Black Light / UV light

Black Light / UV light
If you walked around all night with a portable black light, you would discover that there are phosphors all over the place. There are lots of natural phosphors, in your teeth and fingernails, among other things. There also a lot of phosphors in man-made material, including television screens and some paints, fabric and plastics. Most fluorescent colored things, such as highlighters, contain phosphors, and you'll find them in all glow-in-the-dark products. Clubs and amusement parks use special black light paint that glows different colors. You can also buy fluorescent black light bubbles, invisible black light ink, fluorescent black light carpet and even fluorescent black light hair gel.

Ordinary highlighters work well as "black light pens." Under the black light, the fluorescent ink glows!

In addition to making people and fluorescent posters look cool, black lights have some practical applications. For example:
Appraisers use them to detect forgeries of antiques. Many paints today contain phosphors that will glow under a black light, while most older paints do not contain phosphors.
Repairmen use them to find invisible leaks in machinery -- they inject a little fluorescent dye into the fuel supply and illuminate it with a black light. For example, they might detect an invisible air conditioner leak by adding fluorescent dye to the refrigerant. Black lights can be used to detect counterfeit bills.
Law enforcement officers can use them to identify counterfeit money. The United States and many other countries include an invisible fluorescent strip in their larger bills that only shows up under a black light.
Amusement parks and clubs use them to identify invisible fluorescent hand stamps for readmission.
Forensic scientists use them to analyze crime scenes. To pick out fingerprints, for example, they often dust with fluorescent dye under a black light. This makes it easier to pick the fingerprints out from surrounding dirt. Black lights can also identify semen and other bodily fluids that naturally fluoresce.
Most of these uses, as well as dozens of others, follow a common theme -- the black lights make the invisible visible or isolate one specific substance from everything around it. When you think about it, there are dozens of situations where you could put this phenomenon to work. The applications are potentially endless!

如果你到处走走，整晚用便携式黑色轻，你会发现有地方都发光材料。有很多天然的发光材料，在牙齿和指甲，除其他外。那里荧光粉在人造材料，包括电视屏幕和一些油漆、 织物和塑料的也很多。最荧光色的东西，如荧光笔，包含荧光粉，并且你会发现他们都在黑暗中发光产品中。俱乐部和游乐园使用发光颜色不同的特别的黑色亮漆。你也可以买黑色荧光灯泡沫，不可见的黑色光油墨、 荧光黑轻地毯、 甚至荧光灯的黑头发凝胶。

普通荧光笔工作以及"黑轻笔"。在黑色光下荧光油墨发光 ！

除了使人和荧光海报看起来很酷，黑灯有一些实际的应用程序。例如：

估价师使用它们来检测的古董赝品。许多涂料今天包含在黑灯下会发光，虽然多数旧油漆不包含荧光粉的发光材料。

修理工使用它们来查找不可见泄漏在机械--他们小小的荧光染料注入燃料供应和照亮它与黑色光。例如，他们可能会通过向制冷剂添加荧光染料检测隐形空调泄漏。黑灯可以用于检测假钞。

执法人员可以使用它们来标识假币。美国和其他许多国家在其较大的条例草案只出现在黑灯下包括不可见的荧光地带。

游乐园和俱乐部使用它们来标识重新接纳的无形的荧光手邮票。

法医科学家使用它们来分析犯罪现场。从中挑选出指纹，例如，他们常常尘土与黑灯下的荧光染料。这使得更容易地从周围泥土挑指纹。黑灯还可以确定精液和其他自然荧光粉的体液。

大多数的这些用途，以及几十人，遵循一个共同的主题--黑灯使不可见的可见或隔离一个特定物质从周围的一切。

Ultraviolet light frequencies are above violet on the spectrum and are invisible to the human eye.

What Is "Black Light"?

If you turn on a black light bulb in a dark room, what you can see from the bulb is a purplish glow. What you cannot see is the ultraviolet light that the bulb is also producing.

Our eyes can see visible light in a spectrum ranging from red through orange, yellow, green, blue and violet. Above violet is ultraviolet light, which we cannot see. How Sunburns and Sun Tans Work discusses ultraviolet light and its effects on our skin. A black light bulb produces UVA light (as opposed to UVB light, which is much more harmful).

A phosphor is any substance that emits visible light in response to some sort of radiation. A phosphor converts the energy in the UV radiation from a black light into visible light. What you see glowing under a black light, whether on a fluorescent poster or an invisible hand stamp or a newly washed white T-shirt, are phosphors.

