Question (not homework): Quantum phenomena and the Macroscopic world

Click For Summary

Discussion Overview

The discussion revolves around the relationship between quantum phenomena and macroscopic objects, specifically addressing the de Broglie wavelength of everyday objects like bullets and its implications in the context of quantum mechanics and classical physics.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant raises a question about the existence of a de Broglie wavelength for macroscopic objects, particularly when the wavelength approaches the Planck length, suggesting that quantum effects may not be relevant at this scale.
  • Another participant argues that even if a de Broglie wavelength exists for such objects, it is unmeasurable and thus irrelevant, asserting that classical physics suffices for practical applications.
  • A third participant challenges the notion that physics should not seek to understand "what actually happens," implying a desire for deeper understanding beyond practical utility.
  • Another participant suggests that the wave character of macroscopic objects is negligible compared to their size, indicating that quantum interference effects would not be observable in practical measurements.

Areas of Agreement / Disagreement

Participants express differing views on the relevance and implications of quantum mechanics for macroscopic objects. There is no consensus on whether the de Broglie wavelength has any practical significance or if quantum phenomena can be ignored in classical contexts.

Contextual Notes

Limitations include the assumptions regarding the applicability of quantum mechanics to macroscopic objects and the definitions of measurable effects in quantum theory versus classical physics.

FisiksIdiot
Messages
7
Reaction score
0
I was doing a question while back about finding the de Broglie wavelength of a bullet with a given mass traveling at a given speed- easy stuff. However, when the result was very similar but slightly larger than the Planck length which I'd stumbled across on my few jaunts through Wikipedia, it got me thinking.

If the Planck length is the smallest concievable length (according to Wikipedia, we haven't covered it as such in lectures), and a normal day to day moving object has a de Broglie wavelength smaller than this length, is there actually a de Broglie wavelength at all? Would quantum phenomena cease at this point? I would be intrigued to find out more from someone who knows more than I do about quantum physics.

Thanks and sorry in advance if I've posted this in the wrong place!
 
Physics news on Phys.org
i do not think this is a useful question.

just know that even if there was a wavelength it is unmeasurable. so it doesn't matter what "actually happens" the fact is that it behaves just like Newton physics.

just think of quantum physics as a useful tool that gives the right answers. if you get really deep into the theory of that stuff it is just too confusing and will rarely, if ever, be used for the design of practical devices. i never regretted this approach.
 
I thought the whole point of Physics was to find out 'what actually happens'.
 
I think that even if it is times larger, the wave character is still too minuscule comparing to the value of the measurement. For example, the computed distances between maximums of the double slit of bullet is way way smaller than the radius of the bullet, therefore when can only discern the linear combination of probabilities without the interference term (which brought forth by QM).
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
Replies
2
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 41 ·
2
Replies
41
Views
6K
  • · Replies 45 ·
2
Replies
45
Views
13K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K