貓真的有九條命嗎
摘要:研究貓體內神祕的神經系統疾病的科學家發現，貓的中樞神經系統具有自我修復並恢復功能的超強能力。
一些人迷信貓有九條命，因爲貓從高處摔下來不僅不會死，甚至都很少受傷。這個事實給人的感覺是貓即使是遇到了什麼不測也可以起死回生。其實，貓能夠逃過一些人類都逃不掉的災禍，並不是因爲它們命大，只是因爲它們有一些特殊的優勢罷了：
Some people believe in the superstition that cats have nine lives, because cats can survive falls from high places with few, if any injuries. This gives the appearance that the cats return to life after sustaining afatal accidents. The ability of the cat to survive these accidents that would kill humans or other animals is not due to multiple lives, but to several advantages they possess：
1. 玲瓏、輕盈的體態在接觸地面時起到了很大的緩衝作用。
1. Their small size and low body weight soften the impact as they make contact with the ground after falling from great heights。
2. 擁有高度發達的內耳以及十分靈敏的平衡感。這種平衡感使得貓在降落的時候能過即使的調整姿勢，確保四肢着地。這樣撞擊地面時的衝擊力就被大大擴散了。
2. The highly developed inner ears of cats equip them with an unusually keen sense of balance. This sense of balance allows a cat falling upside down to right himself by rapidly determining his position,repositioning himself, and making any adjustments necessary to ensure that he lands on all fours. Since cats land on all four paws, the impact from landing on the ground is absorbed by all four。
3. 貓在着地時腿是彎曲的，因此不僅是骨頭，還有關節和肌肉都起到了緩衝、擴散衝擊力的作用。
3. Cats bend their legs when they land, which cushions the impact by spreading the impact, not only through bones that could easily break, but through the joints and muscles as well。
很多人對貓從高的地方跌落比從低的地方跌落有更大存活機會這一點感到驚異。紐約的獸醫們用病貓做實驗獲得了支持這一結論的數據：從2~6層墜落的貓中有10%會遇難，而如果從7~32層墜落，則只有5%的貓會遇難。
Most are surprised to learn that a cat stands a greater chance of survival if it falls from a higher place than from a lower place. New York veterinarians gathered data from their feline patients, which clearly supports this fact. Ten percent of their patients died after falling from 2-6 stories, while only five percent of the fatalities occurred when their patients fell from 7-32 stories。
物理原理能夠解釋這一現象。所有物體，不論質量，下落時都有22英里/小時的加速度。物體在下落一定距離後由於空氣阻力都會達到一個終極速度。物體的質量越小，與空氣的接觸面積越大，下落速度越慢。
Laws of physics explain why these survival rates vary. All falling bodies, regardless or their masses,accelerate by 22 miles per hour per second of their falls. The falling object, after traveling a certain distance through the air reaches a final speed, or "terminal velocity," because the object’s friction with the air slows the fall. The smaller the object’s mass, and the greater its area, the more it will slow。
一隻從高處下落的貓在停止加速後會將腿伸展成傘形狀，這樣它與空氣的接觸面就增大了，於是增大的摩擦力會減緩下落速度。雖然貓有很發達的平衡感，它們還是需要很多時間來調整身體，爲四肢着地做好準備。而從較低的高度下落的貓沒有時間伸展身體，增加與空氣的接觸面，從而減速，也沒有足夠的時間調整好降落的姿勢。
A cat falling from a higher floor, after it stops accelerating, spreads its legs into an umbrella shape, which increases the area against which the air must push and increases the friction, thus slowing the cat’s fall. Through the cats highly developed sense of balance, he buys more time to maneuver his body in preparation for landing on all fours. A cat falling from a lower height does not have the opportunity to increase its body’s area, slow its fall, or position his body to land on all four feet.
