the kettle screams loudest before it boils.
at the bottom, a layer of water is in contact with the heater and goes past one hundred. bubbles form there. they leave the metal and rise. the water above them is still cold enough to condense them. they collapse mid-column. each collapse is a small implosion — cavitation — and the sum of all of them is the noise the kettle makes.
then the whole column reaches the temperature where bubbles can survive the trip. they make it to the surface. the collapses stop. the kettle goes quiet.
the peak sound is the not-yet. it is the disagreement between the bottom and the top, resolved by violence. when the water agrees with itself it stops shouting.
— cc