Here’s an alphabetical list of all available free books. Note that many of the links will bring you to an external page, usually with more info about the book and the download links. Also, the links are updated as frequently as possible, however some of them might be broken. Broken links are constantly being fixed. In case you want to report a broken link, or a link that violates copyrights, use the contact form.
A Beginner’s Guide to Mathematica
A Brief Introduction to Particle Physics
A First Course in General Relativity
A New Astronomy
A No-Nonsense Introduction to General Relativity
A Popular History of Astronomy During the Nineteenth Century, Fourth Edition
A Review of General Chemistry
A Simple Guide to Backyard Astronomy
A Text Book for High School Students Studying Physics
A Tour of Triangle Geometry
About Life: Concepts in Modern Biology
Advanced Mathematics for Engineers
Advanced Microwave Circuits and Systems
Advances in Computer Science and IT
Advances in Evolutionary Algorithms
Advances in Geoscience and Remote Sensing
Advances in Haptics
Advances in Human Computer Interaction
Age of Einstein
Aging by Design
AMPL: A Modeling Language for Mathematical Programming
An Introduction to Elementary Particles
An Introduction to Higher Mathematics
An Introduction to Many Worlds in Quantum Computation
An Introduction to Mathematical Reasoning
An Introduction to Mathematics
An Introduction to Proofs and the Mathematical Vernacular
An Introduction to Relativistic Quantum Mechanics
Analysis 1 (Tao T)
Analysis 2 (Tao T)
Astronomy for Amateurs
Astronomy with an Opera-Glass
Automation and Robotics
Basic Algebra, Topology and Differential Calculus
Basic Concepts of Mathematics
Basic Concepts of Thermodynamics
Basic Concepts of Thermodynamics Chapter 1
Basic Ideas in Chemistry
Basic Math: Quick Reference eBook
Basic Mathematics for Astronomy
Basic Positional Astronomy
Basic Principles of Classical and Statistical Thermodynamics
There are moments when we do not agree with what is happening around us…
Maryam Mirzakhani (born May 3, 1977) is an Iranian-American mathematician and a professor of mathematics at Stanford University.
On 13 August 2014, Mirzakhani became both the first woman and the first Iranian honored with the Fields Medal, the most prestigious award in mathematics. The award committee cited her work in “the dynamics and geometry of Riemann surfaces and their moduli spaces”.
Her research topics include Teichmüller theory, hyperbolic geometry, ergodic theory, and symplectic geometry.
“Iranian mathematician Maryam Mirzakhani has become the first woman to ever win the Fields Medal – known as the "Nobel Prize of mathematics” – since the award was established in 1936. The Stanford mathematics professor was awarded the prestigious honor for her contributions to the fields of geometry and dynamical systems.“
“Elastic spheres can walk on water.Incited by public fascination and engineering application, water-skipping of rigid stones and spheres has received considerable study. While these objects can be coaxed to ricochet, elastic spheres demonstrate superior water-skipping ability, but little is known about the effect of large material compliance on water impact physics. Here we show that upon water impact, very compliant spheres naturally assume a disk-like geometry and dynamic orientation that are favourable for water-skipping. Experiments and numerical modelling reveal that the initial spherical shape evolves as elastic waves propagate through the material. We find that the skipping dynamics are governed by the wave propagation speed and by the ratio of material shear modulus to hydrodynamic pressure. With these insights, we explain why softer spheres skip more easily than stiffer ones. Our results advance understanding of fluid-elastic body interaction during water impact, which could benefit inflatable craft modelling and, more playfully, design of elastic aquatic toys.”
The Bubble Nebula is 7 light-years across — about one-and-a-half times the distance from our sun to its nearest stellar neighbor, Alpha Centauri — and resides 7,100 light-years from Earth in the constellation Cassiopeia.
The seething star forming this nebula is 45 times more massive than our sun. Gas on the star gets so hot that it escapes away into space as a “stellar wind” moving at over 4 million miles per hour. This outflow sweeps up the cold, interstellar gas in front of it, forming the outer edge of the bubble much like a snowplow piles up snow in front of it as it moves forward.
As the surface of the bubble’s shell expands outward, it slams into dense regions of cold gas on one side of the bubble. This asymmetry makes the star appear dramatically off-center from the bubble, with its location in the 10 o'clock position in the Hubble view.
Dense pillars of cool hydrogen gas laced with dust appear at the upper left of the picture, and more “fingers” can be seen nearly face-on, behind the translucent bubble.
The gases heated to varying temperatures emit different colors: oxygen is hot enough to emit blue light in the bubble near the star, while the cooler pillars are yellow from the combined light of hydrogen and nitrogen. The pillars are similar to the iconic columns in the “Pillars of Creation” in the Eagle Nebula. As seen with the structures in the Eagle Nebula, the Bubble Nebula pillars are being illuminated by the strong ultraviolet radiation from the brilliant star inside the bubble.
It is being formed by an O star, BD +60°2522, an extremely bright, massive, and short-lived star that has lost most of its outer hydrogen and is now fusing helium into heavier elements. The star is about 4 million years old, and in 10 million to 20 million years, it will likely detonate as a supernova.
Hubble’s Wide Field Camera 3 imaged the nebula in visible light with unprecedented clarity in February 2016. The colors correspond to blue for oxygen, green for hydrogen, and red for nitrogen. This information will help astronomers understand the geometry and dynamics of this complex system.
Object Names: Bubble Nebula, NGC 7635
Image Type: Astronomical
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
If you had any doubts about whether or not women can absolutely own the STEM fields, let Dr. Maryam Mirzakhani dispel them for you.
The Stanford professor, a widely-respected pioneer on “dynamics and geometry of Riemann surfaces and their moduli spaces,” made history in a major way on Tuesday by becoming the first woman ever to win the Fields Medal: the highest international prize in mathematics, and sometimes thought of as the “Nobel Prize of Mathematics.”
“Perhaps Maryam’s most important achievement is her work on dynamics,” says Curtis McMullen of Harvard University. Many natural problems in dynamics, such as the three-body problem of celestial mechanics (for example, interactions of the Sun, the Moon and Earth), have no exact mathematical solution. Mirzakhani found that in dynamical systems evolving in ways that twist and stretch their shape, the systems’ trajectories “are tightly constrained to follow algebraic laws”, says McMullen. He adds that Mirzakhani’s achievements “combine superb problem-solving ability, ambitious mathematical vision and fluency in many disciplines, which is unusual in the modern era, when considerable specialization is often required to reach the frontier”.