Black holes move in the same way as any other object of the same mass, for example a star.
When they merge they are typically orbiting each other already in a similar way to binary stars. When they orbit the system will lose energy to gravitational radiation causing the black holes to spiral inwards. (This happens for all orbits, including the Earth's). Eventually they merge sending out a tremendous amount of gravitational radiation.
The gravitional pull of a black hole is just as strong as another object of the same mass. The difference is that the mass is concentrated to a point in the center. This is what makes them impossible to escape from.
It was believed the the whole universe could maybe collapse back into one point (like a black hole). Now it is believed that the universe will keep expanding forever. Actually the universe seems to be expanding ever quicker due to dark energy. But no one knows what dark energy is.
When they merge they are typically orbiting each other already in a similar way to binary stars. When they orbit the system will lose energy to gravitational radiation causing the black holes to spiral inwards. (This happens for all orbits, including the Earth's). Eventually they merge sending out a tremendous amount of gravitational radiation.
The gravitional pull of a black hole is just as strong as another object of the same mass. The difference is that the mass is concentrated to a point in the center. This is what makes them impossible to escape from.
It was believed the the whole universe could maybe collapse back into one point (like a black hole). Now it is believed that the universe will keep expanding forever. Actually the universe seems to be expanding ever quicker due to dark energy. But no one knows what dark energy is.