Science Scoops


Killer Sound!

There’s a war going on, and the sound could kill you! That’s right. Welcome to “Car Wars” and the fight to build the world’s most powerful sound system.

The most powerful mass-produced car stereo appears to be a 1,200-watt system. Troy Irving of Augusta, MI, might think that this is laughable. Just look inside his 18-year-old Dodge Caravan. It has 72 amplifiers and 36 big 16-volt batteries, which put out 130,000 watts of power. That’s enough energy to rattle his nine 5-inch subwoofers or power 52 homes for a couple of seconds. You won’t see Irving driving this sound machine down the street. Weighing in at 10,000 pounds, the minivan, which is filled with $80,000 worth of sound equipment, isn’t meant for the road — mainly because there’s no room for a driver.

But who cares? The purpose of this audio system is to play a single frequency (74 Hertz ); 1 Hz is a frequency cycle of one one sound wave per second. The system is also designed to blow the “ears” off of competitors. (Actually, the competition is held behind closed car doors — with no ears present. Audiologists are thankful for that.)

Irving, you see, is a “dB (decibel) drag racer.” According to Popular Science magazine, dB drag racing is an obscure but growing international “sport” in which competitors blast their systems for two or three seconds at a time to establish whose sound system is loudest.

The loudest score Irving ever got was 176.6 dB — almost 10,000 times louder than a shotgun blast (140 dB). Although that’s a world-class sound, it’s a bit shy of the loudest ever measured. That honor belongs to Mike Jones of Lubbock, TX. He holds the overall world record for the loudest sound in his class (extreme 5,000 watts plus): 178.7 decibels! The magnitude of the sound, Jones says, is enough to “suck air out of your lungs; you would throw up and it would leave you disoriented and sick for days. This is the kind of loudness that causes a heart murmur.”

If you’re interested in checking out yearly competition stats, then take a deep breath, protect your ears, and visit Jones’s Web site: www.termpro.com/asp/competitorstats.asp?Competitor_ID=1190

CAUTION: Any sound system reaching even 100 decibels can be harmful to your hearing!

Secret Chambers?

How do you find a secret chamber in a 206-foot-high Mexican pyramid? With space dust, of course!

That’s right. Arturo Menchaca, head of Mexico’s National Autonomous University’s physics institute, and his colleagues are installing a device to detect muons — subatomic particles left over when cosmic rays hit Earth. You see, muons can pass through solid objects. When they do, they leave tiny traces that a $500,000 muon detector will measure, like an X-ray machine does.

Menchaca and his team are using this technology to search for burial chambers inside a 2,000-year-old Mexican pyramid at the sacred site of Teotihuacan (TAY-oh-tee-HWA-can — The Place Where Men Become Gods). Since there are fewer muons in an empty space than in solid rock or earth, the scientists will be able to spot any holes inside the pyramid. If they detect such a hole, they will likely tunnel into the pyramid in the hope of finding a burial chamber and solving a long-standing puzzle: Who ruled the city of Teotihuacan? At its pinnacle, the city harbored 150,000 people, and its influence reached hundreds of miles to modern-day Guatemala — but no one today knows the city’s true name or who its founders were.

This attempt would not be the first time such technology was employed. A Nobel prize–winning scientist, Luis Alvarez of the University of California, Berkeley, used muon technology in a scan of the Khephren pyramid in Egypt in the 1960s, proving that there were no hidden chambers in that pyramid

Massive Mystery Flashes!

We usually associate lightning with the region of air between a cloud and the Earth. About 14 years ago, however, strange luminous events (known as red sprites and blue jets) were photographed accidentally in the air just above thunderstorms. Recently, however, a new phenomenon has been imaged above a thunderstorm in the South China Sea — an enormous 55-mile-high (88-km), luminous electric discharge that traveled from the top of a thunderstorm to the very edge of Earth’s atmosphere!

Atmospheric physicist Han-Tzong Su (National Cheng Kung University in Tainan, Taiwan) and his team first observed the new phenomenon last July during a thunderstorm raging near Luzon Island in the Philippines. They were actually in Taiwan observing distant storms with the hope of photographing a sprite or some other known transient luminous event. For that purpose, Su had set up low-light-level cameras at the southern tip of Taiwan. Low-light-level cameras are usually needed because these events appear and disappear so quickly that they are not visible to the human eye.

To Su’s surprise, he and his team had captured not a jet or a sprite, but something massive and entirely new. They observed three tree-shape jets and two carrot-shape ones spreading outward and upward from the thundercloud. The researchers named these events "gigantic jets." They cover 25 miles (40 km) at their widest point, and are estimated to have a volume of about 7,200 cubic miles (30,000 cu. km). "That’s equivalent to ten billion Olympic-size swimming pools," says Su. Despite their scale, each of the events had come and gone within less than half a second.

It’s the first time that luminous events spanning the entire distance from the cloud top — around 10 miles (16 km) up — to the ionosphere have been recorded, he says. Su believes that they may be an electric link between the thunderclouds and the ionosphere. They may also be playing an important role in atmospheric chemistry. The discharges of current from these jets could cause reactions between gases to produce ozone, or convert nitrogen to a form available to life on Earth’s surface.

