Let’s go bats 让我们去蝙蝠

Bats have a problem: how to find their way around in the dark. They hunt at night, and cannot use light to help them find prey and avoid obstacles. You might say that this is a problem of their own making, one that they could avoid simply by changing their habits and hunting by day. But the daytime economy is already heavily exploited by other creatures such as birds. Given that there is a living to be made at night, and given that alternative daytime trades are thoroughly occupied, natural selection has favoured bats that make a go of the night-hunting trade.  It is probable that the nocturnal trades go way back in the ancestry of all mammals. 蝙蝠有一个问题:如何在黑暗中找到自己的方式。他们在夜间捕食,不能使用光来帮助他们找到猎物,避免障碍。你可能会说,这是自己的问题,他们可以避免仅仅通过改变他们的习惯和狩猎。但白天经济已经严重利用其他生物如鸟。这只不过是一个生活,晚上,考虑到替代日间交易彻底占领,自然选择的蝙蝠在夜间捕猎的。很可能,夜间交易在所有哺乳动物的祖先。

In the time when the dinosaurs dominated the daytime economy, our mammalian ancestors probably only managed to survive at all because they found ways of scraping a living at night. Only after the mysterious mass extinction of the dinosaurs about 65 million years ago were our ancestors able to emerge into the daylight in any substantial numbers. 在恐龙统治白天时经济,我们哺乳动物的祖先可能只有设法生存下来,因为他们发现晚上刮的生活方式。只有在神秘的大规模灭绝的恐龙大约在6500万年前我们的祖先能出现在白天任何实质性的数字。

Bats have an engineering problem; how to find their way and find their prey in the absence of light. Bats are not the only creatures to face this difficulty today. Obviously the night-flying insects that they prey on must find their way about somehow. 蝙蝠有一个工程问题,如何找到他们并找到猎物没有光。蝙蝠是今天不是唯一陷入这种窘境的动物。显然,那些昆虫——他们必须找到他们的方式。

Deep-sea fish and whales have little or no light by day or by night. Fish and dolphins that live in extremely muddy water cannot see because, although there is light, it is obstructed and scattered by the dirt in the water. Plenty of other modern animals make their living in conditions where seeing is difficult or impossible. 深海鱼类和鲸鱼有很少或没有光线在白天还是黑夜。鱼和海豚生活在极其浑水无法看到,因为虽然有光,它被污垢阻塞和分散在水中。许多其他现代动物谋生的条件在看到是困难的或不可能的。

Given the questions of how to manoeuvre in the dark, what solutions might an engineer consider? The first one that might occur to him is to manufacture light, to use a lantern or a searchlight. Fireflies and some fish ( usually with the help of bacteria ) have the power to manufacture their own light, but the process seems to consume a large amount of energy. 鉴于在黑暗中如何调动的问题,解决方案可能一个工程师考虑什么?对他的第一个可能发生的是光制造,使用灯笼或者探照灯。萤火虫和一些鱼(通常是细菌的帮助下)有能力制造他们自己的光,但这一过程似乎消耗了大量的能源。

Fireflies use their light for attracting mates. This doesn’t require a prohibitive amount of energy. A male’s tiny pinprick of light can be seen by a female from some distance on a dark night, since her eyes are exposed directly to the light source itself. However, using light to find one’s own way around requires vastly more energy, since the eyes have to detect the tiny fraction of the light that bounces off each part of the scene. The light source must therefore be immensely brighter if it is to be used as a headlight to illuminate the path, than if it is to be used as a signal to others. In any event, whether or not the reason is the energy expense, it seems to be the case that, with the possible exception of some weird deep-sea fish, no animal apart from man uses manufactured light to find its way about. 萤火虫用它们的光亮来吸引异性。这并不需要高得惊人的能量。雄性萤火虫的微小光点从一段距离可以被一个女一个漆黑的晚上,因为她的眼睛是可以直接和光源接触的源代码本身。然而,使用光来找到自己的方式需要更大的能量,因为眼睛检测很小的光反射的每个部分。光源必须无比光明的如果要作为头灯照亮道路,比如果要作为一个信号。在任何情况下,不论原因是能源费用,它似乎是如此,可能除了某些奇异的深海鱼类,没有动物除了人使用人造光来找到它的方法。

What else might the engineer think of? Well, blind humans sometimes seem to have an uncanny sense of obstacles in their path.

 工程师认为是什么呢?盲人有时似乎有一种不可思议的感觉障碍的路径。

 It has been given the name ‘facial vision’, because blind people have reported that it feels a bit like the senses of touch, on the face. One report tells of a totally blind boy who could ride his tricycle at good speed round the block near his home, using facial the face, although the sensation may be referred to the front of the face, like the referred pain in a phantom, limb, the sensation of facial vision , it turns out, really goes in through the ears, Blind people , without even being aware of the fact, are actually using echoes of their own footsteps and of other sounds, to sense the presence of obstacles. 它被称作“面部视觉”,因为盲人说,感觉有点像触摸的感觉,表面上。一份报告讲述了一个完全失明的男孩可以骑三轮车在他家附近的街区,快速地使用面部的脸,虽然感觉可能被前面的脸,像幽灵的牵涉性痛,四肢,面部的感觉视野,事实证明,确实在穿过耳朵,盲人,甚至没有意识到这一事实,实际上是用的自己的脚步声和其他声音,感觉障碍的存在。

Before this was discovered, engineers had already built instruments to exploit the principle, for example to measure the depth of the sea under a ship. After this technique had been invented, it was only a matter of time before weapons designers adapted it for the detection of submarines.  Both sides in the second world war relied heavily on these devices, under such codenames as Asdic (British) and sonar (American),or RDF(British),which uses radio echoes rather than sound echoes.在被发现之前,工程师们已经开发利用的原则,制造仪器例如测量海水的深度在一艘船。这种技术被发明后,它只是一个时间问题武器设计师适应潜艇的探测。双方在第二次世界大战严重依赖这些设备,在这样的开发代号为声纳(英国)和声纳(美国),或RDF(英国),它使用无线电回应,而不是声音的回声。

The Sonar and Radar pioneers didn’t know it then, but all  the world now knows that bats. Coined the term ’echolocation ‘ to cover both sonar and radar, whether used by animals or by human instruments. 声纳和雷达的先驱们不知道,但现在全世界都知道蝙蝠。创造了“定位”这个词涵盖声纳和雷达,是否由动物或仪器使用。