如果您打开一个黑色灯泡在黑暗的房间里，你可以看到从灯泡是紫色的发光效果。您不能看到的是灯泡也生产的紫外线光。

我们的眼睛可以看到可见光光谱范围从红色到橙色、 黄色、 绿色、 蓝色和紫色。紫的上面是紫外线光，我们看不到。如何晒伤和太阳晒黑的工作讨论紫外线光和及其对我们的皮肤的影响。黑色灯泡生产 UVA 光 （而不是 UVB 灯，更多有害的）。

紫外线光的频率高于紫的光谱和对人的眼睛是不可见。

你看到发光的黑灯下是否上荧光的海报或看不见的手戳或新水洗白色 t 恤，是荧光粉。

磷是发出可见光在某种辐射响应的任何物质。荧光粉将中紫外辐射的能量从黑色光转换成可见光。

Black Light Designs

The conventional black light design is just a fluorescent lamp with a couple of important modifications. Fluorescent lamps generate light by passing electricity through a tube filled with inert gas and a small amount of mercury. (See How Fluorescent Lamps Work for more information.)

When energized, mercury atoms emit energy in the form of light photons. They emit some visible light photons, but mostly they emit photons in the ultraviolet (UV) wavelength range. Because UV light waves are invisible to the human eye, fluorescent lamps have to convert this energy into visible light. They do this with a phosphor coating around the outside of the tube.

Phosphors are substances that give off light -- or fluoresce -- when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons jumps to a higher energy level, causing the atom to vibrate and create heat. When the electron falls back to its normal level, it releases energy in the form of another photon. This photon has less energy than the original photon, because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum -- the phosphor gives off white light we can see.

Black lights work on this same principle. There are actually two different types of black light, but they work in basically the same way.

A tube black light is a basically a fluorescent lamp with a different sort of phosphor coating. This coating absorbs harmful shortwave UV-B and UV-C light and emits UV-A light (in the same basic way the phosphor in a fluorescent lamp absorbs UV light and emits visible light). The "black" glass tube itself blocks most visible light, so in the end only benign long-wave UV-A light, along with some blue and violet visible light, passes through.

An incandescent black light bulb is similar to a normal household light bulb, but it uses light filters to absorb the light from the heated filament. It absorbs everything except the infrared and UV-A light (and a little bit of visible light).

In both of these light designs, the emitted UV light reacts with various external phosphors in exactly the same way as the UV light inside a fluorescent lamp reacts with the phosphor coating. The external phosphors glow as long as the UV light is shining on them.

UV灯

傳統的UV燈設計是只螢光燈和幾個重要的修改。螢光燈通過傳遞通過充滿惰性氣體和汞量小管電力產生光。（見螢光燈的工作原理的詳細資訊）。當通電，汞原子會發出能量以光子的形式。他們發出一些可見光子，但大多是他們發射的紫外線 (UV) 波長範圍光子。因為紫外線光波是人眼不可見的螢光燈有將這種能量轉化為可見光。他們這樣做與外管周圍的螢光粉塗層。螢光粉的發光 — — 或螢光粉 — — 當他們受到光的物質。當一個光子擊中一個磷原子時，螢光粉的電子之一跳到更高的能量水準，導致原子振動並產生熱量。當電子下跌回到正常水準時，它釋放形式的另一個光子的能量。這個光子具有較少的能量比原始的光子，因為一些能量丟失作為熱。在螢光燈、 散發的光是在可見光譜--螢光粉散發出白色的光，我們可以看到。UV燈工作在這個相同的原則。其實兩種不同類型的黑色光，但它們的工作方式基本上相同。UV光是基本上一種不同的螢光粉塗層的螢光燈。這種塗層吸收有害的短波紫外線-B 和紫外 C 光和發射的紫外線 A 光 (在相同的基本方式在日光燈螢光粉吸收紫外線和發出可見光)。"黑色"玻璃管本身塊最可見光，所以最後只有良性長波紫外線 A 光，以及一些藍、 紫可見光，穿過。黑白熾燈燈泡是類似于一個普通的家用燈泡，但它使用的濾光鏡來吸收來自加熱燈絲的光。它吸收一切除了紅外線和紫外線 A 光 (和一點點的可見光)。在這兩這些輕型設計，散發的紫外線光反應與各種外部黃磷中完全相同的方式作為紫外光裡面日光燈螢光粉塗層與反應。外部螢光粉發光，只要 UV 燈照耀著他們。

How Bioluminescence Works 生物发光体

How bioluminescences work?                 

