Bernoulli’s Principle – Agnes Christina

Long time ago, when I was in Junior College, me and a group of friends rented bicycles to cycle around a beach park. At one point of time, my bicycle was moving side by side with my friend’s bicycle. We were in a fast but manageable speed, chatting with each other. Everything was great, until we noticed that our bicycles are moving closer and closer towards each other. We crashed onto each other, we all fell down and my elbow was gushing blood like there was no tomorrow.

Weeks after that incident, I kept thinking, why did the crash happen?

As a triple-science student that hated physics, I automatically associated the incident with Bernoulli’s Principle. Bernoulli’s Principle is simple: an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy. In short, the faster a fluid moves, the smaller its pressure. And fluid here means air, gases and water. How to make a fluid moves faster? We can manipulate the fluid to go through a tiny, constricted area. When we have managed to achieve the high speed, we could easily benefit from the pressure difference between the fluid and the surrounding.

Have you seen videos of two speeding cars, side-by-side, that end up crashing sideways against each other?

That is one famous example of a Bernoulli’s Principle in action. I assume, this is a similar case with my bicycle crash. The gap between the two bicycles acted as a constricted area, causing the air flow in that constricted area to move faster, thus creating a low-pressure zone compared to the other sides of the bicycles. Hence, the pressure from the other sides of the bicycles pushes us to the low-pressure zone between our bicycles, making us moving closer towards each other and eventually crashing into each other.

11 years ago, a theatre friend called me “anti-collectivism”, because as a theatre practitioner, I do not have nor belong to any theatre group.

I could not even manage a bicycle in a beach park, how would you expect me to maneuver in a group of theatre practitioners? In a tight-knit theatre group, we all move together in beautiful synchronicity, and as we get closer and closer, we know, we are all bound to crash into each other, leaving all of us scarred and bloody.

I am not scared of blood, but I am wary of responsibility.

I ponder on partnership all the time. Just like the implication of Bernoulli’s Principle, a partnership could be destructive, but it could also be beneficial.

You see, Bernoulli’s principle does not only exist in two vehicles crashing, but it is the theorem, in which a plane could fly.

The curved shape of an airplane wing causes air to movefaster. over the top than the bottom. This creates lower pressure above the wing. Since the pressure below the wing is
higher than above the wing, the wing is lifted up.

However, in the case of a flying plane, one of the involved parties should lay low and be a higher-pressure zone on the ground. I figure, this is not the partnership that I want. I hate
being the stepping stone for other people’s career, therefore, there is no way I am going to do the same to others.

I hate being a liability more than facing responsibility.

The most beautiful application of Bernoulli’s Principle, to me, is the perfume bottle. Squeezing the bulb of a spray bottle forces air through a narrow tube, increasing its speed. This creates a low-pressure area that pulls liquid up from the container, where it is then atomized into a spray. Everyone could then enjoy the delightful scent of the perfume.

The concept of a perfume bottle seems nice. But in reality, the one who benefits the most is the perfume liquid. The finger pressing the spray bottle and the air being forced through the narrow tube in the spray bottle are the unsung heroes that catapult the perfume liquid out of the bottle. What everyone remembers is the scent of the perfume. I would love to be the perfume liquid, enjoying the freedom out in the air, but I do not have the heart to enslave the finger to squeeze the spray bottle, and to manipulate the air in the narrow tube to unknowingly pull me up from the bottle.

One thing that I don’t want to be in this life, is to be indebted.

The slyest application of Bernoulli’s principle is slipstreaming, or drafting in car racing.

In the immediate behind a speeding racing car, there is a turbulent region of fluid flow, where the fluid pressure is lower than the surrounding. When a racing car tails another car in front of it, it enters this low pressure zone, thus enabling this tailing car to accelerate with minimal additional power. And when the time is ripe, this tailing car could easily and efficiently overtake the car in front.

Imagine being the leading car.
You have spent so much effort to move forward, only to be exploited as a tool for social climbing by the tailing car.

I am not the best person in socializing. I am really bad in making small talks. Creating projects and hiring freelancers is my trusted method of gaining a new friend. To me, business is the simplest, yet foolproof form of human-to human connection. I need something from you, and you get a form of payment in return. Clean-cut. If I find working with you unsatisfactory, I do not have any obligation to keep in touch with you.

Of course, I am very self-centered. I need to be selfish, as I need to protect myself. The less people I make connectionwith, the less negative implication I would face.

But life is unsterile, and Bernoulli’s Principle can only be applicable in a controlled laboratorial condition. I bumped into an academic journal that debunks the validity of
this principle.

For this principle to be applicable, it assumes that the fluid in its system has constant speed, zero viscosity, no friction within its system, and no external forces introduced to the system. Moreover, how do you create “constricted pipe” to manipulate the flow of fluid in real life? Life is not a pipe.

I was shaken, out of relief, and out of fear.

I am relieved that a partnership does not always go like Bernoulli’s Principle. The vehicles will not crash sideways and the tailing racing car would not overstep its boundaries. But all the things that I assume out of a partnership are rendered inapplicable by one academic journal. The plane could not fly now, and the perfume scent would stay undiscovered in the
bottle.

What should I do? I have been gripping tightly onto a foolish assumption all along.

I searched deeper. I need to redeem myself from this failed principle. How to make this principle work?

And I found Coandă Effect.

Coandă Effect is an observed real-life phenomenon that when a jet of fluid is passed over a curved surface, it bends to follow the surface. So, fluid does have the possibility to be
manipulated and the “constricted pipe” could possibly be constructed as well in real life.

With the existence of Coandă Effect, Bernoulli’s Principle could actually be applicable in real life.

I, indeed, was a fool to hold onto Bernoulli’s principle as a model for partnership. Life is not a laboratory, and partnership does not make us human; it is relationship that does.

I have been looking at myself and all the people around me through the wrong angle.

Coandă Effect explains why Bernoulli’s Principle could be applicable in real life, while Bernoulli’s principle is the physical manifestation of Coandă Effect.

And indeed…. The people around us explains the what, who, when, where and why we are.

And in turn, we are the physical manifestation of the people around us.

With a renewed angle of viewing myself and others, I found myself reviewing my own partnership, or, relationship in life. Is it a natural relationship with no obligations, no rules, and no expectation?

Through “Brides should not sew their own wedding dresses”, I might have found the value of a life companion.

To all the people that I have co-existed in this life with, thank you for being the Coandă Effect to my Bernoulli’s Principle, and I hope to do the same to you.

— Agnes Christina