It haunts you when you're trying to eat your dinner in peace. It disturbs you when you're trying to watch TV. It even keeps you awake in the wee small hours. It's the insufferable, interminable drip-drip-dripping of a leaky tap. Well, scientists at the University of Cambridge have finally figured out what's causing what is almost certainly the world's most infuriating sound.
A mesmerising video shows the moment a water droplet bounces off a surface and is made to spin at more than 7,300 revolutions per minute (RPM). The properties of a droplet change depending on what it hits and scientists have manipulated this process to make them gyrate. Scientists say the findings could allow for future developments for hydro-energy collection, self-cleaning and anti-icing. Researchers from the Institute of Chemistry, part of the Chinese Academy of Sciences, say the observed process opens up a promising avenue for the delicate control of liquid motion. Huizeng Li and colleagues published the research in the journal Nature Communications and write in the abstract: 'Droplet impacting and bouncing off solid surface plays a vital role in various biological/ physiological processes and engineering applications.
Bubbles containing trapped bacteria can act as tiny'microbial grenades', new research shows. Scientists found these tiny natural explosives had the power to launch microorganisms into the air at speeds of more than 30 feet (10m) a second. A single droplet is thought to carry up to thousands of microorganisms, and each bubble can emit hundreds of droplets. A bubble covered in bacteria floating on the water's surface also lasts ten times longer than an uncontaminated one, scientists also found. During this time the cap of the contaminated bubble gets thinner, according to researchers at Massachusetts Institute of Technology (MIT).
It's the sound of water droplets falling one after another, maybe from a leaky faucet or through a cracked ceiling. It's the kind of sound that can keep you up all night. University of Cambridge engineer Anurag Agarwal feels your pain. While visiting a friend in Brazil in 2016, Agarwal couldn't ignore the water that steadily dripped through the leaky roof and fell into a bucket below. "It was a rainy period, and the downfall was torrential," he says.
While action films would have you believe otherwise, bullets travelling through water are far slower – and less accurate – than those fired through the air. But now, DSG Technology has developed a range of supercavitating ammunition that can effectively'swim' longer distances to hit the target. As a result, the firm says the Cav-X bullets can be used with standard weapons in multi-environment battles for diver support, harbour protection, and even submerged shooting positions. While action films would have you believe otherwise, bullets travelling through water are far slower – and less accurate – than those fired through the air. But now, DSG Technology has developed a range of supercavitating ammunition that can effectively'swim' longer distances The Cav-X supercavitating bullets come in 5.56mm, 7.62mm, and 12.7 mm, and can be fired from'air to water, water to water, and water to air, including partially-wet weapons, semi or full auto,' according to DSG.