Here are some things that won't make water boil faster: watching the pot, adding salt. And here's something that does: nano-structures made from plant viruses, which subtly alter the physical properties of bubbling water.
Everyone who has impatiently watched a saucepan boil knows to watch for the bubbles that start forming at the bottom. These bubbles actually make a huge difference; they form an insulating layer between the stove and the water, so that heat can't get to the water. But what if the bottom of your saucepan wasn't a simple, flat surface?
The Guardian reports on intriguing research by Matthew McCarthy of Drexel University. McCarthy's lab is growing tobacco mosaic viruses, which commonly infect tobacco plants. Their viruses are genetically modified to have tiny hooks, so they will stick to almost everything. The Guardian explains:
When poured over a surface, the virus self-assembles into a layer of nano-tendrils, each pointing upward like a blade of grass. The surface is then covered with a microscopically thin layer of nickel, rendering the virus inert. The remaining "metallic grass" wicks liquids across the surface, allowing the water and element to remain in contact.
When these nickel nano-structures are used to coat a surface, they prevent bubbles from sticking against it. Less insulation means more heat transfer -- three times more, in fact. That translates to water that boils more efficiently.
As handy as this might sound for your stove, the technology might be most useful in industrial situations, such as nuclear reactors or supercomputers that need cooling. But it's good to know that even something as simple as heating water can be improved. [The Guardian, Drexel University]