Physics Discussion: Objects, Fields, and Waves

This analysis clarifies the distinction between localized objects, fields, and waves in response to the question: "Can an object have vibration/movement without mass?"

Core Insight: In modern physics, mass is not an absolute requirement for vibration or movement. Vibrations are fundamental properties of fields, which can have massless excitations (like photons) that propagate and oscillate.

1. Localized Entity with Boundaries

The Classical "Object"

This matches our everyday intuition of a discrete, countable thing with a clear boundary separating it from its surroundings.

Localization: It exists at a definite location (here, not there). You can point to it.

Impenetrability: Two such objects cannot occupy the same space simultaneously (for matter, per the Pauli exclusion principle).

Countability/Conservation: You can count them. Combining objects yields a larger lump, not a merged field (atom count is conserved).

Intrinsic Properties: Mass, charge, etc., are carried with the object as it moves.

Example: A baseball, a planet, an electron (when measured as a particle).

2. Field

The Fundamental Substance

A field is a physical quantity that has a value at every point in space and time. It is not an object but the medium or stage from which objects arise. In quantum field theory (QFT), particles are excitations of their underlying fields.

Non-localization: It exists everywhere within its domain. You don't point to the field; you point to a region of the field.

Permeability: Fields can overlap and pass through each other without interaction. The electromagnetic and electron fields coexist in the same space.

Dynamical Nature: It can vibrate, oscillate, and carry energy and momentum through its variations.

Source of Particles: Particles are excitations or quanta of their underlying fields.

Example: The electromagnetic field (light, forces), the electron field, the Higgs field, the gravitational field (spacetime metric).

3. Wave

A Behavior or Pattern

A wave is not a distinct entity but a pattern of disturbance that propagates through a field or medium, transferring energy without permanent displacement of the medium.

It is a Process: A wave in water is not separate from the water; it is a shape the water temporarily takes.

Delocalization: A pure wave (like a perfect sine wave) is inherently spread out with no single location.

Localizable into Packets: Combining many waves creates a wave packet—a localized, moving lump. This is the quantum description of a particle.

Example: A sound wave (pressure disturbance), a water wave, a photon (a wave packet in the electromagnetic field).

Synthesis: How This Answers the Original Question

When we say a photon "vibrates," we mean:

1. The electromagnetic field exists everywhere.
2. A photon is a localized excitation (a wave packet) of that field.
3. The "vibration" refers to the oscillating values of the electric and magnetic field vectors within that wave packet as it propagates.

The photon is the localized entity, but not a "little ball." It is a knot of energy and momentum in a field, exhibiting wave-like properties (frequency, wavelength).

The Bridge: Quantum Field Theory (QFT)

QFT unifies these concepts:

1. The fundamental reality is fields.
2. Fields are quantized—they vibrate only in discrete energy amounts.
3. A particle is a quantum of field vibration.

Analogy:

• Field = A vast, placid lake (exists everywhere).
• Quantum = The rule that waves must be made of whole, indivisible "lumps" of water.
• Particle/Wave = A single "lump" of wave (a wave packet) moving across the lake. It is localized (trackable) but wave-like (has frequency, can interfere).

Summary: Conceptual Distinction

Concept	Nature	Localized?	Primary Example
Localized Object	A discrete thing (often an excitation of a field).	Yes. Has a well-defined position or range.	An electron (when measured, it clicks at one detector point).
Field	The underlying substance or medium filling space.	No. It is everywhere. It has values at points.	The electron field. Its vibration is the electron.
Wave	A pattern of disturbance in a field/medium.	Typically no (spread out), but forms wave packets that are localized.	The photon's electromagnetic waveform. Its frequency is the "vibration."

Final, Crucial Point: In modern physics, every "particle" is a vibration of a field. The distinction blurs:

• The "localized entity" (particle) is the quantized excitation.
• The "wave" is the shape and behavior of that excitation.
• The "field" is the fundamental entity that is excited.

Thus, mass is not required for a field to vibrate. The vibration of the massless electromagnetic field is light.

This explanation bridges classical intuition with quantum field theory, showing how vibration and movement transcend the classical requirement for mass.