Complex natural phenomena can be anything from our bodily processes to interactions between the elements of nature. There is always a reason behind what we experience and a possible link to the science that we study. Some we may be familiar with; others may provide exciting applications to the different theories we have learnt. Read on to find out more about the various phenomena happening around us and the science behind them.
1. Lightning, thunder, electricity and sound
The most common natural phenomenon that we see and experience in Singapore would probably be the formation of lightning and thunder. As the temperature of the clouds drops below the freezing point, water vapour is converted into its solid state, forming ice. The ice molecules gain kinetic energy and start to vibrate inside the cloud, making them collide and rub against each other, producing charges that we would eventually see as lightning.
As for thunder, it comes later than lightning as lightning has to occur first for the sound of thunder to be produced. When lightning strikes the Earth, a column of air is opened, called a “channel”. Once the light is gone, the air channel then collapses back in on itself, creating a sound wave that we would recognise as thunder.
2. Rainbow formation and light
Rainbows are multicoloured arches that we occasionally see on rainy days. But why do we only catch a glimpse of them periodically? This is because rainbows are an optical phenomenon that only appear when specific sunlight and atmospheric conditions are met – and the viewer has to be in the correct position to see them.
When a downpour nears its end, and the sun reveals itself from the departing clouds, the sunlight shines on the water droplets floating in the air. As the light passes through the water droplets, it bends and splits the light, which is comprised of several wavelengths, into the seven distinct colours we see in a rainbow.
Sometimes, we might even see a double rainbow, which has a second arc with the colours of the rainbow reversed. The second arc is formed due to sunlight being reflected twice on the inside of the water droplets.
3. Sweating and thermodynamics
To understand why we sweat, we need to understand the first law of thermodynamics. Energy is neither created nor destroyed, and it can only be changed or transferred from one form to another. Since the energy level has to stay constant, it can only be converted from one form to another.
When our body heat rises above a certain level, our skin will start to produce sweat. The latent heat of vaporisation causes your sweat to evaporate, which transfer the heat into the atmosphere, allowing our body temperature to drop to acceptable levels. This is consistent with the first law of thermodynamics, as no heat is lost but merely transferred.
4. Giant permafrost explosions and pressure
Moving on to a rare phenomenon that occurred recently, let us explore the science behind the permafrost explosions sighted not too long ago in Siberia. Permafrost is a permanently frozen layer of soil and other particles held together by ice on or under Earth’s surface.
Frozen gases, such as methane, were trapped underneath this surface. When the methane was heated, turning it into a gaseous state, the pressure built up created a force large enough to collapse the ground, with blocks of ice and soil being thrown a measurable distance from the epicentre.
5. Waterspouts and Bernoulli’s principle
Moving closer to home, Singaporeans also experienced a natural phenomenon in the form of a giant waterspout not too long ago. The waterspout is a column of cloud-filled wind rotating over a body of water, and it is formed from the condensation in the clouds.
Bernoulli’s principle states that when there is an increase in the speed of a fluid, there would be a simultaneous decrease in static pressure or the fluid’s potential energy. This change stems from the fact that the sum of pressure energy, kinetic energy, and potential energy per unit mass must remain constant.
The high speed at which the fluid moves in a waterspout causes a decrease in pressure, forming the “eye” at the centre, similar to what is observed in a hurricane. At the most intense stage, the waterspout appears as a column of water with a hollow funnel and may be surrounded by vapour.
Reading about the various applications of physics principles helps us appreciate how science can impact our daily lives. These multiple theorems can appear to us not just on paper but also in nature.