Determining Electron's Momentum and Position Simultaneously

  • Context: High School 
  • Thread starter Thread starter lisathomas
  • Start date Start date
  • Tags Tags
    Electron
Click For Summary
SUMMARY

This discussion centers on the challenge of determining an electron's momentum and position simultaneously, referencing the principles of quantum mechanics (QM). The analogy of a ceiling fan is used to illustrate the classical limitations of measuring speed and position, which do not apply to subatomic particles. The conversation highlights the fundamental differences between classical trajectories and quantum states, emphasizing that electrons do not have defined paths. The conclusion is that traditional analogies fall short in explaining quantum behavior.

PREREQUISITES
  • Understanding of quantum mechanics principles
  • Familiarity with quantum numbers (1s2, spin -1/2)
  • Basic knowledge of atomic structure and electron behavior
  • Concept of wave-particle duality
NEXT STEPS
  • Research the Heisenberg Uncertainty Principle
  • Explore quantum state vectors and their implications
  • Study the concept of wave functions in quantum mechanics
  • Investigate experimental techniques for measuring electron properties
USEFUL FOR

High school science teachers, students studying chemistry and physics, and anyone interested in the principles of quantum mechanics and electron behavior.

lisathomas
Messages
3
Reaction score
2
TL;DR
Is it possible to retrospectively determine the position and speed of an electron at the same moment?
Hi. I am a high school science teacher (A&P, Chem, and Environ Bio & Eco) so my understanding is limited on subatomic particles...please forgive me if this is a really stupid idea.

I teach my chem students about electrons, orbitals, electrons' "address" using the four quantum numbers, 1s2 -1/2 spin. I use the example of an airplane's propellers or a fan's blades to explain that we can know how fast they are traveling or their exact position but not both at the same time. I was watching my fan in my bedroom this morning turning around and around and I would pick a blade and watch it then allow it to blur in with the rest as I watched all the blades turn at a slow speed. Then, I began to blink my eyes rapidly which allowed me to take "moment pictures" which allowed me to see the placement of each blade and the speed of my eyes opening and closing with the change in position of the blades allowed me to "measure" the speed. Is there some way we could do that in a lab with electrons?
 
Last edited by a moderator:
Physics news on Phys.org
An atom is a bound energy state of its constituent particles. The electrons do not have classical trajectories, in terms of position as a function of time; or, momentum as a function of time.

QM involves an entirely different description of nature, based on states and state vectors, as opposed to classical trajectories. The ceiling fan analogy doesn't apply, I'm sorry to say.
 
  • Like
Likes   Reactions: Delta Prime and lisathomas
Wow! Thank you for the clear explanation.
 
  • Like
Likes   Reactions: berkeman and weirdoguy
Wish when I was in school I had a teacher curious enough to post this
 
  • Like
Likes   Reactions: ersmith and lisathomas
Oh, thank you! That is so kind.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 29 ·
Replies
29
Views
2K
  • · Replies 21 ·
Replies
21
Views
2K
  • · Replies 11 ·
Replies
11
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K