AST101H5 Lecture Notes - Lecture 7: Celsius, Scale Of Temperature, Anders Celsius
Document Summary
To understand objects beyond earth we need information from those objects. Light from astronomical objects is the source of almost all of our information. We study the properties of light on earth to understand the light from beyond earth. Newton discovered white light is the mixture of all colours. Sorting white light into the different colors produces the spectrum of light. Light is a form of energy - sunlight warms the earth. Light is a form of energy that travels through the vacuum of empty space. Light"s speed in a vacuum is a constant for all color. C = 300,000 km/s - the fastest possible speed. Light"s speed is slower in transparent material (air or glass or water or plastic or ) than in a vacuum, and different colours have different speeds. Answering this question took centuries of study. Experiments found that light is a wave of electric energy and magnetic energy.
