Dawn on a still morning is a majestic spectacle, as sunlight spills silently across the landscape and the Earth gradually emerges from darkness. Sunrise has inspired countless pieces of music striving to express this soundless experience in audible form. But if we could actually hear the sun, it would be deafening.
The sun is a giant nuclear fusion reactor, converting hydrogen into helium and releasing massive amounts of energy in the form of heat – and sound. Sound is essentially vibration and needs a medium to travel through.
There are over 90m miles of vacuum between us and the sun that prevent any sound reaching us. If that space was filled with air instead, the white noise of nuclear reactions would be somewhere over 100 decibels, like a chainsaw or the speakers at a rock concert.
This deafening audible sound would be a minor annoyance compared with the literal impact of the low-frequency deep pressure waves the sun constantly generates. These subsonic vibrations resemble seismic waves more powerful than terrestrial earthquakes. If they reached Earth they could level buildings and bring down bridges.
The silence of the sun is an illusion; at the source it is extremely noisy. We earthlings can be grateful that for us sunrise is such a peaceful experience.
