Heisenberg 2

2. PREPARATION PRESENTATION
 GUIDED BY
MR. GYAN RAO
DHOTE
 PRESENTED BY
RANJANA KHAMRA

3. TOPIC
HEISENBERG UNCERTAINTY
PRINCIPLE

4. Quantum Mechanics
Concepts
The Uncertainty Principle

5. HEISENBERG'S UNCERTAINTY
PRINCIPLE (NOBAL PRIZE 1932)
 WERNER HEISENBERG (1901 -
1976) was one of the greatest
physicists of the twentieth century. He
is best known as a founder of
quantum mechanics, the new physics
of the atomic world, and especially for
the uncertainty principle in quantum
theory. He is also known for his
controversial role as a leader of
Germany's nuclear fission research
during World War II. After the war he
was active in elementary particle
physics and West German science
policy.

6. Heinsenberg (1924 - 25)
 In the period 1924-25 Heinsenberg
created theory of Quantum Mechanics.
 It overcame some of the problems with
Bohr’s theory.
 It was first developed using
noncommuting algebra and then by
matrices.

7. The Uncertainty Principle
 The measuring process in QM always
effects the subjected quantum particle.
 The more exact the measurement the
greater the effect.
 Reducing the accuracy reduces the
effect on the particle.
 It is impossible in principle to make the
effect arbitrarily small.

8. Heisenberg Uncertainty
Principle
 The uncertainty principle may be stated
as:
 If a measurement of position of made with
precision and a simultaneously
measurement of momentum is made with
precision , then the product of the
uncertainties can not be smaller than the
order of .
x∆
p∆

9. Heisenberg Uncertainty
Principle
 From the uncertainty principle ≥∆∆ px
p
h
x
∆
≥∆∴
π2

10. A PARTICLE IS REPRESENTDE
BY A WAVE PACKET/PULSE
 Since we experimentally confirmed that particles are wave in
nature at the quantum scale h (matter wave) we now have to
describe particles in term of waves (relevant only at the
quantum scale)
 Since a real particle is localised in space (not extending over
an infinite extent in space), the wave representation of a
particle has to be in the form of wave packet/wave pulse

11. THANKS