Each source emits concentric waves. Where two crests meet: amplified.
Where a crest meets a trough: cancelled. The pattern in between
is not in either source — it only exists in the meeting.
Freeze to reveal the nodal lines —
the hyperbolas of permanent silence where the two waves always cancel.
They don't move. They are the fixed geometry of the meeting.
Coordinates overlays the elliptic family —
curves of constant sum-of-distances from both sources. Together with the hyperbolas,
they form elliptic coordinates: the complete geometry of any two-body system.
Drag anywhere to move the center.