Newton's Great Synthesis

It is hard to overstate the importance of Isaac Newton in our modern understanding of physics and mathematics. Read the 3.2 Newton’s Great Synthesis to learn about the man and his contributions to science.
You’ve probably learned about Newton’s Laws of Motion and the concept of density in a previous science class. These fundamental physics principles will pop up from time to time in our astronomy class. Let’s review these ideas using one of my favorite video games. Watch The Physics of “Osmos.”
Another foundational physics principle that appears in astronomy is the Conservation of Angular Momentum. Here are three excellent demonstrations of the phenomenon: 1) the spinning sphere, 2) the spinning professor, and 3) the spinning figure skater.
Explore 3.3 Newton’s Universal Law of Gravitation to understand how gravity, described by Newton’s law, governs the attraction between masses and influences celestial motions, enabling the calculation of astronomical object masses.
Newton’s Universal Law of Gravitation implies that there is a force between every object that has mass. That means two people standing next to each other experience a gravitational attraction toward one another. How can this be? Why don’t we feel this force? Well, compared to other forces we encounter, gravity is incredibly weak. Notice that the gravitational constant, G, is 6.67x10^-11 (or 0.0000000000667). Gravitational forces only become significant when there are tremendous masses involved (like the mass of planets and stars). Nonetheless, the gravitational attraction between ordinary objects here on earth can be detected and measured. One of the best illustrations of this is the famous Cavendish Experiment.
By combining Newton’s Law of Gravity with Kepler’s Third Law, astronomers obtained an incredibly useful tool for understanding the universe - an equation that relates the mass of an object to its orbital properties. It’s truly amazing that we can measure the properties of objects in space, just by observing them from a great distance. Watch How big is it? to learn more and see an analogy of what makes this so amazing.
If you like, just for fun, you can watch this Isaac Newton vs Bill Nye Epic Rap Battle starring Weird Al.