Light and Colour: Understanding the 573 nm Wavelength | 光与颜色：理解573纳米波长

📚 Light and Colour: Understanding the 573 nm Wavelength | 光与颜色：理解573纳米波长

Light is a form of electromagnetic radiation that our eyes can detect. Different wavelengths of visible light are perceived as different colours. The number 573 represents a wavelength of 573 nanometres (nm), which lies in the yellow-green region of the visible spectrum. In this article, we will explore the science of light, how wavelengths determine colour, and how objects appear coloured.

光是一种我们眼睛可以检测到的电磁辐射。不同波长的可见光被感知为不同的颜色。数字573表示573纳米（nm）的波长，它位于可见光谱的黄绿区域。在本文中，我们将探讨光的科学、波长如何决定颜色，以及物体如何呈现颜色。

1. What is Light? | 什么是光？

Light is a transverse wave consisting of oscillating electric and magnetic fields. It travels at a speed of approximately 3 × 10⁸ metres per second in a vacuum. Light can be described both as a wave and as a stream of particles called photons.

光是一种由振荡的电场和磁场组成的横波。它在真空中以约3 × 10⁸米每秒的速度传播。光既可以描述为波，也可以描述为由称为光子的粒子组成的流。

In physics, the wave model is useful for explaining phenomena like interference and diffraction. The particle model helps explain the photoelectric effect and emission spectra. For IGCSE Science, you need to know the basic wave properties of light: wavelength, frequency, and speed.

在物理学中，波动模型有助于解释干涉和衍射等现象。粒子模型有助于解释光电效应和发射光谱。对于IGCSE科学，你需要了解光的基本波动性质：波长、频率和速度。

v = f × λ

The wave equation relates wave speed (v), frequency (f), and wavelength (λ). Since light speed is constant in a vacuum, a higher frequency corresponds to a shorter wavelength, and vice versa.

波方程将波速（v）、频率（f）和波长（λ）联系起来。由于光在真空中的速度是恒定的，因此频率越高，波长越短，反之亦然。

2. The Electromagnetic Spectrum | 电磁波谱

Light is only a small part of the electromagnetic spectrum, which includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. These are arranged in order of increasing frequency and decreasing wavelength.

光只是电磁波谱的一小部分，电磁波谱包括无线电波、微波、红外线、可见光、紫外线、X射线和伽马射线。它们按照频率递增、波长递减的顺序排列。

Visible light ranges from about 400 nm (violet) to 700 nm (red). Within this range, each wavelength corresponds to a specific colour. The human eye is only sensitive to this narrow band of electromagnetic radiation.

可见光的范围大约从400纳米（紫色）到700纳米（红色）。在此范围内，每个波长对应一种特定的颜色。人眼只对这种窄带电磁辐射敏感。

Colour	Approximate wavelength (nm)
Violet	400 – 450
Blue	450 – 490
Green	490 – 560
Yellow	560 – 590
Orange	590 – 630
Red	630 – 700

Light of wavelength 573 nm falls between green and yellow, so it is often described as yellow-green or chartreuse. This wavelength is close to the peak sensitivity of the human eye, which is why the eye is most sensitive to green-yellow light in bright conditions.

波长为573纳米的光落在绿色和黄色之间，因此通常被描述为黄绿色或chartreuse。该波长接近人眼的峰值灵敏度，这就是为什么在明亮条件下人眼对黄绿光最敏感。

3. Visible Spectrum and Wavelengths | 可见光谱与波长

The visible spectrum is a continuous band of colours produced when white light is dispersed by a prism. Each colour emerges at a different angle because different wavelengths are refracted by different amounts.

当白光通过棱镜发生色散时，会产生连续的彩色光带。每种颜色以不同角度射出，因为不同波长的光折射程度不同。

Red light has the longest wavelength and is refracted the least; violet light has the shortest wavelength and is refracted the most.

红光波长最长，折射最小；紫光波长最短，折射最大。

In IGCSE questions, you may be asked to identify colours from given wavelengths. For example, a wavelength of 500 nm is blue-green, 600 nm is orange-red, and 573 nm is yellow-green.

