Origins of the Universe, Earth, Dinosaurs, and Humans

Vocabulary flashcards covering the origins of the universe, Earth, and life on Earth, with corrected scientific details.

Big Bang

The leading explanation for the origin of the universe; about 13.8 billion years ago, the universe began expanding from a hot, dense state.

Universe

All of space, time, matter, and energy; includes galaxies, stars, planets, and Earth.

Atom

The basic unit of matter, composed of a nucleus of protons and neutrons surrounded by electrons; atoms form molecules that build all substances, including Earth.

Solar nebula

The rotating disk of gas and dust around a young Sun from which the planets, including Earth, formed about 4.6 billion years ago.

Earth formation

The process by which Earth formed from accretion of material in the solar nebula, roughly 4.5 billion years ago.

Dinosaurs

A group of reptiles that dominated Earth during the Mesozoic Era, roughly 230 to 66 million years ago.

Humans (Homo sapiens)

Anatomically modern humans who emerged around 300,000 years ago, long after the era of dinosaurs.