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Science Made Simple
Science in the News - 1997

OCTOBER, 1997

Learning One Thing at a Time

We all know that it takes a lot of practice to learn a new physical skill. It also takes time. A new study has shown that your brain needs 5 to 6 hours to permanently store these new memories.

As you practice a new skill, memories are first stored in a temporary location in the front of the brain. Later, they are moved to a permanent place in the back. Working on a second new skill during those 6 hours could erase memories of the first skill. It may be better to spend that time on things you already know.

Fastest Car on Earth

On October 15, a British jet-powered car became the first land vehicle to officially travel faster than the speed of sound. It happened 50 years and a day after pilot Chuck Yeager first flew through the sound barrier.

The car, called the Thrust SSC, was driven across a 13 mile course in the Nevada desert by Andy Green, a Royal Air Force pilot. To be official, there had to be two runs completed within one hour. The first run was clocked at 759.333 mph and the second at 766.609 mph. They were averaged together to give 763.035 mph. The speed of sound, which depends on altitude and weather, was calculated to be 748.111 mph, so Green traveled at Mach 1.02.

This was not the first time that Green drove the SSC faster than the speed of sound. On October 13, he made two runs averaging 762 mph, but missed the official record. Those runs were not completed within one hour because of problems with the drag parachute used to slow the car down.

Powerful Star

There is a star near the center of the Milky Way Galaxy that puts out 10 million times more energy than our Sun. It is about 25,000 light years from Earth and can not be seen with the naked eye because interstellar dust absorbs most of its visible light. The Hubble Space Telescope used a sensitive infrared camera take its picture.

It is called the Pistol Star, because it is surrounded by a bright, pistol-shaped nebula (gas cloud.)

The star is huge, at least 60 times as massive as our sun. It has a radius of 93 to 140 million miles. For comparison, the Sun's radius is 430,000 miles, and the distance from Earth to the Sun is about 93 million miles. As large as this star is now, it was even bigger when first formed, between one million and three million years ago. Then, it may have been up to 200 times as massive as our Sun.


SEPTEMBER, 1997

Happy Anniversary

This month, Elmer's® Glue celebrates its 50th anniversary. And it is hard to imagine life without it. A short history lesson: Borden Inc. bought a small glue company named Cascorez in 1929. Then, in 1947 they began selling Cascorez All-Purpose Glue, the first white glue for general and household use. It was a dry material that had to be mixed with cold water, and cost 29 cents for 2 ounces. Elmer the bull has been around since 1939. In 1949, the company changed its name to Elmer's. Elmer and Elsie the cow (which appears on Borden's milk) now have a baby bull, named Elmer Jr, or E.J.

The microwave oven also celebrated an anniversary, its 30th. The original Amana Radarange sold for $495, and weighed 91 pounds. At first, it was greeted with a lot of suspicion, and even fear. People did not know what to do with it. Today, almost 90 percent of US homes have a microwave oven. Americans say it is the number 1 new technology that has made their lives better. (Number 2 is the telephone answering machine. Number 3 is the automated teller machine.)

Calcium and You

Nutrition experts have increased the recommended daily amount of calcium for most people by about one serving per day. Adults should get 1000 milligrams (previously 800 mg.) This is the amount in 3 to 4 servings of calcium rich foods daily. Teens, whose bones are still growing, need more - 1300 milligrams - which is 4 to 5 servings daily. One serving is one 8 ounce glass of milk or calcium-fortified orange juice, one cup of yogurt, or one and a half ounces of cheese. (You can get calcium from other sources, but it takes 2 and a half cups of broccoli to equal one cup of milk)

They also suggested an upper limit for calcium. Taking more than twice the recommended amounts increases the risk of developing kidney stones.

In addition to calcium, there are new guidelines for other nutrients needed for strong bones, including phosphorus, magnesium, vitamin D and fluoride. The new recommendations are called Dietary Reference Intakes, and they are designed to help promote good health. The old recommendations, called the Recommended Dietary Allowances (RDA's) were designed to prevent rare deficiency diseases, like scurvy.

Bacteria Genes Decoded

Scientists have determined the genetic sequence of a type of E. coli bacteria often used in laboratories. The E.coli have 4,288 genes containing 4.6 million base pairs.

