Lecture 04: Measuring the Earth

Where are we? Where is someplace else? And how do I get there from here? These are questions we need to answer both on the Earth and in the sky to assign a location to a place or celestial object on the surface of a sphere. This lecture includes a review of angular units and the ...  Show more

Why do celestial objects appear to rise and set every day? How does this depend on where you are on the Earth, or the time of year? In today's lecture we we set the heavens into motion and review the two most basic celestial motions. Apparent Daily Motion reflects the daily rotat ...  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 ...