De Broglie wave length, lambda=h/mv

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SUMMARY

The discussion centers on the application of the De Broglie wavelength formula, λ = h/mv, to macroscopic objects, specifically a 10 kg stone moving at 100 m/s. The calculated wavelength of 1.05 x 10^-37 meters is significantly smaller than the Planck length of 1.6 x 10^-35 meters, raising questions about the observation of quantum mechanical effects in larger bodies. Participants emphasize that the De Broglie wavelength must be large enough to yield observable quantum effects, which is not feasible for macroscopic objects like stones. The consensus is that quantum effects are typically only observable in small molecules due to their larger wavelengths relative to the Planck length.

PREREQUISITES
  • Understanding of the De Broglie wavelength formula (λ = h/mv)
  • Knowledge of Planck length (1.6 x 10^-35 meters)
  • Familiarity with quantum mechanics principles
  • Basic physics concepts related to mass and velocity
NEXT STEPS
  • Research the implications of the De Broglie wavelength in quantum mechanics
  • Explore the significance of Planck length in theoretical physics
  • Study the conditions under which quantum effects are observable in macroscopic objects
  • Investigate the limitations of classical physics when applied to quantum phenomena
USEFUL FOR

Students of physics, quantum mechanics researchers, and anyone interested in the intersection of classical and quantum theories will benefit from this discussion.

matteo16
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for each massive body is assigned a wave length by the De Broglie formula: lambda=h/mv

but, for example, a stone which has a mass of 10 kg and which is moving with a speed of 100 m/s, is assigned a wave length that goes beyond the Planck length that is the limit.
how is this possible?
thus, if i want to see the QM effects on it i would to observe it at a distance lower than the Planck length
and this is impossible.
 
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Planck Length = 1.6 × 10^−35 meters

In your case, lambda = 1.05 x 10^-37 meters.

I don't see how this "goes beyond the Planck length". To see QM effects, the de Broglie wavelength has to be large enough to give observable effects.
 
scarecrow said:
Planck Length = 1.6 × 10^−35 meters

In your case, lambda = 1.05 x 10^-37 meters.

I don't see how this "goes beyond the Planck length". To see QM effects, the de Broglie wavelength has to be large enough to give observable effects.

1.05 x 10^-37 meters is lower than 1.6 x 10^-35(that is the limit) and so how this is possible?
how can this value surpass the limit?
 
for one thing, a stone is a macroscopic object, it is made up of a large number of "more fundemental" particles. you plug blindly into a formula (this could be called "proceeding formally") and you get an answer than doesn't make sense to you. this means you have to think about what you are doing and not just plug into a formula.
 
matteo16 said:
for each massive body is assigned a wave length by the De Broglie formula: lambda=h/mv

but, for example, a stone which has a mass of 10 kg and which is moving with a speed of 100 m/s, is assigned a wave length that goes beyond the Planck length that is the limit.
how is this possible?
thus, if i want to see the QM effects on it i would to observe it at a distance lower than the Planck length
and this is impossible.

That is right And that is one possible reason why nothing larger than a small molecule has ever demonstrated quantum effects.
 

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