Status Updates From Inventing Reality: Physics ...

"Since we never find a distribution of meter readings, but always a single reading, and since quantum mechanics seems to predict only probability distributions, human consciousness must somehow induce the probability distribution to collapse. We can agree with Wigner that there is something about human beings that leads to this collapse..."

Last chapter and epilogue were fun and satisfactory answers to "Is physics invented or discovered?"

“Einstein said we cannot compare our theories with the real world. We can compare predictions from our theory with observations of the world, but we “cannot even imagine . . . the meaning of” comparing our theories with reality.”

“The minute we begin to talk about this world, it somehow becomes transformed into another world, an interpreted world, a world delimited by language—a world of trees, houses, quarks, and leptons. In order to deal with the world we have to talk about it (or measure it, or shape it—in any case we engage the world in terms of our symbols, whether we are building a pyramid or a Superconducting Super Collider).”

“In the final analysis, physics is only indirectly about the world of nature. Directly, it is talk about experimental arrangements and observations. What is not given to physicists by nature, but rather is invented by them, is what they say about these outcomes, the language they use to talk about nature.”

“For each of them an abstract language can be mapped onto features of the world in a variety of ways. But there seems to be no unique way of combining a mathematical language and a part of the world. Our words apparently do not hook onto the world in only one way. If there is no absolute relationship between physical theories and the world, how can we know how the world is “really” put together?”

“The history of physics is a story of the relationship between experiment and theory. Without the observations of Tycho there could have been no theory of Kepler. Without experiments of Ampere, Oersted,
and Faraday there could have been no Maxwellian electromagnetism. The relationship works both ways. Without Einstein’s general relativity there would have been no eclipse photographs in 1919 by
Eddington.”

“Many physicists believe the simplicity of nature is revealed by the fact that the world can be described by a family of quantum field theories involving local gauge symmetry and spontaneous symmetry breaking.” Oh! Of course so simple. Duh! 🤣

“Someone once likened studying the nature of matter by using a particle accelerator to studying the mechanism of a watch by smashing it against the wall and looking to see what pieces fly out.” It’s so funny and impressive that we have found out so much of the universe by just smashing things together and shooting them around

"In the same way that two electrons can be said to interact by exchanging photons, two nucleons can be said to interact by exchanging the new Yang
Mills gauge particles. These gauge particles can be thought of as neutralizing any arbitrary change in the convention distinguishing protons from neutrons by transforming protons into neutrons and vice versa."
Ok bro what the hell are we doing here cmon now

“When two electrons meet, one electron can emit a virtual photon, which is absorbed by the second electron. Physicists describe this process by saying that two electrons interact by exchanging a virtual photon. This represents yet another way to talk about force: A force arises when virtual gauge particles are exchanged.”
Everything is just abstractions. Physics is just a language like a programming one is.

"Physicists found that a number measured in the same units as angular momentum could be associated with the “orbit” of an electron. Talking about this number as though it were angular momentum allows physicists to talk about the conservation of angular momentum at the subatomic level in the same way they talk about the angular momentum of merry go-rounds or planets." Just making stuff up along the way xD

“From here on in it will be increasingly important to keep Bohr’s admonition in mind: “There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns only what we can say about nature.”

"Feynman explored what would happen if he talked in terms of electric forces that act directly over distances without any intervening field. He found that he had to make use of EM effects that travel both forward and backward in time. This description leads to exactly the same description of the world that Maxwell’s equations lead to." I'm starting to think that math/physics were invented and not discovered

"Allowing positive infinities to cancel negative infinities is not legitimate as far as mathematicians are concerned, but physicists had no other alternative and hoped these problems would not prove in
surmountable." The math we do as physicists sometimes is hilarious bruh we saw infinity was a problem in quantum field theory and said ok just cancel it with negative infinity duh

“The world on the atomic scale, at least, does not seem to be some particular way, whether physicists observe it or not. The atomic world appears to have particular qualities only as the result of measurements physicists make. Quantum mechanics is a way of talking about nature that allows physicists to predict how the world will respond to being measured.” No way of knowing what the world is independent of us

“It is true that some things physicists thought made perfect sense, like the paths of electrons, do not turn out to be useful ways of talking, but this discovery does not make the world any less objective. The feeling we have that this realization makes the world “subjective” only shows how wedded we are to the idea…”

“Since the time of Newton, if not before, physics has been thought of as the search for the laws of nature—the laws describing how God established the natural world. From Bohr’s perspective this search is misdirected; the laws of physics are our laws, not nature’s.” Sometimes I tend to get lost in my physics work that I forget that everything is just made up for humans to understand lol

“Only when physicists talk about what has yet to occur can their statements be tested. Electrons are not like marbles. When we do not measure an electron’s path, we cannot even say that it has a path. Position and motion do not seem to be properties of the subatomic world; they seem to be our way of talking about the subatomic world.” Finally getting to the language philosophy part!

"The path light takes allows it to get from one place to another in the shortest possible time. Fermat’s principle seems to suggest that light knows the possible paths and chooses the one that takes the least amount of time. How could light know beforehand which path would be the
quickest? How could an electron know both slits were open?" Double slit always fun to think about, but I know the real answer I wont tell

"The earth’s motion is no more fundamental than the sun’s; it depends upon one’s point of view. The notion that the earth moves around the sun
leads to a much simpler view of a nature harmoniously reflecting Newton’s or Einstein’s laws, but as for which “really” moves, Einstein said there could be no answer." Idk this got me thinking about relativity a lot. What does it mean to move? To who? Where? When? Ahhhhhh swag

“The two processes were distinct in the interpretation of Maxwell’s equations, but Einstein was sure this distinction must be artificial—he believed that only the relative motion between the magnet and the coil should be important.”

Lil piece of history about the start of special relativity was nice

"Time points from the more orderly (the ice cube) to the less orderly (the puddle). The direction of time is not an absolute, but rather a statistical effect. Of all the possible outcomes, most have a greater degree of disorder than any particular arrangement we might be considering. If we wait long enough, we might see an ice cube form out of a puddle of water. It is not impossible; it is just very, very unlikely."

“The language of thermodynamics is even more fundamental than Newtonian physics. The laws of thermodynamics can be expressed in several different ways whose equivalence is not always apparent. For example, one way of expressing the second law is to say there can be no machine that gains its energy from a source colder than itself.” I always think of entropy increases with time but this is nice too.

“Models of the Physical World” section started to make me enjoy this book a lot more. Nice summary of physics history and then starts talking about how real (or not real) energy, fields or action at a distance models are etc. “Energy is an accountant’s notion, like the national debt—real enough, but one cannot point to it or put it in a vault.”

Hamilton declared that an object or collection of objects moves in such a way that the action— a quantity closely related to the Lagrangian, or the energy of the system—always has the smallest possible value. He showed that the action for the route actually taken is always smaller than the action for any other route. In other words, a system moves in such a way that it minimizes the action.

“Lagrange formulated a mathematical expression, called the Lagrangian in his honor, which is simply the difference between the kinetic and potential energy for every point in an object’s path.”