在IGCSE考试中，你可能会被问到根据给定波长识别颜色。例如，500纳米是蓝绿色，600纳米是橙红色，573纳米是黄绿色。

4. The Case of 573 nm | 以573纳米为例

Why is 573 nm special? This wavelength corresponds to the transition of sodium atoms in some laser systems, and it also lies near the peak of the human eye’s photopic (bright-light) sensitivity curve. In bright light, the cone cells of the retina are most sensitive to green-yellow light around 550–570 nm.

为什么573纳米特殊？该波长对应于某些激光系统中钠原子的跃迁，并且它也接近人眼明视觉（亮光）灵敏度曲线的峰值。在明亮光线下，视网膜的视锥细胞对大约550–570纳米周围的黄绿光最敏感。

For a pure 573 nm source, the perceived colour is a bright, vivid yellow-green. This property is used in laser pointers that are classified as “green” laser pointers, although their exact wavelength may be 532 nm or 573 nm depending on the type.

对于纯573纳米光源，感知到的颜色是明亮、生动的黄绿色。此特性被用于激光指示器，这些指示器被归类为“绿色”激光笔，尽管它们的实际波长可能是532纳米或573纳米，具体取决于类型。

5. How Eyes Perceive Colour | 人眼如何感知颜色

The human retina contains two types of photoreceptor cells: rods and cones. Rods are sensitive to low light levels and do not detect colour. Cones require brighter light and are responsible for colour vision.

人类视网膜包含两种类型的感光细胞：视杆细胞和视锥细胞。视杆细胞对弱光敏感，不检测颜色。视锥细胞需要更明亮的光线，负责色觉。

There are three types of cone cells, each sensitive to different ranges of wavelengths:

有三种类型的视锥细胞，每种对不同波长范围敏感：

S-cones are most sensitive to short wavelengths (blue-violet).
M-cones are most sensitive to medium wavelengths (green).
L-cones are most sensitive to long wavelengths (red-orange).

S视锥细胞对短波长（蓝紫色）最敏感。

M视锥细胞对中波长（绿色）最敏感。

L视锥细胞对长波长（红橙色）最敏感。

When light of 573 nm enters the eye, it stimulates the M-cones strongly and the L-cones moderately, while the S-cones are hardly stimulated. The brain interprets this combination as “yellow-green”.

当573纳米的光进入眼睛时，它会强烈刺激M视锥细胞，中度刺激L视锥细胞，而S视锥细胞几乎不受到刺激。大脑将此组合解释为“黄绿色”。

6. Reflection and Absorption | 反射与吸收

An object appears a certain colour because of the way it reflects and absorbs light. A red apple looks red because it absorbs most visible wavelengths (including blue and green) and reflects the red wavelengths to our eyes.

物体呈现某种颜色是因为它反射和吸收光的方式。红苹果看起来是红色的，因为它吸收了大多数可见波长（包括蓝光和绿光），并将红色波长反射到我们的眼睛。

If a surface reflects all visible wavelengths equally, it appears white. If it absorbs almost all wavelengths, it appears black. A surface that reflects only 573 nm light would appear yellow-green to a viewer.

如果表面对所有可见波长等量反射，则它呈现白色。如果它吸收几乎所有波长，则呈现黑色。一个只反射573纳米光的表面，观察者会看到黄绿色。

Incident light → absorption (except reflected colour) → reflected light enters eye

This principle explains how filters work in photography and how pigments are mixed in paints. Colour is not a property of the object itself; it depends on the wavelengths that reach our eyes.

该原理解释了摄影中滤光片的工作原理以及油漆中颜料的混合方式。颜色不是物体本身的属性；它取决于到达我们眼睛的波长。

7. Mixing Colours | 颜色混合

There are two main colour models: additive and subtractive. IGCSE Physics often asks about additive mixing of coloured light.

