I shall discuss the recent situation in the neutron physics. Namely,
(1) signals for violation of the CKM unitarity after recent reevaluations
of the neutron decay amplitude; (2) the neutron lifetime problem related
to about 10 s discrepancy between the neutron lifetimes measured using so
called bottle and beam methods; (3) neutron-antineutron and neutron-mirror
neutron oscillations and experimental situation; (4) astrophysical
consequences for neutron stars and cosmic rays.
With support from FCT through project UIDB/00777/2020