  We discuss the macroscopic quantum tunneling from the black hole to the white
hole of the same mass. Previous calculations in Ref.[1] demonstrated that the
probability of the tunneling is $p \propto \exp(-2S_\text{BH})$, where
$S_\text{BH}$ is the entropy of the Schwarzschild black hole. This in
particular suggests that the entropy of the white hole is with minus sign the
entropy of the black hole, $S_\text{WH}(M)=- S_\text{BH}(M)= - A/(4G)$. Here we
use a different way of calculations. We consider three different types of the
hole objects: black hole, white hole and the fully static intermediate state.
The probability of tunneling transitions between these three states is found
using singularities in the coordinate transformations between these objects.
The black and white holes are described by the Painleve-Gullstrand coordinates
with opposite shift vectors, while the intermediate state is described by the
static Schwarzschild coordinates. The singularities in the coordinate
transformations lead to the imaginary part in the action, which determines the
tunneling exponent. For the white hole the negative entropy is obtained, while
the intermediate state -- the fully static hole -- has zero entropy. This
procedure is extended to the Reissner-Nordstr\"om black hole and to its white
and static partners, and also to the entropy and temperature of the de Sitter
Universe.
