Lecture 18: The Apple and the Moon - Newtonia...

Why do Kepler's Laws work? In this lecture I will describe Newton's generalization of Kepler's Laws of Planetary Motion so that they will apply to any two massive bodies orbiting around their common center of mass. I will introduce families of open and closed orbits, the circular ...  Show more

Why are there two high tides a day? This lecture examines tides caused by the differences in the gravity force of the Moon from one side to the other of the Earth (stronger on the side nearest the Moon, weaker on the side farthest from the Moon). The Sun raises tides on the Earth ...  Show more

There was a time when science and religion worked in harmony, as two parts of a celestial design. Astrologer and philosopher Johannes Kepler oversaw this marriage of theory and belief when he proposed the revolutionary laws of planetary motion in the early 17th century. Amidst pe ...  Show more

Melvyn Bragg and guests discuss the flow of particles from the outer region of the Sun which we observe in the Northern and Southern Lights, interacting with Earth's magnetosphere, and in comet tails that stream away from the Sun regardless of their own direction. One way of defi ...  Show more

Melvyn Bragg and guests discuss the pioneering Danish astronomer Tycho Brahe (1546 – 1601) whose charts offered an unprecedented level of accuracy.In 1572 Brahe's observations of a new star challenged the idea, inherited from Aristotle, that the heavens were unchanging. He went o ...  Show more

The sun is out, the weather is warm, and summer school is in session! Neil deGrasse Tyson, co-host Matt Kirshen, and astrophysicist Charles Liu answer fan-submitted questions on mathematics, the Big Bang, the laws of physics, neutrinos, relativity, Pluto, the smell of the Milk ...