Newtonian mechanics and Maxwell’s Electromagnetic Theory of light

1. THE SPECIAL THEORY
OF RELATIVITY
( N e w t o n i a n M e c h a n i c s &
M a x w e l l ' s E l e c t r o m a g n e t i c
T h e o r y o f L i g h t )
Physical Science

2. Specific Learning Objectives:
• Explain Newtonian Mechanics and Maxwell's
Electromagnetic Theory
• Explain how special relativity resolved the
conflict between Newtonian Mechanics and
Maxwell's Electromagnetic Theory

3. The Special Theory of Relativity was
coined and developed by Albert Einstein in
1905 as an answer to the long-debated
conflict between James Clerk Maxwell’s
Theory of Electromagnetism and Isaac
Newton’s three Laws of Motion.

4. NEWTONIAN MECHANICS
Newtonian mechanics is grounded on the use
of Newton’s three laws of motion. The
mechanics explains that space (distance),
time, and mass, are absolute. This means that
the distance between two objects and the time
that passes between two events does not
depend on the environment where the object is
in.

5. Furthermore, according to Newton’s
second law, objects in the environment
moves in a straight line; hence, the
change of location from one
environment to another environment
must register a straight line to other
straight lines.

6. MAXWELL’S ELECTROMAGNETIC
THEORY OF LIGHT
James Clerk Maxwell had predicted
that the electric field, magnetic
field, and light are different
representations of the same
phenomena or event.

7. He further predicted that visible lights are
electromagnetic waves that move in a
manner like ripples in the water when a
stone is dropped. According to Maxwell,
light as a wave have both electrical and
magnetic components and that it moves at
a constant speed of 186,000 miles per
second. It means that the speed of light is
the same for everything and for all
observers.

8. THE CONFLICT
There is only one conflict between the two
theories: according to Maxwell, light in a
vacuum moves at 186,000 miles per second. And
it does not change for all observers and
situation. However, according to Newtonian
physics, all speeds are relative – meaning speed
depend on the observers, viewpoint and
situation.

9. RESOLUTION: Einstein and the Special Theory
of Relativity In 1905, Albert Einstein published
his observation about the differing ideas of the
two theories through the special theory of
relativity. His theory is based on the
observations of events from different
viewpoints. He stressed that while Newtonian
physics is true, Maxwell’s theory is also correct.
He resolved the opposing ideas by establishing
the two foundations of the special theory of
relativity.

10. •The first principle in Einstein theory is the
consistent law principle— It states that all
motions are relative to the selected
reference frame or viewpoint. It means that
the motion of an object is based on the
observers’ viewpoint. The laws of physics
are the same in all frames of reference that
are moving at a constant velocity with
respect to one another

11. Example: A teenage boy is standing inside
a train that is passing equally between two
oak trees. Because the train is moving, he
saw that a lightning struck the tree on his
left first then the tree on the right. Another
boy, who is standing at a train platform,
also saw the same event. Only, in his
viewpoint, the lightning struck both trees at
the same time.

12. •The second principle in Einstein’s theory
deals with the speed of light— This is the
constancy of speed. He established that
light moves in a speed of 186,000 miles per
second and is the same for all observers’
viewpoint. The speed of light in an empty
space has the same magnitude for all
observers regardless of their velocity.

13. Example: An astronaut that is moving
towards the source of light will think
that light is moving at 186,000 miles per
second. Hence, an astronaut that is not
moving towards the source of light will
think that light is moving at 186,000
miles per second.

14. In short, regardless of the rate movement of
the source of light and the rate movement of
the astronauts, the speed of light will remain
the same. These two postulates clarify that if
two events happen at different places, it is
not always likely to say which of the two
events happens first or that they occur at the
same time.

15. THANK YOU!
Prepared by:
• Jesamie M. Eroja
• Nashenne Elmedo