Why do we expect the cosmic background radiation to be almost, but not quite, the same in all directions?
A) The overall structure of the universe is very uniform, but the universe must have contained some regions of higher density in order for galaxies to form.
B) The temperature of the universe can be found by taking an average over the entire sky, but individual stars will create peaks in the spectrum over small angles.
C) Dark matter consisting of WIMPs greatly smooths out the spectrum, but the small patches of light matter create peaks in the spectrum.
D) The overall structure of the universe is very uniform, but the synthesis of different elements produces varying signatures within the background spectrum.
E) The overall structure of the universe is very uniform, but intervening gas between us and the era of nuclei absorbs wavelengths depending on the composition and redshift of the gas.
Question 2
What was one of the first observations that hinted at limitations in Newton's theory of gravity?
A) deviations in the motion of the planet Uranus in the sky
B) deviations in the motion of the planet Mercury in the sky
C) shifts in position of stars close to the Sun during solar eclipses
D) failure to explain why all objects fall at the same rate in a gravitational field
The four ways in which animals exchange heat with the environment are radiation, evaporation, convec
Boundaries within landscapes created by human activity (background) and natural environmental gradie
How Axis Tilt Affects the Intensity of Solar Radiation
Chim-Pom, in collaboration with Junichi Kakizaki, Radiation-Exposed Flowers Harmony.
Changes in Radiation-Absorbing Gases
Chart showing average yearly dose of radiation from natural and human-made sources