Probably One of the Most Important Cosmological Discoveries in A Long Time: Baryon Acoustic Oscillations

Probably not of interest to most of you, but if you are serious about understanding the claims of “Big Bang” cosmology, you have to understand Baryon Acoustic Oscillations. This link is to a new article in Sky and Telescope magazine (for amateurs who love astronomy).

The basic idea is that the early universe was opaque to light since protons, electrons, neutrons, etc, were not combined into atoms because the much smaller universe was very hot. Light couldn’t travel very far (were talking nanometers here) before being absorbed or bouncing off of things. As a result, light (photons) caused an enormous pressure that pushed matter away from each other. This caused matter to be in large bubbles, like a soap bubble, with all of the “stuff” on the outside shell, but not inside. These bubbles are on the order of 400 million light years across. When the universe cooled enough for atoms to form, something amazing happened…the universe became transparent to light. Light could now travel freely from one place to another, moving light years or even billions of light years without hitting anything. Th moment in time that atoms formed and the universe became transparent to light is what is called the Cosmic Microwave Background Radiation signal you might have heard of. Since light could travel freely the outward pressure went away and gravity took over, allowing star and later galaxies to form. In the lingo of cosmology the universe stopped being radiation dominated and became matter dominated. (We now live in a dark energy dominated universe by the way. That change happened after this event we are talking about.)

The key is that the bubbles of matter produced by the BAO effect can still be measured in the present universe by looking at millions of galaxies and measuring the distances to them (assuming of course the distance can be measured). This has been one of the goals of the Sloan Digital Sky Survey for years. Results are just being released and the BAO signal is dramatically clear. The lingo is the discovery is 10 sigma, meaning there is a 1 in 6 with 22 zeros chance that random noise would produce the observed bubbles. This means the bubbles of matter are real.

Of course, it is worth noting that a Big Bang cosmology predicts BAOs.