| A | B |
|---|
| al-Haytham | studied how vision works (light travels to the eye) about 1000 A.D. |
| Ptolemy | light beams bend when they go from air to glass (about 100 A.D.) |
| Michelson | refined the measurement of the speed of light (in 1920) |
| speed of light | 300 000 km/s |
| Ole Romer | In 1676, estimated the speed of light |
| Euclid | dicovered that the angle of incoming beams of light equal the angle of the reflected beam (400 B.C.) |
| Newton | interested in the colours of the rainbow; found that white light is made of different colours of light. Worked with prisms. (1700 A.D.) |
| Descartes | a French thinker who had proposed that sunlight was changed to form coloured light. |
| Advantage of a space-based telescope | no interference from the earth's atmosphere |
| Pythagoras | 500 B.C.- believed that rays leave our eyes and sense the surroundings |
| Leewenhoek | 1800's. Used a simple microscope and founded the science of microbiology |
| Archimedes | studied the reflection of light - 200 B.C. |
| Optical Device | any technology that uses light |
| microscope | combines the power of at least two lenses - the eye piece and the objective lens |
| telescope | magnifify and collect light. There are two types: reflecting and refracting. First invented in 1800s |
| Galileo | used telescope to revolutionize the study of astronomy |
| refracting telescope | have two lenses; the larger is the objective lens which gathers light and focusses it to the eyepiece, and the smaller magnifies the image |
| reflecting telescope | uses a large circular mirror that curves inward which gathers light. Another mirror directs light to the eyepiece. |
| binoculars | two short refracting telescopes. Not as powerful as telescopes, but more convenient |
| Four properties of light | light travels in straight lines, light can be reflected, light can be bent and light is a form of energy |
