The numbers the
universe agrees on.
From the oscillation of a cesium atom to the structure of the human psyche — a catalogue of the constants that hold, everywhere, for everyone.
Almost everything is a matter of perspective. A short list of things is not.
Hot and cold depend on what is touching your skin. Fast and slow depend on what you are standing on. Even the passage of time, for the observer in motion, stretches and contracts like fabric. The universe is, in this sense, a place of opinions.
But beneath the opinions there is bedrock. A short list of numbers and ratios that every observer — whether on Earth, on a planet orbiting Proxima Centauri, or falling toward a black hole — would write down the same way. These are the constants. They do not change with location. They do not drift with time. They are, in the most literal sense available to science, what is real.
This guide is broader than physics. The first chapters catalogue the constants of matter, energy, light, and gravity. The later chapters turn inward — toward the constants of life, of perception, of mind. Jung argued that the psyche, like the cosmos, has invariants of its own. Those are here too, treated honestly: not measured in joules, but mapped wherever humans have left a record.
A single atom,
in perfect agreement with itself.
For most of human history, a second was an inheritance — from the rotation of the Earth, the swing of a pendulum, the calibration of a chronometer at sea. These were good but mortal definitions. The Earth wobbles. Pendulums drift.
Today, the second has a sturdier home: a single isotope of cesium. The electron at the outermost shell of cesium-133 occupies one of two slightly different energy states. When it transitions between them, it emits a photon at a frequency so stable, and so identical across every cesium-133 atom that has ever existed, that we now define the second as exactly 9,192,631,770 oscillations of that radiation.
An atom in Tokyo, an atom on Mars, an atom in the cold dust of the Oort cloud — all will resonate at this same frequency. International atomic time, maintained as the weighted average of around four hundred cesium clocks, disagrees with itself by less than one second every three hundred million years.
Time & Frequency
Time is the dimension along which causality flows. These constants anchor it.
Nothing travels faster
than light in a vacuum.
The number itself is arbitrary; the constraint is not. Light moves at the maximum speed at which any form of information or causality can propagate through the universe. Above that speed, there is no above.
Since 1983, the meter has been defined as the distance light travels in 1/299,792,458 of a second. The speed of light is therefore exact by construction. Every other length on Earth is now measured against the second — itself measured against a cesium atom — in a chain of definitions that begins, ultimately, with the universe and works its way back.
Light & Electromagnetism
The maximum speed of causality, and the parameters governing every electric and magnetic phenomenon in the cosmos.
Gravity & Curvature
By far the weakest of the four fundamental forces — yet the architect of every galaxy, every star, every world.
The Quantum
The granular constants that determine the discrete, lumpy nature of matter and energy at the smallest scales.
The Cosmos
Parameters describing the universe as a whole — its expansion, its temperature, its density.
The Mathematical
Constants that arise not from measurement but from pure logic. Unitless. Eternal. The same in any universe that contains arithmetic.
The Planck Scale
The natural units of the universe — derived from G, c, and ℏ alone. The scale at which the laws of physics, as we know them, cease to apply.
Chemistry & Atoms
The constants that govern how matter combines, how electrons orbit, how heat radiates.
Information & Computation
The newest branch of physics: the laws and limits of information itself. There are constants here, too.
Biology & Life
Every organism on Earth — every microbe, every redwood, every whale — uses the same code. These are its constants.
Perception & Cognition
The constants of the human interface — the resolution, bandwidth, and bottlenecks of the only mind you can directly study.
Patterns that recur
across every culture.
Carl Jung's claim was that the psyche, like the cosmos, has invariants. He called them archetypes — innate organizing structures of the unconscious that surface, again and again, in the myths, dreams, religions, and art of every people who have ever lived. The Hero. The Shadow. The Wise Old Man. The Mother. The Trickster. They appear in cultures that have never spoken to each other. They appear in the dreams of patients who have never read about them.
These are not constants in the sense of joules or kelvins. They are not measured in instruments. But they recur with a regularity that demands a name. Jung's hypothesis — that the human psyche shares deep structure across the species — remains contested in detail, and increasingly supported in outline by cognitive science and comparative mythology. What follows is a brief catalogue of the most stable of these patterns.
The Psyche
Universal patterns of the inner cosmos — Jung's catalogue of what the mind keeps producing, no matter where in the world it grows up.
Animus
Why this is reliable.
Consider what an astonishing thing it is that these numbers exist. We have no obvious right to a universe whose behavior can be summarised in a few dozen parameters. We have no guarantee that the speed of light here is the speed of light in a galaxy a billion light-years away. And yet every check we have ever performed has come back negative. The constants are constant. Not approximately. Not on average. Constant.
Distant light. When we observe a quasar twelve billion light-years away, the photons reaching our telescopes were emitted twelve billion years ago. Their spectral lines fall exactly where laboratory measurements predict, to within parts per million. Atoms in the early universe obeyed the same fine-structure constant they obey today.
The cosmic microwave background. The relic radiation from 380,000 years after the Big Bang has a temperature of 2.725 kelvin in every direction. For that radiation to be so uniform, the physical laws governing matter and light must have been identical in regions of the early universe causally disconnected from each other.
Atomic clocks. If the fundamental constants were drifting, modern frequency standards would have noticed. They have not. The drift, if any, is bounded at less than one part in 10¹⁷ per year.
The constants of mind are softer evidence, by necessity. We cannot put the Shadow under a spectrometer. But here too there is a remarkable invariance: the same patterns appear in cultures that have never spoken, in dreams of patients who have never read the theory, in myths recorded a continent and a millennium apart. Whatever they ultimately are, they are there.
Almost everything in your life is in flux. Relationships, weather, opinions, prices, governments, stars. But somewhere a cesium atom is ringing at 9,192,631,770 cycles a second, and it will keep doing so for as long as there are cesium atoms. Somewhere a child is dreaming of a hero, a shadow, a wise stranger — the same dream a child dreamt in Sumer four thousand years ago. These are the only things you can be sure of. They are also, perhaps, the most beautiful things we have found.