Some things never change

Invariance. Constancy. Immutability. As we exist in the here and now, as we travel through space and time, as our lives get linked with one another, and as our states get entangled, the fundamental rules governing the universe do no change regardless of when, where, and how you observe them. Events and circumstances follow them. They remain forever etched in our cosmos—constant, unchanging, immutable, invariant. Even as we evolve from commonplace to outlandish, from banal to profound, from naive to perceptive, from simple to complex, some experiences remain the same. Dropping your car keys in the streets of Vienna this year is the same event as dropping your car keys in the roads of Ho Chi Minh next year. A free fall experiment conducted in the University of the Philippines will yield the same result if conducted in Ateneo or in De La Salle University (assuming all local variables are controlled). Gravity worked the same way 13.7 billion years ago during the Big Bang as it does today in 2026 as I write this article. The north pole of a magnet attracts the south pole of another. A positively charged particle (like a proton) attracts a negatively charged particle (like an electron). Genuinely, opposites attract. And, despite entropy and the arrow of time, there are some things that never change in space and in time. The laws of science are invariant (even as entropy increases). This concept is a cornerstone of modern science.

Why do rules remain as a game progresses? Rules provide the fundamental structure and constraints that transform a collection of actions and events into a consistent, holistic, and enjoyable experience. Rules establish what is possible and what is not. Without rules, games would become confusing, unfair, and potentially dangerous. We enjoy classic board games like chess, Scrabble, and Monopoly because the rules allow for combining skills, strategy, and luck. We appreciate modern board games like Catan and Pandemic because the rules allow for creativity in building and evaluating options. Rules, too, exist because of entangled reasons: structure and identity, fairness and balance, safety and order, challenges and fun, agreement and understanding. So, why does invariance matter? The best answer is predictability. Because the universal laws are constant, scientists can use current observations to predict future events (like lunar and solar eclipses. rise and fall of tides, El Niño and La Niña events, disasters, and global climate change scenarios, etc.) and reconstruct the past (the Jurassic period, the Big Bang, etc.).

Another good answer is universality. Invariance allows us to apply what we have learned here on Earth (in our homes, in our labs, in our fields) to the entire world outside of us empowering domains like astrophysics and cosmology. That some things never change from the past to the present to the future implies the conservation of energy. A study desk lamp switched on does not produce 100 percent light from electricity. Feel the heat (energy) it produces as you put your hand nearer the lamp. Truly, energy can neither be created nor destroyed but can only be transformed from one form to another. That some things never change in space implies the conservation of momentum. As you rush to your next class carrying your heavy backpack and a stack of books, the inattentive student you bump will get thrown offtrack (just as you will be) by the momentum you transfer to him and from him during the inadvertent collision. That the laws are constant implies that some things remain untouched, unchanged, and are conserved.

And yet, amidst the constancy, invariance, and immutability of the laws of nature and the laws of the universe, disorder abounds, disorganization permeates, and entropy increases. The reason is mathematical: it’s the statistical number of states (i.e. of particles, of lives). One life’s evolution in space and in time represents something specific to that life. Even identical twins do not have the same set of traits, temperament, mental, emotional, social faculties as they traverse through life’s challenges, adventures, joys, and mishaps. Their lives get entangled with ours and others. They form entangled and involved lives specific to their needs, interests, wants, and whims. With roughly 1.6 million twins born annually worldwide, that’s a lot of contribution to the world’s disorder, and to the universal entropy. Thus, it is the sheer number of things (multiplicity) and their different states (conditions) that contribute to an ever-evolving disorganized world. Thanks to entanglement. The arrow of time makes us certain that no two lives will ever be the same amidst the background of invariant, constant, immutable laws of the universe. *Entropy persists, gravity notwithstanding.

*The contrast between the law of increasing entropy (the second law of thermodynamics) and the symmetric laws (time-invariant, like the law of gravity) represents one of the most significant paradoxes in physics.