A benign (or harmless) type of the bacteria lives in most people's intestines, where it helps digestion. Other types of E. coli cause outbreaks of food poisoning that sicken or kill many people each year. By understanding the differences between these types, scientists could create new drugs or even vaccines against this kind of food poisoning. E. coli was responsible for the recent recall of 25 million pounds of ground beef. E. coli in apple juice, lettuce and fruit has also caused food poisoning outbreaks.


JULY/AUGUST, 1997

Improving Athletic Performance

Those tight exercise shorts are good for more than just showing off the results of your workouts. A study at the Penn State Center for Sports Medicine found a 12 percent improvement in the performance of athletes wearing stretchy spandex clothes. The tight clothes compress the muscles, which reduces muscle vibration and fatigue, and increases strength and endurance.

Snowballs from Space

Is the Earth being bombarded by huge snowballs from space? That's one possible explanation of new data from NASA's Polar satellite.

Oxygen in the atmosphere normally gives off UV (ultraviolet) light during the day. This glow can be seen by special instruments on orbiting satellites. In the early 1980's, physicist Louis Frank noticed dark spots on UV pictures of the Earth. He suggested that the spots were clouds of water vapor, which came from small comets breaking up in the atmosphere. Other scientists rejected his idea.

Iow, UV cameras on the Polar satellite have found more dark spots. UV and visible light cameras have also seen long streaks of bright light just above the Earth's atmosphere. Frank thinks the streaks are water vapor and other gases given off by small comets as they near the planet.

If Frank's theory is true, these comets could have added enough water to fill several oceans since the Earth was formed. There may, of course, be other explanations of the dark spots and streaks of light, and the studies will continue.

Houseflies and Ulcers

Many ulcers are caused by a bacterium called Helicobacter pylori. About 30 percent of people in the United States, and up to 70 percent of people in developing countries are infected.

How is the infection spread? Food or water contaminated by fecal matter may be one way. Another may be houseflies. New studies show that flies can carry the bacteria on their surface, and in their gut and droppings. Improving sanitation may help slow the spread of these germs: for instance, keep food covered and refrigerated, and wash your hands often. (This, of course, is good advice for preventing the spread of many diseases.)


JUNE, 1997

Summer Tidbits

Although it may feel like summer starts as soon as school ends, summer officially begins June 21.

The arrival of July will be delayed while an extra second is added to the end of June. The "leap second" will be inserted on June 30, just before midnight Universal Coordinated Time (formerly called Greenwich Mean Time) which is 8 P.M. Eastern Daylight Time. Leap seconds are added to keep our clocks matched to the spinning of the Earth. The last leap second was added on December 31, 1995, and there have been 20 since 1972. While you don't have to change the clock on your VCR, keeping exact time is very important in areas like communications, navigation, power transmission and many scientific studies.

Bugged by bugs? Here's something you can try: change your clothes. Mosquitoes and stinging insects are attracted to the colors blue and yellow.

July 4 will have more than fireworks and parades to look forward to this year; the spacecraft Mars Pathfinder is scheduled to land. It carries a small rover called Sojourner, which will study the Martian surface.

Dinosaur Blood

Scientists say they have found bits of dinosaur blood in a 65 million year old T. rex fossil. The scientists, from Montana State University, believe they found heme. Heme is the part of a hemoglobin molecule that carries oxygen in the blood.

In most fossils, the bone tissues are completely replaced by minerals. When this animal died, the inside of its bones were preserved almost unchanged. The scientists looked for dinosaur cells and DNA, but found none. They were able to find the heme protein using six different chemical tests.

Recently, other scientists have said they found ancient proteins, or ancient DNA preserved in amber, but no one has been able to duplicate their results. For example, scientists in Utah believed they found 80 million year old dinosaur DNA, but it turned out to be human DNA instead. The Montana State University researchers worked very carefully, trying to avoid sample contamination and other problems. Their work will encourage other scientists to keep looking for biological molecules in fossils.

T. rex with Gout

One of the most complete tyrannosaur skeletons ever discovered was found in South Dakota in 1990. Scientists nicknamed it "Sue" (although nobody knows what sex it was.)

Earlier studies showed that Sue suffered from many painful conditions, including deep gashes on her face, a dinosaur tooth stuck in her ribs, and a broken leg which did not heal well. A new study adds to her problems; Sue probably suffered from gout. Gout is a painful disease, where the bones dissolve and sharp mineral crystals form in the joints. Gout was probably rare in dinosaurs. Studies of 83 other tyrannosaurus finger bones found only one which may have had gout.

