时间:2018-12-30 作者:英语课 分类:英语流行话题阅读:语境识词4500


英语课

  Unit 42

Answer to the Mystery of Life Is Four

Scientists have found a simple mathematical relationship that connects the whole nature, from the tiniest cell to the vast forest of the Amazon. The connections are all based on the three dimensions of the physical world -- length, depth and width -- plus one, making the number 4. "Four is the magic number of life," says Dr. Geoffrey West of the Santa Fe Institute in New Mexico, a keynote speaker at the NZ Institute of Physics annual conference last week.

Dr. West, a British-born physicist 1, and US ecologists James Brown and Brian Enquist have found more than 50 biological relationships, such as between body size and heart rate, which are based on numbers taken to the power of 1/4.

Much of the theory is based on mathematics that can confuse the mind of anyone who struggled through School Certificate maths. Suffice to say that it centers on equations involving square roots and numbers to the power of 1/4. In simple maths, says Dr. West, "if you are 16 times bigger than your dog, your heart rate is half the dog's rate." Average body size and lifetime are also related in the same ratio. So in principle, if you are 16 times the size of your dog, you will live twice as long. We do better than that, thanks to modern medicine, but the average lifetime of pre-European Maori was around 30.

Remarkably 2, combining these two relationships means that the heart of every mammal beats roughly the same number of times in its average lifetime -- around 1.5 billion times -- regardless of whether it is a dog or a human, a mouse or an elephant. The implication is clear -- we can't beat nature. "This says that there is a maximum lifespan for a given size," Dr. West says.

He and his colleagues have found that similar "quarter-power" rules govern every kind of life on Earth, from the rate at which single-celled bacteria absorb energy to the height of those Amazon trees. They believe this uniformity is because every living thing is made up of distribution networks carrying blood, air and other nutrients 3 first through big tubes such as the aortic 4 artery 5 and then through a succession of smaller tubes to the capillaries 6, which finally distribute the nutrients to cells. Within each class of the last stage of the chain, species, such as mammals, the size of the capillaries, is the same. So are the cells that we are all made of. But as the organism gets bigger, the distribution network increases more than would be expected -- as if it had a fourth dimension. It is this increase in dimensionality that accounts for the 4. The 4 represents actually 3 + 1, where 3 is the dimensionality of the space we live in.

Auckland University physicist Dr. Peter Wills says the theory developed by Dr. West and his colleagues is widely accepted, even though it is still being developed. "There is a great deal of interest in the approach he has taken," Do. Wills said. "I don't know anybody who thinks it's nonsense."



n.物理学家,研究物理学的人
  • He is a physicist of the first rank.他是一流的物理学家。
  • The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。
ad.不同寻常地,相当地
  • I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
  • He made a remarkably swift recovery. 他康复得相当快。
n.(食品或化学品)营养物,营养品( nutrient的名词复数 )
  • a lack of essential nutrients 基本营养的缺乏
  • Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》
adj.大动脉的
  • The arterial pulse pressure in aortic insufficiency is widened. 主动脉瓣闭锁不全时脉搏压变宽。 来自辞典例句
  • Valvular heart disease, usually aortic and mitral insufficiency, can complicate a variety of systemic diseases. 瓣膜性心脏病,以主动脉瓣及二尖瓣闭锁不全为最常见,可使各种全身性疾病变得复杂。 来自辞典例句
n.干线,要道;动脉
  • We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
  • The aorta is the largest artery in the body.主动脉是人体中的最大动脉。
毛细管,毛细血管( capillary的名词复数 )
  • The blood flows from the capillaries back into the veins. 血从毛细血管流回静脉。
  • While Joe sleeps, a large percentage of his capillaries are inactive. 当乔睡觉时,他的毛细血管大部分是不工作的。
学英语单词
acanthoidine
adjacent line
air-breather
ambiguohypoglossal
avoking
bestower
buffer reagent
buy-and-holds
catanator
caveling
chlordan
cost-reimbursement
de-activation
Deinotherioidea
democratic values
desoxypyridoxine
dexamethasones
diameter of working disk
diatonic auxiliary note
discretamine
domain magnetization
double-layer fluorescent screen
dropper plate of free grain
Drusze
dynamicize
editon
elbow equivalent
electrode-travel motor
embraced
endomycopsis hordel
Engler viscosimeter
fairwells
fang-likest
fawns on
federal radio act 1927
fling oneself into the breach
fluoroolefin
free-taking
general staff
grinding media charge
hachi
hard-fightings
Hatsukaichi
HRST
ignition of precipitate
inverse mercator
iodine trap
jM-factor
karhunen loeve transform (klt)
kemerer
laughing-eyed
liege poustie
light-alloy armo(u)r
Longué-Jumelles
lophocoronids
Louis Henri
market chaotic
multistage linear amplifier
Narfeyri
Ngoso
octuplex
optical fiber ribbons
organised-crimes
pass in a program
pelviroentgenography
photoelectrocatalytic reactor
phrenemphraxis
polar moments of inertia
portcullised
practice range
prevelar
primordisl endoderm cells
reave
Rectocillin
residual concentration
Riemann upper integral
rifle shot
safo
saltations
screw-tap
sebiferic acid
second anchor
short-lived asset
sleight-of-hand
sniol
sound-barriers
speed change control
stalk extractor
structurality
Tharrawaw
thirst bucket
thoughted
three-dimensional imaging
throw dust in someone's eyes
transnationally
unwed mother
vel non
voiced sounds
votes down
well-customed
wharfies
wrecking