A build-it-yourself book
Special relativity, general relativity, quantum mechanics, quantum field theory, the Standard Model and string theory — derived, not asserted. Nothing is stated that has not been built, and every step that is quoted rather than proved is marked as such.
Ask what stays the same when you change your point of view. Whatever survives is real; whatever does not was a fact about where you were standing.
Above: the light cone, which no change of frame can move, and the hyperbolae of constant interval. Each marker is one event, shown from a continuously changing point of view. It slides, and never leaves its own curve. That is the whole thesis, drawn.
The same material, at three depths. They cross-reference each other, so you can move between them at any point.
The full derivations, with interactive figures, worked examples and problems whose solutions unfold when you want them. Start at the definition of a derivative.
Plain languageEvery explanatory passage in the book, collected in order and readable as one continuous essay. No equations anywhere in it. It stands entirely on its own.
ReferenceEvery mathematical object: where it was introduced, the question it was invented to answer, and every later chapter that spends it. Follow any symbol back to its origin.
Seven subjects, one idea — pick a symmetry, write the most general law invariant under it, then quantise. Each part is that sentence wearing different clothes.
Numbers describe a thing only relative to a choice. The useful description is the one in which a hard problem falls apart into independent pieces.
Forces are the wrong primitive. Attach one number to each possible history, and nature selects the history where that number stops changing.
The speed limit is built into the geometry, not the materials. Magnetism turns out to be electricity, seen from a moving frame.
Gravity is not a force but the shape of the arena. Free fall is the straightest available motion.
“What state is this in” stops having a single answer. The mathematics was already built in Part 0.
Particles stop being fundamental. The field is; particles are its excitations, the way notes are excitations of a string.
Demand a symmetry hold locally rather than globally, and a force appears to enforce it. Every force is that one demand.
Gravity refuses the treatment that worked for everything else — followed by an honest account of what is known and what is conjecture.
Written for someone who can grasp anything but wants the bricks laid one at a time.
No “it can be shown that”. Where a result is quoted rather than derived it carries a ⚑, so you always know what you are standing on.
Routine algebra folds into collapsible boxes, but the reasoning stays on the page. A reader who opens none of them can still follow every argument.
Each interactive figure has to show something a static picture cannot, and most of them measure the result rather than illustrating it.