Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!

This course provides an introduction to the universe beyond the Earth. We begin with a study of the night sky and the history of the science of astronomy. We then explore the various objects seen in the cosmos including the solar system, stars, galaxies, and the evolution of the universe itself. As an online course, it is equivalent to 6 lecture hours, and satisfies science requirements for the AA and AS degree. It is designed to be thorough enough to prepare you for more advanced work, while presenting the concepts to non-majors in a way that is meaningful and not overwhelming. We will consider the course a success if you have learned how to think about the universe critically in an organized, logical way, and to have enhanced your appreciation of the sky around us.

" The fundamental concepts, and approaches of aerospace engineering, are highlighted through lectures on aeronautics, astronautics, and design. Active learning aerospace modules make use of information technology. Student teams are immersed in a hands-on, lighter-than-air (LTA) vehicle design project, where they design, build, and fly radio-controlled LTA vehicles. The connections between theory and practice are realized in the design exercises. Required design reviews precede the LTA race competition. The performance, weight, and principal characteristics of the LTA vehicles are estimated and illustrated using physics, mathematics, and chemistry known to freshmen, the emphasis being on the application of this knowledge to aerospace engineering and design rather than on exposure to new science and mathematics."

This course includes Quantitative introduction to physics of the solar system, stars, interstellar medium, the Galaxy, and Universe, as determined from a variety of astronomical observations and models. Topics: planets, planet formation; stars, the Sun, "normal" stars, star formation; stellar evolution, supernovae, compact objects (white dwarfs, neutron stars, and black holes), plusars, binary X-ray sources; star clusters, globular and open clusters; interstellar medium, gas, dust, magnetic fields, cosmic rays; distance ladder; galaxies, normal and active galaxies, jets; gravitational lensing; large scaling structure; Newtonian cosmology, dynamical expansion and thermal history of the Universe; cosmic microwave background radiation; big-bang nucleosynthesis. No prior knowledge of astronomy necessary. Not usable as a restricted elective by physics majors.

The Moon and the sun look roughly the same size in the sky because although the sun’s diameter is ~400 times greater than the Moon’s, the sun is ~400 times farther away from the Earth as the Moon is! The Moon goes through phases because as it rotates around the Earth, different parts of the Moon are made visible to us from the sun’s light. Created by Sal Khan.

This book is a journey through the world of physics and cosmology, and an exploration of our role in this universe. We will address questions such as: What if the force of gravity were a little stronger? What if there were more of fewer atoms in our universe? What if Newton and not Einstein had been right? Would we still be here? Can the universe exist without us to observe it? Can chance explain the world around us, as well as us?

The purpose of this book is to phrase these questions and pursue the consequences of potential answers through rigorous scientific reasoning; in the process we will learn how the very small and the very large are interconnected, and even how we can affect events that happened six billion years ago.

Licensed CC-BY-4.0 with attribution instructions on page 2 of the document.

Table of Contents

Introduction 7
The fundamental forces 10
The force of gravity 18
What if … the force of gravity were different? 23
The electric and magnetic forces 26
The electric force 27
What if … the electric force were different? 39
The magnetic force 48
What if … the magnetic force were different? 58
The strong and weak forces 59
What if … ? 65
How do forces work? 74
The history of the universe 85
What if … ? 94
The history of our species 106
Odds 124
The building blocks of the universe 128
What if … ? 140
Dark energy 150
What if … dark matter were more interesting? 159
When you do not look…. 162
Manifestations of the wave nature of matter 169
The delayed choice experiment: Affecting the past 186
What if … ? 191
The story so far 195
Unification and our role 199
Fine-tuning? 214
The Multiverse and aliens 226
The laws of physics 234
The Anthropic Principle and Puddle Theory 237
Post mortem 249
Further reading and chapter notes 251

Can you avoid the boulder field and land safely, just before your fuel runs out, as Neil Armstrong did in 1969? Our version of this classic video game accurately simulates the real motion of the lunar lander with the correct mass, thrust, fuel consumption rate, and lunar gravity. The real lunar lander is very hard to control.

Can you avoid the boulder field and land safely, just before your fuel runs out, as Neil Armstrong did in 1969? Our version of this classic video game accurately simulates the real motion of the lunar lander with the correct mass, thrust, fuel consumption rate, and lunar gravity. The real lunar lander is very hard to control.

