交流磁偶极场

This is Scientific American's 60-Second Science. I'm Adam Hinterthuer. Got a minute? Don't be fooled by those big bovine eyes and the mouth slowly chewing cudcows have a magnetic personality. At least thats the claim made by German researchers in the

发表于:2018-12-24 / 阅读(116) / 评论(0) 分类 Scientific American(八)月

Radiation causes damage at the most fundamental level. It mutates the blueprint of life, DNA. Earth's magnetosphere is our crucial defense. It's so fundamental to our evolution and continued existence that the race is on to understand why it's changi

发表于:2019-01-22 / 阅读(64) / 评论(0) 分类 自然百科2011年

Earth's magnetic field has reversed thousands of times since its formation 4.5 billion years ago. And scientists now believe that the next reversal is imminent. The race is on to predicting exactly when it will occur. In 2010, the European Space Agen

发表于:2019-01-22 / 阅读(50) / 评论(0) 分类 自然百科2011年

As the reversal approaches, the decay of our magnetic field will continue and cosmic radiation will get increasingly close to the Earth's surface. As the reversal approaches, the decay of our magnetic field will continue and cosmic radiation will get

发表于:2019-01-22 / 阅读(68) / 评论(0) 分类 自然百科2011年

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 theres lots of solar storms. And right now where the sun is taking a little napp

发表于:2019-01-22 / 阅读(106) / 评论(0) 分类 自然百科2011年

Six years later, they come to believe these light flashes are the results of high energy, heavy cosmic rays penetrating the spacecraft and the crew members' eyes. These/ protons or electrons, just very, very high energy, ripped / part of atoms, sprin

发表于:2019-01-22 / 阅读(82) / 评论(0) 分类 自然百科2011年

Glatsmire's model shows that the magnetic poles swap places spontaneously due to / complex processes within the core. We were used to the idea that a compass points somewhere near the North Pole and hence we can use it for navigation, but there are p

发表于:2019-01-22 / 阅读(67) / 评论(0) 分类 自然百科2011年

By analyzing thousands of lava samples, geophysicists discover/ that the Earth's magnetic field has reversed over 18,000 times in the last 20 million years. On either side of these reversals is a long period of dramatically reduced field strength. Du

发表于:2019-01-22 / 阅读(65) / 评论(0) 分类 自然百科2011年

We drive them about 20 miles away to the North, and release them, and we track them as they try to fly back home. We drive them about 20 miles away to the North, and release them, and we track them as they try to fly back home. Hes up, OK. Holland wa

发表于:2019-01-22 / 阅读(78) / 评论(0) 分类 自然百科2011年

By analyzing different samples of lava, Herrero / Bervera has built up a picture of how the filed has changed since long before humans were around. They are actually the recorders of the Earth's magnetic field in hundreds of years, thousands of years

发表于:2019-01-22 / 阅读(78) / 评论(0) 分类 自然百科2011年

If we could flip a switch and just turn off the Earth's magnetic field, it will take about 15,000 years to disappear, based on the rate of decay of the field that we've seen over the last 150 years. It's currently decaying at a rate that would see an

发表于:2019-01-22 / 阅读(68) / 评论(0) 分类 自然百科2011年

In polar regions where the magnetic field is / weakest, auroras glow in the sky. These dazzling displays of colored lights form when solar particles slam into gases in our atmosphere causing them to glow. The stronger the solar wind, the more dramati

发表于:2019-01-22 / 阅读(81) / 评论(0) 分类 自然百科2011年

Scientists believe that the South Atlantic Anomaly, is a sign of a global decline in the magnetic field. Evidence of this comes from a surprising source. Dr. Mimi Hill uses pottery to uncover the secrets of earth's magnetic past. Ancient pots tell us

发表于:2019-01-22 / 阅读(72) / 评论(0) 分类 自然百科2011年

It's clear from the fact that the Martian crust is strongly magnetized, that there must have been a magnetic field on Mars in the past, that the only way we know to magnetize rocks is for them to form in the presence of magnetic field. Why did Mars l

