We don't know for certain. Right now, based on evidence we've accumulated, we believe that we're in a rare temperate plateau between normally hot and cold extremes, and that we're accelerating in a slide towards the hot state.
This is all based on large amounts of inference. It could be completely wrong, but right now it matches the accumulated evidence to the best of our ability to compare and analyze.
Of course, just because you know your world model may be faulty, doesn't mean you should live your life catering to the possible faultiness. In other words, just because you can hedge your bets on your belief doesn't mean you should hedge your actions. I recognize that there's an outside chance that I may be hallucinating the chair in front of my computer desk right now, but I'm still going to sit on it without even pausing. :)
F.Y.I.
Khabibullo Abdusamatov is chief of the Space Exploration Department of the Central Astronomical Observatory of the Russian Academy of Sciences, the supervisor of the Astrometria project of the Russian part of the International Space Station, Doctor of Physical Sciences.
05.10.2006 |
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Solar Cycle 25 peaking around 2022 could be one of the weakest in centuries. May 10, 2006: The Sun's Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. "It's off the bottom of the charts," he says. "This has important repercussions for future solar activity."
Right: The sun's "Great Conveyor Belt" in profile. "Normally, the conveyor belt moves about 1 meter per secondwalking pace," says Hathaway. "That's how it has been since the late 19th century." In recent years, however, the belt has decelerated to 0.75 m/s in the north and 0.35 m/s in the south. "We've never seen speeds so low." According to theory and observation, the speed of the belt foretells the intensity of sunspot activity ~20 years in the future. A slow belt means lower solar activity; a fast belt means stronger activity. The reasons for this are explained in the Science@NASA story Solar Storm Warning. "The slowdown we see now means that Solar Cycle 25, peaking around the year 2022, could be one of the weakest in centuries," says Hathaway. This is interesting news for astronauts. Solar Cycle 25 is when the Vision for Space Exploration should be in full flower, with men and women back on the Moon preparing to go to Mars. A weak solar cycle means they won't have to worry so much about solar flares and radiation storms. Above: In red, David Hathaway's predictions for the next two solar cycles and, in pink, Mausumi Dikpati's prediction for cycle 24. On the other hand, they will have to worry more about cosmic rays. Cosmic rays are high-energy particles from deep space; they penetrate metal, plastic, flesh and bone. Astronauts exposed to cosmic rays develop an increased risk of cancer, cataracts and other maladies. Ironically, solar explosions, which produce their own deadly radiation, sweep away the even deadlier cosmic rays. As flares subside, cosmic rays intensifyyin, yang. Hathaway's prediction should not be confused with another recent forecast: A team led by physicist Mausumi Dikpata of NCAR has predicted that Cycle 24, peaking in 2011 or 2012, will be intense. Hathaway agrees: "Cycle 24 will be strong. Cycle 25 will be weak. Both of these predictions are based on the observed behavior of the conveyor belt." How do you observe a belt that plunges 200,000 km below the surface of the sun?
Right: Hathaway monitors the speed of the Conveyor Belt by plotting the drift of sunspot groups from high to low solar latitude. This plot is called "the Butterfly Diagram." The tilt of the wings reveal the speed of the Conveyor Belt. [More] Using historical sunspot records, Hathaway has succeeded in clocking the conveyor belt as far back as 1890. The numbers are compelling: For more than a century, "the speed of the belt has been a good predictor of future solar activity." If the trend holds, Solar Cycle 25 in 2022 could be, like the belt itself, "off the bottom of the charts." |