Telescopes
Author: Bartosz Rychlak
The telescope is one of the basic optical devices used to observe distant objects. Hans Lippershey, a Dutch lensmaker, is said to be an inventor of it. First optical devices where known many years ago. It is believed that the sky and the galaxy was observed ancient nations such as Assyrians, Persians or The Arabic People. They had already knew that Saturn is surrounded by rings. However, Lippershey was first to build a fully functional telescope, which was simultaneously the prototype of it's later versions. There is an interesting story connected with that invention. More or less, in the same time the other Dutch optician – Jacob Metius made a similar device, but Hans was faster and he posted his patent few weeks earlier. But it was used rather to watch items placed on the Earth like opera glasses.
Pioneer in observation of our galaxy was Galileo – Italian physicist, astronomer and philosopher. He built his own, improved version of telescope and he used it for his astronomic researches. Galileo stated that the surface of Moon isn't smooth, like people used to think or that the Milky Way is made of millions stars, that Jupiter owns satellites. He also noticed such phenomenons as spots on Sun, phases of Venus, Saturns' rings – he published those theories in a book called "Siderius nuntius" in 1610. His future studies proved also the heliocentric thesis of Copernicus.
Some theoretics
There are two fundamental types of telescopes: lenticular (refractors) and mirror (reflectors). They are built for different purposes and at different advanced level. Each one has advantages and disadvantages but every telescope has some obligatory elements. It must contain an eye-piece. It's a small lens with short focal length placed near the eye of observer. Another important thing is an object-glass or a mirror – it depends on the type of device. It's size, or to be more precise – relations between the focal length of object-glass and eye-piece – affects the zoom of our telescope. But we can't get infinite big picture. There are some mechanical obstacle like distortions of big-sized object-glass or it's enormous weight. Those devices are put into a body-tude. It also contains some specialist equipment witch eliminate two primary defects - spherical aberration (blurred picture) chromatic aberration (light fission).
Hubble Space Telescope
Hubble Space Telescope (HTS) it's a mirror telescope with diameter of 2.4 m placed on Earth's orbit about 600 km above it's surface, outside the atmosphere. HTS is a part of space observatory of the Great Observatories project. The telescope was named after famous American astronomer – Edwin Hubble. It was put into our orbit on 24th April 1990. It was made by two space agencies – NASA and ESA, weighs about 11.5 tons, 13.1 m long and cost 1.5 billion American dollars.
Not long after it was put on the planetary, first pictures were took. As it showed up – they were blurred. The telescope was damaged. Hopefully defect wasn't so serious. It was caused by a very small chip of paint witch was obtained on one of the mirrors. In 1993 NASA sent a space shuttle - Endeavour – and the HTS has been fixed. One of numerous achievement the Hubble's Telescope was discovering the new planet near the Epsilon Erandi system in 2000. It's about 10,5 astronomical units from Sun. The new planet was observation for almost three years.
HTS is probably the famous space telescope, but it is just one of many examples contemporary optical devices witch are used to experience our World. There are thousands of astronomical observatory with “big guns” directed towards the sky. Thanks to them, we discover undiscovered planetary systems, new galaxies etc. In some way we can go to the future and see what's behind clouds, sky, galaxy and penetrate secrets of the Universe.