What does the CMB tell us?

The CMB is useful to scientists because it helps us learn how the early universe was formed. It is at a uniform temperature with only small fluctuations visible with precise telescopes.

When was relic radiation present in the universe?

This light set out on its journey more than 14 billion years ago, long before the Earth or even our galaxy existed. It is a relic of the universe’s infancy, a time when it was not the cold dark place it is now, but was instead a firestorm of radiation and elementary particles.

Why is CMB Now microwave radiation?

The Big Bang theory predicts that the early universe was a very hot place and that as it expands, the gas within it cools. Thus the universe should be filled with radiation that is literally the remnant heat left over from the Big Bang, called the “cosmic microwave background”, or CMB.

Why are the anisotropies so significant?

The anisotropies appear on the map as cooler blue and warmer red patches. These anisotropies in the temperature map correspond to areas of varying density fluctuations in the early universe. Eventually, gravity would draw the high-density fluctuations into even denser and more pronounced ones.

What is known as the dark age in the history of the universe?

Beginning about 400,000 years after the Big Bang and lasting hundreds of millions of years, this so-called dark age of the universe marked the last time when empty space really was empty; no planets, no suns, no galaxies, no life — just a fog of hydrogen atoms forged by the Big Bang and left to slosh through the …

Why is the cosmic microwave background an oval?

It is oval shaped because that is a common way to represent a sphere (such as a globe, or a planet, or the sky) on a flat screen. It is the entire sky, transformed (Mollweide projection) so as to print on a flat surface while preserving the relative area of features.