Could almost nothing really be something? Fourier series.

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Discussion Overview

The discussion revolves around the concept of representing "almost nothing" as "something" through the lens of Fourier series and quantum mechanics. Participants explore the implications of functions that are small except in localized regions, and how this relates to the nature of reality in quantum mechanics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that a function defined in a large box can be represented as an infinite Fourier series, which sums to nearly zero except in a small region.
  • Another participant cautions that the question of whether basis waves are "really there" parallels the question of the reality of components in a vector, asserting that the state of nothing can be considered real despite the infinite non-zero components in its basis representation.
  • A participant introduces the Dirac-delta function as a concept that is zero everywhere except at a single point, questioning its applicability to describe vectors and states.
  • Another participant speculates on whether a 3-dimensional vector can be represented by three Dirac-delta functions, expressing curiosity about the delta function's relevance to abstract vectors.
  • One participant brings up the Gaussian function as an example of a function that can be near zero except in a small region, questioning the implications of letting the box become very large.
  • A later reply mentions the Feynman Path Integral in quantum mechanics and its derivation from the Dirac Delta function, pondering if all of physics could be derived from it.

Areas of Agreement / Disagreement

Participants express various interpretations of the concepts discussed, with no clear consensus on the nature of reality concerning the functions and their representations. Multiple competing views remain regarding the implications of the Dirac-delta function and its relationship to quantum mechanics.

Contextual Notes

Some participants note the speculative nature of the discussion and the need for caution when discussing personal theories and references that are not peer-reviewed.

Spinnor
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Could almost nothing really be something? Fourier series.

Say we have a large box. Say we have some function defined in this box that is square integrable. Say this function is small except for some small region in the box. This function could be represented as an infinite Fourier series, an infinite sum of functions that add to nearly zero for most of the box but constructively sum for some small region.

In a similar way we can add waves in quantum mechanics such that probability is small but for some localized region in a box. Could the Universe be such that when we have a region with low probability of finding a particle that there really exist this infinite set of waves that just happen to sum to zero at that spot at that time?

Could almost nothing "really" be something?
 
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Spinnor said:
Could the Universe be such that when we have a region with low probability of finding a particle that there really exist this infinite set of waves that just happen to sum to zero at that spot at that time?

Keep on studying QM, since what you are describing is basically a Fourier transform. The part about the basis waves being "really there" deserves a word of caution: this is identical to the question of whether the components of a 3D vector in a particular basis are "really there", and in any case science does not answer these questions. Having said that, my answer is that the vector is more real than its components, and so I think that the state of nothing is real and the fact that you choose to express nothing in a basis with infinitely many non-zero components does not make those non-zero components real.
 
I'm not sure what you're saying, but what you describes sounds to be something like the Dirac-delta function, which is zero everywhere but at the origin where it is infinite and integrating over a region epsilon on both sides of the origin gets you 1(this is admittedly a "fake" function). This function happens to be the eigenfunction of the coordinate operator (x, y, or z).
 
Matterwave said:
I'm not sure what you're saying, but what you describes sounds to be something like the Dirac-delta function, which is zero everywhere but at the origin where it is infinite and integrating over a region epsilon on both sides of the origin gets you 1(this is admittedly a "fake" function). This function happens to be the eigenfunction of the coordinate operator (x, y, or z).

That's pretty interesting, I didn't even know that. Does that mean that a 3-dimensional vector is/can be described by 3 Dirac-delta functions? I've glanced at the delta function but I'm not too familiar with its applicability. I see no reason that this wouldn't also work for abstract vectors and 'states', but I must ask if this is the case.
 
Matterwave said:
I'm not sure what you're saying, but what you describes sounds to be something like the Dirac-delta function, which is zero everywhere but at the origin where it is infinite and integrating over a region epsilon on both sides of the origin gets you 1(this is admittedly a "fake" function). This function happens to be the eigenfunction of the coordinate operator (x, y, or z).


I'm thinking of the Gaussian function that can be near zero but for some small region.:

f(x) = a*e^(-((x-b)^2 /2*c^2)))


By the definition of the Gaussian we must let the box get very large?
 
It's interesting to note that the Feynman Path Integral of Quantum Mechanics for at least a free particle can easily be derived from the Dirac Delta function as noted here:

http://hook.sirus.com/users/mjake/delta_physics.htm

This makes me wonder if all of physics could be derived from the Dirac Delta function.
 
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Zz.
 
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