光的屬性Light properties

光是由不同波長和頻率的電磁射線組成的。 這些射線在伽馬射線區域的波長小至 10-11 m，在光譜的無線電波區域具有米長的波長。 電磁輻射的可見光波長從藍光的 400 x 10-9 m 到紅光的 700 x 10-9 m 不等。

Light is made up of electromagnetic rays of different wavelengths and frequencies. These rays are with wavelengths as small as 10-11 m in the gamma-ray region to meter-long wavelengths in the radio wave region of the spectrum. The visible light of electromagnetic radiation is wavelengths varying from 400 x 10-9 m for blue light to 700 x 10-9 m for red light.

【圖一】

光的一些特性包括波長和頻率。 頻率（通常以赫茲為單位）是特定時間內的波數。 波長（通常以納米為單位）是波中兩點之間的距離。 頻率和波長既有直接的關係，也有相反的關係。 例如，如果兩個波以相同的速度傳播，它們是反向相關的。 波長較短的波具有較高的頻率，而較長波長的波具有較低的頻率。 如下圖所示：

Some properties of light include wavelength and frequency. Frequency (typically measured in Hertz) is the number of waves in a specific time. Wavelength (typically measured in nanometers) is the distance between two points in a wave. Frequency and wavelength have both direct and inverse relationships. For instance, if two waves are traveling at the same speed, they are inversely related. The wave with shorter wavelength will have a higher frequency while a longer wavelength will have a lower frequency. This is represented in the picture below: 

【圖二】Resources: https://sites.google.com/a/coe.edu/principles-of-structural-chemistry/relationship-between-light-and-matter/light-properties

頻率和波長可以通過光速聯繫起來。 光以每秒 3.00 x 108 米的速度移動。 光速、頻率和波長都可以用方程式表示。 λν=c f 求解 c，光速。 v 代表頻率，λ 代表波長。 如前所述，這是一種反比關係，因為當其中一個值上升時，另一個值下降。 使用這個基本方程，您還可以求解波長和頻率以獲得它們的方程。

Frequency and wavelength can be related through the speed of light. Light moves with the speed of 3.00 x 108 meters per second. Speed of light, frequency, and wavelength can all be expressed in an equation. λν=c f is solved for c, speed of light. v represents frequency and λ represents wavelength. As mentioned previously, this is an inverse relationship because as one of the values goes up, the other value goes down. With this basic equation, you can also solve for wavelength and frequency to get their equations as well. 

正如波長和頻率與光有關，它們也與能量有關。 波長越短，頻率越高，對應的能量就越大。 因此，波長越長，頻率越低，能量就越低。 能量方程為 E = hν。

E代表能量，

h 代表普朗克常數 (6.626 x 10-34 J·s)，並且

v 代表頻率。

Just as wavelength and frequency are related to light, they are also related to energy. The shorter the wavelengths and higher the frequency corresponds with greater energy. So the longer the wavelengths and lower the frequency results in lower energy. The energy equation is E = hν.

E represents energy,

h represents Planck's constant (6.626 x 10-34 J · s), and

v represents frequency.

能量方程是頻率和能量之間的直接關係，因為隨著頻率的增加，能量也會增加。 這是可能的，因為 h 是一個常數。

The energy equation is a direct relationship between frequency and energy because as frequency increases, so does energy. This is possible because h is a constant. 

1.          光的三原色Light Color Primaries (RGB)—加法原則系統additive color system

紅色、綠色和藍色是光的原色——它們可以以不同的比例組合成所有其他顏色。 例如，紅光和綠光加在一起被視為黃光。 原色 RGB 以 100% 的亮度組合，產生白色。 這種加色系統意味著顏色是通過光波產生的，這些光波以特定的組合形式相加產生顏色，並且它被光源（如電視和計算機顯示器）用來產生各種顏色。 當不同比例的紅、綠、藍光進入你的眼睛時，你的大腦可以將不同的組合解釋為不同的顏色。

Red, green, and blue are the primary colors of light—they can be combined in different proportions to make all other colors. For example, red light and green light added together are seen as yellow light. The primary colors RGB, combined at 100-percent brilliance, produce white. This additive color system means that colors are created through light waves that are added together in particular combinations to produce colors, and it is used by light sources, such as televisions and computer monitors, to create a wide range of colors. When different proportions of red, green, and blue light enter your eye, your brain can interpret the different combinations as different colors.

