Many subjects in the National Curriculum include the study of light and dark – the most obvious being science. However the topic can be effectively used as a foundation for literacy, numeracy, art, history and RE lessons. In RE specifically, the topic of light can effortlessly lead into an investigation into various Festivals of Light, such as Hanukkah and Diwali.

Ways of thinking about light

From the time of the ancient Greeks, people have thought of light as a stream of tiny particles. After all, light travels in straight lines and bounces off a mirror much like a ball bouncing off a wall.

The idea of the light wave came from Christian Huygens, who proposed in the late 1600s that light acted like a wave instead of a stream of particles. In 1807, Thomas Young backed up Huygens’ theory by showing that when light passes through a very narrow opening, it can spread out and interfere with light passing through another opening. Young shone a light through a very narrow slit. What he saw was a bright bar of light that corresponded to the slit. But that was not all he saw. Young also perceived additional light, not as bright, in the areas around the bar. If light were a stream of particles, this additional light would not have been there. This experiment suggested that light spread out like a wave. In fact, a beam of light radiates outward at all times.

Albert Einstein advanced the theory of light further in 1905. Einstein considered the photoelectric effect, in which ultraviolet light hits a surface and causes electrons to be emitted from the surface. Einstein’s explanation for this was that light was made up of a stream of energy packets called photons. Modern physicists believe that light can behave as both a particle and a wave, but they also recognise that either view is a simple explanation for something more complex.

What is light?

To understand light waves, it helps to start by discussing a more familiar kind of wave – the one we see in the water. One key point to keep in mind about the water wave is that it is not made up of water. The wave is made up of energy travelling through the water. If a wave moves across a pool from left to right, this does not mean that the water on the left side of the pool is moving to the right side of the pool. The water has actually stayed roughly where it was. It is the wave that has moved. All waves are travelling energy, and they are usually moving through some medium, such as water. Light waves are a little more complicated, and they do not need a medium to travel through. They can travel through a vacuum. A light wave consists of energy in the form of electric and magnetic fields.

Natural Light

Light from the Sun brings energy to Earth – energy that can be absorbed by plants for photosynthesis, by the oceans to evaporate water and cause rain, by photocells and solar panels to create electricity and so on. When light enters the human eye and falls on the retina, it sets off photochemical and neurological processes that result in seeing. Radio waves, television transmissions, microwaves, ultraviolet light, X-rays are all forms of electromagnetic waves just like light, but with a different wavelength. The human eye cannot perceive these wavelengths, but instruments can pick them up.

History of Electric Lighting

In October 2004, the 125^th anniversary of the incandescent lamps was celebrated. It was first patented in 1880 and became the foundation for a new industry. Most children will know what electric lights are, and being able to just flick a switch and turn a light on is now something we take for granted. The history of electric light begins with Thomas Edison. His greatest contribution to the problem of electric light was in filament design. He tried over 6000 alternative filament materials over two years, and after testing substances from around the world, Edison found platinum to be effective.

However, it was expensive and provided only limited efficiency as a practical filament. Finally Edison tried carbonized cotton sewing thread. On Sunday evening, 19^th October 1879, Edison and his assistants powered up his cotton filament and took turns watching it around the clock. More than 40 hours later it was still glowing and Edison knew that he had the problem solved. The invention of the electric light bulb was announced in the New York Herald on 21^st December 1879. Light bulbs went on sale in 1880 and while the first full-scale introduction of the Edison lighting system was made in London at Holburn Viaduct in early 1882, the era of general electric illumination via a centralised municipal power source began on 4^th September 1882, at the Pearl Street Station, New York City.

Hanukkah

Hanukkah is often included when teaching light as a topic. It is more usual for this to be done in Key Stage1. Hanukkah, which means ‘dedication’ and is also referred to as ‘The Festival of Lights’, is a Jewish festival which begins on the Hebrew date of the 25^th of Kislev and lasts eight days, through to the 2^nd of Tevet.

Hanukkah commemorates the victory of the Maccabees (led by Judah) over the Hellenistic Syrians in a revolt that took place around 165 BC. The victory in itself was considered a miracle, but Jewish legend gives an additional explanation for Hanukkah rituals. Once the Temple Mount in Jerusalem had been reclaimed, the Temple had to be rededicated. According to legend, only one jar of sacramental oil was found, enough for one day. Miraculously, the oil burned for eight days, thus the eight days of Hanukkah.

