Einstein's Theory of Special Relativity
Physics: AQA A Level, topic 12.3.2
Einstein's Theory of Special Relativity
Einstein had two postulates (theories) as part of his theory of special relativity.
Einstein's first postulate
- Einstein’s first postulate of special relativity states that:
- Physical laws have the same form in all inertial frames.
- An inertial frame is one in which objects will not accelerate if they are left untouched by external forces (Newton’s first law).
- This postulate essentially states that experiments will have the same result in any inertial frame of reference.
Einstein's second postulate
- Einstein’s second postulate of special relativity states that:
- The speed of light in free space is invariant.
- This means that the speed of light will not change if the observer or the source is moving.
Test yourself on Einstein's Theory of Special Relativity
Which of Newton's laws is most important in an inertial frame of reference?