PHY 150 - Final Exam Review Questions with Correct
Answers.
Anthropic Principle
Idea that physical laws must be the way they are because otherwise we could not be here to
measure them.
Critical Density
In cosmology, the density that is just sufficient to bring the expansion of the universe to a stop
after infinite time.
Cosmic Background Radiation
Microwave radiation coming from all directions that is the redshifted afterglow of the Big Bang.
Cosmological Principle
The assumption that, on the large scale, the universe at any given time is the same everywhere—
isotropic and homogeneous.
Dark Energy
The energy that is causing the expansion of the universe to accelerate; its existence is inferred
from observations of distant supernovae.
Dark Matter
Non luminous material, whose nature we don't yet understand, but whose presence can be
inferred because of its gravitational influence on luminous matter.
Galaxy
Answers.
Anthropic Principle
Idea that physical laws must be the way they are because otherwise we could not be here to
measure them.
Critical Density
In cosmology, the density that is just sufficient to bring the expansion of the universe to a stop
after infinite time.
Cosmic Background Radiation
Microwave radiation coming from all directions that is the redshifted afterglow of the Big Bang.
Cosmological Principle
The assumption that, on the large scale, the universe at any given time is the same everywhere—
isotropic and homogeneous.
Dark Energy
The energy that is causing the expansion of the universe to accelerate; its existence is inferred
from observations of distant supernovae.
Dark Matter
Non luminous material, whose nature we don't yet understand, but whose presence can be
inferred because of its gravitational influence on luminous matter.
Galaxy
