It turns out we make it up as we go along and that's a foundational piece of why it's been so successful.
Apparently there's been some discussion about the connection of physics and some quest for an ultimate truth on a social media site I gave up. A few people reached out and asked my opinion. Starting down the path as a teenager, I thought science was after some deep and ultimate truth. Some grand and beautiful underpinning of the Universe. I was wrong. It took time, but finally as a grad student I had come to know better.
What physics does is build mathematical models that describe observations. (why math works so well is another discussion - but it just does) The hypothesis models that are robust enough to survive different experimental techniques and are predictive become accepted theory. It's very much an iterative process and the models get progressively better with more predictive models coming into use as appropriate. The Standard Model is the best we have for particle physics. It has some warts, but it's far and away the most accurate theory devised. General Relativity is the benchmark for gravity. Both are under constant study and that study has led to radically different views of the Universe and how it has and will evolve.
But to the question from the birdsite. What is real? Is a proton real and what is it made of? What about the spin of a particle? Is dark matter or the dark force real? For the electron and the quarks and gluons that make up protons and neutrons, the most accurate and way to think about them is as excitations in fields that spread throughout the universe. You, the computer screen you're looking at, your dog and your lunch are vast assemblages of field excitations. It's far from intuition and these models are rarely taught until the junior year and that's usually at a high level as the math is a bit intense. It may seem weird, but it's much more predictive than anything else. And gravity being spacetime that changes it's curvature around mass and mass that responds to the curvature of spacetime isn't exactly Newton's falling apples.
Current accepted theory addresses serious flaws in earlier work. The earlier work was good enough given the sophistication of measurements, but tools improve with time. It turns out most (but not all!) of applied physics and engineering doesn't have to worry about these deeper descriptions as these are fields that usually apply to things roughly our size moving a low speeds. There's an interesting notion called complementarity that tells you it's okay to use less precise, but easier to understand, models when you don't need extreme accuracy. We live in a world where models with a Newtonian underpinning are usually valid.
In a way it's how we perceive things. We only sense a tiny amount of the electromagnetic spectrum, our hearing misses quite a bit, our sense of time misses large and small intervals and our size is roughly between that of the Sun and a hydrogen atom. We don't perceive much of the reality around us - we have to use our imaginations to figure out how to ask the right questions and see more deeply.
So we build models. We don't work out the equations of motion, but we walk, throw balls, drive cars and so one. We have a fair amount of information for these simple actions. Physical models quickly get more difficult. How do you predict an earthquake and its severity? When and where tornadoes will do damage? We build approximations, but that's all they are. Better models will come using the scientific process. Even if it's a messy undertaking, it's proven to be the best approach we have. And there's a foundational principle you have to deal with - one that Feynman famously articulated:
The first principle is that you must not fool yourself and you are the easiest person to fool.
More complex and social sciences come into play. Predicting markets and economic models don't have the twelve digit accuracy seen in the Standard Model .. they generally don't make it past the decimal point. They're also a stab at reality. Social models are often poorly constructed with bad data and analysis - a major "AI" issue these days. And how we understand each other as people. We all build models. Hopefully they're good enough.
For a long time I believed you could change minds about the causes and threat of global warming through education.Silly me - it turns out to be a fool's errand. We all have different views of reality. We can witness an event and see differing realities. These lenses can be very different and culturally driven. Quite a bit of work has been done trying to understand how this works. Recently a podcast chat with psychologist Jer Clifton was recommended by Corinne. I give it two thumbs up and recommend it to anyone who has to deal with other people in almost any capacity. It may even make you think twice about how you interact with others.
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