Feb. 1, 2009
Here Comes the Sun
A History of the Star at the Center of Our Lives
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This image provided by NASA's Solar and Heliospheric Observatory (SOHO) shows a new sunspot (upper right) which emerged Sept. 23, 2008. (AP Photo/NASA/ESA)
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Photo Essay Total Eclipse Of the Sun Eyes turn to the sky as a rare spectacle sweeps over much of the world.
Some show-off, that sun. Performing its fire dance not just on Sunday, but every day, morning and night, the world over, for all of us Earthlings … rich and poor, old and young … no ticket required.
What exactly is the sun?
"It's a big ball of hydrogen gas," said Owen Gingerich, professor of astronomy and history of science emeritus, at the Harvard Smithsonian Center for Astrophysics.
Not so big. In fact, kind of middling for a star … but enormous compared to the Earth.
"It's one thing to say, well, the diameter of the sun is 100 times the diameter of the Earth," Gingerich told Teichner. "But you don't really get the impression of how big the sun really is unless you can see it in three dimensions."
How old is the sun? "About five billion years," said Gingerich, who assured us, "it's just about halfway through its lifetime."
It's really hot, maybe 28 million degrees Fahrenheit at its core, and it's burning up. There are nuclear reactions going on inside it all the time. When the energy works its way to the surface, we see it as sunshine..
At the relatively safe distance of 93 million miles away, the Earth orbits around the sun. It takes 365 days … a year. Life-giving time for planting and growing and harvesting crops.
No wonder so many civilizations built great monuments, like Stonehenge in England, to plot the seasonal doings of the sun, or Chichen Itza in Mexico, or the Konark Sun Temple in India.
No wonder the sun was a god to the ancient Egyptians, the Greeks, the Romans, the Incas.
They knew then that the sun influenced almost every aspect of their existence. We know now it even determined the color of our skin.
"Our ancestors who evolved close to the equator have very darkly pigmented skin, adapted to very high levels of radiation," said Nina Jablonski, head of the anthropology department at Penn State University and an expert on skin.
"And then as we dispersed away from the equator, in our evolution we evolved lightly pigmented skin to cope with less solar radiation," Jablonski said.
Around the equator the earliest humans developed a kind of permanent suntan. This dark coloring containing something called melanin. How's this for amazing: Melanin acted like a natural sunscreen, blocking ultraviolet radiation but allowing in exactly the right amount of vitamin D.
"We need vitamin D," Jablonski said. "So the sun shines, ultraviolet B shines on the skin and makes vitamin D chemically in the skin, right there."
Now fast forward to, say, present-day Scandinavia, where sometime around ten thousand years ago people lost their permanent tans. In northern weather, under a weaker sun, they don't require protective color.
Speaking of weather … there is actually solar weather, and we're all affected by it.
Richard Fisher heads NASA's heliophysics division, which studies solar activity. He showed us images from 2003 when there was lots of sunspot activity.
"These guys are pretty big!" he said. "They're as big as Jupiter, 40,000 kilometers across."
Sunspots are intense magnetic fields, and when a lot of them appear, it's a signal that a season of violent solar weather is on the way.
The sun flings out swirling streams of electrical current called solar winds, and when they reach the Earth's atmosphere, we see the spectacular aurora borealis, the northern lights.
NASA can also simulate solar storms, in order to see these great explosions of radiation and magnetic particles erupting from the sun's atmosphere, called its corona.
"We'll see one of these disturbances on the sun, understand its direction, and we just start the stopwatch and say, 'Well, it's gonna be about, you know, fifty hours and we should expect to see a possible solar-induced effect at the Earth," said Fisher.
And that means trouble. An astronaut on a space walk could actually die from exposure to the radiation. Communications systems on planes flying over the poles often fail. GPS signals get screwed up. In 1989 a solar storm incinerated a transformer in Quebec, leaving 6 million Canadians without power...
For NASA, learning how to predict solar weather so that disruptions can be planned for (or even prevented) is a practical justification for the seventeen satellites it has in space already analyzing the sun, with more to come.
In a NASA "clean room," Fisher showed us the next satellite to go into orbit, the most sophisticated solar observatory that's ever been in orbit. "It is the cornerstone of our NASA program for about the next decade," he said.
Its planned launch, November. Its mission, barely thinkable even ten years ago ... in effect, a sonogram of the sun's gassy interior.
Yes, deep inside, where solar weather forms. It should send back pictures ten times better than high definition television.
