In its purest form, it’s odorless, nearly colorless and tasteless. It’s in your body, the food you eat and the beverages you drink. You use it to clean yourself, your clothes, your dishes, your car and everything else around you. You can travel on it or jump in it to cool off on hot summer days.
Many of the products that you use every day contain it or were manufactured using it. All forms of life need it, and if they don’t get enough of it, they die. Political disputes have centered around it. In some places, it’s treasured and incredibly difficult to get. In others, it’s incredibly easy to get and then squandered. What substance is more necessary to our existence than any other? Water.
At its most basic, water is a molecule with one oxygen atom and two hydrogen atoms, bonded together by shared electrons. It is a V-shaped polar molecule, which means that it’s charged positively near the hydrogen atoms and negatively near the oxygen atom. Water molecules are naturally attracted and stick to each other because of this polarity, forming a hydrogen bond. This hydrogen bond is the reason behind many of water’s special properties, such as the fact that it’s denser in its liquid state than in its solid state (ice floats on water). We’ll look closer at these special properties later. Далее
Although nearly three-quarters of our planet is covered in water, only 1 to 2 percent can support terrestrial life. Growing human demand, the proliferation of urban sprawl, and wasteful agribusiness consumption are draining our reservoirs and straining water treatment, distribution, and disposal systems. As water is hijacked from rivers and streams, the amount of sand that accumulates on beaches also diminishes, threatening the health of vital coastal wetlands and wildlife.
Droughts, flooding, and other extreme weather events exacerbated by climate change are also making fresh water an increasingly scarce commodity. In fact, the struggle over the world’s depleting water resources, much like with oil today, is a crisis that will likely come to a head some time this century.But even if you live in an area with abundant water resources, helping to conserve what comes out of your faucet will also save you money and energy. Here are some ways you can help, excerpted from 50 Ways to Save the Ocean (2006, New World Library) by David Helvarg. Далее
From cooking fish on a rock to building a DIY wood gasifier from old cans, Paul Osborn of BC Outdoor Survival has shown us some pretty cool little survival tricks in his time.
But the title of his latest video had me a little flummoxed—can you really start a fire with water? It turns out that what Paul is talking about is creating a lens using nothing but water and household plastic wrap—and then using that lens to focus the sun’s rays on a piece of paper or other flammable material. (Like these DIY firelighters Paul showed us how to make before.)
It turns out that his water trick is not only possible, but relatively simple. The biggest challenges appear to be keeping the light focused, stopping your lens/balloon from dripping on the fledgling fire, and of course if you are a survivalist video blogger, maintaining steady camera work as you do it. Далее
Didn’t age like a fine wine…
One of the great scientific questions has now been answered. No, it’s not something about the Higgs Boson or the Riemann hypothesis… Rather, we now know what the water that has been sequestered 1.5 miles underground in Timmins, Ontario, for between 1 and 2.6 billion years tastes like. Barbara Sherwood Lollar, an Earth sciences professor at the University of Toronto, closed her eyes and took a sip of the world’s oldest water discovered so far for science. Далее
The results of a new study led by George Washington University Professor Tianshu Li provide direct computational evidence that nucleation of ice in small droplets is strongly size-dependent, an important conclusion in understanding water’s behavior at the nanoscale. The formation of ice at the nanoscale is a challenging, basic scientific research question whose answer also has important implications for climate research and other fields.
Ice cube (stock image). According to a new study, nucleation of ice in small droplets is strongly size-dependent, an important conclusion in understanding water’s behavior at the nanoscale.
The crystallization of ice from supercooled water is generally initiated by a process called nucleation. Because of the speed and size of nucleation — it occurs within nanoseconds and nanometers — probing it by experiment or simulation is a major challenge. Далее