John Zweber, age 12, of Cottage Grove, Minn., for his question:
WHO MADE THE FIRST TELESCOPE?
After World War II, a giant radio telescope was developed that sees by radio waves emitted by celestial bodies, just as they emit light rays that affect our eyes. The radio telescope can tune in on stars and galaxies that give off no light or only faint light; it can penetrate the clouds of cosmic dust and gas that fill space; and it can be used in any kind of weather.
A telescope is an instrument that gives us a chance to look out into distant space.
As far back as the 1200s, scientists experimented with magnifying lenses. Then in 1608, a Dutch optician named Hans Lippershey made what historians believe could be called the world's first telescope. But Lippershey was refused a patent for his invention.
Hearing about Lippershey's instrument, the Italian astonomer Galileo in 1609 built his first telescope. It was a crude instrument that magnified objects only 33 times.
Even though the field area of Galileo's telescope was very small, he nevertheless made some outstanding discoveries. It was Galileo who first saw the rings of Saturn, four of the satellites of Jupiter and the mountains and craters on the moon.
An English scientist, mathematician and astronomer named Sir Isaac Newton during the early 1700s came up with a new type of telescope: it made use of a reflecting mirror instead of a combination of lenses, which had been used earlier. Using an eye piece on the side, the instrument is known as the Newtonian telescope.
A bit later, in France, a scientist named N. Cassegrain came up with another type of reflecting telescope which is called the Cassegrainian.
In 1931, a German optician named Bernhard Schmidt invented a combination refractor reflector telescope. Ordinary telescopes can be used to observe only a small part of the sky, but the Schmidt instrument can actually photograph large areas of the sky.
The largest Schmidt telescope in the world is now in use in Califonia's Palomar Observatory. The lens is 48 inches and the mirror is 72 inches wide.
In 1963 at Kitt Peak National Observatory, the McMath solar telescope was completed. This instrument can be used to photograph and study the sun, solar flares and sunspots.
The largest refracting telescope in the world is at Yerkes Observatory at Williams Bay, Wisc. The object lens of the telescope has a diameter of 40 inches.
One of the largest reflecting telescopes in the world is the Hale telescope, dedicated in 1948 at the Palomar Observatory. This telescope has a reflecting mirror of 200 inches.