Travel Near a Black Hole
One of the interesting things is travel near a black hole. If one were to take a space ship near a black hole and than step out into space, the astronaut would soon witness things differently than the crew on the space ship. Since the space ship and crew are staying safely away from the black hole, things will appear differently to them than from the astronaut’s point of view, because they are in an inertial reference frame. The astronaut is entering the area affected by the black hole and will soon experience an acceleration due to the gravity of the mass of the black hole. The first change will be in the passage of time. Since the black hole is curving the ‘fabric’ of space-time, the watch on the astronaut appears to run slower according to the clock on the space ship. Another difference is when the astronaut is near the event horizon. The crew on the space ship will see the astronaut ‘frozen’ in time, just floating above the black hole. However the astronaut will notice him/her self-accelerating into the black hole. While the astronaut appears ‘frozen’ above the black hole, the force due to gravity will start to stretch or ‘spaghettify’ the astronaut. This is only a concern if the black hole is small, because the force of gravity will tear the astronaut apart. However if it’s a huge black hole, the acceleration will be similar to the acceleration due to gravity here on earth and the slope into the singularity will not be as steep.