12 Uses of Light in Our life| Its Importance and significance

Light is a valuable resource present in nature.

It is one of the most interesting things which has been surprising the scientists for long.

Even Albert Einstein was fascinated by the light so much. This lead him to propose E=MC², and also study the photon and wave nature of light.

But many of us are not aware of it due to lack of direct knowledge about its use.

Of all the sources of light, sun light is the most common so, we will discuss the uses of light in life from all the sources.

Uses of Light in Our life:

The significance of light is seen in

1. Food: Photosynthesis is a concept in biology wherein food is synthesized by use of light. Light is the sole source of food generation for all living organisms on the earth. Except for a few chemotrophic bacteria almost all living beings depend on light for their food and energy.

Plants and other autotrophs synthesize their own food materials by use of light. The light converts to reserve energy in the form of food by a process known a photosynthesis. Here the light energy is used to synthesize carbohydrates. The autotrophs like plants use carbon-dioxide and water {CO2 +H2O= C6H12O6} to form carbohydrates in the presence of sunlight.

From these plants animals get the required food materials and the required energy for living.

These carbohydrates convert back into carbon dioxide and water releasing the energy from within after digestion in body.

So plants depend on sunlight for their own food and animals depend on plants. Thus all the living beings are dependent on light for food.

This phenomenon is present both on the earth and also the marine environments.

Energy for bio-molecules synthesis: After food (carbohydrates) is consumed, it broken down into energy. This energy is in the form of ATP (adenosine triphosphate).

This ATP is to build up the body proteins and maintenance of physiology. The cell and nucleus mechanism use this energy to from m-RNA.

This m-RNA in the presence ATP again translates into hormones, enzymes, proteins and fats required for the body. Thus the light energy conserved as food is used up to build and maintain the body.

2. For Vitamin D synthesis: Vitamin-D is a type of vitamin which does need to supplied from external source. This is because it can be synthesized from ergosterol and cholesterol by irradiation with sunlight. When the light fall on the skin, the ergosterol below the skin converts to vitamin-D. So if some one stays away from sunlight for long, he tends to develop vitamin-D deficiency.

3. Vision: All animals, birds are able to see the objects around them due to presence of eyes. But without light these eyes might be absolutely of no us . Because of light, the eyes can receive the image of the objects and send the information to the brain. From this visual information we comprehend the objects. Hence we can notice that in darkness we could see nothing. So light makes us able to see objects around.

4. Colors: This whole world looks beautiful due to colors. But in darkness we see no colors. This is because all the colors in this world are possible only due to light. The light has many spectra. Each spectra has a color and these are broadly referred as VIBGYOR. In full form it is








All these color have different wavelengths and frequency. And when light falls on an object, it absorbs some spectra and reflects others making it look colorful. So it is the ability of the object to absorb some spectra of light and reflect others make it look colorful.

5. Maintenance of temperature: Light is a form of energy. And sunlight has huge energy by which the temperature on the earth is maintained such that life exists on the earth.

If you think why? just imaging those areas of earth without proper light in the whole year. Those areas are very cold and even heavy snowfall occurs. If the sunlight is absent, the temperature of the earth can drop drastically such that the whole water on the earth frozen. If this happens, the animals especially homeotherms die instantly due to low temperatures. Even the poikilothermic animals may find it difficult to survive. So light is essential to maintain temperature on the earth and thereby life.

6. Maintains Body clock or circadian rhythm : Every day light keeps plants and animals ticking with time.

Uses of light

photo credit:nipitphand

There is a clock inside both plants and animals which keep them active during day and relaxed at night. This clock is controlled by light.

Plants broaden their leaves during day time starting from sunrise till sunset. Even we can notice leaves and few flowers like sunflower which bent towards light through the day.

Also the plants grow in the direction of light as auxin a plant growth hormone is regulated by light.

Birds, insects and animals are also controlled by light. We can notice birds stop making noise at evening and start making noise early in the morning. This habit is controlled by light.

Provide vision for various movements for all animals.

7. Drying and evaporation: Sunlight helps in drying of soil, forests, air and rocky surfaces due to its ability to heat up. Also it helps water evaporate from oceans and water ponds. This drying is helpful in two ways to life on earth like

a) Water cycle: The water cycle is a way by which fresh water on the earth surface is kept recycled for drinking and irrigation. The water from land evaporates to form clouds. These clouds again cause rainfall so as to return the fresh water to the earth surface. So due to rains there is fresh water to drink and also use for irrigation. Without water cycle, all the water on the earth would remain in the ocean so that no water is available to drink. Or, the water on the earth surface would be so filthy such that it is unfit for drinking. So sunlight contributes to water cycle and there by maintains rainfall and water for human use.

b) Scavenging: Sunlight helps in keeping the nature clean. Due to drying there is no growth of weeds, algae and other microbes keeping the environment clean and tidy. Even dead bodies and other waste material get dried and lose their mass and get degraded fast.

8. Sterilization: Light especially it ultra violet component is a good sterilizing agent. Haven’t you noticed in a super market or hospital the use of UV lamps. These UV lamps are good sterilizers. The UV rays kills the microbes in the air keeping the area sterile. So UV light is classified under dry method of sterilization.

Sunlight is an efficient sterilizing agent. When blankets and other hospital mattress are dried in sunlight, all the microbes get killed.

What is the importance of light

Image by:Pixomar

9. Solar energy: Sunlight helps to generate green energy or renewable energy.

Solar panels imbibe sun rays and convert it into electric energy which can be used for domestic needs.

Now we began to realize the importance of solar energy. It is one of the alternative energy or renewable energy which is safe to the environment. It generates no pollution and and harmful wastes. Other means of energy generation by use of coal and atomic energy is responsible for global warming.

So if we shift towards this form of energy we will be saving the environment.

10. Spectroscopy: Light is used for analysis of compounds by spectrophotometry. This spectroscopy can be used for both qualitative and quantitative analysis. There are many forms of spectroscopy which vary based on the spectra and wavelength of light used. Some of them include colorimetry, atomic absorption spectroscopy. This spectroscopy is further extended to be combined with other analytical techniques like chromatography.

11. Light and plant development: Plants grow towards sky as they are guided by light. The plant growth hormone namely Auxin is responsible for it. The hormone is present the apical parts (tips) of growing regions. based on the availability of light, it directs the growth. That is the plant grows towards light. So you can notice some plants taking different turns when they are in between the other plants to reach the sun light. But why plants need light? Because they need light to synthesize their own food.

12. Signal system: Light is the key visible signals. We use light as traffic signals, navigation signals etc.

Even our TV remote use infra red light rays to give signal to Television.

Thus light which appears to be simple phenomenon of universe has divers use to humans and life on earth.


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