022-Relativity Science Physics Senior High School

Physics

1. Relativity

2. QUESTIONS:
What is an inertial frame of reference?
What are the 2 postulates of special
relativity?
What are the consequences of the
postulates of special relativity?

3. Relativity

4. Inertial Frames of Reference
•Place or location where
motion is observed.
•Person inside the train
is not moving through
an observer inside but
it is moving through an
observer outside.

5. The speed of a person walking on a train depends on
the frame of reference of the observer:
1.Inside the train ~1km/h
2.The ground ~60km/h
3.The center of the Earth ~1600km/h
4.The Sun ~110,000km/h
Inertial Frames of Reference

6. For example, you a baseball player…
•Your POV: while walking you are
throwing and catching a ball upward
in the air.
•POV of an observer on your side: the
observer sees you throwing and
catching a ball in projectile motion.

7. Special Relativity
•A scientific concept that shows that,
in differing inertial frame of
references different laws of physics
are observed. It is stated here that
time and space affects one another.

8. Postulates of Special Relativity
•Albert Einstein concluded the postulates
in special Relativity
1.All laws of nature are the same in all
uniformly moving frames of
reference.
2.The speed of light in free space has
the same measured value for all
observers, regardless of the motion
of the source or the motion of the
observer; that is, the speed of light is
a constant.
This Photo by Unknown Author is licensed under CC BY

9. •Differences in inertial frames of
reference makes the light beam
reflected through a mirror follow
different paths.

10. Relativistic Speeds
•In this postulate therefore, as an object
travels closer to the speed of light,
•TIME SLOWS DOWN
•LENGTH SHORTENS
•MASS INCREASES

11. Time Dilation
•In this scenario,
would it not make
sense that light
would take a longer
time to travel in this
scenario?

13. Twin Paradox

14. Time Dilation
This is referred to as the
“Twin Paradox”

15. 2. An observer at rest sees a rocket ship
containing an astronaut moving at a speed
of 0.93c. What will be the dilated time
interval clocked by the astronaut on the
rocket ship if the observer at rest recorded
a time interval of 2 minutes?

16. Length Contraction
•As objects move through spacetime, space as
well as time changes. In a nutshell, space is
contracted, making the objects look shorter
when they move by us at relativistic speeds.