Turning Points: Special Relativity

Question 1

What is an ether?

Answer 1

It is a prediction of a medium for light wave

Question 2

What was the aim for Michelson-Morley Experiment?

Answer 2

To determine the speed of the Earth’s motion relative to its ether

Question 3

What did Michelson and Morley design?

Answer 3

Interferometer

Question 4

What is the procedure for Michelson-Morley experiment?

Answer 4

1. Semi-silvered glass block split the beam of monochromatic light into 2 beams
2. The light travels at right angles to both mirrors
3. The observer sees the interference pattern from 2 beams
4. The apparatus is rotated 90 degrees and pattern is observed

Question 5

In Michelson-Morley experiment, What is the predicted results?

Answer 5

• Pattern would shift
• As path length or speed of light depending on the orientation relative to motion of apparatus so ether exists

Question 6

In Michelson-Morley experiment, What is the actual results?

Answer 6

• No shift in pattern
• No evidence of ether
• speed of light is invariant

Question 7

How are bright and dark fringes formed?

Answer 7

Bright fringes formed when two light beams are in phase and vice versa for dark.

Question 7

How are bright and dark fringes formed?

Answer 7

Bright fringes formed when two light beams are in phase and vice versa for dark.

Question 8

What is inertial frame of reference?

Answer 8

Those that move in constant velocity relative to each other but frame that is accelerating or rotating is not inertial frame

Question 9

What are Einstein’s two postulates?

Answer 9

1. Speed of light in free space is invariant
2. Laws of physics are in same form in all inertial frames

Question 10

What is t nought (t0)

Answer 10

time that is observed when stationary (proper time)

Question 11

What is l0

Answer 11

proper length

Question 11

What is m0

Answer 11

rest mass