The most important Hanukkah ritual is the candle lighting. Jews light candles in a special candleholder called a ‘menorah’ or a ‘hanakkiah’. Each night, one more candle is added. The middle candle, called the ‘shamash’, is used to light each of the other candles and it is lit every night. Therefore, on the first night of Hanukkah, two candles are lit (the shamash and the candle for the first night) and on the last night there are nine lit candles.

Diwali

Looking at the celebration of Diwali is a common introduction to Hindu beliefs and practices at Key Stage 2. Telling the story of Rama and Sita is a useful starting point to help pupils understand why lights are an important focal point in all Diwali celebrations. The festival of Diwali has existed from time immemorial, ever since man became aware of truth and untruth, darkness and light, death and immortality. Diwali (or alternatively Deepawali, Deepavali or Divali) is the Festival of Light. Hindus celebrate it all over the world.

The true meaning of Diwali can be expressed as being to bring light where darkness prevails, truth where untruth prevails, to bring life where death prevails, to brighten our surroundings, to illuminate our minds. Deepavali in Sanskrit means ‘row of lighted lamps’ and is one of the most important Hindu festivals. It falls on the Amavasya of the month of Kartik every year in the Hindu calendar. By the English or Western calendar this festival generally occurs over a period that covers the last week of October to the first half of the month of November.

The festival signifies the triumph of light over darkness, good over evil, justice over injustice and intelligence over ignorance. The goddess worshipped at Diwali is Mother Lakshmi or Lakshmi Mata. Lakshmi Mata is the goddess of light, wealth and beauty and is also associated with prosperity, luck, riches, abundance, financial well being and generosity. In statues and artwork Lakshmi Mata is portrayed wearing gold and lotus flowers either sitting on a lotus, standing on one, wearing lotus blossoms in her hair and on her gown, or holding a lotus blossom which to many Hindus symbolises fertility, spiritual power and purity.

At Diwali it is not surprising to see elaborate preparations being made to welcome the goddess into the homes of devotees. Though it is titled as being a festival, it is one with a difference, since at the heart of the festival is a very significant religious observance as Lakshmi Mata is honoured and worshipped in the form of pujas, singing bhajans and with the chanting of mantras.

Did you know?

A rainbow is an arch formed by light refracted by drops of water diffused in the air. You can see it when you have the sun behind your back and you look at the rain. In the brightest or primary bow, often the only one seen, the colours are arranged with the red outside. Above the perfect bow is a secondary bow, in which the colours are arranged in reverse order; this bow is dimmer, because of a double reflection within the drops. When the sunlight enters a raindrop it is refracted, or bent, and reflected from the drop in such a way that the light appears as a spectrum of colours. The colours can be seen, however, only when the angle of reflection between the Sun, the drop of water and the observer’s line of vision is between 40 and 42 degrees.

Download the Light and Dark Project Plans:

Light and Dark Literacy Project Plans:

• Literacy Project 1: Light Stories (Key Stages 1 and 2)
• Literacy Project 2: Rainbow Rhymes (Key Stage 1)
• Literacy Project 3: The Vocabulary of Light (Key Stage 2)

Light and Dark Numeracy Project Plans:

• Numeracy Project 1: Count the Lights (Key Stage 1)
• Numeracy Project 2: Speeding Light (Key Stage 2+)

Light and Dark Science Project Plans:

• Science Project 1: Sources of Light (Key Stages 1 and 2)
• Science Project 2: Why Can’t We See in the Dark? (Key Stage 2)
• Science Project 3: Coloured Shadows (Key Stages 1 and 2)
• Science Project 4: Photosynthesis (Key Stages 1 and 2)
• Science Project 5: Through the Pinhole… (Key Stage 2)

Light and Dark History Project Plan:

• History Project 1: The History of Light (Key Stage 2)

Light and Dark Art and Design Project Plans:

• Art and Design Project 1: Drawing Shadows (Key Stages 1 and 2)
• Art and Design Project 2: Kaleidoscopes (Key Stage 2)

Light and Dark Religious Education (RE) Project Plans:

• RE Project 1: Hanukkah (Key Stages 1 and 2)
• RE Project 2: Diwali (Key Stages 1 and 2)