The formation of stars in the early Universe
Today’s Video of the Day from NASA Goddard describes how sound waves called baryon acoustic oscillations (BAOs) influenced the creation of stars and the distribution of the galaxies more than 10 billion years ago.
In the first 500,000 years of its existence, the Universe was not filled with stars and galaxies, but with a sea of charged particles that formed a dense fluid that behaved in a nearly uniform manner. As the particles repelled each other, they created waves of sound that moved through the plasma.
Later, when atoms formed, the ripples basically froze in place. Without the repulsive pressure of the plasma, gravity became the dominant force, explains NASA.
Leftover clumps from the plasma contained more mass, which allowed them to collect additional material with their gravity. Over the course of hundreds of millions of years, the clumps eventually became stars.
Video Credit: NASA Goddard