The idea that waves do not carry matter – just energy – is quite fascinating.

When we’re by the sea watching beautiful swell lines marching from infinity through the horizon line and toward the shore, our vision witnesses two things: a form and movement.

In other words, and to make it even simpler, we watch a kind of hidden rolling pin traveling underneath the water surface in our direction.

Eventually, that cylindrical shape we call a wave feels the bottom of the ocean and collapses closer to the beach.

We tend to associate things we see with our eyes with matter, thus mass (weight and inertia).

Wikipedia’s “matter” entry says it all in the first sentence.

“Matter is any substance that has mass and takes up space by having volume,” the article tells. And this description is quite clear, isn’t it?

It’s objects and palpable things.

So, when we look at a wave, we tend to see a “thing” in motion, just like a Formula 1 car going at full speed at Monza’s starting straight.

The Avalanche vs. The Wave

Now, let’s make this exercise a bit more complicated before detailing the shocking fact on why a wave isn’t matter/mass, but energy.

An avalanche is a matter with mass in motion that carries and transforms energy.

So, when we look at snow rapidly moving downhill under the influence of gravity, we witness a physical phenomenon involving both.

The avalanche consists of matter – snow, ice, rocks, soil – so it definitely has mass.

However, simultaneously, because of gravity, the mass has potential energy at the top of the slope.

So, as the avalanche starts and accelerates, that potential energy is converted into kinetic energy (motion), plus some heat, sound, and mechanical destruction.

Interestingly, a wave is different from an avalanche. A wave is pure energy.

In an avalanche, what’s moving downhill is the matter itself (snow, rocks, etc.).

In a wave, the medium (like water or air) mostly stays in place, while energy travels through it.

A Wave Is Like a Fluttering Flag

It’s quite unbelievable. Think about swells like a flag fluttering in the wind.

The fabric of the flag mostly stays in place. It doesn’t blow across the field and vanish, but it oscillates, moving back and forth, up and down.

What you see traveling down the flag – those ripples and flutters – is a wave pattern, not the fabric itself moving along.

In a wave, the water molecules don’t travel across the open ocean with the wave.

They mostly move in small circles or up-and-down paths (transverse waves); what actually moves across the sea is the energy carried by the disturbance.

And this is surprisingly interesting, right?

So, once again, a wave is just energy transported through a medium. Mass mostly oscillates but doesn’t travel long distances.

Words by Luís MP | Founder of SurferToday.com