Why Does Light Exist? The Universe's Most Fundamental Question

We see, feel, and use light every day. But have you ever wondered why light exists at all? A new video from Aeon Video poses this most fundamental question about our universe.

Light: The Universe's Operating System

Light isn't just what helps us see things. According to modern physics, light is the universe's operating system. In Einstein's relativity, light speed serves as the absolute reference point. In quantum mechanics, photons mediate interactions between matter and energy.

But here's where it gets interesting: if light explains the universe's laws, what explains light itself?

What Physics Can and Can't Tell Us

Physicists excel at describing light's properties and behavior. Light is electromagnetic radiation, exhibits wave-particle duality, and travels at 186,000 miles per second in a vacuum. These characteristics have been verified through countless experiments.

Yet when it comes to why light exists, science hits a wall. This isn't a failure of physics—it's a window into the fundamental nature of human inquiry. We're brilliant at answering "how" but still rely on philosophy for "why."

The Cultural Lens on Existence

Different cultures approach this question differently. Western philosophy, from Plato's theory of forms to modern scientific philosophy, has long sought the "ground of being"—some ultimate reason for existence.

Eastern traditions often take a different approach. Taoist philosophy, for instance, suggests that existence simply is—like water flowing naturally downhill, requiring no external justification.

Science's Philosophical Predicament

21st-century science has achieved remarkable breakthroughs, yet remains humble before the ultimate "why" questions. Quantum mechanics' uncertainty principle, relativity's spacetime concepts, and recent multiverse theories all assume light's existence without explaining its necessity.

This might not be science's limitation but rather a structural feature of human cognition. Since we perceive the world through light, perhaps we're fundamentally unable to step outside that framework to examine light objectively.

The Question Behind the Question

Asking why light exists might really be asking why anything exists at all. It's the cosmological version of Leibniz's famous question: "Why is there something rather than nothing?" Light becomes a proxy for the deeper mystery of existence itself.

Some physicists suggest that light exists because the universe "wants" to maximize entropy—to spread energy as evenly as possible. Others propose that light is simply an inevitable consequence of the mathematical structures that govern reality.