Describing the universe
In terms of time, distance ,and organization
What's astronomy ?
Objectives
1.Identify the visible and non visible parts of the electromagnetic spectrum.
2.Compare refracting telescopes and reflecting telescopes.
3.Explain how telescopes for no visible electromagnetic radiation differ from light telescopes.
Astronomy Vocabulary
Universe
The universe is commonly defined as the totality of existence, including planets, stars, galaxies, and all matter of energy.
Light year
The distance that light travels in one year; about 9.46 trillion kilometers.
Astronomical unit
The average distance between the earth and the sun; approximately 150million kilometers.
Electromagnetic spectrum
All of the frequencies or wavelengths of electromagnetic radiation.
Refracting telescope
A telescope that uses a set of lenses to gather and focus light from distant objects.
Reflecting telescope
A telescope that uses a curved mirror to gather and focus light from distant objects.
Describe the Electromagnetic Spectrum
Visible radiation is a form of energy that is part of the electromagnetic spectrum. Visible light is a small amount of energy and can be seen by human eye. Invisible radiation are invisible wavelengths that include infrared waves,microwaves, radio waves,ultraviolet rays, x-rays, and gamma rays.invisible radiation are short wavelengths that are blue and violet and cannot be see by the human eye.
Comparing the Refracting and Reflecting telescopes.
A Refracting telescope uses a set of lenses to gather and focus light from distant objects.Refracting telescopes have lenses that bend in special ways .One problem is that the lenses focuses different colors of light at different distances, also it is difficult to make large lenses if the required strength and clarity.
Reflecting telescopes is a telescope that uses a curved mirror to gather and focus light from distant objects. When light enters the mirror it is reflected to another mirror and the to the eyepiece.Reflecting telescopes are 10 meters in diameter and it can gather more light that refracting telescopes and are easier to make. Astronomers are planning to build an OWL which means Overwhelming Large Telescope which would be 100 meters in diameter .