physics is everywhere

we live in a world ruled by invisible laws of physics, even when we don’t notice them.

today, i want to talk about my favorite subject: physics. it’s one of those fields that quietly explains almost everything around us, from the color of the sky to why we feel dizzy after spinning in circles. i picked a few everyday phenomena that most of us have experienced but rarely stop to think about. i had to revisit some of these concepts myself while writing this, so think of this as learning together rather than pretending to be newton.

and one more thing: if you think physics is boring, i hope this article changes your mind.

why don’t we feel the earth spinning?

this has been one of my favorite questions since childhood. i still remember asking my teacher in sixth grade why we couldn’t feel the earth spinning. i understood part of the explanation back then, but it wasn’t until ninth grade, when another physics teacher explained it in depth, that i truly fell in love with the subject.

the earth rotates at nearly 1,600 km/h at the equator. despite moving that fast, we never notice it.

the reason is surprisingly simple. according to newton’s first law of motion, we feel changes in motion—acceleration—not constant, uniform motion. it’s the same reason you don’t notice movement inside a plane cruising smoothly at a constant speed, but you immediately feel the aircraft accelerate, brake, or turn.

everything around us—the atmosphere, the oceans, buildings, trees, and even our bodies—is moving together with the earth at the same speed. since there is no relative motion between us and our surroundings, it feels as though we’re standing perfectly still.

why is the sky blue?

white sunlight is actually made up of every color in the visible spectrum.

when sunlight enters earth’s atmosphere, it collides with tiny air molecules. shorter wavelengths, such as blue and violet, scatter much more efficiently than longer wavelengths like red. this phenomenon is called rayleigh scattering.

then why isn’t the sky violet?

there are two reasons:

• our eyes are much more sensitive to blue light than violet.
• a significant portion of violet light is absorbed in the upper atmosphere.

during sunrise and sunset, sunlight travels through a much thicker layer of atmosphere before reaching us. by then, most of the blue light has already scattered away, leaving behind the beautiful reds, oranges, and pinks we see every evening.

why don’t we sink through the floor?

here’s something that sounds almost unbelievable.

the atoms in your body never actually touch the atoms in the floor.

what prevents you from falling through is the electromagnetic force. the negatively charged electrons surrounding the atoms in your body strongly repel the electrons in the floor. that repulsion creates what we experience as solidity.

in other words, standing on the floor isn’t really about atoms physically touching one another—it’s about invisible electric fields pushing against each other at the quantum level.

why do we see lightning before thunder?

this is one of the easiest examples of physics in everyday life.

light travels at roughly 3 × 10⁸ m/s, while sound moves through air at only about 343 m/s.

because light is vastly faster than sound, the flash from a lightning strike reaches your eyes almost instantly, while the sound takes much longer to travel the same distance. that’s why you always see lightning before you hear thunder.

why does hot coffee cool down?

a freshly brewed cup of coffee never stays hot forever.

heat naturally flows from hotter objects to cooler surroundings until thermal equilibrium is reached. this behavior is described by the second law of thermodynamics.

the rate at which the coffee cools is explained by newton’s law of cooling: the greater the temperature difference between the coffee and the surrounding air, the faster the coffee loses heat.

entropy also plays an important role. energy naturally spreads out over time, making concentrated heat gradually disappear until everything reaches the same temperature.

why do we get dizzy after spinning?

this was another childhood mystery for me.

inside your inner ear are tiny semicircular canals filled with fluid. these structures act as your body’s motion sensors and help maintain balance.

when you spin, the fluid inside these canals begins moving as well. after you suddenly stop, the fluid keeps moving for a short time. your brain receives conflicting information: your eyes say you’ve stopped, while your inner ear still senses rotation.

that mismatch creates the familiar feeling of dizziness.

conclusion

physics isn’t just a collection of equations in a textbook. it’s the reason the sky is blue, why coffee cools down, why thunder arrives after lightning, and why you can stand on the ground without falling through it.

once you start noticing it, physics appears everywhere.

if you’re looking for inspiration, watch oppenheimer or interstellar. they’re fantastic reminders that physics can be both beautiful and deeply human. reading good physics books also helps build intuition beyond solving equations.

the next time you watch a sunset or feel the wind before a storm, remember that there’s physics behind every moment. once you begin seeing it, it’s hard to stop.