ONE MAN'S VIEW OF SCIENCE

One scientist, Franklin M. Harold, gave an interesting view of science in the Epilogue of his book, The Way of the Cell*. I would like to quote him: "I have come to think of science as a kind of game, whose object is to make sense of the world. Players are bound by strict rules: the imagination must ever be disciplined by reason, observation and experiment, and no cheating, please! It is the most engrossing game ever invented, one to which I and many others have happily dedicated our lives; and it has revealed much that is new, true and important. But we must never forget that the game of science is played on a board, and most of what matters most to human beings lies off the board. Science has little useful to say about good and evil, right and wrong, justice and oppression, and the strange ways of the human heart. Science can often explain what is happening, and it can sometimes forecast the future and distinguish wisdom from folly. But it provides no basis for ethical choice, nor the will to act. About what it means to be human, individual scientists often hold strong opinions; but science must be silent." *Oxford University Press, New York, 2001

A VERY MUCH MALIGNED GAS

With our almost religious fervor to embrace the idea of global warming, carbon dioxide in our atmosphere is getting a bad rap. Rarely mentioned are the other so-called green house gases: water vapor and methane. With about three-quarters of the Earth covered by water, water vapor is tough to do much about. And methane is emitted by many living things notably we humans, cattle and termites.

Carbon dioxide occupies less than 0.04% of the air we breath, but has admittedly a profound effect on our planet. Without it, the average temperature of the Earth would be well below freezing. Our distance from the Sun, makes its warming effect not enough to keep us toasty. Even more importantly, carbon dioxide keeps us from starving. It is the crucial source of all our food. Plants use the sun's energy to break apart carbon dioxide and turn it into the carbon-based molecules that make up our food. Every year some 100 billion tons of carbon dioxide are converted into plant material. This provides the foodstuff that feeds every animal and human on Earth.

Unfortunately, when anything is burned for energy to drive our world--be it wood, oil, coal or natural gas, carbon dioxide is produced as a by-product. Even the slow burning of food in animal or human metabolism creates carbon dioxide. Plants convert water and carbon dioxide into sugars and starches and give off oxygen as a by-product. We and other animals eat plant tissues and burn them with oxygen for energy while exhaling carbon dioxide. This is how nature preserves the cycle of life.

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How Telescopes and Binoculars Work

The closer an object is brought to our eyes, the larger it appears. There is a limit, however, to how close to our eyes we can bring an object and still see it clearly. This is about 10 inches. Placing a lens between the eye and an object allows the object to be moved closer than 10 inches. The object then appears larger as experienced by anyone who has used a so called magnifying glass. To magnify an object greatly, would require that it be very close to the eye. This may not be practical in most cases and impossible in the case of an astronomical body or a bird in a distant tree. Here is where the optical scheme used by microscopes, telescopes and binoculars can help us out. The curved surface of a glass lens can bend light rays coming from an object in a coherent way so as to form a small image or "picture" of the object at a fixed point within the tube of the optical device. Although the image "hangs" in mid-air, it nevertheless is real. It can actually be seen by placing a white card at the image (focal) point within the tube. Once an image is formed by the objective lens, a second lens (or lenses) called an eyepiece is used to enlarge it. The eyepiece allows the eye to come very close to the image while keeping it at a comfortable distance. By selecting eyepiece lenses of different surface curvature, almost any magnification can be obtained. The actual magnification is determined by the focal length of the objective lens (distance from lens to image) divided by the focal length of the eyepiece. A 200 inch focal length objective lens used with a 1 inch focal length eyepiece produces a magnification of 200X.

What Do Calories Taste Like?

Many weight conscious people are concerned about their daily calorie intake. But what does a calorie taste like--sweet, sour or salty? This, of course, is a nonsensical question because a calorie doesn't have a taste because a it is not a substance, but a unit of measure. In this nutritional context, it is the measure of the energy content of a food. Technically, a calorie is defined as the amount of heat energy it takes to raise the temperature of one gram (about 1/30th of an ounce) one degree Celsius. A nutritional calorie is defined to be 1000 times bigger (kilocalorie) than the standard one and is frequently capitalized Calorie. --- All forms of energy can be converted from one form to another--heat to electrical, for example, or electrical to light or mechanical energy. Take a jelly bean, for example. It weighs about 3 grams and is almost 100% sugar. If one gram of sugar is completely burned, it would produce 4.1 Calories of heat energy. Therefore, one jelly bean is equivalent to 12.3 Calories. This is enough energy to keep a 60 watt light bulb operating for 14.3 minutes. By comparison, a can of beer or a donut will keep the lamp lit for nearly three hours. The Calories and thus the energy in a quarter pound hamburger will keep the lamp burning for almost 20 hours. --- All human activities expend energy--some activities more than others. Just sleeping uses some 1.2 Calories per minute, standing 2.0, walking 3.7, bicycling 7.7 and swimming a walloping 13 Calories per minute. As food is metabolized (burned) in our bodies, the energy released drives the chemistry of our muscles to produce mechanical motion. Some of the energy, of course, is lost to the environment in the form of heat.

SCIENCE--What's It All About

It is often asked what is science and how does it work. Lots has been written on this subject, but the clearest and most concise explanation I have run across is by Dr. Eric Chaisson in his recent book, Epic of Evolution*. He says “The scientific method normally works like this: First, gather some data by observing and object or event, then propose and idea to explain the data, and finally test the idea by experimenting with Nature. Those ideas that pass the tests are selected, accumulated, and conveyed, while those that don’t are discarded. In this way, by means of a selective editing or pruning of ideas, scientists discriminate between sense and nonsense. We gain an even better approximation of reality. Not that science claims to reveal the truth--whatever that is--just to gain an increasingly accurate model of Nature."

