Oct 28, 2026 · 21 min · 17 segments
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Matt O'DowdHost
Now, before we start thinking about vibrating quantum fields or even fields at all, let's talk about vibrations.

Anyone who's ever strummed or shredded knows that a stretched string vibrates with a certain frequency when plucked.

A larger amplitude and or larger frequency means the vibration carries more energy.

At any point in time, every point on a vibrating string is displaced by some distance from its relaxed or equilibrium position.

Guitar strings are one-dimensional, but we can expand the analogy to any number of dimensions.

Everywhere on the surface of a vibrating drum skin, there's a displacement from the flat equilibrium state in the up-down direction.

Every point in space has some displacement in some imaginary extra direction, analogous to but not the same as a fourth dimension.

For example, in a 3D room full of air, sound waves are oscillations in air density.

But at every point in the room, a sound wave can cause air density to oscillate to higher and lower values.

We describe air density as a field because it has some value everywhere in the space of the room.

And that's all a field is, some property that has some value throughout the space.

If this were a quantum mechanical guitar string, then there'd be a minimum amplitude for the vibration that depended on its frequency.

And every larger vibration would have to be a whole number, an integer multiple of the smallest amplitude.

This is exactly how light behaves, as was first realized by Max Planck and proved by Einstein.

Now, before we start thinking about vibrating quantum fields or even fields at all, let's talk about vibrations.

Anyone who's ever strummed or shredded knows that a stretched string vibrates with a certain frequency when plucked.

A larger amplitude and or larger frequency means the vibration carries more energy.

At any point in time, every point on a vibrating string is displaced by some distance from its relaxed or equilibrium position.

Guitar strings are one-dimensional, but we can expand the analogy to any number of dimensions.

Everywhere on the surface of a vibrating drum skin, there's a displacement from the flat equilibrium state in the up-down direction.

Every point in space has some displacement in some imaginary extra direction, analogous to but not the same as a fourth dimension.

For example, in a 3D room full of air, sound waves are oscillations in air density.

But at every point in the room, a sound wave can cause air density to oscillate to higher and lower values.

We describe air density as a field because it has some value everywhere in the space of the room.

And that's all a field is, some property that has some value throughout the space.

If this were a quantum mechanical guitar string, then there'd be a minimum amplitude for the vibration that depended on its frequency.

And every larger vibration would have to be a whole number, an integer multiple of the smallest amplitude.

This is exactly how light behaves, as was first realized by Max Planck and proved by Einstein.
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