Animals that use their sense of sight to navigate generally have a hard time getting around without light. Some, like owls, have very large eyes that they use to collect lots of light. They also use their other senses to gather information about their surroundings. Humans, on the other hand, have put a lot of effort into creating portable, often artificial light sources, from torches to light bulbs and LEDs. Some bioluminescent life forms have an entirely different approach -- they make their own light and carry it around in their bodies.

Many animals use the light they produce the same way people use flashlights or searchlights. But an­imals produce light very differently from the way light bulbs do. Traditional light bulbs create light through incandescence. A filament inside the bulb gets very hot and emits light. This process isn't particularly efficient, since generating enough heat to create light wastes an enormous amount of energy.

Glowing animals, on the other hand, typically create light through luminescence. In luminescent animals, chemical compounds mix together to produce a glow. It's a lot like the way the substances inside a light stick combine to make light. Luminescence is far more efficient than incandescence. It neither requires nor generates much heat, so it's sometimes known as cold light.

Scientists had a basic idea of the difference between incandescence and luminescence as far back as 2,500 years ago. In the 1600s, researchers began to discover exactly how animals make their own light. But since different animals use different substances, scientists still don't know precisely how every bioluminescent species makes light. In some cases, researchers haven't figured out why an animal makes light or how it controls its on-off switch. Bioluminescence can also be difficult t­o study, since many animals exhaust their luminescent abilities when captured. In other cases, the process of capture destroys the light-producing organs.­

没有光，动物很难用它们的视觉导航感应去寻路。不过，像猫头鹰，有非常大的眼睛，用来收集大量的光。他们也使用他们的其他感官收集有关其周围环境的信息。人，另一方面，已投入了大量的努力创建便携式、 经常人工光源，从到灯泡和 Led 手电筒。一些生物发光的生命形式有完全不同的方法 — — 他们使他们自己的光和拿着它到处在他们的尸体。

许多动物使用他们生产的人使用手电筒或探照灯的同一方式的光。但动物产生光非常不同的灯泡做的方式。传统的灯泡创建通过白热光。灯丝灯泡里的变得非常热，发出光。这一过程不是能源的特别有效，因为生成足够的热量来创建光浪费了大量。

另一方面，发光的动物，通常需要创建光线通过发光。发光的动物，在化学化合物组合在一起以产生发光。它很像荧光棒内的物质结合，使光的方式。发光是比白热的有效得多。它既不需要也不会生成很大的热量，所以它有时被称为冷光源。

科学家们已经白热和发光早在 2500 年前的区别的基本思路。在 17 世纪初，研究人员开始发现确切的动物如何发出自己的光。但是由于不同的动物使用不同的物质，科学家仍然不知道正是每个发光的物种如何使得光线。在某些情况下，研究人员还没有想出一个动物为什么使得光线或它是如何控制其开关。生物发光的科学研究也很难去做，因为很多的捕捉情况下生物的发光能力会疲惫甚至失灵，又或者在捉捕的过程中或之后它们的发光器官被伤害到无法使用了。.

Bioluminescent Life Forms

You can find bioluminescent life forms all over planet Earth. On land, glowing species of fungus feed on rotting wood, creating the eerie nighttime phenomenon known as foxfire. In some types of fungus, the whole structure glows. In others, like the jack-o'-lantern mushroom, only part of the fungus -- in this case, the gills -- emits light.

There are also other bioluminescent land animals, including insects, centipedes, millipedes and worms. One of the most widely-known luminescent insects is the firefly. People who live near fireflies often think of them as brightly flashing adult insects, but firefly larva glow as well. Glow worms are also insects -- they're the larvae of various species of flies and beetles. Some people refer to fireflies as glow worms because some female fireflies are wingless and look more like worms than insects.

Most of the world's bioluminescence exists in the ocean, not on land. Bioluminescent life forms live throughout the ocean's depths, but most exist in one particular zone -- the twilight zone. This zone is also known as the despotic, or poorly lit, zone. It's deeper than the sunlit, or euphotic, zone, but shallower than the midnight, or aphotic zone. Its exact depth depends on a number of factors, including the composition of the water and the features of the ocean floor. But in general, the twilight zone extends from about 660 feet (201 meters) to about 3,300 feet (1006 meters) deep.

