My Essay (Part III) - Galileo to Newton

Newton's Principia, with his actual pen-strokes on correction.

Galileo not just only discovered there are other moons on other planet. He also proposed that all things move due to acceleration of gravity. This was demonstrated by Galileo, as rumour has it, was done at the top of the Pisa tower when he dropped two balls, one ball made of iron and the other made of wood. The result is that both balls of the same size dropped at the same time landed on the floor together at the same time suggest that different weight does not affect the speed of the balls. Another experiment was he put a ball on an incline plane and let it roll from the top to the bottom and he found that the ball is moving faster and faster. We call it accelerating. So the question is what drives the ball to accelerate?

The legacy of Galileo was indeed profound and it made an impact as how science is done. As quoted from physicist Leon Lederman’s book: The God Particle

“For our purposes, he (Galileo) was a physicist, and a great one, far beyond his advocacy of Copernicanism. He broke new grounds in many fields. He blended experiments and mathematic thinking. When an object moves, he said it’s important to quantify its motion with mathematical equation. He always asked “how do things move? How? How?” But he didn’t ask “Why? Why is the ball falling?” He was aware that he was just describing motion, a difficult enough task for his time.”

Galileo didn’t mention that why the ball is falling, and that needed another great mind to solve the puzzle. Enter Isaac Newton. Sir Isaac Newton is perhaps one of the greatest minds of all time. He revolutionised the way we see how objects move and he literally created a new branch of mathematics for it. In 1687, Newton published the celebrated “Philosophiae Naturalis Principia Mathematica” which is perhaps the single most important work ever published in physical sciences.

In the seminal masterpiece, Newton described how everything in this universe worked – Force. In the papers were three immutable laws that describe all motions in the universe. Suddenly, the universe became a measureable, definite clockwork. The first law was the concept of inertia, which is a fancy word that simply means: an object does not move or moves in a constant velocity until an external force acts on it. This is particularly useful in your life when you tried to get your ketchup conveniently by hitting at the bottom end of the bottle repeatedly, the sudden force acting on the bottle propel the sauce out from its bottle. The second law is quite simply F = MA. It’s a simple mathematical relation. Let’s read it out loud; “Eff equals to Emm Ayy”. What that means was the force is equal to the product of the mass and the acceleration of the object. The third law is better. It says that when a force is exerted on an object, the object exerts the same force back on the opposite direction. (Every action there’s a reaction). So next time if someone bitch-slapped you, don’t bother. Because your face already slapped that person’s hand on that painful moment! (You felt pain more due to the more pain receptors on the surface of your cheek than the slapping palm)

Quantum Quotes

The quantum mechanics solution, that is, "Don't worry!" We can't measure it, is logical enough, but not satisfying to most human minds, which strive to understand the details of the world around us. For some tortured souls, the quantum unknowable-ability (Heisenberg's uncertainty principle) is still too high a price to pay.

Our Defense: This is the only theory we know now that works. Ugly but it works.



- adapted and edited from "The God Particle" 1993 L. Lederman

How elegant is our Universe?

Negative from the 1919 Eddington's experiment proving gravity does indeed bend light rays.

As Einstein’s general relativity is finally proven experimentally by Sir Eddington’s expedition in 1919, the good news spread like wild fire. A student asked Einstein what if Eddington’s experiment has not found the prediction of his theory (the bending of starlight due to a massive body). Einstein replied:

“Then I would have been sorry for the dear Lord, for the theory IS correct.”

Of course, if the theory was disproven by the experiment, his theory of relativity will not become a pillar for modern physics as we know it.

What Einstein meant was general relativity describes gravity with such a deep inner elegance, with such simple yet powerful ideas, that he finds it hard to imagine that nature can just pass it by. General relativity, in Einstein’s view, was almost too beautiful to be wrong.


In physics, as in art, symmetry is a key part of aesthetics. Physicists describe the two properties of physical laws – that they do not depend on when and where you use them – as symmetries of nature. For example, the physics laws applies on the surface on the earth, applies exactly the same on the moon, on mars, on the edge of the galaxy and so on. By this usage physicist means that nature treats every moment in time and location in all of space identically – symmetrically – by ensuring that the same fundamental laws are in operation. Much in the same way that symmetries affect art and music, such symmetries are deeply satisfying; they highlight an order and coherence in the workings of nature.


The elegance of rich, complex, and diverse phenomena emerging from a simple set of universal laws is at least part of what physicist mean when they invoke the term “beautiful”.


-Adapted and edited from The Elegant Universe by Brian Greene.

Shattering Elegance

Who Ordered That? (On the discovery of Muon particles)

-Isidor Isaac Rabi

About Extraterrestial Intelligence

Either we are alone in the universe, or we are not.
Either thought is frightening.

-Arthur C. Clarke