# The three major conflicts in modern physics,Special and general relativity

Topics: General relativity, Special relativity, Spacetime Pages: 8 (962 words) Published: November 3, 2013
The Three Major Conflicts
1.

Conflict between Newton’s law of
motion and Maxwell’s law of
electromagnetism:
• Newton’s laws---run fast enough,
you can catch up a beam of light.
• Maxwell’s electromagnetism---no matter how hard you chase after a light beam, it still retreats
from you at light speed.
• This conflict gave birth to special
theory of relativity
• According to special relativity,
space and time depend on one’s
state of motion.

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2.

Conflict between Einstein’s special
relativity and Newton’s law of
universal gravitation.
• Special relativity---no influence
or disturbance of any sort can
travel faster than the speed of
light.
• Law of Universal gravitation---involves influences that are transmitted instantaneously over
vast distances of space
simultaneously.
• This conflict gave birth to
general relativity.
• According to general relativity--space and time can warp and curve in response to the
presence of matter or energy--such distortions to the fabric of space and time transmit the
force of gravity from one place
to another at exactly the speed
of light.
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3.

Conflict between general relativity and
quantum mechanics:
• The gently curving geometrical
form of space and time
incompatible with the microscopic
behavior implied by quantum
mechanics.
• What really happens to space, time
and matter when crushed together at
the moment of the big bang or at the
central point of a black hole?
• The central problem of modern
physics.

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Special Relativity:
What happens if we chase after a beam of
light, at light speed?
• According to Newton---we will catch up
the light waves and they will appear
stationary.
• According to Maxwell---there is no such
thing as stationary light.
Space and time as measured by distances and
durations are not experienced identically by
every one.

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Postulates Of special relativity
1. The principle of relativity:
• There is no way for you to
of motion with out making some
direct or indirect comparison with
outside objects.
• All force free motion is relative.
There is no absolute constant
velocity motion. only comparisons
have any physical meaning
• The laws of physics are absolutely
identical for all observers
undergoing constant velocity
motion.
2. The constancy of the speed of light:
• The speed of light is the same in
all constantly moving frames–it
travels at 670 million miles per
hour regardless of bench marks for
comparison.

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Consequences of Special relativity
1. Time dilation:
Motion affects the passage
of time; it fundamentally
affects the ticking of any and
all clocks regardless of their
particular design of
construction.
In comparison to a
stationary clock, the rate of
moving clock becomes slower
and slower as it moves faster
and faster:
A moving clock ticks more
slowly than a stationary clock

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I. Simultaneity
• Things that are simultaneous from
the view point of some observers
will not be simultaneous from the
view point of others, if the two
groups are in relative motion.
• Simultaneity is not a universal
concept that every one, regardless
of its state of motion agrees upon.

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• Time elapses more slowly for an
individual in motion than for an
individual at rest---this can be
applied to time as measured by
heart beats and the decay of
body parts.
• Experimental Confirmation:
2 micro seconds.
The average life expectancy
of muons increases
dramatically if they move at
an appreciable speed(their
life time increases by a
factor of ten if they move at
0.995c)
• If people were to zip
around as quickly as
these muons,their life
expectancy would also
increase by the same
factor.

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General Relativity
What happens if a rope in an elevator
breaks?
If a person falls freely he will not feel his
own weight
If we are holding a...