发表于:2019-01-22 / 阅读(64) / 评论(0) 分类 自然百科2011年

The loss of the magnetic field has a catastrophic impact on the planet's evolution. Mars becomes the red planet we see today. If earths magnetic protection continues to fade, would it suffer the same fate? If it vanishes completely, the planet might

发表于:2019-01-22 / 阅读(83) / 评论(0) 分类 自然百科2011年

Easily confused by this idea, there has a big thawed iron inner core, so that I think it's just the bar magnet, just permanent magnet frozen in nad, and that's where causes all the magnetic field. But it's too hot inside the Earth, that can't happen

发表于:2019-01-22 / 阅读(74) / 评论(0) 分类 自然百科2011年

As the vast sphere reaches / maximum speed, something incredible happens. Huge lines of magnetism arc in and out of the model core. Well, we can't see the magnetic field coming out of the experiment, we can measure them, we can put many different mag

发表于:2019-01-22 / 阅读(77) / 评论(0) 分类 自然百科2011年

Larry Newitt from the Geological Survey of Canada charts the movement of the magnetic North Pole as it wanders the icy reaches of northern Canada. To determine where the magnetic pole / is, we can't rely on one single observation. What I try to do is

发表于:2019-01-22 / 阅读(77) / 评论(0) 分类 自然百科2011年

Blockson's computer model reveals that at the South Atlantic Anomaly, the magnetic field isn't just weaker than anywhere else on the planet. It's actually reversed polarity. There is a patch on the core in the South Atlantic where things are not poin

发表于:2019-01-22 / 阅读(79) / 评论(0) 分类 自然百科2011年

The latest data from the twin Voyager spacecrafts suggest the outer edge of the solar system is not smooth but filled with giant magnetic bubbles. Scientists say the turbulent bubbles are the result of the interaction between the Suns magnetic field

发表于:2019-02-06 / 阅读(108) / 评论(0) 分类 英语新闻
学英语单词
absolute experiment
adnams
aft section
aglossostoma
Als Sd.
anthologize
areologists
artificial mutation
b. m. thyreohyoidei
beading needle
bend reduction factor
billfishing
breech-block
C-G
charge mixture
Christmas tree effect
coehorn
comprehensive materials consumption quota
confessarius
cost estimation techniques
coupling degree
Cromarty Firth
cumulative compounded DC machine
cuzzies
cystial pore
decitropine
defeatedly
delusion-like idea
demonstration reactor
dudeks
eminelntia cruciformis
fallrates
feces
firing circuit for flash lamp
Ford SYNC
fracture of cervical vertebral body
fraudulent intent to avoid tax
front-surfaced mirror
futurist manifesto
gastrointestinal systems
gill cowl
glareanus
glyeopyrrolate
guild-ale
half-side formula
hark forward
herpes zoster virus
Honolulu County
in the line of duty
indolizidine
irrelatively
japanese-american
jelly powder
kiss spot
lethe gemina zaitha
levely
live on tally
long term requirements
low output laser system
lucullan feast
Mahukona
managed service provider
molly-dook
multiplexed communication
Nang-do
oil isoperms
parcel sth up
phenomenon
pikromerite (picromerite)
pilgrimised
plantlouse
powder-blower
principalis
proton-proton
pulmonary disease due to Mycobacterium intracellularis
rex sole
sale value of normal growing stock
Saururus chinensis
script-editors
semi passive
shank milling cutter
shoulder board
simple mean
sluice gate
soil magnetic susceptibility
sound level difference
spurious leg
stack transfer
statement of the case
steel spacer
subgiant spiral
synthetic kernel
tar baby
tend out on
thalamostriate vein
thymocrescin
two-dimensional Z-transform
type line
united states secret services
vinger
vocal tract
winter spore