How long does it take your kettle to boil after you switch it on? Depending on a number of things – including how much you filled it, the hardness and starting temperature of the water and the efficiency and condition of your kettle, it’ll usually take between one minute and several. Not long to wait for a cup of tea, you might think – but for those who really need to get to that cuppa as soon as possible, scientists might have found a new way to do it.
Researchers at the Hamburg Centre for Free-Electron Laser Science have concocted a way to boil water in less than one-trillionth of a second – literally faster than the eye can see. Using a concentrated “flash” of terahertz radiation, water goes from cold to 600 degrees centigrade in next to no time. Terahertz radiation is made up of electromagnetic waves, and the flashes are generated with free-electron lasers that instantly make water molecules vibrate extremely violently. After the heating process has taken place, the water molecules remain intact.
However, don’t expect to see this process replacing the kettle in your home any time soon – in fact, the process is currently completely theoretical, although it has been tested in computer models. Rather than helping you to get to your morning cup of tea a few minutes earlier, it’s likely that scientists will use the ultrafast heating process to perform new experiments in chemistry and biology.
“The idea is to heat-up the ‘solvent’ so that many molecules start the desired chemical process at the same time and then watch the reaction evolve,” said Dr Oriol Vendrell of the centre. He added: “The transient and hot environment achieved by the terahertz pulse could have interesting properties, like a matrix to study activated chemical processes.”