貓咪喝水不濺地 巧妙運用液體慣性 大有學問美國研究團隊發現,貓咪能很優雅地喝水,不像狗會把水濺得到處都是,原因在於貓能巧妙運用慣性與地心引力的原理。雖然貓喝水是家常便飯的小事,不過其物理原理的瞭解卻少得可憐。美國麻省理工學院的生物物理學家Roman Stocker等人,以Stocker的寵物貓Cutta Cutta及收容所的膠原蛋白另外九隻貓作為研究對象。慣性原理(Inertia)可以表述為:一個不受任何外力(或者合外力為0)的物體將保持靜止或勻速直線運動。牛頓的慣性原理是古典力學的基礎之一,並且對慣性原理的理解也隨著現代物理學的發展而出現了改變。 English麻省理工學院生物物理學教授史托克(Roman Stocker)和同僚及維吉尼亞理工大學與普林斯禮服頓大學的兩名生物機械工程專家,以史托克自家寵貓「Cutta Cutta」為對象研究後發現,貓喝水時,會用舌尖輕碰水的表面,所以不會破壞水的表面張力;然後快速縮回舌尖,這個動作讓水瞬間拉出一道水柱,而慣性作用會使水柱上升,進而入嘴,加上貓能俐落地在地心引力作用前闔上嘴巴,所以不會造成處處滴水的邋遢樣。反觀狗喝訂做禮服水時,舌尖會往前伸進水裡,並彎成杯狀,再大口把水撈到嘴裡,因而常常會弄濕地面。史托克領導的團隊利用高速攝影機拍到「Cutta Cutta」喝水的連續動作,並將研究結果發表於《科學》(Science)周刊。頗讓人意外的是,貓舌上粗糙的乳突(俗稱絲狀乳頭)完全未參與整個喝水的過程。不過貓咪控制舌尖吞吐時間則非常重要,好房網必須在地心引力作用於水柱之前,俐落地收回舌尖。根據研究,貓舌一秒可以吞吐四次,而吞吐頻率和貓種有關,體型越大,吞吐時間越慢,所以喝水也越慢。研究團隊說,了解貓喝水的動作有助物理學家釐清重力和慣性的關連,也有助日後機器人和其他生物力學應用的設計。 Cutta Cutta (12x slower) How Cats Lap: Water Uptake 西服by Felis catusAnimals have developed a range of drinking strategies depending on physiological and environmental constraints. Vertebrates with incomplete cheeks use their tongue to drink; the most common example is the lapping of cats and dogs. We show that the domestic cat (Felis catus) laps by 租屋a subtle mechanism based on water adhesion to the dorsal side of the tongue. A combined experimental and theoretical analysis reveals that Felis catus exploits fluid inertia to defeat gravity and pull liquid into the mouth. This competition between inertia and gravity sets the lapping frequency 西裝外套and yields a prediction for the dependence of frequency on animal mass. Measurements of lapping frequency across the family Felidae support this prediction, which suggests that the lapping mechanism is conserved among felines. 住商房屋Source:http://www.sciencemag.org/cgi/content/abstract/science.1195421Cutta Cutta (67x slower) Mystery of how cats lap is revealedIt is a mystery that has long puzzled cat lovers: exactly how do their feline companions lap up liquids so elegantly?Now, with the help of high-speed cameras and a pet 買屋cat, a team of researchers think they have the answer. They found that cats use their tongues to delicately draw up water without breaking the surface of the liquid.The scientists, who published their study in the journal Science, say this differs from dogs, who employ a messy scooping action to 酒店兼職quench their thirst.I would say cats know more about fluid mechanics than dogs”

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