*Colombia University Press, 2006.

Electricity/Magnetism

Electricity is one of our most important forms of energy. It illuminates are nights, powers our factories and heats many of our homes. Like so many other very familiar and ubiquitous things around us, we sometimes fail to appreciate their origin and their relationship to other natural things. Electricity, like other forms of energy, obeys the basic physical principle that it cannot be created or destroyed only changed from one energy form to another. So what is it and how do we produce it?

First of all, electricity is the energy resulting from the movement of charged particles. These particles are the building blocks of the atoms of all things--rocks, air and are own bodies. Two of the three particles that constitute atoms, electrons and protons, have a property in addition to their mass called charge. It happens that the charge on these two particles is different, so scientists, for want of a better term, arbitrarily have called the charge on the electron negative and the one on the proton, positive. As you may remember from high school science, like charges (two negative or two positive) repel each other and unlike charges (a positive and a negative) attract each other. Luckily, the total number of positive and negative charges in atoms are normally equal. Therefore, the effects cancel each other and things are electrically neutral, i.e. appear to have no charge.

If by some means electrons are dislodged from their atoms (relatively easy in metals that is why they are good conductors of electricity) and get them moving, an electric current results. Of course, it takes countless billions of electrons moving together to accomplish any real work. A battery, by chemical action, strips some electrons from atoms and delivers them to one terminal while atoms now with a net positive charge remain at the other terminal. If an external conducting path is provided, a current will flow. Electrons will move toward the positive terminal attempting to restore the electrical balance. An electric current continues to flow until the battery chemicals are depleted. Since the current produced by a battery always flows in one direction (negative to positive), it is called direct current (DC).

The lights in our homes and businesses are not powered from batteries, but rather from the alternating current (AC) power line. The electrons in our house wiring go no where but accomplish their work by simply oscillating back and forth 60 times a second. Alternating current is created by power plant generators using the principle of electromagnetism.

Around every magnet is a field of force. That’s what every science student has seen traced out by iron filings on a surface above a magnet. If a conductor (a wire or coil of wire) is moved across a magnetic field or a magnetic field is moved in relation to the conductor, an electric current will flow in the conductor. The electrons in the conductor ‘feel’ the magnetic force and are accelerated by it. The current only flows while either the conductor or magnetic field is moving and stops when either motion ceases.

An electric generator is a device that rotates a huge coil of wire through a powerful magnetic field to create an electric current. The coil is rotated by a turbine powered from falling water, the wind, or steam generated from water by burning coal, oil, or by the heat of a nuclear reactor. As the coil rotates, the conductor moves up through the magnetic field and then down through it with each rotation. The result is that the current changes direction with each rotation resulting in alternating current.

The word electromagnetism suggests the intimate relationship between electricity and magnetism. They are like the two sides of the same coin. While a magnetic field can create an electric current, an electric current also creates a magnetic field around the conductor. A magnetic field is frequently concentrated by winding the conductor into a coil around a iron core. This forms an electromagnet which is energized whenever current is applied to the coil. Such a device in a form called a solenoid, is used to convert an electric current into a mechanical action. Solenoids operate such things as water valves in wash machines, dishwashers, etc. Solenoids in devices called relays can also remotely operate switches that can turn things on and off like your furnace .

More Than Meets the Eye

Anyone who follows science even a little knows that our universe is incredibly vast. In addition to Earth and other planets circling our star, the sun, there are countless billions of other stars. These form great, rotating islands of stars called galaxies that also number in the billions. In recent years, astronomers have found that what we see in the universe may be only a small fraction of the "stuff" that exists out there. Measurements of the rotation speed of galaxies show that they are rotating faster than they should for the amount of material they contain, and should be flinging their stars out into space. In other words, the combined gravity of the galaxy's constituent stars do not have enough mass to hold the galaxy together. Since galaxies are not coming apart, astronomers were forced to theorize that there must be more stuff in the galaxies than what they see or detect with instruments. They have called this stuff Dark Matter. No one, currently, has any idea of what it is. In addition to dark matter, astronomers have discovered another cosmic anomaly. They have known for some time that galaxies are all moving away from each other as space and the universe expands. This expansion has been going on ever since the universe began with the big bang some 14 billion years ago. However, the gravitational attraction of all the galaxies for each other should be slowing down the universe's expansion. Over the past several years, astronomers have decided to measure what this rate of slowdown is. They did this by measuring two things in distant galaxies. First, the galaxy's speed of recession as indicated by their red shift--how their light is reddened due to the stretching of their light waves by the expansion of space. Second, the galaxy's distance. This is done by finding in the galaxy a particular type of star whose intrinsic brightness is known and measuring how its light is dimmed by its distance. Astronomers refer to such known brightness stars as a standard candles. The particular kind of star used in this study and occasionally found in galaxies, is called a Type Ia Supernova . When you make a graph of red shift (speed of recession) versus distance you would normally expect it to be a sloping straight line if the universe was expanding at a constant rate. If the plot curved slightly downward, the universe's expansion was slowing down as was expected. What they were surprised to find was that the plot curved upward indicating that the supernovae were dimmer than expected. That meant that the galaxies were farther away than expected, and that the universe's expansion was not slowing down but accelerating. Apparently the gravity created by all the galaxies and dark matter must be counteracted by some repulsive or anti-gravity force. What this force, termed Dark Energy, is no one has a clue. Under current thinking, the visible stuff (planets, stars, galaxies, etc.) makes up only about 4% of the mass of the universe. Dark Matter represents about 23% and Dark Energy (Einstein showed that energy and matter are equivalent) about 73%. Cosmologists have some big mysteries to solve, so stay tuned!