The Illusion of Reality: How Physics Challenges Our Perception of Existence
This video explores the idea that what we perceive as reality – the objects we see, the things we touch, even ourselves – might not be "real" in the way we commonly understand it. Modern physics, particularly quantum field theory, presents a view of the universe that is fundamentally different from our everyday experience.
The Problem with Time and the Quest for Unification
Earlier discussions about loop quantum gravity revealed a surprising finding: by mathematically removing time, a critical variable in physical formulas, physicists made significant progress in unifying gravity with quantum mechanics. This unification is a major goal, driven by the belief that a few simple equations can describe all physical laws of the universe. The difficulty in unifying gravity and quantum mechanics has plagued physicists, and loop quantum gravity offers a potential, albeit radical, approach.
Beyond Time: The Disappearance of Matter
The implications of this theory extend even further. If time itself might not exist, then the existence of matter becomes questionable. Everything we see and touch could be simply underlying "fluctuations." This challenges our fundamental understanding of the universe.
The Gap Between Physics and Common Sense
Modern physics has diverged significantly from common-sense understanding. Einstein's theory of relativity, formulated over a century ago, remains difficult for many to grasp. Quantum mechanics, also nearly a century old, is similarly challenging. This highlights the disconnect between the physics of the very small and our everyday experience. The universe as understood by physicists is vastly different from how we, as ordinary people, perceive it.
Quantum Field Theory: A Universe of Fields
Quantum field theory, a modern evolution of quantum mechanics, provides the most accurate framework for describing the universe. It's underpinned by the Yang-Mills theory, developed by Nobel laureate Yang Chen-Ning. But from the perspective of quantum field theory, the universe might not contain "entities" as we typically perceive them.
The Illusion of Solidity
We interact with objects like tables and phones, and experience physical pain, leading us to believe in a world of solid objects. However, quantum field theory suggests that everything is essentially empty space. Tables, phones, even ourselves, are largely devoid of substance.
The Nature of Touch
When we "touch" a table, we aren't actually making physical contact at the atomic level. Instead, the electromagnetic force between the electron clouds of our fingers and the table creates the sensation of touch. The atomic nuclei never truly interact. This is similar to someone shouting "stop!" without actually touching you – you feel the resistance without direct contact.
Sensory Perception: A Brain Interpretation
Even seemingly direct experiences like feeling water on our hands are not as straightforward as they seem. The sensation of "wetness" is the brain's subjective interpretation of touch, temperature, and pressure. Similarly, sight and sound are the brain's interpretation of electrical signals from the eyes and ears.
Fields and Excitations: The Building Blocks of Reality
If our senses deceive us, what is the true nature of reality? Matter is composed of molecules, which are made of atoms. Atoms consist of nuclei and electrons. However, in quantum field theory, electrons are not solid particles but excitations of a field.
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Imagine a vast, invisible sheet: the electron field.
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Normally, the sheet is flat.
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When we poke the sheet, a bubble appears. This bubble is an electron.
The electron is not a persistent object but a temporary "ripple" in the electron field; an event, not an object. Atomic nuclei, composed of protons and neutrons, are themselves made of quarks. Quarks are also excitations of their respective fields (quark fields). Light, composed of photons, is an excitation of the electromagnetic field. Therefore, the universe isn't made of solid "things," but of the vibrations of various fields. It's a collection of events on various "sheets," rather than solid material objects.
The Concept of Fields: A Revolution in Physics
The concept of "field" is fundamental to physics. Michael Faraday, a self-educated scientist who began his career as a "cleaner," introduced the concept of "lines of force" to describe electromagnetism, a precursor to the modern understanding of fields. A field is a mathematical structure that assigns a quantity to each point in spacetime. The evolution of these quantities is governed by specific mathematical equations. Fields are the invisible "cosmic background" that permeates all of spacetime. Each fundamental particle corresponds to a field, and particles are temporary "fluctuations" in these fields. A particle's appearance and disappearance correspond to changes in the state of the field.
The Emergence of Mass and Matter
If the universe consists of fields rather than solid objects, how do we explain the mass, volume, and "materiality" of objects, including ourselves and our phones?
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Everything is a Combination: All matter is a composite result. For example, a block of iron appears solid, but at the quantum level, it consists of atoms comprised of electrons and quarks.
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Excitations of Fields: These electrons and quarks are not little "things" but are excitations of invisible "fields."
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A Collective Vibration: The iron block we see and touch is the sum of these countless "vibrations" or field excitations combined.
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A Resonant System: The particles are stably connected by electromagnetic forces and strong interactions, forming a macroscopic "entity."
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Stable Patterns: The iron block is a stable shape formed by multiple wave patterns superimposing on an invisible water surface.
In essence, the universe isn't made of bricks and mortar but of waves, energy, and the emergence of information. What we call "reality" is just a collection of entities that aren't truly there from a more fundamental perspective.