But can those images beat our view of the sun, with the horizon as its stage, and the power to move us ...
For more info:
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Best-selling author Mitch Albom on his first nonfiction work since "Tuesdays with Morrie."
Besides, *this* article has nothing at all to do with global warming; I get really tired, since I spend many hours daily (I'm retired) online browsing through various articles and their discussion threads only to find completely off-topic comments. Just earlier today I read a really nice, feel-good, makes-you-all-warm-and-fuzzy piece about the triply-confirmed confirmation of the presence of water on Luna only to run across, in the second or third response, a diatribe (complete with a lot of capital letters, exclamation marks, and terribloe spelling -- against the space program, and how we ought to be using this money on Earth, how Obama is worthless, blah, blah, and more wretched, irritating blah.
NOW to the article. A nicely presented piece, one easily accessible to anyone, even if they previously had never thought about Sol and the role it plays in our lives.
A rhetorical mquestion just popped into my mind: wonder if Google is going to have a Google Sun on up the road? I suspect they will, since they already have Google Earth/Sky/Moon/Mars, though maybe Google Mercury might be the next project, since it's being mapped now.
Well, I never tire of astronomical topics, so I really enjoyed this article (and will be looking forward to "Google Does Sol"!).
Dalton Minimum was a period of low solar activity, lasting from about 1790 to 1830. Like the Maunder Minimum and Spvrer Minimum, the Dalton Minimum coincided with a period of lower-than-average global temperatures.
You will find a lot of concerned people with more knowledge than I at the link below. It is not only the lack of sunspots that is of concern but also their weakness.
http://solarcycle24com.proboards106.com/index.cgi?board=general
I''m an astronomer. My first area of study was solar physics. I''m not currently working on the Sun, but I''m reasonably familiar with the issues. (I''m now working on exoplanet detection, with minor work on Mars geo.)
In a nutshell, I''m saying that the current transition between solar cycle #23 & #24 is within the range of data values we have seen in the past century.
You seem to be arguing that the current transition is the start of a little ice age.
Really - which of the two statements seems the more outrageous (to use your term)?
Example - the Atlantic hurricane season runs from June 1st to Nov 30th. If there were no hurricanes as of June 15th, would you then assume that there would be zero hurricanes the year? Or, would it be less outrageous to say that there is some variability on when hurricanes show up?
Sunspots are the tops of solar magnetic storms. They are a visible manifestation of the Sun''s weather. And much like predicting the weather here on Earth, we do not yet have the ability to predict when, exactly, a storm will brew on the Sun. We are confident that there will be storms, but they may be two weeks away rather than next week.
BTW, here is the official sunspot count for the past month (Wolf Method):
Jan 7th = 11
Jan 9th = 11
Jan 10th = 14
Jan 11th = 17
Jan 12th = 20
Jan 13th = 12
Jan 19th = 11
Jan 29th = 11
A slow month, but not spotless, just as we would expect during solar minimum.
[continued...]
Your link from NASA on the magnetic field, while interesting, does not mention weather or climate once on the page. That page is not making your point for you, so what is your point?
Since you are quoting NASA (from science.nasa.gov):
"It does seem like it''s taking a long time," allows Hathaway, "but I think we''re just forgetting how long a solar minimum can last." In the early 20th century there were periods of quiet lasting almost twice as long as the current spell. Most researchers weren''t even born then. Hathaway has studied international sunspot counts stretching all the way back to 1749 and he offers these statistics: "The average period of a solar cycle is 131 months with a standard deviation of 14 months. Decaying solar cycle 23 (the one we are experiencing now) has so far lasted 142 months--well within the first standard deviation and thus not at all abnormal. The last available 13-month smoothed sunspot number was 5.70. This is bigger than 12 of the last 23 solar minimum values." In summary, "the current minimum is not abnormally low or long."
As for your observation on the stratosphere, I thought that we were talking about the Sun. I''ll leave comments about atmospheric physics to those who are more knowledgeable about such matters.
You raise a great question about how the sunspot count has to be adjusted over time, to account for the steady improvements in astro instruments. The daily sunspot number is computed using a formula devised by Rudolph Wolf in 1848: R = k (10g+s),
R is the sunspot number; g is the number of sunspot groups on the solar disk; s is the total number of individual spots in all the groups; and k is a variable scaling factor (usually 1) that accounts for observing conditions and the type of telescope (binoculars, space telescopes, etc.). Scientists combine data from lots of observatories -- each with its own k factor -- to arrive at a daily value. The k value adjusts data from scope to scope and from one era to the next.