【圖三】

1.          顏料三原色Pigment Color Primaries (CMY, CMYK)—

減法原則系統subtractive color system

青色、洋紅色和黃色是顏料的原色——顏色被介質吸收和反射。 有時黑色 (K) 也被認為是一種主要顏料，儘管黑色可以通過等量大量混合純青色、品紅色和黃色來獲得。 減色模型是指通過吸收可見光的波長來產生顏色，並將其應用於繪畫和印刷。 未被吸收的光波長被反射，反射光最終成為我們看到的顏色。Cyan, magenta, and yellow are the primary colors of pigment—the color is absorbed by and reflected off of media. Sometimes black (K) is also considered a primary pigment, although black can be obtained by combining pure cyan, magenta, and yellow in equal and large amounts. The subtractive model means that colors are created through absorbing wavelengths of visible light, and it is applied to painting and printing. The wavelengths of light that don’t get absorbed are reflected, and that reflected light ends up being the color we see.

【圖四】

{Resource for learning light color primaries (RGB) and pigment color primaries (CMY/CMYK): https://javalab.org/en/three_primary_colors_en/}

吸收一種顏色的光，比如紅色，會導致物體直接感知到綠色——綠色。 但是，並非每種材料都是彩色的，有些材料是黑色的。 教師可以評論說，材料不吸收可見光，或者其吸收發生在可見光範圍之外的材料看起來是無色的。 並且材料吸收所有波長的可見光呈現黑色。

Absorption of one color of light, say, red, results in a perceived color of the object directly across– green. However, not every material is colored, and some materials are black. The instructor can remark that materials absorb no visible light or whose absorptions occur outside of the visible range appear colorless. and that materials absorb all wavelengths of visible light appear black. 

 1.  第一個實驗，我們使用小熊軟糖。 來自綠色雷射光的光被紅色糖果吸收但被綠色糖果透射。 類似地，來自紅色雷射光的光被紅色糖果傳輸並被綠色糖果吸收。 學生可以測量完全吸收雷射光所需的每種顏色的糖果數量。 這個實驗生動地強調了物體顏色與被吸收和透射的光的特定波長之間的關係

For the first experiment, we use gummy bears. The light from the green laser is absorbed by the red candy but transmitted by the green candy. Similarly, light from a red laser is transmitted by red candy and absorbed by the green candy. Students can measure how many candies of each color it takes to absorb the laser light completely. This experiment vividly underscores the relationship between the color of objects and the particular wavelengths of light that are absorbed and transmitted

2.      第二個實驗，學生需下載並使用適用於 iPhone 或 Android 的應用程序 RGB 顏色檢測器來測量紅/綠/藍 (RGB) 對小熊軟糖顏色的貢獻。 用手機拍攝照片，程序將其分解為顏色樣本。 用戶選擇最具特徵的樣本進行分析，並報告該樣本的 RGB 貢獻（透射光）。 學生通過將每個小熊軟糖樣本的 RGB 除以背景的 RGB 來報告每個小熊軟糖的標準化 RGB 內容。

For the second experiment, students need to download and use an application for the iPhone or Android, RGB Color Detector, to measure the Red/Green/Blue (RGB) contributions to the color of the gummy bears. A photo is taken with the cellphone, and the program breaks it down into color swatches. The user selects the most characteristic swatch for analysis and the RGB contribution (transmitted light) for that swatch is reported. Students report the normalized RGB content for each of the gummy bear by dividing the RGB for each gummy bear swatch by the RGB of the background.

3.      第三個實驗，一些橄欖油可能含有葉綠素，比不含葉綠素的橄欖油看起來更綠。雖然葉綠素不會增加油的風味特徵，但它與來自較年輕橄欖的油相關。這些油通常含有更多的抗氧化劑並具有更綠色的橄欖味。螢光可用於識別某些材料的存在。葉綠素在電磁波譜的藍光波段吸收最強，其次是紅光波段，但對綠光和相鄰波段的吸收很差，所以含有葉綠素的組織呈現綠色。葉綠素也會發出紅色螢光。綠色激光筆提供足夠的能量來很好地激發葉綠素。大多數綠色食用染料不是螢光的。可以將食用色素添加到廉價油中，使其看起來好像是綠色橄欖油。通過將綠色激光筆穿過橄欖油，可以很容易地檢測到這種欺騙行為。即使是綠油，如果不發螢光，也不含葉綠素。