Update - Ice on the Moon?

As often happens in the world of science, there is new information which seems to contradict earlier studies. Last December, scientists at the Lunar and Planetary Institute (LPI) in Houston reported evidence of ice near the south pole of the moon. They had spent two years studying radar signals from Clementine, a spacecraft orbiting the moon.

Now, scientists using the Arecibo radio telescope in Puerto Rico say they have found no evidence of ice on the moon. They believe the unusual radar signals from Clementine come from very rocky surfaces, not ice. The scientists at LPI disagree with the new findings, and defend their original study. Another spacecraft, the Lunar Prospector, will be sent to the Moon in September. Maybe then we will learn more.

Editor's note: This is a good example of how scientists work. Science is a process of discovery. This process is called the "scientific method," and here are the steps:
(1) Observe the data.
(2) Study and classify the data.
(3) Propose a hypothesis. (Make assumptions and draw conclusions which explain what you have seen.)
(4) Do experiments to test the hypothesis.
(5) Formulate a theory. (Clearly state the general principle which explains the observations.)
(6) Have other people test the theory.
(7) The theory is accepted, revised or rejected, based on the data and tests.
(For example, long ago, people thought that the earth was flat. Later, observations and experiments did not support that theory, and it was rejected.)

MAY, 1997

Butter-side down

When you drop your toast, does it always seem to land butter-side down? Is this just a figment of your imagination? Is it an example of Murphy's Law? (A bit of popular folklore: "Anything that can go wrong, will go wrong.") Or can it be explained by the laws of physics?

A British scientist, Robert Mathews, decided to try and find out. He did experiments which showed that a piece of toast falling off the table usually does land butter-side down. In addition, he was able to explain why. It's just nature - the laws of physics, not the laws of Murphy.

When toast slips off a plate, gravitational forces cause it to flip over once. There isn't enough time for it to flip over again before it hits the floor. If the table was higher (at least 10 feet tall) then the bread could flip again and land butter-side up. For tables that height, people would have to be 15 feet tall, which he concludes is unlikely on Earth. So things really could not have turned out any other way.

Mathews also confirmed that the laws of probability favor accumulating odd socks over time. (However, he did not discover where they went.)

Computer Chess

IBM's computer, Deep Blue, defeated world chess champion, Garry Kasparov. The final score was 3 1/2 games to 2 1/2. Deep Blue won 2 games, Kasparov won 1 and there were 3 draws in the match. Last year, Kasporov won a similar match, 4 games to 2, against an earlier version of the computer.

Deep Blue has been improving. It is now faster, and has had programing help from another chess grand master. Deep Blue can calculate 200 million chess positions a second, or 50 billion positions every three minutes.

Can the computer think? Probably not the way that we think. However, it made some moves in the second game which really seemed to surprise Kasporov. And after last years match, Kasparov said he had seen the beginnings of genuine thought in the computer.

Other than chess, what could a supercomputer like Deep Blue be used for? Its data handling and calculating abilities could be useful for air traffic control, financial analysis, atmospheric modelling, and other things. If you're interested, a similar model would cost $2 million.

T. rex with Gout

One of the most complete tyrannosaur skeletons ever discovered was found in South Dakota in 1990. Scientists nicknamed it "Sue" (although nobody knows what sex it was.)

Earlier studies showed that Sue suffered from many painful conditions, including deep gashes on her face, a dinosaur tooth stuck in her ribs, and a broken leg which did not heal well. A new study adds to her problems; Sue probably suffered from gout. Gout is a painful disease, where the bones dissolve and sharp mineral crystals form in the joints. Gout was probably rare in dinosaurs. Studies of 83 other tyrannosaurus finger bones found only one which may have had gout.


APRIL, 1997

Extraterrestrial Ocean

NASA scientists believe they have discovered an ocean underneath the frozen surface of Europa, one of Jupiter's moons. Europa's surface is very bright and smooth. There are few impact craters from meteors or asteroids, which suggests that the surface is relatively young. Pictures sent back by the Galileo spacecraft show that Europa is covered with fracture lines and a jumble of large blocks of ice. It looks a lot like the pack ice covering parts of the Arctic ocean here on Earth.

