Chapter 11: Introduction to Section 3

Question 1

A collision of a large celestial object—comets, asteroids, and so on—with the Earth is called an ______ ______.

Answer 1

impact event

Question 2

A layer of sediment with high amounts of _________ spread across the planet, is known as the _________ – _________boundary .

Answer 2

iridium, Cretaceous–Paleogene

Question 3

Paleontologists had known for decades that _________ dinosaur fossils are found only below the K–Pg boundary but did not know why until about forty years ago

Answer 3

nonflying

Question 4

The is ________ ________is based upon a thought experiment on the overwhelming mathematical probabilities that there is life elsewhere in our galaxy, not to mention the universe

Answer 4

Fermi Paradox

Question 5

A highly intelligent, technologically advanced civilization may develop self-replicating machines that might colonize other planets, and through logarithmic growth, the galaxy and the universe. These are called: _____ _____ _____.

Answer 5

Von Neumann Probes

Question 6

The _________ _________argues that the galaxy is indeed filled with intelligent, technologically advanced extraterrestrials that observe us at a distance

Answer 6

Zoo Hypothesis

Question 7

According to Rafalovich in the introduction to Section 3, having a keen ______ may work against species longevity.

Answer 7

intelligence