Planck length and quantized position

Click For Summary

Discussion Overview

The discussion revolves around the concept of Planck length and its implications for the quantization of position in physics. Participants explore whether position can be quantized in whole integer multiples of Planck length, referencing theoretical frameworks and interpretations of recent developments in quantum gravity.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions if position can be quantized in integer multiples of Planck length, proposing a mathematical framework to support this idea.
  • Another participant asserts that the Planck length is merely a scale at which a quantum theory of gravity is necessary, rejecting the notion of quantized position.
  • A participant requests a link to the article that sparked the original inquiry, indicating a desire for further context.
  • Concerns are raised about the interpretation of statements from the article regarding the Planck length and its implications for the divisibility of space.
  • Some participants express skepticism about the reliability of non-physics sources in understanding complex topics like the Planck length.
  • There is acknowledgment that the nature of phenomena at the Planck scale remains uncertain and is an area of ongoing research.

Areas of Agreement / Disagreement

Participants express differing views on whether position can be quantized at the Planck scale, with some supporting the idea and others rejecting it. The discussion reflects multiple competing interpretations and remains unresolved.

Contextual Notes

Participants reference various interpretations of the Planck length and its implications, highlighting the complexity and ongoing debates in the field of quantum gravity. There are indications of differing understandings of the implications of recent theoretical developments.

Lit
Messages
3
Reaction score
0
After reading an article on Planck length, I began to wonder whether or not the theoretical limit implied that position could be quantized in whole integer multiples of Planck length?

To demonstrate what my question is asking mathematically I hope you will scrutinize the equations below:
If given two objects O1 and O2 (ignoring uncertainty for the time being) with positions (x1,y1,z1) and (x2,y2,z2), respectively, it seems the equations below would hold true:
L_p=\sqrt{\frac{\hbar G}{c^3}}
\frac{\sqrt{\left(x_2-x_1\right)^2+\left(y_2-y_1\right)^2+\left(z_2-z_1\right)^2}}{L_p}=K where K must be an integer.

If the above equation follows the integer condition, then change in position for an object moving from (x1,y1,z1) to (x2,y2,z2) should also follow the integer rule (One can treat object 1 as the object at its position before the change in position, and object 2 as the object after changing its position). Because of this, the wave function of a particle must take an argument which moves the particle an integer multiple of the Planck length away from its previous position. So:
\left\{\frac{\Psi \left(x_2,t_2\right)-\Psi \left(x_1,t_1\right)}{L_P}\right\}\subseteq \mathbb{Z}

Please let me know if I have made any mistakes in my understanding of Planck length/logic.
- Lit
 
Physics news on Phys.org
Lit said:
After reading an article on Planck length,
If you could post a link to that article you read, it would be very helpful.
 
Lit said:
After reading an article on Planck length, I began to wonder whether or not the theoretical limit implied that position could be quantized in whole integer multiples of Planck length?

No. The Planck length is simply the length scale at which we expect to need a quantum theory of gravity in order to describe physics properly.
 
DennisN said:
If you could post a link to that article you read, it would be very helpful.


http://faculty.washington.edu/smcohen/320/GrainySpace.html
 
The_Duck said:
No. The Planck length is simply the length scale at which we expect to need a quantum theory of gravity in order to describe physics properly.


In the article it says "You have finally hit rock bottom: a span called the Planck length, the shortest anything can get. According to recent developments in the quest to devise a so-called "theory of everything," space is not an infinitely divisible continuum. It is not smooth but granular, and the Planck length gives the size of its smallest possible grains.", am I misinterpreting this section, or is there a controversy surrounding this claim?
 
The_Duck is right.

A New York Times article cited in a philosophy class is not a replacement for a physics text.
 
Lit said:
In the article it says "You have finally hit rock bottom: a span called the Planck length, the shortest anything can get. According to recent developments in the quest to devise a so-called "theory of everything," space is not an infinitely divisible continuum. It is not smooth but granular, and the Planck length gives the size of its smallest possible grains.", am I misinterpreting this section, or is there a controversy surrounding this claim?

That is not what recent developments say.

What's going on at the plank scale is, at the moment, one big mystery. Of course research is ongoing, and hopefully it will eventually be resolved, but as of now we simply do not know.

As Vanadium 50 correctly says, The Duck is spot on.

Thanks
Bill
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 6 ·
Replies
6
Views
2K