Curves of constructive and destructive interference from two point sources
Waves from two coherent, spatially separated sources of oscillations interfere in such a way that the oscillations are amplified in some directions in space (constructive interference: antinodes of lines or maximum intensity) and completely weakened in some directions (destructive interference: nodal lines or minimum intensity). Examples are water waves, sound waves, light waves ... .
This applet allows you to visualize and study this phenomenon. You can change the distance b between the sources, as well as the wavelength λ. In these cases, the selected interference lines (actually curves) are hyperbolas.
Experiments related to these phenomena that I find interesting can be found, for example, in the following videos:
1. Interferenz Wasserwellen, Jörg Kronenberg
2. The Original Double Slit, Experiment, Veritasium
3. Interference Demo: Speakers, Physics Demos
4. Interferenz, Rene Matzdorf
The next applet considers the case of far-field interference.
Near interference field of two coherent radiation sources
P.S. Very useful demo applet "Interference from Two Sources".