Books

If you are able to contribute, it will go to support OpenIntro (not the author), a US-based nonprofit working to spread open materials, e.g. by providing desk copies to instructors considering this text. This listing is in collaboration with the textbook's author, Jim Hefferon. Linear Algebra's official websitePaperbacks are $22openintro.org

Leanpub revenue supports OpenIntro. OpenIntro is a US-based nonprofit that provides textbook services to help increase adoption of OER textbooks and save students money. These textbook services are fully financed by Leanpub contributions on supported books. APEX Calculus website: apexcalculus.comOpenIntro website: openintro.org

I wanted to understand how ChatGPT and other large language models (LLMs) really work, so I read a lot of books, watched YouTube videos, asked hundreds of questions, and wrote it all down. This book is the result. If you want to understand how large language models like ChatGPT actually work, from tokens and vectors to transformers and training, this book will explain it in a clear, approachable way.

Data analysis is now part of practically every research project in the life sciences. In this book we use data and computer code to teach the necessary statistical concepts and programming skills to become a data analyst. Instead of showing theory first and then applying it to toy examples, we start with actual applications and describe the theory as it becomes necessary to solve specific challenges. The book includes links to computer code that readers can use to follow along as they program.

A complete foundation for Statistics, also serving as a foundation for Data Science, that introduces inference using randomization and simulation while covering traditional methods. Leanpub revenue supports OpenIntro, so we can provide free desk copies to teachers interested in using our books in the classroom. More resources: openintro.org.

Functional Magnetic Resonance Imaging (fMRI) is the most widely used technique for investigating the living, functioning human brain as people perform tasks and experience mental states. This book covers the design, acquisition, and analysis of fMRI data.

Quantum computing is real, but is frankly surrounded by a thick fog of hype. Do you want to see it clearly, understand its realities, and even consider joining it as a professional software engineer?

Greenhouse gas emissions have caused considerable changes in climate, including increased surface air temperatures and rising sea levels. This e-textbook presents a series of laboratory exercises in R that teach the Earth science and statistical concepts needed for assessing climate-related risks. These exercises are intended for upper-level undergraduates, beginning graduate students, and professionals in other areas who wish to gain insight into academic climate risk analysis.

Coherent Mathematics (CoMath) — Mathematics That Earns Its StructureWhat if mathematics did not precede physics — but emerged from it?Conventional mathematics assumes its foundations: sets, numbers, operations. Coherent Mathematics (CoMath) assumes only one thing: coherence is not given. Coherence is what survives.From this single axiom, CoMath reconstructs the mathematical universe bottom-up. Numbers, geometry, iteration, and the exponential structure are not postulated — they are derived. The constants of nature are not inserted — they follow. The chain is complete:Geometry → Iteration → Planck Scale → Constants → Time → Schrödinger → Quantum MechanicsZero free parameters. No circular reasoning. No unjustified axioms.CoMath V4 presents:A rigorous axiomatic foundation built on coherence as the sole primitiveDerivation of π, φ, e, ln, and exp from pure iteration structureThe Planck-to-electron mass ratio m_P/m_e from geometry aloneA new perspective on Riemann, Hodge, and the foundations of formal mathematicsDeveloped in direct collaboration between human intuition and AI formalizationThis is not mathematics applied to physics. This is mathematics derived from the structure of reality. "Real science begins with a thought, not an equation." — Jens Deutschmann

Fractal Uncertainty Theory (FUT) — A New Foundation of PhysicsSunflower, quasicrystal, spiral galaxy, cosmic web — they all do the same thing.What if quantum mechanics, gravitation, the fundamental constants, and the large-scale structure of the universe all follow a single principle? Not as a metaphor — but mathematically derivable, with zero free parameters?Fractal Uncertainty Theory (FUT) constructs physics from two primitive operations: Rotation (ℛ) and Recursion (ℱ). From their interference emerge π and φ, the four forces as a unified spectrum, the fine-structure constant α = 1/137, the Planck scale, the Schrödinger equation — and six resolved Millennium Problems.FUT V9 presents across 478 pages and 35 chapters:Derivation of fundamental constants from pure geometry (zero free parameters)Dark energy and dark matter as consequences of the Void Exponential Feedback mechanismThree spatial dimensions + time from icosahedral A₅ symmetryThe Higgs-centered particle structure as a periodic systemRigorously documented progress on Riemann, Yang-Mills, Hodge, P≠NP, and beyondNo speculative model. No retroactively fitted constants. A theory that begins with a thought — and ends with testable predictions. "Real science begins with a thought, not an equation." — Jens Deutschmann ISBN 978-3-9828681-0-3 | Available on Amazon KDP

Las señales estaban ahí. Nadie sabía interpretarlas. El fenómeno ya había comenzado.

Una señal detectada una sola vez. Un registro que no debería existir. El origen nunca pudo confirmarse.

Perché la mente non è un labirinto, ma un rizoma

Siamo ciò che osserviamo e osserviamo ciò che sfugge

En 1977, una señal de radio de origen desconocido fue registrada durante 72 segundos. Su estructura fue precisa. Su intensidad, inusual. Nunca volvió a aparecer. Este libro reconstruye el evento desde su evidencia técnica real: detección, instrumentación, condiciones de registro y límites de interpretación. No agrega teorías. No fuerza conclusiones. Expone un caso real que sigue abierto.