Only a small amount of light from the sun reaches this depth of the ocean. Seawater absorbs red, orange and yellow sunlight and scatters violet light, so the light that reaches the twilight zone is bluish-green in color. This is partly because blue-green light has a short wavelength, so it has more energy with which to penetrate the water. Check out How Light Works to learn more about the behavior of different wavelengths of light.

Lots of bioluminescent animals live at this depth, including jellyfish, squid, shrimp, krill, marine worms and fish. Most make light that has a wavelength of roughly 440 to 479 nanometers. This matches the blue-green sunlight that exists in this part of the ocean. The animals' glow can travel a long way, and it can blend in with the light from above. In some parts of the ocean, these animals, not the sun, are the primary source of light.

生物发光的生命形式

你可以找到生物发光的生命形成遍布地球的行星。在陆地上，泛着种木耳饲料腐烂的木头，营造阴森恐怖的夜间现象被称为火狐。在某些类型的真菌，整个结构呈。在其他国家，像鬼火蘑菇，只有部分的真菌-在这种情况下，鳃-发出的光。

还有其他的生物发光的陆生动物，包括昆虫，蜈蚣，千足虫和蠕虫。其中的最广泛的公知的发光昆虫的萤火虫。人们谁住在附近的萤火虫往往认为他们是明亮闪烁成虫，但萤火虫幼虫发光。萤火虫昆虫-它们是不同种类的蝇类和甲虫幼虫。有些人把一些雌性萤火虫，因为无翅，看起来更像是昆虫蠕虫比。

世界上大部分的生物发光在海洋中的存在，而不是在陆地上。住整个海洋深处生物发光的生命形式，但大多数存在于一个特定的区域- 暮色区。这个区域也被称为disphotic，或光线不足，区域。它比阳光明媚，或透光，区域更深，但比午夜或无光区较浅。其确切的深度取决于若干因素，包括组合物，水和功能的海底。但在一般情况下，暮色区域从约3300英尺（1006米），深约660英尺（201米）。

只有一小部分来自太阳的光量达到这个深度的海洋。海水吸收红色，橙色和黄色的阳光和散射紫外光，使光线到达暮色区域是蓝绿色的颜色。这部分是因为蓝绿色的光的短波长，因此它具有更多的能量与渗透水。检查光的原理更多地了解不同波长的光的行为。

许多生物发光动物生活在这个深度，包括海蜇，鱿鱼，虾，磷虾，海洋蠕虫和鱼类。大多数有大约440至479纳米波长的光。这相匹配的蓝绿色的阳光中存在的这部分海洋。动物焕发可行驶很长的路要走，它可以融合在一起，光线从上面。在一些地方的海洋，这些动物，而不是太阳，是光的主要来源。

Why Animals Make Light

Scientists don't know why all bioluminescent forms of life glow. For example, several earthworm species create a luminescent secretion that doesn't have an obvious purpose. The reason for some mushrooms' glow is also unclear, although some scientists theorize that it attracts insects that spread the mushrooms' spores. A few animals light up when nearby animals start to glow, and there's not always a clear reason for this behavior.

This uncertainty exists in the ocean as well as on land. Some species of single-celled plankton called din flagellates glow when disturbed. Tides, storms, swimming marine life and passing ships can cause large numbers of this plankton to produce light simultaneously. Din flagellates are responsible for the phenomenon known as the milky sea, which causes the ocean to glow. In some cases, this glow is so bright that it interferes with marine navigation.

The burglar-alarm theory is a possible explanation for how this response to disturbance helps the plankton survive. If a small fish begins to feed on the plankton, the disturbed plankton emits a flash of light. The light attracts larger fish, which are likely to be the smaller fish's predators. In other words, the flash of light is an alarm that warns nearby big animals of the presence of little animals. However, this system doesn't seem to be as foolproof as some of the better-understood uses for bioluminescence.

Here's a rundown of some of the primary uses for bioluminescence on land and at sea:

·         Communication: Fireflies flash at one another in a species-specific pattern, often in order to find a mate.

·         Locating food: In the twilight depths of the ocean, some fish species use their light like a spotlight to find prey.

·         Attracting prey: Some species, like the angler fish, use a luminescent lure to attract other fish.

·         Camouflage: In the darker parts of the ocean, it's hard to see anything below you, but it's easy to see the silhouette of what's above you. For this reason, some species produce spots of light on their undersides, which blur their outlines and allow them to blend in with the light from above. This is also known as counter-illumination.

