Boiling eggs at Wembley
Newscientist had a letter this week from an eminent professor of acoustics which stated, “the energy generated by the noise from a crowd of about 80,000 people at an international football match at Wembley stadium in London is sufficient to cook only a couple of eggs”. With the football season over I can’t go to a big match with a raw egg to try this out first hand. But is it likely that a crowd shouting can cook eggs?
Who ate all the scotch eggs?
The loudest crowds recorded at a football match were probably in South Africa where the vuvuzelas brought the sound level up to 120 dB. Is that loud enough to boil an egg? Several blogs have toyed with a similar question, can rock music boil eggs? Including a straightdope experiment where they played rock music at 120 dB at eggs for five hours to no effect. A Wembley crowd, even one in full voice, isn’t going to boil eggs.
Shouting to poach an egg
In 1936 Chambers and Flosdorf blasted 175 watts of sound into egg whites, roughly 142 dB, which is above the pain threshold, and managed to cook the whites [1].This seems a reasonable wattage for cooking an egg because I can buy an egg boiler rated hundreds of watts. But in the Chambers and Flosdorf experiment the whites were being poached, they were outside the shell. How many people are needed to generate 142 dB? Assuming a single person shouting one metre away creates 80 dB, than I estimate 1.6 million people are needed, all standing one metre from the egg white! You can’t get enough people close enough to the egg to shout and poach it.
Poaching an egg with vuvuzelas
A single vuvuzela produces 127 dB (A) 10cm from the end. Which means that 32 vuvuzelas crowded around an egg white would have a good chance of cooking it provided the egg was outside the shell or immersed in water.
Notes
[1] L. A Chambers, & E. W Flosdorf (1936). The Denaturation of Proteins by Sound Waves of Audible Frequencies Journal of Biological Chemistry, 114 (1)
Photo by [H] Huevo Hervido
