You've touched on one of the deepest philosophical implications of modern physics, and it's a point of profound debate and interpretation, particularly when considering the nature of photons. Let's unpack your statement: "Yeah, this is really a stunning conclusion then because it's right it's mass energy. Equivalence so it's saying there's a non-materialist bases for reality. We're just calling it a particle a photon." The Core Idea: Mass-Energy Equivalence (E=mc^2) and Planck's Relation (E=hf) The combination of these two equations (hf = mc^2, or m = hf/c^2) fundamentally tells us that energy and mass are two sides of the same coin. They are interchangeable. * Mass can be converted into energy: This is famously demonstrated in nuclear reactions (like in the sun or atomic bombs), where a tiny bit of mass transforms into a huge amount of energy. * Energy can be converted into mass: This happens in particle accelerators, where high-energy photons can, under the right conditions (usually interacting with matter or strong fields), produce particle-antiparticle pairs (e.g., an electron and a positron), which have mass. The "Non-Materialist" Interpretation and the Photon This is where the philosophical discussion truly begins. * What is "Matter" (Materialism)? Traditionally, "materialism" in philosophy holds that everything in the universe, including consciousness, is fundamentally composed of matter. Matter is typically defined as having mass and occupying space. * The Photon's Nature: A photon, by definition, is a quantum of light or other electromagnetic radiation. Critically, a photon has zero rest mass. It always moves at the speed of light in a vacuum (c). Despite having no rest mass, it carries energy (E=hf) and momentum (p=E/c = hf/c). * The "Non-Materialist" Argument (or "Beyond Traditional Materialism"): If reality is fundamentally about energy, and energy can exist without mass (as in the case of a photon), then the traditional definition of "materialism" (where everything is mass) seems incomplete or insufficient to describe all of reality. * Energy as a more fundamental concept? Some interpretations suggest that energy, or more broadly "fields," might be a more fundamental underpinning of reality than "particles" or "mass." Mass itself could be seen as a manifestation or localized concentration of energy (or field excitation). * The photon as a "non-material particle": The very concept of a photon challenges the intuitive notion of a "particle" as a tiny, solid, massive thing. It's a packet of energy, an excitation of an electromagnetic field, with wave-like and particle-like properties, and no rest mass. If you define "matter" as anything with rest mass, then photons are not matter. Yet, they are undeniably real, measurable, and interact with matter. Physicalism vs. Materialism Because of these complexities, many contemporary philosophers and physicists prefer the term "physicalism" over "materialism." * Physicalism is a broader philosophical stance that asserts that everything is ultimately physical, or supervenes on the physical. The "physical" here isn't limited to just "matter with mass," but includes everything that physics describes: energy, fields, space-time, fundamental forces, and particles with or without rest mass. Under physicalism, photons are perfectly "physical." Conclusion on "Non-Materialist Basis for Reality": * Traditional materialism (where everything is reducible to massive particles) does face a challenge from concepts like photons and fields that carry energy and are fundamental constituents of reality but lack rest mass. * Modern physics, however, describes a reality where energy is a conserved quantity that can manifest as both mass and massless entities. It's not necessarily "non-materialist" in the sense of implying a spiritual or supernatural basis. Instead, it expands our understanding of what constitutes "physical reality" beyond just tangible, massive objects. * The "stuff" of the universe is not just "lumps of matter," but also includes dynamic fields and quanta of energy (like photons) that, while not having rest mass, are demonstrably real and fundamental. So, while it doesn't necessarily lead to a spiritual or idealist worldview, it certainly pushes beyond a simplistic "everything is solid little balls" view of reality, suggesting a more nuanced and dynamic "physical" foundation. It highlights that mass is just one form that energy can take, and energy itself is a more encompassing concept.