Heiseinberg's Microscope - Trigonometric and Interpretation questions

AI Thread Summary
The discussion revolves around the interpretation of equations related to Heisenberg's microscope, specifically the equations for position uncertainty (Δx) and momentum uncertainty (Δp_x). There is confusion regarding the relationship between sin(2θ) and the approximations used in the provided solution, particularly why Δp_x is approximated as 2(h/λ)(sin(θ)). Participants explore the implications of minimizing Δx by reducing λ, questioning how this affects the uncertainty in momentum and its relation to the Heisenberg Uncertainty Principle. The conversation also touches on the difficulties of measuring both position and momentum simultaneously, seeking clarification on the approximations and their physical significance. Overall, the thread emphasizes the nuances of these equations and their interpretations in quantum mechanics.
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Homework Statement


The problem along with its solution is attached as ProblemSolution.jpg.

Homework Equations


Δx = λ/sinθ (Eq. 1)
Δp_x = (h/λ)(sinε) (Eq. 2)

The Attempt at a Solution


In Wikipedia, I found this article: http://en.wikipedia.org/wiki/Heisenberg's_microscope which uses (Eq. 2) from the “Relevant equations” section above but, comparing it to my attached jpg file, ε = 2θ so I feel that the equation should become Δp_x = (h/λ)(sin(2θ)) but my jpg file states that it is Δp_x ≈ 2(h/λ)(sin(θ)) instead. Why is this the case? I even confirmed with Wolfram Alpha that sin(2θ) ≠ 2sin(θ). sin(2θ) = 2sinθcosθ but I don't see any cosθ anywhere.

Also, in the solution in the jpg file, there is the Δp_x ≈ 2h(v/c)sinθ equation; is it this equation that “[shows] that if we minimize Δx by reducing λ, this will result in a loss of information about the x-component of the elctron momentum?” If so, then what's the purpose of the Δx Δp_x product? Is the value of Δx Δp_x ≈ 4πħ = 2h supposed to be an approximation to the Heisenber Uncertainty Principle equation: Δx Δp_x ≥ ħ/2? Lastly, the last part of the solution says “We can attempt to overcome this difficulty by [ . . .].” What's the difficulty we are attempting to overcome? Is it the difficulty of measuring both the position and momentum of an electron simultaneously? Could someone please explain, confirm and/or deny these things to me even if it seems obvious to you?

If more information is needed or you want me to rephrase something, just ask.

Any input would be GREATLY appreciated!
Thanks in advance!
 

Attachments

  • ProblemSolution.jpg
    ProblemSolution.jpg
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You didn't attach the file.
 
Sorry lol but, I just did now. :)
 
All of these equations, on your pdf and on wikipedia, are all approximations. Maybe they all roughly explain the same thing?
 
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http://spiff.rit.edu/classes/phys314/lectures/heis/heis.html

This lecture thing I found when I googled Heisenberg's microscope kinda defends my angle approximation idea.

Now that I look at this lecture, I'm pretty sure they are getting that 2 from the fact that the uncertainty in p ranges from -hθ/λ to +hθ/λ?

so Δpx=2hθ/λ (or sinθ if youd like)

As far as I can tell, wikipedia and your pdf are giving different but adequate explanations of the same thing.
 
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Sorry for the late response and thank you! Those notes were also aesthetically pleasing to my eyes. :)
 
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