Describing the universe
In terms of time, distance, and organization
What is astronomy ?
Objective
2) Identify the visible and nonvisable parts of the electromagnetic spectrum.
3) Compare reflecting telescope
4) Eplains how telescope for nonvisable electromagnetic radiation differ from ligh telescope.
Universe
The universe is commonly defined as the totality of existence, including planets, stars, galaxies, the contents of intergalactic space, and all matter and energy.
Astronomical unit
The distance that light travels in one year; about 9.46 trillion kilometers
Light year
The average distance between the earth and the sun; approximately 150 million kilometers (symbol, AU)
Electromagnetic spectrum
The average distance between the earth and the sun; approximately 150 million kilometers (symbol, AU)
Refracting telescope
A telescope that uses a set of lenses to gather and focus light from distance objects
Reflecting telescope
A telescope that uses a curved mirror to gather and focus light from distance
Describe the electromagnetic spectrum
The shortest wavelengths of visible light are blue and violet, and the longest wavelengths of light are orange and red. Visible light is also a form of energy that is part of the electromagnetic spectrum. Also, visible light is broken into up into different colors because they have different wavelengths. Only visible light can be seen with the human eyes.
Invisible light also has its differences from visible light, like it can not be seen with the human eyes. Invisible wavelengths are shorter if the color is violet and are longer if the color is red. Invisible waves are also known as infrared waves, microwaves, radio waves, ultraviolet rays, x rays, and gamma rays. Since the invisible light can not be seen with the human eyes, invisible radiation has to be detected with instruments that were designed for detecting electromagnetic radiations.
Comparing Refracting and Reflecting Telescopes
Reflecting telescope that uses a curved mirror to gather and focus light from distant objects. These lenses are easier to make than the refracting lenses. The mirrors inside the telescope can be made larger without affecting the quality of the image and focuses the light to the second mirror. The second mirror inside the telescope is used to reflect the light .