Describing the Universe
The electromagnetic spectrum and telescopes
What is astronomy?
Objective
2. Compare refracting and reflecting telescopes.
3. Explain how telescopes for non-visible electromagnetic radiation differ from light telescopes.
Astronomy Vocabulary
Universe
The universe contains galaxies which have many stars and solar systems and in those solar systems there are planets. Our galaxy is called the Milky Way. There is only one universe and is the cause of all existence.
Light Year
The light year is the measurement used to measure distances out of our solar system. One light year is 10 trillion kilometers or about 6 trillion miles.
Astronomical Unit
The measurement from the sun to earth is one astronomical unit which is 149,597,870,700 m or 92,955,807.273 mi exactly. This is used for measuring distances inside the solar system.
Electromagnetic Spectrum
The electromagnetic spectrum is a bunch of types of radiation. The radiation that travels and spreads out as it goes, it becomes visible light like a lamp in your house or radio waves that come from a radio station are two types of radiation. Other examples of electromagnetic radiation are microwaves, infrared and ultraviolet light, X-rays and gamma-rays.
Refracting Telescope
A refracting telescope is a type of telescope that is used to gather and focus light from distant objects. These telescopes bend light through the lens and magnifies it to the eyepiece.
Reflecting Telescope
A reflecting telescope is a telescope which uses one or two curved mirrors that reflect light and form an image.
Electromagnetic Spectrum
Visible EM Radiation
A visible electromagnetic spectrum would be white light because when it passes through the prism it is broken into a set of colors which creates rainbows. Visible radiation has a shorter wavelength than red and violet light.
Invisible EM Radiation
An invisible electromagnetic spectrum would be infrared waves, microwaves, radio waves, ultraviolet rays, x rays, and gamma rays which cannot be seen by the human eye but can be seen by using special instruments. Infrared radiation can be read by using a simple thermometer because the heat from thee radiation is read by the thermometer.
Comparing the Refracting and Reflecting Telescopes
A Refracting Telescope is used to gather and focus light from distant objects. These types of telescopes use a special lens that bends light hat passes through and focuses the light and then magnifies it to the eyepiece. The only problem people have with these telescopes is the lens, since the lens has to be large to handle the great amount of strength and clarity required for it to create the image because the size of the lens is dependent to see distant objects.
The Reflecting Telescope is also used to gather and focus on far objects in space but this telescope uses mirrors which is cheaper to make and can be changed without affecting the telescopes image quality. These telescopes use two mirrors, when starlight enter the telescope he light is reflected onto the curved mirror and then reflected onto a second mirror under the eyepiece where you can see the image. These telescopes can be up to 10m in diameter which is the largest in the world.
Invisible Light Telescope
Refracting and reflecting telescopes are used to collect and study visible light. Although visible light provides valuable information, it only represents a tiny portion of the electromagnetic spectrum. To see the rest of the spectrum, which consists of invisible colors, researchers need to use telescopes that are capable of detecting wavelengths that to the corresponding type of light. Invisible light telescopes usually detect Infrared radiation because it is the light we see from the sun.