Subtle physical phenomena that are often counterintuitive
As we go through our daily routine, not a second thought is given to the physical laws that are always at work in our world. Philosophers have often referred to these as ‘natural’ laws because they are embedded in the machinery of our universe.
When you take a closer look, some of these subtle forces are quite powerful. Yet, despite our fragility as humans, we have managed to adapt to them. Let us examine these fascinating physical laws that we don’t notice that much.
The Coriolis Effect is a powerful force of nature that affects the ocean’s currents, weather patterns, and even affects air travel. As much influence as the Coriolis Effect has on our daily lives, and not many people have even heard about this phenomenon.
Amazingly, this affects many things, like air currents and even planes, which have traveled long distances around the world. But they appear as though they have moved in a curve and not a straight line. The reason for this is the bizarre part of the explanation. It is because things at different locations of the Earth are moving at different speeds.
Let us illustrate this by looking at extremes. Consider a person standing on the equator for 24 hours. He or she has moved about 24,900 miles relative to an outside observer — although the person stood in one spot. Now consider a person standing about three feet from the North Pole. They will take the same 24 hours to move only six feet — relative to an observer.
A prime example of the Coriolis Effect is when naval ships fire their massive guns at sea. When they fire huge shells for several miles at their enemies, they have to factor in this effect to hit their targets.
The way our society measures temperature and the environment can be both complex and subjective. Our perception of outside temperatures can be influenced by factors like our mood, our physiology, and the humidity.
One metric that we often hear about from our local weather forecasts is the wind chill factor. The wind chill is not the actual temperature; rather, it is the temperature that it ‘feels like’ outside — based on the wind speed.
What makes the wind chill factor so weird is that it seems to defy logic at times. For instance, suppose the outside temperature is 38 F degrees, and there is an 8 mile per hour wind blowing. This equates to around a 32 F degree wind chill factor, yet none of the water puddles around you will freeze.
Also, the wind chill factor doesn’t apply at every temperature — only the cooler ones. There’s no such thing as a wind chill at 90 F degrees. Most official charts don’t apply to temperatures above 40–50 F degrees.
The concept of the wind chill factor was first introduced by two scientists in the 1940s. American scientists Paul Siple and Charles Passel were working in Antarctica and wanted to measure the effects of how wind causes objects to lose heat more quickly.
In the 1960s, the military put this concept to use in order to prepare their troops for missions in cold climates. Before long, it had caught on and was being used by weather services nationwide.
Objects in Earth’s Orbit are actually free-falling
Most people don’t think very much about the concept of objects in orbit — and why should they? It’s not something they see or even concerns them in most cases.
But in reality, all the satellites and debris that is orbiting our planet is free falling. This is a little hard to wrap your head around because it is so counterintuitive.
Let’s look at it this way. Isaac Newton taught us that an object in motion would stay in motion unless acted upon by another force. So if we remove the gravitational force of the Earth, the objects in Earth’s orbit would drift off into deep space.
Since the Earth has a gravitational force, objects in its orbit move circularly around the globe. As long as the speed of these orbital objects is fast enough to overcome Earth’s gravity, they remain in orbit. But when they stop or lose speed, they will begin falling toward Earth’s surface.
While in orbit, they are technically in free-fall, but their velocity is overcoming gravity.
Atmospheric air pressure
As residents of the planet Earth, we are living daily under the pressure of 1,000 kilograms of air, which about the weight of a small compact car⁴. This is because our atmosphere is quite heavy, and the volume of air above us is applying around 14.7 pounds per square inch (PSI) of pressure.
Incredibly, we humans have adapted to living under this pressure without being crushed because we absorb equal air pressures within our bodies. However, if an impermeable object like a plastic bottle were to be released at a high altitude, they would be crushed by the atmospheric pressure by the time it reached the ground.
While we might think of sound as an isolated phenomenon, we often miss the fact that sound waves are greatly affected by speed. An Austrian physicist named Christian Doppler was the first to identify that moving objects like sirens and train whistles create sound waves. As they all move, the sound waves actually accumulate in front of the object and then disperse behind them.
This wave disturbance is called the Doppler Effect. Every human alive can intuitively distinguish an approaching ambulance from one that is moving away — based on the sounds they hear. But very few understand the physics that is at work here.
When the ambulance approaches, the sound waves we hear have shorter wavelengths. And then, when the ambulance moves away from us, the wavelengths get longer.
Incidentally, the Doppler Effect can be applied to more than sound waves. We see it in action when a ship moves through the water as waves bunch up in front of the ship and then disperse in its wake. The Doppler Effect also applies to light waves. If we could travel at light speeds, we could observe color shifts from the Doppler Effect in light waves.
Whenever we change substances from one state to the next, we typically think of them moving from a solid to a liquid and then to a gas — or vice versa. Sublimation is where a substance skips a step and goes from a solid directly to a gas.
For example, water can transform directly into vapor from ice. Sublimation often causes glaciers to vanish into thin air as sunlight turns its ice into steam.
There are even metallic elements like arsenic that can go directly into a gaseous state when it’s heated. Generally speaking, in order to achieve sublimation, a solid substance must first be slightly below its melting point. From there, an increase of heat or a drop in pressure will allow it to transform directly into a gaseous state.
Heat accelerates freezing
We all know how water is the most vital liquid in the world. It also happens to be one of the more mysterious of nature’s compounds.
Perhaps one of the most mysterious properties of water is that it freezes quicker when using hot water instead of cold water. While this certainly defies logic, it is certainly a fact, and it’s called the Mpemba effect⁷.
Believe it or not, this unique property of water was discovered over 3,000 years ago by Aristotle. To this day, no one really understands why water does this.