·         Mimicry: The cookie-cutter shark has one unlit patch on its underside, which resembles a smaller fish when viewed from below. When a large predator approaches, the shark can take a large bite and then flee. This allows the cookie-cutter shark to prey on animals that are much larger and more powerful than it is.

·         Self-defense: When threatened, some animals release a cloud of bioluminescent fluid, similar to the way squid defend themselves with a cloud of ink. Others use a bright flash to blind predators.

 

 

为什么动物要发光？

科学家不知道为什么所有的生物发光形式的生命的光芒。例如，一些蚯蚓建立一个发光分泌的，不具有明显的目的。一些蘑菇发光的原因目前还不清楚，但也有一些科学家推断它吸引昆虫传播的蘑菇的孢子。几个动物亮起时，附近的动物开始发光，并有明确的原因，这种行为并不总是。

这种不确定性存在于海洋以及陆地上。有些种类的单细胞浮游生物称为腰鞭毛虫发光时的忐忑。潮汐，风暴，游泳，海洋生物和过往船只可能会导致这些浮游生物的大量产生光的同时。腰鞭毛虫是负责的现象被称为乳白色的海，这会导致海洋发光。在某些情况下，这种发光是如此明亮，它会干扰与海洋航行。

防盗报警理论对干扰的响应如何帮助浮游生物的生存是一个可能的解释。如果一个小的鱼开始不安的浮游生物为食的浮游生物，发出一道闪光。光吸引更大的鱼，这是可能是较小的鱼的天敌。换句话说，闪光灯的强光报警，警告附近的大型动物的存在，各种小动物。然而，这个系统似乎并没有一些更好的理解使用生物发光万无一失。

这里有一个破败的一些陆地上和海上生物发光的主要用途：

·         通讯： 萤火虫闪存在一个特定物种的模式，往往是为了找到一个伴侣。

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·         定位的食物：在黄昏的海洋深处，某些鱼类使用他们的光像聚光灯一样寻找猎物。

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·         吸引猎物：有些品种，像琵琶鱼，使用发光诱惑吸引其他鱼类。

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·         伪装：在暗部的海洋，这是很难下面你什么都看不到，但可以很容易地看到什么是你上面的轮廓。出于这个原因，一些物种在其底面产生的光点，模糊的轮廓，并让他们融合在一起，光线从上面。这也被称为反照明。

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·         模仿：千篇一律的鲨鱼在它的下面有一个熄灭补丁，它类似于一个较小的鱼时，从下面看。当的大型捕食者方法，鲨鱼可以采取一个大咬，然后逃离。这允许千篇一律的更大，更强大，比它是动物，鲨鱼的猎物。

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·         自我 - 防御：受到威胁时，一些动物释放云生物发光液，类似于鱿鱼捍卫自己的云墨水的方式。其他使用了明亮的闪光盲大鳄。

How Animals Make Light

In general, bioluminescence involves the combination of two types of substances in a light-producing reaction. One is aluciferin, or a light-producing substance. The other is aluciferase, or an enzyme that catalyzes the reaction. In some cases, the luciferin is a protein known as a photoprotein, and the light-making process requires a charged ion to activate the reaction. Neurological, mechanical, chemical or as-yet-undiscovered triggers can start the reactions that create light.

Often, the process requires the presence of other substances, like oxygen or adenosine triphosphate (ATP). ATP is a molecule that stores and transports energy in most living organisms, including the human body. The luciferin-luciferase reaction can also create byproducts like oxyluciferin and water.

The terms luciferin and luciferase both come from a Latin term lucifer, which means "light-bringer." They are generic terms rather than the names of particular chemicals. Lots of different substances can act like luciferins and luciferases, depending on the species of the bioluminescent life form. For example, the luciferin coelenterazine is common in marine bioluminescence. Dinoflagellates that obtain food throughphotosynthesis use a luciferin that resembles chlorophyll. Their luminescence is brighter after very sunnydays. Some shrimp and fish appear to manufacture their luciferin from the food they eat.