Back when I was working at a reporting observatory I ALWAYS saw far more sunspots than the "official" number we reported. We had to adjust the count to even the sensitivity of our equipment to what could be seen by the standard 1850''s ''scope.
Bottom line - I''m not aware of a single solar physicist who is concerned about the length of the current solar minimum. Are there any out there?
~ Michael
Of course, if you want "proof" that Terra has just experienced a "Deca-Ice Age" or so, um, well, you can ask those fine folks at a place like Heartland, the members of which are, um, maybe cousins of the doctors who worked for tobacco companies in the 50's and 60's. . . . THEY'LL sure set you straight. Ahem.
Of course, if you want "proof" that Terra has just experienced a "Deca-Ice Age" or so, um, well, you can ask those fine folks at a place like Heartland, the members of which are, um, maybe cousins of the doctors who worked for tobacco companies in the 50's and 60's. . . . THEY'LL sure set you straight. Ahem.
You said, "It is to bad that the article didn%u2019t dwell more on cycles of sunspot activity. These cycles correspond to global climate conditions."
A connection between the sunspots and climate is possible but unproven.
You said, "The sun has been absent of sunspots for more than a year."
Mostly correct, and as expected. Sunspot activity is on an 11-year cycle, tracked by astronomers since 1755, and very regular. The transition between cycle #23 & #24 is proceeding apace.
This cycle: http://solarscience.msfc.nasa.gov/images/ssn_predict_l.gif
Since 1755: http://spaceweather.com/glossary/images2009/zurich.gif
You said, "This diminished sunspot activity could become a cooling trend similar to the Little Ice Age."
A huge leap! The solar minimum we are in now has been expected and predicted. I don''t see how you can project the current solar minimum into a little ice age.
You said, "So, get out those carbon dioxide machines and help to stop the coming ice age.... Earth climate report: The earth is beginning to cool. Really cool."
That''s just silly. The Earth is not cooling.
2008 was the 10th warmest year on record. (http://apps1.eere.energy.gov/news/news_detail.cfm/news_id=12198) The ten warmest years on record have all occurred since 1997.
The Earth is warming. And, the cause is NOT the Sun.
Sun Dying as Ice Age Looms
Experts predict a new ice-age is imminent as sunspots disappear. John Andrews of Solar24, the sun watchdog, said, "This could be the end of life as we know it". NASA scientists are at a loss to explain the dying sun. "It''s true that we have not seen this amount of inactivity for centuries but there is no need for alarm" Dr Hathaway announced he is leading an expedition to Alpha Centauri but denied he was jumping ship "It is just part of NASA''s ongoing search for habitable planets" he said. The UK government have been quick to react by setting up a Cold Comfort Committee whilst red faced Global Warming pundits are rushing to their thermometers, "Once the ice age ends we will be back to square one." PM Gordon Brown speaking from Royal Navy1 in the Caribbean said a New World Order may be needed to protect the worlds population. Conspiracy Theorists say the sunspots have been deliberately destroyed by NASA probes to create an ice-age "Once half the world is frozen they will take over" insisted alien king John Lear. President Obama still warming the oval office chair said, "We will do everything that is necessary, even if it means moving our great nation to Iran and Iraq."
Fun fact: an image of the sun can heat things to half as hot as the sun itself, or thereabouts. A giant solar image can toast iron oxide so that it loses some of its oxygen, becoming a lower oxide of iron. Then at lower temperatures, near room ''T'', this lower oxide divides itself into particles of metallic iron and particles of the former, higher oxide.
This gives the makings of either an iron-burning solar power plant that works all year, or simply a solar iron plant, if iron is what you want.
Fun fact: an image of the sun can heat things to half as hot as the sun itself, or thereabouts. A giant solar image can toast iron oxide so that it loses some of its oxygen, becoming a lower oxide of iron. Then at lower temperatures, near room ''T'', this lower oxide divides itself into particles of metallic iron and particles of the former, higher oxide.
This gives the makings of either an iron-burning solar power plant that works all year, or simply a solar iron plant, if iron is what you want.
Solar weather report:
The sun is quiet today. Really quiet.
Earth climate report:
The earth is beginning to cool. Really cool.
- by swanny2031 February 1, 2009 12:44 PM EST
- More great, education, and fun information can be found by listening to ''Why the Sun Shines'' by the group They Might Be Giants
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