Where does the heat to melt the ice come from? Not from the sun, which is very far away. The heat probably comes from tidal forces caused by the gravitational pull of Jupiter and the other moons, and from the radioactive decay of elements in Europa's core.

Liquid water is one of the key requirements for life as we know it, along with a source of heat, and organic chemicals. Is there primitive life on Europa? The answer will have to wait until we can land a space probe there and sample the water.

Run or Walk in the Rain?

If you are caught out in the rain without a raincoat and you want to stay as dry as possible, should you walk or run for cover? In 1995, British scientists calculated that it did not make much difference, one way or another.

But some other scientists now disagree. They made their own calculations using different assumptions, and found that you will stay drier if you run. The two scientists then decided to test their calculations. They marked a 100 meter (about 328 ft) course, and waited for rain. Both men were about the same size. They wore identical dry clothing. One walked the course and the other ran. Afterwards, they weighed their wet clothes and found that the one who ran was about 40 percent drier.

So, come in out of the rain. And run!


MARCH, 1997

Hello, Dolly!

British scientists have done something many people thought was impossible: they created the first clone of an adult mammal. The clone, named Dolly, is a seven month old sheep, grown from a cell of an adult ewe.

What is a clone? A clone is a copy - a genetic copy. Genes are the instructions for life. They tell a cell what to do and how to do it. Genes make each individual plant or animal different and unique. But a clone has the same genes as the original organism.

Cloning is not new. Plants have been cloned for centuries. New plants are often grown from cuttings from another plant. Also, plants like pineapples, strawberries and carnations are sometimes cloned using a method called "tissue culture." One benefit of cloning is that we can make many copies of the best and healthiest plants.

It has been much more difficult to clone animals. Frogs have been cloned, but they died as tadpoles, never living long enough to become adult frogs. Mice, sheep and cattle have been cloned from embryos (a very early stage of an animal's development.) But Dolly is the first healthy clone of an adult mammal.

How did they do it? (1) An unfertilized egg was taken from a sheep. (2) The egg's nucleus (which contains the genes) was removed. (3) A cell was taken from the udder of a pregnant sheep. It was "starved," so that it stopped growing. (4) The two cells were fused, or combined, into one. The fused cell was implanted into a third sheep, where it grew normally. (5) The clone was born. It was genetically identical to the pregnant sheep in step (3).

This sounds much easier than it actually was. To end up with one clone, the scientists started with 277 udder cells. And they needed a way to make the egg cell accept a new nucleus. They did that by starving the cell in step (3).

It may soon be possible to clone many types of animals. Will we also be able to clone human organs, or even whole human beings? We have only begun to think about the morality of cloning technology. Maybe the question to ask is not whether we can clone humans, but instead, should we clone humans?


FEBRUARY, 1997

Supertasters

Do you hate broccoli? Really, really hate it? Well, you may have a good reason. Scientists have found that many of our food preferences are inherited.

These researchers say that people can be grouped by how they respond to a bitter-tasting chemical called PROP (6-n-propythiouracil.) About 25% of people can not taste PROP at all. They are called non-tasters. About 25% of people find PROP so bitter it is sickening; these are the supertasters. The rest find it mildly bitter, and they are called tasters.

The difference is found on your tongue. Supertasters have up to 1100 taste buds per square centimeter, while non-tasters have as few as 11. The supertasters are more sensitive to bitterness, as well as other flavors in food. At some time in the past, this may have been useful. Many poisonous plants are bitter. But so are many healthy foods, like broccoli and grapefruit.

Supertasters also seem more sensitive to food temperature, texture and fat content. This is because each taste bud is connected to two kinds of nerves: taste nerves and touch nerves (including pain and temperature.)

This research may explain some of your likes and dislikes. But not all food preferences are inherited. Many are learned. And whether or not you like fruits and vegetables, they are still good for you.

A cure for flu?

A new pill, called GS 4104, may someday be used to cure influenza. The drug worked well in several animal studies. It prevented the flu when taken before infection, and cured the flu when taken within 60 hours after symptoms began. Human tests will start later this year. (A similar drug, taken in nasal drops, is already being tested. )

GS 4104 could replace annual flu shots. Different flu vaccines are now needed each year, because there are many different strains of flu, and the viruses mutate rapidly. This new drug works on a part of the virus that is very similar between strains. It blocks an enzyme on the surface of the virus needed in reproduction.

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