This Is What the Birth of the Universe Sounded Like | Mark Whittle | TED

The universe, contrary to popular belief, is filled with sound waves traveling through its tenuous atmospheres. One of the most fascinating cosmic sounds originates from the early universe, shortly after the Big Bang. By observing light from distant regions, we look back in time, even to a period before galaxies formed. This light, from the universe's hot, glowing youth, has traveled through an expanding space, stretching from light waves to microwaves – the cosmic microwave background. Initially, this background appeared uniform. However, with more sensitive telescopes, slight variations in brightness emerged, revealing patches of higher and lower temperature and pressure in the primordial gas. These are the peaks and troughs of massive sound waves, about 90 decibels loud (rock-concert level) but at an incredibly low pitch, 50 octaves below human hearing. These sound waves were generated by gravity, as denser regions of matter pulled in surrounding gas, causing it to compress and rebound, creating spherical waves. The distribution of matter created a range of wave sizes, like organ pipes of different lengths, producing a spectrum of pitches. Analyzing this spectrum reveals a fundamental tone and harmonics, similar to a musical instrument or a human voice, though broader. Computer calculations accurately model this primordial sound, matching the data and providing insights into the universe's fundamental properties. This acoustic era ended when the universe cooled and became transparent, freezing the sound waves in place. These frozen waves influenced the formation of stars and galaxies, leaving faint traces in the large-scale structure of today's universe. Ultimately, these cosmic structures may trace back to quantum vibrations during the universe's inflationary period, connecting the quantum and cosmic realms. The speaker also presented a musical interpretation of these primordial sounds, transforming them into melodies and rhythms, and even a choral work, highlighting the profound connection between the universe's origins and our own existence as conscious observers.