英语听力:自然百科 地球力场 Earth's Force Field—16(在线收听

 During its magnetic cycle, the Sun undergoes periodic changes in activity. Every 11 years, it enters solar maximum.

 
 
 
“This 11 years cycle of solar activity has peaks where there’s lots of solar storms. And right now where the sun is taking a little nappy, but in about 4 years it will head back for solar max, big storms, big disruptions.”
 
 
 
In 2012, the Sun's Activity will peak. For 3 years, the built-up / magnetic energy will generate dark sunspots and increase in solar flares, and hurricane-force solar winds.
 
 
 
“Almost every solar max, there are satellites that are killed. The last solar max destabilized the North American power grid and caused massive blackouts during one of the storms. These are not small storms inconsequential.” 
 
 
 
Earth's magnetic field continues to weaken. Soon this intense solar bombardment could kill more than just power.
 
 
 
The imminent field reversal will have a radical effect on human civilization. But it will also threaten the survival of a number of species. 
 
 
 
Dr. Richard Holland has discovered that as well as using sonar, bats use the Earth's magnetic field to navigate. Holland wants to know how their navigation will be affected by a reversal of polarity.
 
 
 
“We catch bats here in this barn at the Princeton University field station and we subject them to a manipulation of the Earth's magnetic field, or perhaps we’ve just ripped the sensory cells that might be responsible for the detection of the Earth's magnetic field by bats.” 
 
 
 
Holland places individual bats inside this coil. It delivers a very short harmless magnetic pulse which scrambles their internal compass. 
 
 
 
“And pulse as goes to poles, so he's been magnetized, hopefully that should reverse the polarity of the magnetite in the sensory cell, and now we are going to get out there, release him, so we…
  原文地址:http://www.tingroom.com/lesson/zrbaike/2011/259952.html