首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Sunspots act like planet-sized hurricanes that suck in as much material as they spew out, temporarily overriding the laws of mag
Sunspots act like planet-sized hurricanes that suck in as much material as they spew out, temporarily overriding the laws of mag
admin
2013-09-23
27
问题
Sunspots act like planet-sized hurricanes that suck in as much material as they spew out, temporarily overriding the laws of magnetic fields, scientists said on Tuesday.
A team of researchers from NASA and Stanford University said by peering into the Sun for the first time, they discovered how the magnetic fields, which make up the cool dark sunspots on the surface, clump together instead of dispersing. Scientists had previously observed gases pouring out of the sunspots, and thought this was the product of the various magnetic fields repelling each other, in the same way magnets repel each other when brought together. But the researchers said the out-flowing matter is just a surface feature that occurs while the sunspot sucks in new material to hold itself together.
"If you look a bit deeper, you find material rushing inward, like a planet-sized whirlpool or hurricane. This inflow pulls the magnetic fields(back)together, " said Junwei Zhao, one of the Stanford researchers. The pressure in this sunspot hurricane is about 10 times higher than a tropical hurricane on Earth, scientists said. "Without this flow, a sun-spot would not last a day. With it, it lasts for weeks. In the end, the sunspot does get torn apart—but we still don’t know how yet, " Stanford colleague Philip Scherrer, said at a news conference.
To get this deeper knowledge the team used sound wave technology, which they likened to the ultrasound doctors use to capture images of unborn babies. The research showed the magnetic field below a sunspot would cut off the spot’s supply of energy from the Sun’s hot core, turning it into a plug. Any matter above the plug would then cool and become denser, until gravity dragged it and any surrounding gases into the center of the spot at 3, 000 miles per hour. "As long as the magnetic field remains strong, the coding effect will maintain an inflow that makes the structure stable... thereby setting up a self-perpetuating cycle, " the team said in its report.
British scientist Douglas Gough from Cambridge University, described the group’s findings as the solution to a 400-year-old riddle. Understanding the sunspot component would help scientists gain a global knowledge of the Sun, he said. "Take a TV set. It is not simply the sum of its components. And trying to understand the whole requires a greater global knowledge, but you can’t build a TV set unless you know how the components work. It’s the same with the Sun and its components, " Gough said.
The findings are the latest in a long line of sunspot research, which stems back to the early 17th century, when Italian astronomer Galileo Galilei used sunspots to calculate the speed of the Sun’s rotation. His hand-drawn renditions of sunspot locations contrasted sharply with the computer-generated multicolored models of sunspots on display at NASA’s Washington headquarters. "Imagine yourself flying over a lake, you can see the surface but you don’t know how deep it is, how the temperature varies with depth. It was the same with sunspots until now, " NASA’s George Withbroe said.
The sunspot hurricane is about______times higher than a tropical hurricane on Earth.
选项
A、10
B、10 billion
C、10 thousand
D、100
答案
A
解析
细节题。只需在略读时留意,便可从第三段中“The pressure in this sunspothurricane is about 10 times higher than a tropical hurricane on Earth,scientists said.”一句中找到答案[A]。
转载请注明原文地址:https://jikaoti.com/ti/YIJMFFFM
0
专业英语四级
相关试题推荐
Technologydevelopedyearsago,backinthe1990s-issimplybeing【C1】______in2012,inasortof【C2】______mode—sayexperts;
Cellscannotremainaliveoutsidecertainlimitsoftemperature,andmuchnarrowerlimitsmarktheboundariesofeffectivefunct
Cellscannotremainaliveoutsidecertainlimitsoftemperature,andmuchnarrowerlimitsmarktheboundariesofeffectivefunct
Iflawandorder______,neitherthecitizennorhispropertyissafe.
Barbecuinghasbecomean【C1】______partofAmericanlife,asbarbecuegrillsarefoundinthemajorityofAmericanhomes.P
ShoppinghabitsintheUnitedStateshavechangedgreatlyinthelastquarterofthe20thcentury.【C1】______inthe1900smostA
Toaccompanythesongs,NativeAmericansused_______.
TheMastersofBusinessAdministration(MBA),thebestknownbusinessschoollabel,isanintroductiontogeneralmanagement.Th
Aestheticthoughtofadistinctivelymodernbentemergedduringthe18thcentury.Thewesternphilosophersandcriticsofthist
随机试题
下列病理过程中哪一种不见于动脉粥样硬化
心理测验工作应遵守的原则为
A.脾B.胃C.肾D.肝E.肺“水火之宅”是指()
A.商阳B.阳溪C.阳池D.偏历E.合谷手阳明大肠经的经穴是
A.内皮细胞增生B.脏层上皮细胞增C.壁层上皮细胞增生D.成纤维细胞增生E.淋巴细胞增生快速进行性肾小球肾炎的主要病理变化是
A.0.20~0.40B.0.50—0.70C.0.03~0.08D.0.01~0.05E.0—0.01中性粒细胞分类计数参考范围是
在采购地域范围内,邀请不特定的对象参与投标竞争,并按照规定程序从中选择交易对象的一种市场交易行为是指()。
磁力启动器的主要功能特点包括()。
下列有关生态系统的叙述正确的是()。
在师生社会实践和教学实践的基础上,遵循事物发展的规律性;在教学方法、教学内容上大胆想象,扩散思维,敢于求异,在教学中不断创新。这句活体现的是思想政治课的哪一项教学原则?()
最新回复
(
0
)