Cosmic Microwave Background
The oldest light in the universe
The Cosmic Microwave Background (CMB) is a faint thermal signal, detectable only by radio telescope, which originates from the very early universe, over 13.7 billion years ago. At that time, the universe was small in size and extremely hot – filled with light and plasma like the core of our sun. As the universe cooled, the conditions became right for atoms to form, and this early light was free to propagate throughout the expanding space. This is what we observe as the CMB, only now, due to the stretching of its wavelength, we observe it not as light, but as thermal radiation. The signal is almost, but not quite, uniform – the most perfect noise source found in nature, averaging at 2.725° above absolute zero.
The sound of the Cosmic Microwave Background, recorded as radio waves by Arno Penzias and Robert Wilson at Bell Labs, 1964.
Within this noise, however, are vital clues to the origin of the universe, dark matter, the existence of multiverses and cosmic bubble collisions:
One method of analysing the signal is to compute the power spectrum of the signal across the entire sky, comparing temperature fluctuations from point to point to discern patterns and wave-like functions. This analysis reveals a series of harmonically related peaks between distances of 0° to 2°, indicative of waves in the original hot plasma.
In order to experience these patterns, physicist, Dr. Matthew Kleban and composer, Dr. David Ibbett, have collaborated to produce a sonification of this data, collected by NASA’s WMAP probe. By mapping values to frequency (multipole moment) and amplitude (fluctuations), a chord can be produced which reveals the underlying harmonic relationships of the signal.
This sonification simulates the gradual emergence of this chord from total noise - a journey from the early universe to the present day - and goes on to increase the intensity of the peaks to allow the universal harmonies to shine out:
Matthew Kleban's lecture on the CMB and Cosmic Bubble Collisions, filmed at MoR: Origins, May 2016:
Musical works commissioned by Music of Reality:
Fantasy on a CMB Sonification
An improvisation on the many sounds of the CMB - including radio static, the power spectrum sonification, the sonification at harmonic multiples, and instrumental recreations of the universal harmonies.
- David Ibbett