For the third experiment, some olive oils may contain chlorophyll and appear greener than those that do not contain chlorophyll. While chlorophyll does not add to the flavor profile of the oil, it is correlated with the oil being from a younger olive. These oils often contain more antioxidants and have a greener olive flavor. Fluorescence can be used to identify the presence of certain materials. Chlorophyll has the strongest absorption in the blue light band of the electromagnetic spectrum, followed by the red light band, but the absorption of green light and adjacent bands is very poor, so the tissues containing chlorophyll appear green. Chlorophyll also fluoresces red. A green laser pointer provides enough energy to excite the chlorophyll nicely. Most green food dyes are not fluorescent. Food color could be added to an inexpensive oil to make it appear as though it was a green olive oil. This deception can easily be detected by shining a green laser pointer through the olive oil. Even if it is green oil, if it does not fluoresce, it does not contain chlorophyll.

葉綠素的螢光Fluorescence in Chlorophyll

螢光可用於識別某些材料的存在。 對於完整食品分析，螢光技術靈敏度高，實施起來相對便宜，並且易於使用。葉綠素是綠色植物捕獲陽光能量的主要生物分子之一，它是一種螢光分子。 它很容易從植物中提取出來，在黑暗的房間裡，用紫外線燈照射葉綠素和水的溶液，就可以觀察到它的鮮紅色螢光。 其他例子是螢光水母、螢火蟲、貼紙、螢光棒、螢光燈、白熾燈和煙花等。

Fluorescence can be used to identify the presence of certain materials. For intact food analysis, the fluorescence techniques have high sensitivity, are relatively cheap to implement, and are easy to use.

Chlorophyll, one of the principal biological molecules responsible for capturing the energy of sunlight by green plants, is a fluorescent molecule. It is easily extracted from plants, and its bright red fluorescence can be observed in a darkened room by shining an ultraviolet lamp on a solution of chlorophyll and water. The other examples are fluorescent jellyfish, fireflies, stickers, light sticks, fluorescent and incandescent lights, fireworks, etc.

【圖五】Resources: O’Hara et al. 2005

吸收光後會發生什麼事呢？ What can happen after the absorption of light?

(A) 向上箭頭 (i) 表示激發光。 向下箭頭表示當電子從狀態 S1 移動到 S0 時原子發射的光，稱為直接螢光或共振螢光 (ii)。

(B) 向上箭頭表示用越來越短的波長（更高能量）的光子激發。 分子中的光發射可以作為簡單的共振螢光 (ii) 發生，或者，一些激發能量可以通過 S1 中的振動能級 ν1、ν2、ν3、ν4 之間的內部轉換 (iii) 損失，然後作為螢光發射 紅移 (iv)。

(A) Up arrow (i) indicates excitation light. The down arrow represents the emission of light from atoms that occurs when an electron moves from state S1 to S0 and is called direct or resonant fluorescence (ii).

(B) Up arrows indicate excitation with photons of increasingly short wavelengths (higher energy). Emission of light in molecules can occur as simple resonant fluorescence (ii), or alternatively, some of the excited energy can be lost through internal conversion (iii) between vibronic levelsν1, ν2, ν3, ν4 in S1 and then emitted as fluorescent light which is red-shifted (iv).

【圖六】Resources: Blatchly et al. 2014

用綠色 (532 nm) 和紅色 (650 nm) 雷射光指示器從底部照射相同的水和橄欖油樣品，使綠色雷射光指示器從油中的葉綠素發出紅色螢光。 紅色雷射光能量低於綠色雷射光，因此沒有足夠的能量達到葉綠素的激發能級。

The same sample of water and olive oil is illuminated from the bottom with a green (532 nm) and a red (650 nm) laser pointer, causing red fluorescence from the chlorophyll in the oil for the green laser pointers. The red laser energy is lower than the green laser, so it doesn’t have enough energy to reach the excitation level of the chlorophyll.

器材

雷射筆（綠色、紅色）、手機（iPhone或Android）、手電筒、背景紙（白色）、

彩色小熊軟糖、橄欖油樣品、放橄欖油的樣品瓶（樣品瓶直徑2.5厘米，高6厘米，最大容量15毫升）

Laser pointer (green, red), Cellphone (iPhone or Android), flashlight, Background paper (white),

Colorful gummy bear, Olive oil samples, sample bottle to put the olive oil (sample bottle diameter 2.5 cm, height 6 cm, and the maximum volume 15 mL) 

實驗安全事項

1.  請勿將激光對著他人的眼睛。 只需將激光指向您觀察到的物體。

Do not point the laser light at other people’s eyes. Just point out the laser to the object you observe.

