Learn about the origin and evolution of life and the search for life beyond the Earth.

物理學是描述世上質量與能量交互作用的學問，在這門課中我們將為大家介紹近代物理對於世界的認識。我們會從電磁學出發，進展到光學，並進而說明近代物理對人類觀念的突破。

The first MOOC “Photovoltaic solar energy” is a general presentation of the solar photovoltaics technologies in the global energetic context, without extensive details. In particular the description of the solar cell operation is restricted to the ideal case In contrast this second MOOC allows a deep understanding of the properties of solar cells based on crystalline semiconductors. It consists in a general presentation of the physics of the photovoltaics devices with a particular emphasize on the silicon technology that currently represents more than 90% share of the market. Photovoltaic applications of III-V semiconductors are also mentioned. Indeed from a fundamental point of view, a solar cell can be considered as a semiconductor device (a diode) exposed to the sunlight. An introduction to the semiconductor physics is given, followed by the electron transport phenomena in a diode device. A detailed description of the solar cell operation is then provided, including the conversion efficiency limitations. A description of the solar spectrum and the optical properties of the cells are also presented. Finally the crystalline silicon technology is described from the bulk crystalline growth up to the preparation of heterojunctions combining crystalline and amorphous materials.

This course serves as an introduction to the physics of force and motion. Upon completion, learners will have an understanding of how mathematical laws and conservation principles describe the motions and interactions of objects all around us. They will gain experience in solving physics problems with tools such as graphical analysis, algebra, vector analysis, and calculus. The course follows the typical progression of topics of a first-semester university physics course: Kinematics, Newton’s Laws, Energy, and Momentum. Each of five modules contains reading links to a free textbook, complete video lectures, conceptual quizzes, and a set of homework problems. Once the modules are completed, the course ends with an exam. With 100 brief lectures and over 100 problems, this comprehensive course is similar in detail and rigor to those taught on-campus. It will thoroughly prepare learners for their upcoming introductory physics courses, or more advanced courses in physics.

In this course we will seek to “understand Einstein,” especially focusing on the special theory of relativity that Albert Einstein, as a twenty-six year old patent clerk, introduced in his “miracle year” of 1905. Our goal will be to go behind the myth-making and beyond the popularized presentations of relativity in order to gain a deeper understanding of both Einstein the person and the concepts, predictions, and strange paradoxes of his theory. Some of the questions we will address include: How did Einstein come up with his ideas? What was the nature of his genius? What is the meaning of relativity? What’s “special” about the special theory of relativity? Why did the theory initially seem to be dead on arrival? What does it mean to say that time is the “fourth dimension”? Can time actually run more slowly for one person than another, and the size of things change depending on their velocity? Is time travel possible, and if so, how? Why can’t things travel faster than the speed of light? Is it possible to travel to the center of the galaxy and return in one lifetime? Is there any evidence that definitively confirms the theory, or is it mainly speculation? Why didn’t Einstein win the Nobel Prize for the theory of relativity? About the instructor: Dr. Larry Lagerstrom is the Director of Academic Programs at Stanford University’s Center for Professional Development, which offers graduate certificates in subjects such as artificial intelligence, cyber security, data mining, nanotechnology, innovation, and management science. He holds degrees in physics, mathematics, and the history of science, has published a book and a TED Ed video on "Young Einstein: From the Doxerl Affair to the Miracle Year," and has had over 30,000 students worldwide enroll in his online course on the special theory of relativity (this course!).

Welcome to this Big History course! In this course, renowned scientists and scholars from the University of Amsterdam and beyond will take you on a journey from the Big Bang until today while addressing key questions in their fields. After completing this journey you will have developed a better understanding of how you and everything around you became the way they are today. You will also have gained an understanding of the underlying mechanisms that have helped shape the history of everything and how they wil help shape the future. Last but not least, you will have developed the skill to use this knowledge to put smaller subjects into a bigger perspective with the aid of the little big history approach, which can help you develop some new ideas on these smaller subjects.

This course trains you in the skills needed to program specific orientation and achieve precise aiming goals for spacecraft moving through three dimensional space. First, we cover stability definitions of nonlinear dynamical systems, covering the difference between local and global stability. We then analyze and apply Lyapunov's Direct Method to prove these stability properties, and develop a nonlinear 3-axis attitude pointing control law using Lyapunov theory. Finally, we look at alternate feedback control laws and closed loop dynamics. After this course, you will be able to... * Differentiate between a range of nonlinear stability concepts * Apply Lyapunov’s direct method to argue stability and convergence on a range of dynamical systems * Develop rate and attitude error measures for a 3-axis attitude control using Lyapunov theory * Analyze rigid body control convergence with unmodeled torque

This course introduces you to subatomic physics, i.e. the physics of nuclei and particles. More specifically, the following questions are addressed: - What are the concepts of particle physics and how are they implemented? - What are the properties of atomic nuclei and how can one use them? - How does one accelerate and detect particles and measure their properties? - What does one learn from particle reactions at high energies and particle decays? - How do electromagnetic interactions work and how can one use them? - How do strong interactions work and why are they difficult to understand? - How do weak interactions work and why are they so special? - What is the mass of objects at the subatomic level and how does the Higgs boson intervene? - How does one search for new phenomena beyond the known ones? - What can one learn from particle physics concerning astrophysics and the Universe as a whole? The course is structured in eight modules. Following the first one which introduces our subject, the modules 2 (nuclear physics) and 3 (accelerators and detectors) are rather self contained and can be studied separately. The modules 4 to 6 go into more depth about matter and forces as described by the standard model of particle physics. Module 7 deals with our ways to search for new phenomena. And the last module introduces you to two mysterious components of the Universe, namely Dark Matter and Dark Energy.

Most of the phenomena in the world around you are, at the fundamental level, based on physics, and much of physics is based on mechanics. Mechanics begins by quantifying motion, and then explaining it in terms of forces, energy and momentum. This allows us to analyse the operation of many familiar phenomena around us, but also the mechanics of planets, stars and galaxies. This on-demand course is recommended for senior high school and beginning university students and anyone with a curiosity about basic physics. (The survey tells us that it's often used by science teachers, too.) The course uses rich multimedia tutorials to present the material: film clips of key experiments, animations and worked example problems, all with a friendly narrator. You'll do a range of interesting practice problems, and in an optional component, you will use your ingenuity to complete at-home experiments using simple, everyday materials. You will need some high-school mathematics: arithmetic, a little algebra, quadratic equations, and the sine, cosine and tangent functions from trigonometry. The course does not use calculus. However, we do provide a study aid introducing the calculus that would accompany this course if it were taught in a university. By studying mechanics in this course, you will understand with greater depth many of the wonders around you in everyday life, in technology and in the universe at large. Meanwhile, we think you'll have some fun, too.

人类的祖先靠知晓天文而掌握了生存之道。今天，天文学的发展已经深刻且深远地改变了人类对宇宙以及对自身在宇宙中位置的认识。 本课程是一门面向大众开设的天文学入门介绍课程，旨在把天文学中最基本的概念和最前沿的发现用尽可能通俗易懂的语言呈现给大家，彰显出宇宙的美丽和魅力。本课程内容包括：最基本的天体运动和天球概念，天文学研究的基本原理和方法，望远镜的历史和最新发展，光谱学，恒星的性质与演化，宇宙组成和暗物质等。通过学习本课程，学习者可以初步掌握一些天文常识和基本概念，了解探索宇宙的方法，感受宇宙的奥妙。