Big History: The Big Bang, Life on Earth, and the Rise of Humanity

of chemical elements ¿ t this prediction very well. Hydrogen accounts for about three-quarters of all matter, and helium for alm ...

Lecture 7: Threshold 2—The First Stars and Galaxies Threshold 2—The First Stars and Galaxies ................................... ...

Gravity magni¿ ed these differences, splitting vast clouds of matter into billions of smaller clouds. As each cloud contracted, ...

Lecture 7: Threshold 2—The First Stars and Galaxies they have stability, they show emergent properties, and they are sustained b ...

sequence”) generate energy by hydrogen fusion. They also found stars that did not ¿ t this correlation. These were stars at the ...

Lecture 7: Threshold 2—The First Stars and Galaxies How does the force of gravity sculpt matter and energy into new forms? Why ...

Threshold 3—Making Chemical Elements ....................................... LECTURE iv [Russian chemist Dmitrii Mendeleev] foun ...

Lecture 8: Threshold 3—Making Chemical Elements Let’s return to the Hertzsprung-Russell (H-R) diagram. The diagram is a scatter ...

outer layer and collapse around its carbon core, turning into a “white dwarf” about the size of the Earth. It will move across t ...

Lecture 8: Threshold 3—Making Chemical Elements through gold and lead, to uranium. Then they will be scattered throughout nearby ...

Threshold 4—The Earth and the Solar System ................................ LECTURE Life, we’ll see, is too delicate to exist on ...

Lecture 9: Threshold 4—The Earth and the Solar System What followed should be familiar by now. Gravity drew the cloud together. ...

Differences in the materials in different orbits explain the differences between the planets. The young Sun’s heat drove more vo ...

Lecture 9: Threshold 4—The Earth and the Solar System Brown, Big History, chap. 1. Christian, Maps of Time, chap. 3. Delsemme, O ...

The Early Earth—A Short History ..................................................... LECTURE But what I would really like you t ...

Lecture 10: The Early Earth—A Short History the semimolten middle layers of the mantle. Even lighter materials such as granites ...

oxygen was continually being freed by some process occurring on or near the Earth’s surface. That process, as we will see later, ...

Lecture 10: The Early Earth—A Short History different from today’s Earth. How did its surface change to create the familiar geog ...

Plate Tectonics and the Earth’s Geography ..................................... LECTURE You look at a map of the world, and what ...

Lecture 11: Plate Tectonics and the Earth’s Geography continents of South America, Africa, Antarctica, Australia, and India had ...