时间:2019-03-09 作者:英语课 分类:英语听力文摘 English Digest


英语课

  Zippy Aliens

爱因斯坦的狭义相对论认为物体的运动速度越接近光速,时间越慢。在1971年,物理学家理查德·基廷和乔伊·哈夫勒验证了这个假想。他们将4个极为精确的原子钟放在一架普通航行的飞机上。飞行之后,这些原子钟与放在地面的原子钟相比的确慢了59纳秒。它不仅证明狭义相对论完全正确,也说明人们通过坐飞机来长寿,理论上是可行的,所不同的是效果太微弱了。一个人在飞机上飞行80年的时间一共可以赚得400微秒。400微秒实际上只是0.0004秒。但是在粒子加速器里,狭义相对论所预言的时间膨胀效应就不那么微弱了,在美国费米试验室长达40公里的粒子加速器中,次原子粒子可以被加速到光速的90%以上,在这样的速度下,时间的变化明显出现了。在正常情况下寿命很短的粒子,存在的时间大大延长。这证明对这些粒子来说,时间变慢了。


  Since time slows down the closer you get to the speed of light, if alien spaceships could travel at light speed, wouldn't they take longer to get places?

We received a letter from one of our readers with a question about Einstein’s Theory of Relativity: Since time slows down the closer you get to the speed of light, if alien spaceships could travel at light speed, wouldn’t they take longer to get places?

Well, nothing that starts at a lower speed can ever make it to light speed, but theoretically you can come as close as you want. So to keep things simple, let’s say the flying saucers(飞碟) move at just under light speed. Let’s also say that their planet, Zork, is a hundred light years from Earth. How long does it take them to get from Zork to Earth? Just over one hundred years.

Now here’s the tricky 1 part. Since the aliens on board the ship traveled so fast relative to us, time slowed to a crawl for them relative to the way it passed for us on Earth. In a hundred years’ Earth time, the zippy aliens may have only aged 2 a few seconds.

Notice, though, that there’s no going back. Their fellow aliens on Zork who didn’t take the near-light speed trip are all one hundred years older now, too! If our Zorkian visitors turned right around and flew home again, when they got there, they would find it was now two hundred years later.

If humanity 3 ever does build such awesome 4 ships, the fact that time slows down for near-light speed travelers won’t make the ships themselves go any faster or slower. It will, however, make it possible for explorers to go to distant stars in their own lifetimes–just not in the lifetimes of anyone they left behind.

译文:

迅捷的外星人

曾经有位读者来信询问了这样一个关于爱因斯坦“相对论”的问题:一旦时间的速度减缓,我们将接近光速,如果外星飞船以光速飞行,那不是需要更长的时间才能到达目的地吗?

事实上,没有任何以低速运转的物体可以达到光速,但从理论上来说,我们能够与光速无限接近。简单来说,我们假设宇宙飞碟以仅次于光速的速度飞行。再假如,外星人的星球为“卓克”星球,距离地球一百光年,他们从“左克”星球到达地球需要多长时间呢?仅需要一百年多点儿。

可是棘手的问题出现了。既然外星飞碟的飞行速度相对我们来说如此之快,对他们而言,时间的速度就如同爬行一般。地球上的一百年仅相当于他们的数秒钟而已。

值得注意的是,这一切却是不可逆转的。因为在“卓克”星球,那些没有踏上近光速飞行之旅的同类们也将一百岁了。如果我们的“左克”星球来访者抵达后立即掉头返回,当他们到达自己的星球,那也已经是两百年以后了。

如果人类真能制造出那样的飞船,事实是对于那些近光速飞行的人来说时间的速度会变慢,但那不会使得飞船本身的速度加快或减慢。正因为如此,探险家们可能在他们的有生之年到达遥远的外星球,但是请注意,这个有生之年仅仅是他们的,而不是与留在地球的其他人共享的。



adj.狡猾的,奸诈的;(工作等)棘手的,微妙的
  • I'm in a rather tricky position.Can you help me out?我的处境很棘手,你能帮我吗?
  • He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题,只做了个笼统的表述。
adj.年老的,陈年的
  • He had put on weight and aged a little.他胖了,也老点了。
  • He is aged,but his memory is still good.他已年老,然而记忆力还好。
n.人类,[总称]人(性),人道[pl.]人文学科
  • Such an act is a disgrace to humanity.这种行为是人类的耻辱。
  • We should treat animals with humanity.我们应该以仁慈之心对待动物。
adj.令人惊叹的,难得吓人的,很好的
  • The church in Ireland has always exercised an awesome power.爱尔兰的教堂一直掌握着令人敬畏的权力。
  • That new white convertible is totally awesome.那辆新的白色折篷汽车简直棒极了.
学英语单词
2-Sulfanilamidopyrazine
alexoite
allotropic recrystallization
alondra
apparent assimilation
archoplasms
ASHRAE,Ashrae
automatic interrupt system
battle ship
be a unit on
bidas
Binies
Boletales
bronchospirometer
bruncheon
bruvver
caranalyzer
carpentry shop
Cartan invariants
chadisra bipartita
chromatographic component
clamp gate valve
contact inspection
Crochu
d-silver
Delmonicos
dirp
district station
Echinorhynchus moniliformis
elderweds
element expression
erythrocytosis
exohemophylaxis
fanout
Fienen
foreign merchant
Fornelli
fuel control linkage
fusion weld sealing machine
gathering track
genus Lagothrix
gravitational escape velocity
green-and-yellow
gynandroblastoma
heat-flux differential scanning calorimeter
high speed cutter
high-pressure binder spreader
hologram matrix radar
imagestudio
inclined slice
La Farge
landd
lenine
lightingoff
low spiritss
magnetic aberration
main distribution
mammalogies
mccalmon
MHL
mucoviscidosis
multistrip laser
neutron single-particle energy
nitrated oil
nitrofurazone Ointment
object of observation
optical navigation system
ownership of land by the state
palmiers
paradesmus
part-finance
part-throttle reheat
partial shipments and transhipment
pencil of curves of second order
pencil shape beam radar
peretz
pitch-cone
praseodymium carbonate
pre-recruit phase
quadridichotomum
r-y signal
right hemisphere
rodolfoes
script kiddie
secure e-mail
segment unique key
Seignette salt
sequential searches
skerritt
sperone
stochastically increasing
sultines
system management model
tapered piston
tetanigenous
tetarto-brachy-dome
thionocarbamate
transendoscopic
upscalest
well-tried recipe
white rugose rose
yours is to hand