动物如何使光

在一般情况下，生物光发光涉及两种类型的物质的组合中的产生反应。一个是虫荧光素，或产生光物质。另一种是荧光素酶或催化该反应的酶。在某些情况下，荧光素是已知的蛋白质作为发光蛋白，和光的决策过程需要一个带电离子激活反应。神经学，机械，化学或尚未发现的触发器就可以开始创建光反应。

通常情况下，该过程需要存在的其他物质，如氧或三磷酸腺苷（ATP）的， ATP是一种分子，存储和传输能量的生物体，包括人体。荧光素酶反应还可以创建氧合虫荧光素和水等副产品。

条款荧光素和荧光素酶都来自一个拉丁词，这意味着“光使者路西法。“它们是通用的术语，而不是特定的化学物质的名称。有很多不同的物质可以像荧光素和荧光素酶，根据物种的生物发光的生命形式。例如，荧光素腔肠素是常见的磷火。双鞭甲藻通过光合作用获取食物使用类似于叶绿素荧光素。其发光亮度后，非常阳光灿烂的日子。一些虾和鱼，他们吃的食物制造荧光素。

靠光合作用的甲藻物种 有类似叶绿素荧光素。

并不是所有的动物产生自己的光芒。依靠其发光和其他生命形式如何生活轻，可以帮助人类了解动物。

How light works

Light is at once both obvious and mysterious. We are bathed in yellow warmth every day and stave off the darkness with incandescent and fluorescent bulbs. But what exactly is light? We catch glimpses of its nature when a sunbeam angles through a dust-filled room, when a rainbow appears after a storm or when a drinking straw in a glass of water looks disjointed. These glimpses, however, only lead to more questions. Does light travel as a wave, a ray or a stream of particles? Is it a single color or many colors mixed together? Does it have a frequency like sound? And what are some of the common properties of light, such as absorption, reflection, refraction and diffraction?

You might think scientists know all the answers, but light continues to surprise them. Here's an example: We've always taken for granted that light travels fasterthan anything in the universe. Then, in 1999, researchers at Harvard University were able to slow a beam of light down to 38 miles an hour (61 kilometers per hour) by passing it through a state of matter known as a Bose-Einstein condensate. That's almost 18 million times slower than normal! No one would have thought such a feat possible just a few years ago, yet this is the capricious way of light. Just when you think you have it figured out, it defies your efforts and seems to change its nature.

Still, we've come a long way in our understanding. Some of the brightest minds in the history of science have focused their powerful intellects on the subject. Albert Einstein tried to imagine what it would be like to ride on a beam of light. "What if one were to run after a ray of light?" he asked. "What if one were riding on the beam? … If one were to run fast enough, would it no longer move at all?"

Einstein, though, is getting ahead of the story. To appreciate how light works, we have to put it in its proper historical context. Our first stop is the ancient world, where some of the earliest scientists and philosophers pondered the true nature of this mysterious substance that stimulates sight and makes things visible.

光是一次明顯和神秘。我們沐浴在黃色溫暖每一天，並且避開黑暗與白熾燈和螢光燈燈泡。到底是什麼光？當陽光角度通過充滿灰塵的房間，當彩虹出現在一場暴風雨之後或在一杯水中的飲用吸管看起來相互脫節，我們抓到瞥見它的性質。然而，這些瞥見，只能導致更多的問題。光能波、 射線或粒子流作為旅行嗎？它是一種單一顏色或多種顏色混合在一起嗎？它有一個像聲音的頻率嗎？和的光，如吸收、 反射、 折射和衍射的共同屬性是什麼嗎？

您可能認為科學家們知道所有的答案，但光繼續給他們個驚喜。下面是一個例子： 我們一直在為理所當然光傳播老子有什麼在宇宙中。然後，在 1999 年，哈佛大學的研究人員們能夠通過傳遞它通過物質稱為玻色-愛因斯坦凝聚狀態慢一束光到 38 英里 （每小時 61 公里） 一小時。這是比正常慢近 18 萬倍!沒有人會想到這種壯舉可能只是幾年前，然而這是反復無常光明之路。只是當你認為你沒有想明白，它違背你的努力，似乎改變它的性質。

儘管如此，我們在我們的理解來很長的路。一些科學的歷史中最聰明的人有其強大的智力重點主題。阿爾伯特 · 愛因斯坦試圖想像會騎著一束光。"如果一個是運行後一束光嗎?"他問。"如果一個騎橫樑上嗎？…如果有人以足夠快的速度運行，將它不再移動在所有嗎?"

不過，在愛因斯坦，超越這個故事。我們要明白如何光亮工程，把它放在其適當的歷史背景。我們第一站就是物質的古代的世界，其中的一些最早的科學家和哲學家沉思這神秘，刺激的視線，使事情可見的真正性質。

What Is Light?

