I’ve always been fascinated by thunderstorms. Can someone explain why we see lightning before we hear thunder, and what exactly causes both of these phenomena?
In: Physics
Light travels at around 300 000 000 m/s and sound at around 340m/s.
340m/s is close to 3 seconds per kilometer so the sound from lightning 2km away takes close to 6 seconds to reach you.
The time it takes light to travel the same distance is extremely low, we talk about 1/100 of a millionth of a second so we can call it zero.
So you see lightning before you hear thunder because light travels a lot faster than sound.
Thunder is the result of the lightning heating up the air it travels to. If you heat air its pressure increases and it will expand and create a pressure wave that travels outward, sound is a pressure wave. It is fundamentally the same as any explosion, they create high-pressure gases too that expand and create the sound.
Lightning is static electricity between the ground and clouds. It is just like if you rub against something and then get a small static electrical discharge, the voltage and amount of energy is just a lot higher
Latest Answers