Everyone loves a bit of Matey in the bath. Those nice soft bubbles on your skin while you re-enact naval battles and slowly turn into a giant prune.
Yes, there's nothing quite like a good long soak in a bath, but it now turns out that bubble bath has an additional excellent quality - it keeps your bath warmer for longer.
Scientists at the Cavendish Laboratory at Cambridge University were posed a question by Stephen Tindal, who asked whether a thick layer of bubbles on the top of a bath would make any significant difference to the heat retention - in the same manner that bubble wrap can insulate.
Professor Eugene Terentjev initially hypothesised that a thick layer of bubbles would indeed reduce the loss of heat, primarily by the straight diffusion of heat into the air and in water evaporation. However, she believed that the loss of heat via the direct contact of water with the bath tub body would be a more efficient sink of heat - particularly if the bath was an old-style cast iron one rather than a modern acrylic bath.
However, Dave Ansell conducted an experiment on a small scale, taking two identical washing up bowls, filling them with 10 centimetres of water and bubble bath mixture in one, frothing it up to create a layer of bubbles. Both started at 44 degrees centigrade, but an hour in, the bubble bowl was at 38 degrees, while the uncovered one was at just 34 degrees. He found that the bubble bowl was losing heat "at just slightly more than half the rate of the one without bubbles, which means that the bubbles are actually working as a very, very effective insulator."
So there you have it - get bubblin' and you'll be hot, hot hot.
[via The Naked Scientists]
(Images: Rex/The Naked Scientists)