Over the centuries, our view of light has changed dramatically. The first real theories about light came from the ancient Greeks. Many of these theories sought to describe light as a ray -- a straight line moving from one point to another. Pythagoras, best known for the theorem of the right-angled triangle, proposed that vision resulted from light rays emerging from a person's eye and striking an object. Epicurus argued the opposite: Objects produce light rays, which then travel to the eye. Other Greek philosophers -- most notably Euclid and Ptolemy -- used ray diagrams quite successfully to show how light bounces off a smooth surface or bends as it passes from one transparent medium to another.

Arab scholars took these ideas and honed them even further, developing what is now known asgeometrical optics -- applying geometrical methods to the optics of lenses, mirrors and prisms. The most famous practitioner of geometrical optics was Ibn al-Haytham, who lived in present-day Iraq between A.D. 965 and 1039. Ibn al-Haytham identified the optical components of the human eye and correctly described vision as a process involving light rays bouncing from an object to a person's eye. The Arab scientist also invented the pinhole camera, discovered the laws of refraction and studied a number of light-based phenomena, such as rainbows and eclipses.

By the 17th century, some prominent European scientists began to think differently about light. One key figure was the Dutch mathematician-astronomer Christiaan Huygens. In 1690, Huygens published his "Treatise on Light," in which he described the undulatory theory. In this theory, he speculated on the existence of some invisible medium -- an ether -- filling all empty space between objects. He further speculated that light forms when a luminous body causes a series of waves or vibrations in this ether. Those waves then advance forward until they encounter an object. If that object is an eye, the waves stimulate vision.

This stood as one of the earliest, and most eloquent, wave theories of light. Not everyone embraced it. Isaac Newton was one of those people. In 1704, Newton proposed a different take -- one describing light as corpuscles, or particles. After all, light travels in straight lines and bounces off a mirror much like a ball bouncing off a wall. No one had actually seen particles of light, but even now, it's easy to explain why that might be. The particles could be too small, or moving too fast, to be seen, or perhaps our eyes see right through them.

光是什麼？

幾百年來，我們對光的看法發生了巨大的變化。關於光的第一次真正理論來自古希臘人。許多這些理論尋求光形容雷 — — 從一個地方移動到另一條直線。畢，最出名的是定理的直角三角形，提議視覺造成的光線擺脫一個人的眼睛和引人注目的物件。伊壁鳩魯持相反的觀點： 物體產生光線，然後旅行到眼睛。其他希臘哲學家 — — 最明顯的是歐幾裡得和托勒密 — — 用於雷圖相當成功地顯示如何輕彈回光滑的表面或彎曲，它從一個透明介質傳遞到另一個。

阿拉伯學者接受了這些想法和磨練他們更進一步，發展中國家現在稱為幾何光學 — — 將幾何方法應用到的光學鏡片、 鏡像和棱鏡。幾何光學最著名醫生是伊本 · 阿爾海森在當今伊拉克之間西元 965 和 1039年生活。· 伊本 · 阿爾-海森確定人眼的光學元件，並正確描述視覺作為一個過程，涉及彈跳從一個物件到一個人的眼睛的光線。阿拉伯科學家也發明了針孔攝像頭、 發現折射規律和研究了多種基於光的現象，如彩虹、 日食及月食。

到 17 世紀，一些著名的歐洲科學家開始以不同的方式思考光。荷蘭的數學家天文學家惠更斯克利斯蒂安是一個關鍵人物。在 1690 年，惠更斯出版他"論文上輕"，他所描述的波動理論。在這一理論，他推測的一些無形的介質 — — 醚 — — 填充所有空的空間物件之間存在性。他進一步推測那光形式時發光體在這醚導致一系列的波或振動。這些波然後向前推進，直到他們遇到一個物件。如果該物件是眼睛，海浪刺激視覺。

此站為一體的最早和最有口才，波浪理論的光。不是每個人都擁抱它。以撒 · 牛頓是那些人之一。在 1704 年牛頓建議不同 — — 一個描述光作為白血球、 或顆粒。畢竟，光直線傳播的和很像皮球從牆上反彈反彈一面鏡子。沒有人見過粒子的光，但即使是現在，很容易解釋為什麼會這樣。微粒可能太小，或移動太快，將被看見，或也許我們的眼睛看得透。