Applications of physics (Newtonian, statistical, and quantum mechanics) to fundamental processes that occur in celestial objects. Includes main-sequence stars, collapsed stars (white dwarfs, neutron stars, and black holes), pulsars, supernovae, the interstellar medium, galaxies, and as time permits, active galaxies, quasars, and cosmology. Observational data discussed. No prior knowledge of astronomy is required.

Build your own system of heavenly bodies and watch the gravitational ballet. With this orbit simulator, you can set initial positions, velocities, and masses of 2, 3, or 4 bodies, and then see them orbit each other.

Build your own system of heavenly bodies and watch the gravitational ballet. With this orbit simulator, you can set initial positions, velocities, and masses of 2, 3, or 4 bodies, and then see them orbit each other.

These are a set of lecture slide that I have created for the OpenStax astronomy textbook. For each chapter, there are between 2 and 4 sets of slides broken down into topics following the flow of the chapter. In each case, the slides come in three formats: Keynote, PowerPoint and pdf. Note that the slides were created using Keynote so there may be some minor formatting issues in the PowerPoint versions.

Please feel free to use/modify any of these as you find useful for your classes.

How K-Ar dating can be used to date very old volcanic rock and the things that might be buried in between. Created by Sal Khan.

Detection and measurement of radio and optical signals encountered in communications, astronomy, remote sensing, instrumentation, and radar. Statistical analysis of signal processing systems, including radiometers, spectrometers, interferometers, and digital correlation systems. Matched filters and ambiguity functions. Communications channel performance. Measurement of random electromagnetic fields. Angular filtering properties of antennas, interferometers, and aperture synthesis systems. Radiative transfer and parameter estimation.

"2010 marks the 400th anniversary of Galileo's astonishing sightings of features on the moon, stars, and moons around Jupiter that no one had seen before. Recreate these new ways of seeing and exploring from the materials and techniques Galileo had on hand, while you reflect on the times and works of Galileo. What was it like to improvise new ways of seeing and exploring from the materials and techniques on hand? What do we notice? What surprises us? How can we relate to past experience and ideas? What are we curious to research? How does our experimenting grow into our learning? Let your own curiosity drive your explorations."

Global Satellite Navigation Systems (GNSS), such as GPS, have revolutionized positioning and navigation. Currently, four such systems are operational or under development. They are the American GPS, the Russian Glonass, the European Galileo, and the Chinese Beidou-Compass. This course will address: (1) the technical principles of Global Navigation Satellite Systems (GNSS), (2) the methods to improve the accuracy of standard positioning services down to the millimeter accuracy level and the integrity of the systems, and (3) the various applications for positioning, navigation, geomatics, earth sciences, atmospheric research and space missions. The course will first address the space segment, user and control segment, signal structure, satellite and receiver clocks, timing, computation of satellite positions, broadcast and precise ephemeris. It will also cover propagation error sources such as atmospheric effects and multipath. The second part of the course covers autonomous positioning for car navigation, aviation, and location based services (LBS). This part includes the integrity of GNSS systems provided for instance by Space Based Augmentation Systems (e.g. WAAS, EGNOS) and Receiver Autonomous Integrity Monitoring (RAIM). It will also cover parameter estimation in dynamic systems: recursive least-squares estimation, Kalman filter (time update, measurement update), innovation, linearization and Extended Kalman filter. The third part of the course covers precise relative GPS positioning with two or more receivers, static and kinematic, for high-precision applications. Permanent GPS networks and the International GNSS Service (IGS) will be discussed as well. In the last part of the course there will be two tracks (students only need to do one): (1) geomatics track: RTK services, LBS, surveying and mapping, civil engineering applications (2) space track: space based GNSS for navigation, control and guidance of space missions, formation flying, attitude determination The final lecture will be on (scientific) applications of GNSS.

This is an introduction to the study of the solar system with emphasis on the latest spacecraft results. The subject covers basic principles rather than detailed mathematical and physical models. Topics include: an overview of the solar system, planetary orbits, rings, planetary formation, meteorites, asteroids, comets, planetary surfaces and cratering, planetary interiors, planetary atmospheres, and life in the solar system.

Understanding solar eclipses and lunar eclipses. Why don't we have a solar eclipse every new moon (every time the Moon is between the Earth and Sun)? Why don't we have a lunar eclipse every time the Earth is between the Sun and Moon.

The emergence of Western science: the systematization of natural knowledge in the ancient world, the transmission of the classical legacy to the Latin West, and the revolt from classical thought during the scientific revolution. Examines scientific concepts in light of their cultural and historical contexts.