 --> 00:47:47,133
of low solar activity and global cooling.
637
00:47:50,798 --> 00:47:53,750
It has been discovered that
immediately prior to this
638
00:47:53,751 --> 00:47:56,000
the sun's cycle was 13 years
639
00:47:56,001 --> 00:47:58,143
instead of the usual 11.
640
00:48:01,395 --> 00:48:04,622
Furthermore, there have been
dips in solar activity levels
641
00:48:04,623 --> 00:48:07,632
three times in the past 1,000 years,
642
00:48:07,633 --> 00:48:11,301
and before each one, the
sun's cycle had lengthened.
643
00:48:13,995 --> 00:48:16,969
In other words, a pattern
emerged where each time
644
00:48:16,970 --> 00:48:20,483
the sun cycle lengthens, a
period of several decades
645
00:48:20,484 --> 00:48:23,297
of low solar activity follows.
646
00:48:39,840 --> 00:48:42,188
Nobody even knows what the
647
00:48:42,189 --> 00:48:44,181
upcoming solar maximum's going to look like
648
00:48:44,182 --> 00:48:48,349
or when it will be, so
everything is a surprise.
649
00:48:48,350 --> 00:48:52,203
So you need to have as many
eyes on the sun as possible.
650
00:49:03,892 --> 00:49:06,047
The importance of solar observation
651
00:49:06,048 --> 00:49:08,227
is greater than ever before.
652
00:49:13,041 --> 00:49:15,489
In the U.S., a mission is being planned
653
00:49:15,490 --> 00:49:19,188
to send a solar probe directly
into the sun's atmosphere.
654
00:49:23,397 --> 00:49:25,921
In Japan, too, preparations are under way
655
00:49:25,922 --> 00:49:30,315
to launch another solar
observation satellite in 2018.
656
00:49:31,347 --> 00:49:34,658
At the National Astronomical
Observatory of Japan,
657
00:49:34,659 --> 00:49:37,489
Professor Tsuneta of the Hinode project
658
00:49:37,490 --> 00:49:40,640
is leading the development
of this new satellite.
659
00:50:03,434 --> 00:50:05,169
And I think the sun
660
00:50:05,170 --> 00:50:09,030
is very likely having a very
strong effect on our climate,
661
00:50:09,031 --> 00:50:11,081
but we don't understand it scientifically.
662
00:50:11,082 --> 00:50:13,557
So I think it's our duty
as scientists, all of us,
663
00:50:13,558 --> 00:50:16,284
the climate scientists,
the solar scientists,
664
00:50:16,492 --> 00:50:18,458
satellite, physics, everybody
665
00:50:18,459 --> 00:50:21,541
to really pull their capabilities
666
00:50:21,542 --> 00:50:23,684
and understand our star,
667
00:50:23,685 --> 00:50:25,404
which is controlling our lives.
668
00:50:28,111 --> 00:50:31,148
The sun is mother of all life on Earth.
669
00:50:36,342 --> 00:50:38,761
Scientists around the world are researching
670
00:50:38,762 --> 00:50:40,688
what will happen to Earth
671
00:50:40,689 --> 00:50:43,358
when the sun's activity falls.
672
00:50:47,501 --> 00:50:50,925
What they discover will have
important repercussions
673
00:50:50,926 --> 00:50:53,854
for all of us here on Earth.
52925
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