This page is written to make you, the reader, think, disagree, wonder, check and enjoy.

This 9-line summary of textbook physics agrees with 400 years of experiments. Exactly.

The 9 lines, typeset in bold, state that general relativity, the standard model of particle physics and thermodynamics describe all of nature.

The 9 lines show everything we know about natural science and everything we do not know about fundamental physics.

An extended version is here: C. Schiller, Present physics in 9 lines - and implications for its future, preprint.   pdf


The 9 lines contain all present knowledge about nature, including all textbook physics and all observations ever made.

The simplicity of the 9 lines and their vast domain of validity are intensely fascinating.

No known observation and no known measurement contradicts these 9 lines, not even in the last significant digit.

Find a single contradicting observation or experiment and become famous.

The 9 lines determine all equations of physics:

Lines 1, 2 and 3, together, uniquely determine special and general relativity, cosmology, the Hilbert Lagrangian and Einstein's field equations, as told here.

Line 5 uniquely implies thermodynamics.

Lines 1, 2, 4 and 6 to 9, together, uniquely determine quantum field theory and the Lagrangian of the standard model of particle physics, with massive neutrinos and PMNS mixing – often written with a Lagrangian taking a full page in a small font.

The 9 lines show how little math is required to describe nature with high precision.

The 9 lines given on this page improve the humorous 9 lines found here.

The 9 lines resulted from the work of millions of engineers and scientists during 400 years.

Galileo started around the year 1600; line 1 resulted after over 150 years. Line 5 arose from 1824 to 1929, line 6 arose
around 1860, lines 2 and 4 around 1900, line 3 from 1915 to 2002, and lines 7, 8 and 9 from 1936 to 1973.

The 9 lines contain all natural sciences.

They contain physics, chemistry, material science, biology, medicine, geology, astronomy and engineering.

Again: any single observation contradicting the 9 lines will create a sensation.


Three questions are open in fundamental physics.

III    Are all observations in nature described by the 9 lines – or are there phenomena beyond present textbook physics?

For example, to which line do dark matter and dark energy belong exactly?c4

II    Are there any undiscovered lines with new physics – or will  F ≤ c4/4G  remain the last law of physics?

Explored mainly in the years from 1973 to 2002, the force limit is the law of physics discovered last.4
The limit value c4/4G ≈ 3.0 · 1043 N for the local force has passed all checks.4
It allows deducing Einstein's field equations and is the shortest known summary of general relativity.4
Because line 3 on maximum force c4/4G was added to the list only recently, a separate web page is dedicated to it.c4

IIII    What is the common explanation for the 9 lines – or is there none?c4

In particular, what determines the principles in lines 1 to 5?c4
And what determines the choices in lines 6 to 9, i.e., the force spectrum, the particle spectrum and the fundamental constants?c4
The last four lines contain the only known physics effects unexplained by and thus beyond the standard model.c4

Many enjoy searching for answers and some even dedicate their life to it.


This image about how to summarize all sciences in 9 lines, free for reuse, might be useful.

Physics in 9 lines


A video summary, by David Tong, of the standard model and of gravitation is found at
The mathematical expression in the video can be seen as a (symbolic) combination of the 9 lines.

The 9 lines allow measuring progress towards unification, as told here, together with more notes.

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