Does hot water freeze faster than cold water? It seems obvious that the answer should be no, because all things being equal, hot water takes longer to cool down than cold water, and so it couldn’t possible freeze faster.

But observations over thousands of years, as well as countless modern experiments, have shown that the opposite is true – under carefully controlled conditions, hot water at times seems to freeze faster than cold water.

How is this possible? Well, that’s something that still has scientists baffled – in fact, they’re still struggling to prove the effect exists in the first place, as the first episode of Derek Muller’s new science channel, Sciencium, explains.

It turns out that freezing water is a lot more complicated than you might think. Read more

All living creatures are dependent on water to live. When it comes to humans, our brains and hearts are composed of around 70 percent water, while our lungs contain a whopping 80 percent – even our bones are about 30 percent water. To survive, we need close to 2.4 litres daily on average, some of which we get from food. 

But what happens if you’re allergic to water? That’s the case for a rare few, who have a condition called aquagenic urticaria. American teen, Alexandra Allen, was diagnosed with aquagenic urticaria in 2013 – her allergy to water means she has to limit her cleaning rituals to 5-minute cold showers twice a week, cut her hair short and became a vegetarian in order for her body to produce less oil.

“I’m told that someday, my throat might swell when I drink water, but if there’s one thing I’ve learned since getting this, it’s that we all have things to deal with in life,” she told People magazine in April. People with the condition restrict their eating of certain fruits and vegetables with high water content, and often opt for drinking diet soft-drinks instead of tea, coffee, or juice. Read more

An underground source of hot-rock energy may have the potential to produce low-cost fresh water, according to the University of Queensland’s Queensland Geothermal Energy Centre of Excellence.

The Centre’s research has found that Queensland has ample geothermal energy resources to power thermal desalination plants and provide clean water for small towns suffering from water shortages.

Centre Director Professor Gurgenci said the geothermal-powered desalination systems could play a pivotal role in helping ease the water crisis facing small towns.

“This may not be the solution for large-scale desalination needed for cities like Brisbane, but should have a significant contribution in smaller towns like Dalby and Maleny, which have recently experienced extreme water shortages,” he said. Read more

Thanks to the discovery of water trapped inside diamonds from deep underground, geologists are thinking our planet could have much more water inside than we ever knew.

Not only would this require a slight recalculation of the total amount of water our planet happens to hold, it would change how we model everything from the way heat moves through the crust to models predicting the frequency of earthquakes.

Researchers made the find by analysing the way X-rays diffracted through diamonds collected from southern Africa, China, Zaire, and Sierra Leone.

The water molecules found in these diamonds were squeezed into a solid form of ice, but they represent briny pools of liquid water that would be trapped in rocks far, far down – below a section of the mantle called the transition zone. Read more

How much water does it take to turn on a light? It took 10,000 litres to make your jeans. Another three big bathtubs of water was needed for your two-eggs-toast-coffee breakfast this morning.

We are surrounded by an unseen world of water: furniture, houses, cars, roads, buildings – practically everything we use and make needs water.

Even sustainable energy technologies such as solar power require water to generate electricity, writes Stephen Leahy.

“There is no way to generate energy without water,” said Zafar Adeel, co-chair of the UN-Water Task Force on Water Security and director of the Institute for Water, Environment and Health in Canada.

Even solar panels need regular washing to perform well. Wind energy might be an exception, Adeel told IPS from a water conference in Beijing being held during World Water Week.

There is growing recognition that peak oil is nowhere near as important as peak water because there is no substitute for water. The growing shortage of water — 1.2 to 1.7 billion people face scarcity — has alarmed many. Water has been identified as an “urgent security issue”, by a group that last year included both former U.S. Secretary of State Hillary Clinton and the InterAction Council, an association of 37 former heads of state and government. Read more