Particle vs Wave

Particle vs Wave

Microscopic scale: Particle behavior + Wave behavior 😃

Double slit experiment with

S is a source of stream bullet 💥 - the bullet assumed to be indestructible

Quantum View

Double Slit Experiment with Source of Electrons

No. of slits open

Explanation on the Experiment

Interference pattern appeared 😮

Distributions of the electrons on the screen are smooth
sum of these distributions are smooth
A bell-shaped curve

Particle and Wave Behavior

Particle
Wave

How could this interference happen? 🤔
Electron cannot be split, right ? 🤔
How can it appear to go through both slits at once? 🤔

An experiment was carried out to find out which slit actually the electron went. 👍🏻

place a strong light source behind the wall
place Geiger counters all over the screen so that whenever an electron reaches the screen we hear a click on the counter
when an electron passes through either of the slits,
on its way to the counter, the light will scatter to our eyes. (electric charge produce light)

Result: suddenly, the interference dissappeared! ❗
BUT, when turn off the light, the interference appeared again ‼

Why the interference appeared only when we turn off the light? ❓

actually some electrons went through the slits without being seen
there were no photons
around at the right moment to catch them
so, at low brightness levels, we miss some electrons
we hear the click from the counter but see no flash at all
- Conclusion: when the electrons are not seen, they display interference ✅

Actually, it is impossible to identify the slit that each
electron had gone through.
a new fundamental concept: ✨Indeterministic. ✨ (cannot follow particle along its motion nor can determine its path.)
Unlike classical physics, where we can follow accurately the particles along their trajectories)
indicates that electrons display both particle and wave properties 🎉
When electrons are observed/detected one by one, they behave like particle but when they are detected after many measurements (distribution
of the detected electrons), they behave like waves and display an
interference pattern. 😃

Classical View

❓How to write a full description of ❓

Wave- require 2 parameters which is amplitude and phase

Particle - require only 1 parameter which is position

2nd experiment - only S2 is open

3rd experiment- both S1 and S2 are open

1st experiment - only S1 is open

S as a source of waves 〰

wave is represented by complex function where the intensity proportional to its amplitude.

the intensity of the wave is given by

click to edit

2nd experiment-only S2 is open

1st experiment- only S1 is open

3rd experiment - both slits are open

when both slits are open, the total intensity is not equal to the total sum of each intensity
- an oscillating term was added
- the intensity collected on the screen displayed in the interference pattern
- hence, the amplitude need to be summed up (not the intensity)

🚩 Conclusion 🚩

wave exhibit an interference pattern, while the particle does not.
particle : summation of intensity
wave : summation of amplitude

Linear Superposition Principle

✏

✏ .For are complex constants

Wave-Particle Duality

Microscopic scale: Particle behavior + Wave behavior 😃

Microscopic particles behave not according to classical particles and waves.

Quantum results ✏

Something can behave as wave and particle at the same time ⁉

Physical experimental examples featuring this include: Blackbody radiation, photoelectric effect, pair production, compton effect, double slit experiments...

❎ Impossible in Classical mechanics since particles and waves are mutually exclusive entities

✅ Possible in Quantum mechanics

The same material particle is described by both its wave and particle picture.
The wave function is used and it describes simultaneously the wave and particle behavior of microscopic systems.
A quantum system is neither a pure particle nor a pure wave but actually both hence the complementarity principle introduced by Bohr.

Quantum systems provide accurate results only when complementarity principle is respected, meaning not excluding neither the particle nor the wave feature of the system.

The measurement of the Quantum state properties gives only one property, meaning the wave property or particle property not both.
In Quantum mechanics, the aspects of particle and wave manifest only when subjected to and any measurement will destroy the initial quantum state information and give only one property information, either that of a particle or a wave.

Created by:
1) Hamizahtul Nurul 'Izzah bt Zainuddin 🦋
2) Nur Syahera bt Sobri 💜
3) Fazrin Edzrinna bt Zainuddin ❤
4) Ummu Sur Ain bt Mohamad 🍀
5) Meriem Si Chaib ⭐

For double slit experiment, wave function

Amplitude

Intensity of two slits: The sum of intensity of Slit 1 and Slit 2

If only one slit is open at one time, the intensity:

If both Slit 1 and Slit 2 are open, the intensity

Intensity

Intensity is directly proportional to the squared of amplitude

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