A short form presentation on heisenberg uncertainty principle.that what this principle tells us basically.

1. Heisenberg Uncertainty
Principle
Rana MuhammadAqib Altaf
ID# F2017139002
m.aqib722@gmail.com

2. Contents
• INTRODUCTION
• DEFINITION
• WHAT IS POSITION?
• WHAT IS MOMENTUM?
• RELATIONSHIP B/W POSITION AND MOMENTUM
• ENERGY TIME RELATION
• EXAMPLE

3. INTRODUCTION
• Uncertainty principle was stated by Werner Karl
• Heisenberg in 1927.
• This principle gives a very vital relation between
momentum
• and position of an object.

4. Definition
IN QUANTUM PHYSICS…
• A particle is described by a wave.
• Position - Where the wave is concentrated
• Momentum - The wave length
The position is uncertain to the degree that the
wave is spread out.
The momentum is uncertain to the degree that
the wavelength is unclear.

6. POSITION (Δx)
When is it certain?
This means that position is uncertain for conditions
opposite to those mentioned above
NARROW
wave group
GREATER
Range of λ
WELL
DEFINED
Position

7. MOMENTUM (Δp)
When is it certain?
This means that momentum is uncertain
for conditions opposite to those mentioned above.
WIDE
WAVE GROUP
WELL
DEFINED λ
MORE
PRECISE
Momentum

8. Position-Momentum Relation
Position-Momentum Relation-can be precisely derived from the
Schrodinger equation.
• x - the uncertainty in the x-coordinate of the position of an object.
• P - the uncertainty in the x-component of the momentum of that
object.
• h- Planck’s constant.
∆𝑥∆𝑝 ≥
ℏ
2

9. Energy and Time
Another pair of quantities that follow the uncertainty principle
Energy may be in the form of EM waves, so the limited
time available restricts the accuracy with which
Frequency of the waves can be determined.
ΔEΔt ≥ ħ⁄2

10. Continue…..
• The more accurately we know the energy of a body, the less
accurately we know how long it possessed that energy
• The energy can be known with perfect precision (∆E = 0), only if
the measurement is made over an infinite period of time
(∆t = ∞)

11. Implications
• It is impossible to know both the position and momentum
exactly, i.e., ∆x=0 and ∆ p=0.
• These uncertainties are inherent in the physical world and
have nothing to do with the skill of the observer.
• Because h is so small, these uncertainties are not observable
in normal everyday situations

12. Example:
• A pitcher throws a 0.1-kg baseball at 40 m/s
• So momentum is 0.1 x 40 = 4 kg m/s
• Suppose the momentum is measured to an accuracy of 1
percent , i.e.,
• ∆p = 0.01 p = 4 x 10-2 kg m/s

13. Continued….
The uncertainty in position is then
∆𝑥 ≥
ℏ
4𝜋∆𝑝
= 1.33 × 10−33
m
No wonder one does not observe the effects of the
uncertainty principle in everyday life!