During lightning and thundering, why is the lightning seen first and then the thunder heard? Explain.

When we observe the awe-inspiring dance of lightning across the sky, we are witnessing the incredible pace at which light travels. The speed of light is a fundamental constant of nature and clocks in at approximately 300,000 kilometers per second in a vacuum. That's fast enough to circle the Earth nearly 7.5 times in just one second!

Light's stupendous velocity means that as soon as a lightning strike occurs, the discharge illuminates the sky almost instantaneously to the human eye – no matter where you are within sight of the storm. Although the speed of light is slightly slower in air, due to the presence of particles, it's still so fast that the differences are negligible at the distances we perceive lightning.

Following the flash of lightning, the rumble of thunder trails behind, taking a more leisurely pace. The speed of sound, unlike light, is not a universal constant and is affected by the medium through which it moves. At a comfortable temperature of 20 degrees Celsius, sound waves travel through air at about 343 meters per second - a mere snail's pace compared to the speed of light.

Why does sound take its time? Essentially, sound is created by vibrations that physically bump into air molecules, requiring a material medium to travel through. As a result, when thunder roars, it travels to us via a series of molecular collisions, which takes considerably more time than the journey of light photons.

Static electricity is the culprit behind the mesmerizing light show during a storm. It's the build-up of electrical charge on an object, which can occur through friction or the separation of charge in storm clouds. In a thunderstorm, water droplets and ice crystals inside a cloud collide and rub together, causing an electrostatic charge to accumulate.

The cloud becomes polarized, with a positive charge typically at the top and a negative charge at the bottom. This charge separation sets the stage for a dramatic release of energy: if the electrical tension becomes too great, it's discharged in the form of lightning – a spectacular and powerful natural phenomenon.

The spreading out of the thunderous sound after a lightning strike is due to what's termed sound propagation. Sound propagation refers to how sound waves travel from the source through a medium. In a thunderstorm, the energy from the lightning heats the air suddenly and violently, causing it to rapidly expand and send shock waves through the surrounding air. These waves are what we hear as thunder.

The sound of thunder can be deeply affected by the environment. Mountains, buildings, and even temperature variations can cause reflections and refraction of the sound waves, which may alter both the volume and the quality of the thunderclap heard by a listener on the ground.