I Diffraction of point source/s and duality

[jk22]

TL;DR

1 point source and 2 points on a screen, only quantum duality explains this ?

Consider 1 and 2 point sources. Then corpuscular view gives a single peak in those cases, whereas considering the undulation of a quantity along the path gives fringes in both cases.

My question is : is it true that the case single point source gives a single peak and two would give fringes. The point is that only the duality wave/particle of quantum mechanics can explain this (for example collision of particles from several point sources does not exhibit interferences)?

 

[Nugatory]

is it true that the case single point source gives a single peak and two would give fringes.

No. A singe slit produces a single-slit diffraction pattern and the math we use to calculate this pattern (no QM involved, it's classical wave mechanics, well understood in the 19th century) and we use the same equations to calculate the pattern. The only difference is the initial conditions - one slit open or two.

 

[jk22]

I mean an idealized point source not a slit. But quantum mechanics could be involved by computing the diffusion of a delta function or 2 and superposing the resulting wavefunction at different times. In the case of one source, the wf after the source is a chirp of modulus 1, but the factor in front is 1/t. Knowing the particle is traveling at c, $t=\sqrt{x^2+d^2}$ with d the distance to screen, this gives a Lorentzian at power dimension of speed's space divided by 2.