Orbital Path Length Contraction: Explained by Relativity

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SUMMARY

The discussion centers on the concept of orbital path length contraction as explained by relativity, particularly in the context of high-speed particles like electrons. It clarifies that while the orbital path is indeed length contracted, the traditional formula nλ=2πr from Bohr's model is outdated and replaced by quantum mechanics. The conversation emphasizes that relativistic quantum mechanics can accurately describe electron orbitals around heavy nuclei, where relativistic effects are significant. It also highlights the importance of frame of reference in measurements, asserting that no conversion is necessary when not observing from the electron's frame.

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  • Explore quantum mechanics and its evolution from classical models
  • Learn about the mathematical formulation of wave functions in quantum mechanics
  • Investigate the concept of length contraction in different frames of reference
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neilparker62
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Hi

Just wondering about the orbital path of a high speed particle - eg electron in orbit. Is it length contracted? Then how do we manage nλ=2.π.r ?

Neil
 
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nλ=2πr comes from Bohr's model, this has been replaced by quantum mechanics about 90 years ago.
With relativistic quantum mechanics, it is no problem to find orbitals for electrons even around heavy nuclei, where relativistic effects are important. It is problematic to switch to the view of the electron (because it does not have a fixed velocity).
 
Length contraction is a description of a difference in an observation between two different frames of reference. We're not doing any measurements in a frame of reference moving along with the electron, so there is no reason to convert to or from that frame.
 
neilparker62 said:
Hi

Just wondering about the orbital path of a high speed particle - eg electron in orbit. Is it length contracted? Then how do we manage nλ=2.π.r ?

Neil

Orbital path is length contracted, and wavelengths are length contracted. So we don't have a radius, and we have many different lambdas.

So we write: d = n * sum of lambdas, where d is distance traveled when going around the path once.

d changes smoothly when speed changes smoothly.(I assumed this was a question about a high speed hydrogen atom)
 
Last edited:
In an inertial frame of reference (IFR), there are two fixed points, A and B, which share an entangled state $$ \frac{1}{\sqrt{2}}(|0>_A|1>_B+|1>_A|0>_B) $$ At point A, a measurement is made. The state then collapses to $$ |a>_A|b>_B, \{a,b\}=\{0,1\} $$ We assume that A has the state ##|a>_A## and B has ##|b>_B## simultaneously, i.e., when their synchronized clocks both read time T However, in other inertial frames, due to the relativity of simultaneity, the moment when B has ##|b>_B##...

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