有两种主要的颜色模型：加法混色和减法混色。IGCSE物理常考彩色光的加法混合。

In additive mixing, the primary colours of light are red, green, and blue. When red and green light are mixed, the result is yellow. When red and blue are mixed, magenta is produced. Blue plus green gives cyan. Mixing all three primary colours produces white light.

在加法混合中，光的原色是红、绿、蓝。当红光和绿光混合时，结果是黄色。当红光和蓝光混合时，产生品红色。蓝加绿得到青色。混合所有三种原色产生白光。

Notice that yellow light around 573 nm can also be created by mixing red and green lights. However, the perceived colour of a single 573 nm light and a mixture of red+green may look similar to a human, even though their spectral compositions are different. This is why displays use only red, green, and blue pixels to create many colours.

请注意，大约573纳米的黄光也可以通过混合红光和绿光来产生。然而，纯573纳米光的感知颜色与红+绿混合光的颜色，对于人眼来说可能看起来相似，尽管它们的光谱组成不同。这就是为什么显示器只使用红、绿、蓝像素来创建多种颜色的原因。

8. Applications of Colour | 颜色的应用

Understanding wavelengths and colour is important in many real-world applications:

理解波长和颜色在许多实际应用中非常重要：

Traffic lights use red, yellow, and green because these colours are distinctive and easily visible. The yellow light used is often close to 570–590 nm.
Lasers used in ophthalmology, barcode scanners, and laser pointers often operate at specific wavelengths such as 532 nm, 573 nm, or 650 nm.
Optical fibres transmit data using infrared or visible light; selecting the right wavelength minimises signal loss.

交通信号灯使用红、黄、绿，因为这些颜色具有区分度且易于看见。使用的黄光通常接近570–590纳米。

激光用于眼科、条形码扫描仪和激光笔，通常工作在特定波长，如532纳米、573纳米或650纳米。

光纤使用红外光或可见光传输数据；选择合适的波长可以最小化信号损失。

In astronomy, analysing the exact wavelengths emitted or absorbed by stars and planets tells us about their chemical composition and motion using the Doppler effect.

在天文学中，分析恒星和行星发射或吸收的确切波长，可以告诉我们它们的化学成分以及通过多普勒效应得知其运动。

9. Key Formulae and Units | 关键公式与单位

You should remember the relationship between wavelength, frequency, and speed:

你应该记住波长、频率和速度之间的关系：

c = f × λ

where c is the speed of light (3 × 10⁸ m/s), f is frequency in hertz (Hz), and λ is wavelength in metres (m). To convert nanometres to metres, divide by 1 × 10⁹.

其中c是光速（3 × 10⁸ m/s），f是频率（赫兹Hz），λ是波长（米m）。要将纳米转换为米，除以1 × 10⁹。

For 573 nm:

对于573纳米：

λ = 573 nm = 5.73 × 10⁻⁷ m

f = c / λ = (3 × 10⁸) / (5.73 × 10⁻⁷) ≈ 5.24 × 10¹⁴ Hz

This frequency is in the visible range, corresponding to yellow-green light.

该频率在可见光范围内，对应黄绿色光。

10. Summary | 总结

Light of wavelength 573 nm is a beautiful example of how physics explains colour. It lies in the yellow-green part of the visible spectrum, a region to which our eyes are highly sensitive. The wavelength of light determines its colour, and the interaction of light with materials determines what colours we see.

波长为573纳米的光是一个美丽的例子，说明物理如何解释颜色。它位于可见光谱的黄绿色部分，我们的眼睛对该区域高度敏感。光的波长决定其颜色，光与物质的相互作用决定了我们看到的颜色。

For IGCSE Edexcel Science, make sure you can use the wave equation c = f × λ, describe the arrangement of the electromagnetic spectrum, and explain how coloured objects appear the way they do.

对于IGCSE Edexcel科学，请确保你能使用波动方程c = f × λ，描述电磁波谱的排列，并解释彩色物体为何呈现它们的样子。

Published by TutorHao | Science Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）

Light and Colour: Understanding the 573 nm Wavelength | 光与颜色：理解573纳米波长