Curiosity Corner: What is the colour of water?

It’s a question so simple, yet it piques the interest and curiosity the moment we put ourselves in a thinking posture and ask: What is the colour of water?? We learn from childhood textbooks and from observing around us that water actually has no colour. And yet, as we observe our surroundings in the form of oceans, rivers, and even swimming pools, we find water can be blue and green in colour. There’s actually a scientific basis for why water appears colourless and why it appears so colourful sometimes, and we shall examine why in this article.
Water is naturally colourless

Water in its pure form is actually colourless. This is the reason that a certain amount of water in a glass appears clear to our eyes. This is because the water in a glass is transparent enough to allow the passage of light. This occurs as a certain amount of water does not absorb the visible colours of light. This water will appear colourless to the eyes unless a certain amount of something is added to it.

Why large water bodies appear to be blue

Why do oceans and seas appear blue? This is due to the way in which water absorbs different colours from the sun. Sunlight, upon entering water, has colours such as red, orange, and yellow absorbed by water, but blue light travels a certain distance and is reflected back to our eyes. This is why open oceans appear to be deep blue.

Role of reflection of the sky

It is also believed that this is why water appears blue because it simply reflects the colour of the sky, which indeed is true, but is also a secondary reason. Just because calm surfaces reflect the colour of the sky in its true form, even on a cloudy day, it is clear that light absorption in water is an equally prominent reason.

Why some water may appear Green or Brown

Rivers, lakes, and ocean water can be seen as green or brown because of the particles present in the water, vegetation, and sediment. Algae and microscopic organisms reflect light in different ways, depending on how light interacts with what is in the water. Mud, sand, and pollutants in the water are other influences on colour.

Why swimming pools look blue

Swimming pools appear blue due to depth and the reflection of light in the water, as well as the tiles lining the pools. The blue colour in the water is always reflected to produce the bright blue appearance of the swimming pool water, despite the water being colourless.

Curiosity Corner: Why are leaves green in color

Have you ever wondered why so many plants in our surroundings have leaves which are green in colour? Whether it’s a large tree in a distant forest or a plant in our own gardens, green is the colour that rules. This isn't an accidental fact but a consequence of a very significant process which helps plants to live. The green colour of leaves holds a very critical position in understanding how plants generate their food and keep our planet alive. The green colour of leaves also unlocks a very fascinating chapter of science. photosynthesis.

Leaves look green because they have a pigment named chlorophyll. The chlorophyll exists in tiny bodies in plant cells called chloroplasts. The main function of the chlorophyll is to absorb sunlight, including red and blue light. Plants require sunlight in order to produce food. The green light is not absorbed; instead, it is reflected back. Plants cannot live without the help of chlorophyll because they cannot generate energy for existence.

Photosynthesis refers to the process by which plants synthesise their own food using sunlight, water, and carbon dioxide. In photosynthesis, sunlight is absorbed and converted to chemical energy by chlorophyll. It requires sunlight to convert water and carbon dioxide to glucose. Leaves are green due to the presence of chlorophyll because it functions by producing its own food at a higher rate if its leaves are green and full of chlorophyll.

Chlorophyll likely evolved to absorb green light due to the adaptive need for plants to thrive in the available lighting conditions on Earth. Even when green light prevails, it is most readily absorbed by chlorophyll through red and blue lights. By reflecting green light, green plants are not hampered in their food production. Even today, green has largely been established in plant life due to its evolved efficiency.

Leaves are not necessarily green. In autumn or when a plant is stressed, chlorophyll could degrade, showing yellow or red pigments. Natural red or purple leaves appear on some plants due to the presence of anthocyanin pigments. These pigments may safeguard leaves from strong sunlight or insects. A white or yellow leaf condition on a plant could indicate that a plant lacks nutritional elements or that a plant is not healthy.

Green leaves have numerous applications in nature besides being an integral part of plants themselves. In fact, plants have photosynthesis, where they yield oxygen essential for living organisms to breathe. Furthermore, they are at the bottom of the food chain and sustain animals and humans in turn. The presence of green in leaves indicates a vital process of giving life in nature. Indeed, the absence of green leaves would result in a breakdown of nature itself.

Why ice & snow are white

When the water turns into ice or snow, it appears white instead of clear. This is because the light scatters in many directions when it hits the air bubbles in the ice. Instead of passing through without any hindrance, the light is reflected in many directions, making the ice appear white. Nothing has changed with the water. Light is the only thing that has changed.
Can water ever have a colour?

Water, when colourless, can be regarded as tinted in some situations. Water with a high thickness will appear with a hint of blue because of the way it responds to light. In other cases, organic and mineral contents in water can make it appear with various colours, which in fact do not belong to water but to what it contains and reflects.

The simple answer to a curious question. Now, what is the colour of water?

Water is colourless. However, water may look blue, green, brown, or white.