Did Jean Bernard Leon Foucault have any siblings?

When he invented the pendulum duh =l

He was a french scientist that invented the polarizer which is a device that converts a beam of electromagnetic waves into a beam with well-defined polarization.

No, Leon is an only child

Yes he did. He had 4 sibilings. However two of them died in infancy.

yes, Linda (a pianist) and Christian (a cellist) Jean Sibelius was a violinist and the threeplayed piano trios of Sibelius and other in their youth.