Physics is the branch of knowledge that studies the physical world. Physicist investigate objects as small as atoms and as large as galaxies. They study the natures of matter and the energy and how they are related. How do they do this study? Physicist and others scientists  are inquisitive people who look at the world around them with questioning eyes. Their observations lead them to search for the causes of what they see. What makes the sun shine? How do the plants move? Of what is matter made? More often than not, finding expansions to the original questions leads to more questions and experiments. What all scientist hope for are powerful explanations that describe more than one phenomenon and lead to a better understanding of the universe.

Sometimes the result of the work of physicists are only of interest to other physicists. other times their work leads to devices, such as lasers, calculators, computers, which change everyone's life. As an example of how physics works, let's look at the recent history of a field of physics which has produced some of the most important scientific advances of he last few years,"high temperature" superconductivity.
In September 1986, Two Swiss scientist working for IBM Corp. announced that they had discovered a new superconducting material that worked at temperatures as high as -243C, 30degrees above absolute zero, the lowest possible temperatures for matter. Until that time, materials were only superconducting at temperatures close to -273C. this temperature is theoretically the lowest temperature possible. the new material was a ceramic, a glass like material that does not normally conduct any electricity. Even though superconductivity metals had been discovered in 1911, this development was exciting because earlier superconductors worked at temperatures very difficult to reach and maintain. In 1973 a metal alloy had been found that worked at 20degrees above absolute zero, but in the next 13 years no further progress had been made.

Within weeks the discovery was announced, researchers in the United States, China, and Japan had repeated the experiments. That fall scientists tried different materials and increased the temperature to -52 degrees then to 77 degrees, then to 90degree, then in February 1987, to 98 degrees above absolute zero (-175C). In March 1987, three thousand physicists jammed a hotel ballroom for eight hours to hear reports of experiments. In July 1987, President Ronald Reagan held a press conference to watch a demonstration of superconductivity and to announce a United States effort to apply the new developments. By the end of the same year, high school students  had made superconductors  that worked above -196C.

Physicists and engineers have dreamed of many exciting applications for superconducting wires could carry electricity to cities from distant power plants without energy loss. They could be used in magnets that make nuclear fusion  possible, that allow high-speed trains to "float" above the track, that could detect oil and minerals in the Earth, or pinpoint diseased body tissue. superconductors might make possible smaller, faster, more powerful computers. until recently, the problem has been that superconductors worked at such low temperatures that they had to be cooled by liquid helium. Liquid helium is very expensive(more that $5.00 per liter) and difficult to store. The new superconductors can be cooled with liquid nitrogen, which costs the about the same as soda pop. Now some of the dreams may be possible. But first the new materials, now as brittle as glass, must be  modified so they can be made into flexible wires. Even more exciting would be the development of materials that are superconducting at room temperatures.