Scientist Idea
Date: 2015-10-07; view: 658.
__ 1. Einstein a) Light is a wave.
__ 2. Empedocles b) Light consists of tiny particles.
__ 3. Euclid c) Vision results from sreamers or filaments
__ 4. Huygens emitted by the eye making contact with an object.
__ 5. Plato
__ 6. Socrates
Exercise 4. A) Look for the words in the text which have the following meanings.
1. ____________ – the thin wire inside a light bulb.
2. _____________ – the total or partial obscuring of one celestial body by another.
3. ____________ – any natural satellite of a planet.
4. _____________ – a particle representing a quantum of light or other electromagnetic radiation.
5. _____________ – an object with at least one reflective surface.
6. _____________ – a narrow projection of light energy radiating from a source into a beam.
7. _____________ – a multiple star in Centaurus whose three components represent the brightest object in the constellation, 4.4 light-years from Earth.
B) Complete the sentences using the correct form of the words above.
1. How many __________ has Jupiter got?
2. Albert Michelson used a ___________ arrangement to measure the speed of light.
3. Light takes 8 minutes to travel from the sun to Earth and 4 years from the next nearest star, __________.
4. Galileo tried to measure the time a __________ takes to travel to a distant mirror and back, but the time was so short that he couldn't begin to measure it.
5. Plato thought that vision resulted from streamers or _________ emitted by the eye making contact with an object.
6. Roemer did find a variation in the speed of Io's orbits, which caused Io's _________ by Jupiter (the moments when Io passed in front of or behind Jupiter).
7. Light consists of particles called ________.
Exercise 5. Answer the questions to the text.
1. What were the first ideas of light among Greek philosophers?
2. Who was the first to tell that light traveled in wave?
3. What characteristic of light did Huygens provide evidence of?
4. What phenomena did Einstein explain in the theory he published in 1905?
5. What is a photon?
6. What is the nature of light according to modern theory?
7. Who was the first to demonstrate that light travels at a finite speed?
8. Describe Roemer's experiment?
9. How did Huygens interpret the discrepancy in Roemer's experiment?
10. Describe A. Michelson's experiment to measure the speed of light?
11. What was Michelson's experimental value for the speed of light?
12. How much time does it take to travel from the Sun to Earth?
Exercise 6. Are the following sentences true or false. Correct the false ones.
1. The idea that light consists of tiny particles was first proposed in the early 1900s.
2. Photons are massless bundles of concentrated electromagnetic energy.
3. Roemer's measurement of discrepancies in the position of Jupiter's moon Io was the first demonstration showing that light travels at a finite speed.
4. Albert Michelson received the the Nobel Prize for using a system of mirrors to measure the speed of light.
5. Christian Huygens suggested that light had a dual nature.
6. The speed of light is 300,000,000 m/s.
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