I was helping my sister pick her college classes for her first semester, and one of the course descriptions caught my eye:
Despite its title – ``The Big Bang’’ – our modern understanding of the birth and youth of the Universe has only recently included sound —pressure waves coursing through the hot thin gas of an ancient expanding fireball. And yet, it transpires, those sound waves are the seeds from which all future structure grows — from stars, to galaxies, to the galactic tapestry which extends to the cosmic horizon. Even more remarkable, the cosmic sound is an evolving chord, with a fundamental and harmonics — the Universe acts like a giant musical instrument! This seminar explores these newly discovered acoustic aspects of modern cosmology: how we study the ancient Universe; how sound was generated; how we use sound to measure the Universe’s properties; and how sound is ultimately transformed into the first generation of stars.
This sounds intriguing, but as I’m not an incoming freshman thereabouts, I can’t pick up any further detail there. What do we know about the role of sound in the early universe?
Quite a bit, it appears.
http://www.cnn.com/2004/TECH/space/06/02/primal.scream/
http://www.space.com/scienceastronomy/astronomy/inflation_010429.html
BOOMERANG has provided the most precise measurement to date of several of the key characteristics which cosmologists use to describe the universe. Images reveal hundreds of complex regions visible as tiny variations in the temperature of the cosmic microwave background.
The early universe is full of sound waves, compressing and rarefying matter and light, much like sound waves compress and rarefy air inside a flute or trumpet, said Paolo deBernardis, an Italian team member of the BOOMERANG project, in a NASA release detailing the BOOMERANG findings.
By studying the difference in the “harmonic content” imprinted in the cosmic microwave background, the detailed nature of the universe can be discerned.
Google on sound early universe and you’ll get zillions of hits.
So is your sister considering taking a university seminar at the University of Virginia?:
http://www.virginia.edu/provost/usems.htm