Science Scoops


What’s That Smell?

In the classic E.B.White novel Charlotte’s Web, Templeton the rat keeps an unhatched goose egg in Wilbur’s pigpen. One day, the boy Avery tries to capture Wilbur’s spider friend Charlotte. Avery slips, the egg is broken, and the smell of rotten egg fills the barnyard. People and animals run for cover, and Charlotte is saved.

The gas that makes rotten eggs smell, well, rotten is called hydrogen sulfide (chemical formula: H2S). According to two scientists, hydrogen sulfide may one day save lives in another way.

Hydrogen sulfide not only smells bad, but also it is poisonous. It replaces oxygen in the body’s cells, and without oxygen, our cells die. Usually.

In the June 2005 issue of Scientific American, however, researchers Mark Roth and Todd Nystul report that laboratory mice placed in pure hydrogen sulfide gas do not die, but instead enter a sort of hibernation. The mice lose consciousness, and their body temperature drops. After six hours, the mice are given oxygen, and they recover fully.

The scientists believe that as long as all the oxygen is replaced, each mouse’s cells shut down completely. With just a little oxygen present, some parts of their cells might try to keep operating. This could create chemical imbalances that lead to cell death. The key is to replace all the oxygen with hydrogen sulfide. Roth and Nystul believe that this technique might someday be used on humans.

If the scientists are right, then human accident victims might be sent into hibernation with hydrogen sulfide gas. This would give rescue workers extra time to transport injured patients to hospitals. Many lives might be saved by a stinky gas found in rotten eggs.

Expansive Crystals

Who would argue? When you place a solid in a vise and increase the pressure, it should compress, right? Well, an international team of scientists claims that they have discovered a crystal formation that appears to do just the opposite: It appears to expand under pressure.

Meet natrolite — a crystal whose three-dimensional structure contains regularly spaced pores. Yongjae Lee at Brookhaven National Laboratory in Upton, NY, and his colleagues discovered this counterintuitive behavior. They placed a natrolite crystal in a cell filled with a water-alcohol mixture and then squeezed it between two diamond anvils to pressures up to 50,000 times normal atmospheric pressure. Actually, the crystal initially compressed as expected. But when the pressure ranged between 8,000 and 15,000 times atmospheric pressure, the crystal appeared to expand. As the pressure increased further, however, the material compressed again.

Was the expansion some kind of illusion? No. An X-ray analysis of the expansion suggests that the material expanded because water molecules from the water-alcohol solution were squeezed into the pores within the natrolite, causing it to temporarily expand.

The researchers have already come up with a use for natrolite, namely as a crystal sponge for chemical cleanups. You see, when natrolite expands, so too do its pores. So natrolite can absorb pollutants when it’s under pressure. By simply releasing the pressure, the pores will get smaller and trap the pollutants inside.

New Elements Created

Scientists at the Lawrence Berkeley National Laboratory in California are celebrating a smashing success. The researchers used a cyclotron particle accelerator to bombard a lead target with projectiles of krypton atoms. When the krypton atoms smashed into the lead target, the two elements occasionally fused to create the newest, heaviest elements yet: element 118 (118 protons, 175 neutrons) and element 116 (116 protons, 173 neutrons). After forming, element 118 decayed in 0.0001 second to element 116, and then to the already-known element 106 (seaborgium).

The discovery came as a complete surprise to most nuclear chemists. No one thought that such heavyweights could be produced, until recent calculations suggested it could be done. Now the periodic table – a tabular arrangement of elements by their atomic number (the number of protons in an atomic nucleus) – has two new members.

Vanilla Beaners vs. Chocolate Chompers

In summer, nothing satisfies you like a lick of cool, delicious ice cream. The problem is that we’ve got to be concerned about the fat and calories. Ah, but thanks to new ice cream formulas and a variety of fat replacers, there are dozens of ice cream products on the market today that will help us stay healthy.

By definition, low-fat ice creams contain less than three grams (27 calories) of fat per half-cup serving. Though fat grams are regulated, calories do vary greatly among brands depending on the amount of sugar used in formulas – so we still have to be careful. But that is not what this scoop is about. The question, ice cream connoisseurs, is this: Do low-fat ice creams retain the taste and texture of traditional ones?

To find out, chemist Ingoll U. Gruen conducted a taste test at the University of Missouri in Columbia. The conclusion? Most people enjoyed the taste of low-fat chocolate ice cream as much as they did that of traditional chocolate ice cream.

GASP! This is a most surprising and startling finding. Who were these alien taste testers? Certainly "vanilla-beaners" are chuckling, because when they were tested, they turned up their noses at the low-fat versions of their favorite flavor. Low-fat vanilla ice cream, they said, had a harsher, less smooth taste. Are the taste buds of "vanilla beaners" superior to those of "chocolate chompers"? Gruen says they aren’t. "Chocolate is a very complex flavor," he explains, resulting from about 500 different compounds. The complexity of chocolate probably masks any taste change due to the lack of milk fat. Vanilla is a simpler flavor.

Well, if you believe that, there’s a Face on Mars we’d like to show you.