2.  使用護目鏡保護您的眼睛免受激光束的傷害。

Use the goggles to protect your eyes from the laser beam.

實驗廢棄物處理

請勿食用小熊軟糖樣品。 實驗結束後將小熊軟糖以廚餘方式處理或是裝入夾鏈袋中，提供下次實驗驗繼續使用。

Do not eat your gummy bear sample. Throw the gummy bears into the food waste after the experiment 

教學心得

該實驗對學生來說很容易做，也可以在他們的日常生活中使用。 對於教師，在螢光概念之前教授光和顏色概念。 本實驗中物理、生物和化學的性質可以促進學生對跨學科科學學科的學習。

The experiment is easy to do by the student and also can use in their daily life application. For teachers,  teach about the light and color concepts before the fluorescence concept. The nature of physics, biology, and chemistry inside this experiment can promote the student's learning of an interdisciplinary science subject.

1.  Al Riza, D. F., Kondo, N., Rotich, V. K., Perone, C., & Giametta, F. (2021). Cultivar and geographical origin authentication of Italian extra virgin olive oil using front-face fluorescence spectroscopy and chemometrics. Food Control, 121, 107604.

2.  Blatchly, R. A., Delen, Z., & O’Hara, P. B. (2014). Making sense of olive oil: Simple experiments to connect sensory observations with the underlying chemistry. Journal of chemical education, 91(10), 1623-1630.

3.  Moyano, M. J., Heredia, F. J., & Meléndez‐Martínez, A. J. (2010). The color of olive oils: the pigments and their likely health benefits and visual and instrumental methods of analysis. Comprehensive Reviews in Food Science and Food Safety, 9(3), 278-291.

4.  O'Hara, P. B., St. Peter, W., & Engelson, C. (2005). Turning on the light: Lessons from luminescence. Journal of chemical education, 82(1), 49.

5.  YouTube video: Edmund Scientific

https://www.youtube.com/watch?v=VwNKPgo3oxA&t=12s

6.  usability.gov Color Basics

https://www.usability.gov/how-to-and-tools/methods/color-basics.html

7.  PRIMARY COLORS OF LIGHT AND PIGMENT

https://learn.leighcotnoir.com/artspeak/elements-color/primary-colors/

8.  Light properties

https://sites.google.com/a/coe.edu/principles-of-structural-chemistry/relationship-between-light-and-matter/light-properties 

壹、準備活動

★教師準備：

1、  準備器材及材料

2、  準備學習單

3、  學生動線安排及分組

4、  告知學生實驗的安全守則

5、  確保學生實驗之安全

6、  本實驗的科學原理

7、  (10分鐘)前置作業：事先完成步驟1-1至1-2、2-1、3-1至3-5

★學生準備：

1、   遵守實驗安全守則，注意實驗安全

2、   發揮團隊合作的精神

3、   由做中學，瞭解本實驗的科學原理

貳、闖關之前

一、闖關負責關主及學生就位。關主負責解說指導，副關主負責指導與通過與不通過判定。

二、集合參加同學，以小組隊伍排列。

三、說明關卡配置與發下小組闖關卡。

四、安全宣導，請學生注意安全，不可以在場地內奔跑。

五、請學生注意禮貌，進入關關卡和離開關卡都要跟關主問好。

参、進入關卡

1、 (0.5分鐘) 學生向關主問好，教師說明規則及建立默契。

2、 (1.5分鐘) 關主介紹活動內容、實驗方式及安全事項(使用ppt或海報)

3、  (5分鐘)關主事先完成準備材料 ，協助學生由步驟 1-3至1-10、2-2至2-6、3-5至3-10。

4、  (1分鐘)關主指導學生填寫實驗記錄單。

5、  (1分鐘)學生完成實驗後，關主請學生分享結果。

6、  (1分鐘)關主說明實驗反應機制及總結。

7、  關主掌握時間，隨時指導與提醒闖關學生。

伍、闖關結束

1、  收回闖關集點卡。

2、  學生心得分享(包括成功與失敗的原因) 與關卡的相關科學原理。

3、  關主視通關人數給予評分。

4、  關主在闖關卡上簽名或蓋通過章。

5、  學生心得分享(包括成功與失敗的原因) 與關卡的相關科學原理。

6、  鼓勵學生設計更多的不同型態的潛望鏡。