Question #2e212

1 Answer
Nov 4, 2014

Wow, that's a compelling question and a frightening one. Let's set aside the worry that a thick atmosphere filling the earth's orbit would cause it to spiral toward the sun. And let's also not worry about how all of that gas spiraling toward the surface of the sun would crash into it at such speeds that it would heat the surface unbearably and scorch the inner planets with the extra brightness.

We receive energy from the sun at a rate of about 120 Watts per square meter. Suppose that the sun were able to radiate some of that energy as sound. The sun is white hot. Yes, we do teach children to draw it as yellow. And in the late evening we can sometimes look directly at it through lots of atmosphere and see it as orange-yellow. But consider what you see when you look at a sheet of white paper out in the sun in the middle of a clear day. It's not yellow, blue, or any other color. It's white because the sun radiates lots of light across the entire visible spectrum. If you look directly at the sun in the middle of the day, it overwhelms the photo receptors in your eye. Every color receptor is signaling full-blast. We call this white (and, after enough time: blindness).

Let's assume that we can setup the layers of gas between us and the sun so that it transmits about 1% of its power in the audio rather than as light. That's about 1 Watt per square meter. The sound level would be 120 dB. That's about as loud as a chain saw, but not quite as loud as a jet engine. It is, however, on the threshold of being painfully loud. In fact, it would take all of the energy from the sun radiated as sound waves to equal the sound of a jet engine.

But what would it sound like? Would we hear low frequencies from the large solar flares? Would we hear lots of little pops from smaller solar eruptions and gas crashing back down the the surface. Could we hear a specific whine as gas twists through the magnetic field of a solar prominence? Or would it be just too deafening to hear anything? The sound would be loudest at noon. It might taper off gradually as you approached sunset and linger like the fading twilight after the sun disappears from view. I'd hope for a low distant rumble that you can hear from near some active volcanoes - just a constant background growl.