The Speed of Gravity

It’s common knowledge that light travels at a speed of 186,000 miles per second (about 300,000 km per second). But what about gravity? What’s its speed? Well, Albert Einstein — who formulated the most basic theories about space and time in 1915 — had assumed that gravity moved with the speed of light. But until now, no one had been able to measure it. Now astronomers have confirmed that, of course, Einstein was right! The speed of gravity does match the speed of light.

Astronomers Edward B. Fomalout (National Radio Astronomy Observatory) and Sergei Kopeikin (University of Missouri) reached that conclusion after observing a rare alignment of a star and a planet. Actually, the "star" in question was a quasar — the energetic nucleus of a very distant galaxy. Using 10 radio telescopes scattered across the Earth (from Hawaii to Germany), the researchers followed Jupiter as it passed right in front of the quasar. Once the two were aligned, they precisely measured how the quasar’s light was bent by the gravity of Jupiter.

Because scientists knew the exact mass and orbit of Jupiter (thanks to flybys by NASA spacecraft), they were able to predict the amount of deflection and when it should occur. However, the deflection of light would occur as predicted only if the speed of gravity equals the speed of light.

The scientists were not disappointed. Detecting the minute deflection of light, however, was not easy. The task was like trying to measure the size of a silver dollar lying on the Moon’s surface or the width of a human hair from 400 kilometers away.

The speed of gravity is one of the last fundamental constants in physics to be established. Now physicists can test such ideas as that of the superstring, which argues that fundamental particles in the universe are made up of small vibrating loops or strings.

"I Spy" Butterflies

If a butterfly flaps its wings in a wind tunnel, will a revolution in aeronautics occur? That is not a Zen question. In fact, it’s a distinct possibility — one that has attracted the attention of toy manufacturers and the military.

The flap is over a bit of research conducted by British zoologists Robert Srygley and Adrian Thomas (University of Oxford), who made a major breakthrough in our understanding of how red admiral butterflies move their wings.

Butterfly in a wind tunnel
Butterfly in a wind tunnel
(Courtesy Robert Srygley and Adrian Thomas, University of Oxford)

The researchers trained the butterflies to fly toward a fake flower at the end of a wind tunnel. On their way, the butterflies moved through wisps of smoke that the scientists injected into the chamber. High-speed photographs were then taken to see how the wings moved through the smoke. What Srygley and Thomas learned is that butterflies do not flap erratically. Instead, the flapping results from the "mastery of a wide array of aerodynamic mechanisms."

For instance, the red admirals can fly very efficiently, meaning they produce very little turbulence in the surrounding air when they flap their wings. But, they can also move their wings to create (deliberately) swirling vortices in the surrounding air to give them extra lift. What’s more, these butterflies can switch effortlessly among these mechanisms from stroke to stroke. The results will be invaluable to engineers trying to build micro air vehicles, the researchers say.

If engineers ever succeed in understanding just how insects exercise control over such a wide range of abilities, there will be a revolution in aeronautics. Tiny machines that fly like insects will soon be a reality.

"We are now moving in the direction," Srygley says, "where we soon will be able to build 10-centimeter-wingspan aircraft, either radio-controlled or autonomous. They would make an entertaining toy, but if you put a camera on them, then security agencies could send them into small spaces such as caves to see what was going on."

Einstein’s Limit of Light

We all talk about the speed of light flippantly, as if it’s a constant. Light travels at a speed of 186,000 miles per second, we say. But this is not always true. The speed of light may be constant in a vacuum, but it travels more slowly when it’s traveling through, say, air or water.

Well, Kenneth Brecher of Boston University is sick of such generalities. He wants to lay down the law. That’s why he recently proposed that the venerable old speed of light (in a vacuum) be renamed "Einstein’s constant." There’s a Newton’s constant of gravitation, and Planck’s constant of quantum mechanics, so why not an Einstein’s constant? Einstein’s constant will do away with any confusions that might arise when scientists are discussing the speed of light in an environment that is not a vacuum. Think of it. Just say, "Einstein’s constant," and everyone knows you’re talking about the speed of light in a vacuum. Besides, Brecher says, Einstein’s constant also defines other concepts, such as the relationship between space and time and between matter and energy (the famous E = mc2).

Light May Have Slowed Down

Quick, what’s the speed of light?

Well, if you’re on your toes, you would have answered, "To which time are you referring, the past or present?"


Actually, the speed of light, that once-universal constant of 186,000 miles per second, may not be so constant after all. Astronomers now believe that early-on in the universe’s history, the speed of light may have been faster than it is today. If that’s true, nature just threw us a curve ball.

The change is reflected in what astronomers call the "fine-structure constant." The measure of this constant depends on three supposedly fixed quantities, including the speed of light. Well, three years ago, John Webb and his colleagues at the University of New South Wales in Sydney, Australia, used a telescope on Mauna Kea, HI, to determine the fine-structure constant at different points in the universe’s past. They found that six billion years ago, the fine-structure constant was smaller than it is now by about 1 part in 100,000. Supporting evidence came recently when Webb’s team gathered twice as much data, finding that the fine-structure constant changed even more dramatically when they looked back as far as 12 billion years ago.

The variable "constant" contradicts the standard model of particle physics, says Brian Greene, a physicist at Columbia University in New York City. But it might fit into newer theories aimed at unifying all the forces of nature, he says. "If this research holds up, it surely has to be one of the more important discoveries in fundamental physics," Webb says.