Particle in Box: Zero Probability Density at Certain Points

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The probability density at certain points for a particle in a box is zero.Does this imply that the particle cannot move across these points
 
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somebody-nobody said:
The probability density at certain points for a particle in a box is zero.Does this imply that the particle cannot move across these points

No, because by saying that, you are assuming that you CAN track the particle's trajectory every step of the way. All the probability density says is that when you make a measurement, the probability of finding the particle at the nodes is zero.

Zz.
 
somebody-nobody said:
The probability density at certain points for a particle in a box is zero.Does this imply that the particle cannot move across these points

Like ZapperZ said, the probability density merely defines where you can find the particle when you measure. To figure out if a particle will ever move in a spot of "zero", you should use the schrodinger equation.
 
ZapperZ said:
No, because by saying that, you are assuming that you CAN track the particle's trajectory every step of the way. All the probability density says is that when you make a measurement, the probability of finding the particle at the nodes is zero.

Zz.
Yep. The proplem is with the question itself. The OP used the term move, which is a classical idea and not a quantum one. The question is better asked regarding what the probability of finding the particle in this region and then ask what the probability of measuring the particle in this other region after the first measurement was made. If the state is an eigenstate (stationary state) the the probability density will remain constant. But we really don't speak of measuring a particle in a region of zero width (i.e. what's the probability of finding the particle at x = 2?) because that will always be zero.

Pete
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
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