ScienceIQ.com

Lightning Striking Again

What's hotter than the surface of the sun, moves with incredible speed, lasts a few seconds and goes out with a bang? If you said lightning, you're right. Lightning strikes cause thousands of forest fires every year and occasionally cause the death of people. Few who have been hit by lightning live to tell the tale. Yet the process that causes ...

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LightningStrike
Geology

Water In The Ground

Some water underlies the Earth's surface almost everywhere, beneath hills, mountains, plains, and deserts. It is not always accessible, or fresh enough for use without treatment, and it's sometimes ... Continue reading

WaterInTheGround
Medicine

Your Friend, the Fat Cell

A healthy, adult human body contains about 35 billion fat cells. Each contains about 0.5 micrograms of fat. Stored fat is essential to good health. Fat is the body's principal energy reserve. It is ... Continue reading

FatCell
Biology

When A Bass Isn't A Bass

Chilean Sea Bass, a very popular though overfished deep-sea fish, is not a bass at all. It is actually a Patagonian Toothfish (Dissostichus eleginoides), or sometimes its cousin, the Antarctic ... Continue reading

SeaBass
Engineering

A Shear Mystery

Everyone has had problems with a ketchup bottle at one time or another. After struggling and only getting a few drops, a flood suddenly gushes out and buries your food. With perfect timing, the ... Continue reading

ShearMystery

How Sublime

DryIceShow of hands. How many of you can't resist playing with dry ice? Dry ice is carbon dioxide frozen to -109.3 degrees F (-78.5 C). Throw a piece in water and it bubbles and boils. Expose a piece to air and it turns into white fog. The thing that makes dry ice do these tricks is a process called sublimation.

When a solid changes directly to a gas, without first becoming a liquid, we say that it sublimates. At the right temperature, any solid will sublimate without enough pressure. On the surface of the Earth, H2O exists in all three states of matter, including the liquid state. Because there is enough air pressure pressing on the H2O, it can remain a liquid between 32 degrees and 212 degrees Fahrenheit ( 0 and 100 C). But CO2 needs a lot of pressure to form a liquid, about 1,000 pounds per square inch of pressure, much more than is found naturally on the surface of the Earth. So instead, it makes a quick jump from a solid state to a gaseous state. In space, with little or no pressure, (there is no gravity in outer space), sublimation is the rule and not the exception. You won't find any liquids on a trip to Pluto. Here on Earth, if you use dry ice, you won't get a big puddle on your floor, but you may get frostbitten.