They modelled observers (objects like a chair, a scientist, and a spacecraft ) as an aggregation of points connected by physical or chemical interactions that hold everything together as the object travels along a geodesic line. A geodesic line is simply the path in spacetime that a free-falling object follows.
“Each particle of the observer follows a geodesic line determined by the gravitational field,” says Rubiera-Garcia. “Each geodesic feels a slightly different gravitational force, but the interactions among the constituents of the body could nonetheless sustain the body.”
Research suggests tidal forces would not spaghettify the body
A tidal force is a difference in the strength of gravity between two points. The gravitational field of the moon produces a tidal force across the diameter of Earth, which causes the Earth to deform. It also raises tides of several meters in the solid Earth, and
larger tides in the liquid oceans.
If the tidal force is stronger than a body's cohesiveness, the body will be disrupted. The minimum distance that a satellite comes to a planet before it is shattered this way is called its Roche Distance. The artistic image to the left shows what tidal disruption could be like for an unlucky moon.
A human falling into a black hole will also experience tidal forces. In most cases these will be lethal. The difference in acceleration between the head and feet could be many thousands of Earth Gravities. A person would literally be pulled apart. Some physicists have termed this process spaghettification
New work suggests body can stay together
The impact of curvature divergences on physical observers in a black hole space–time, which, nonetheless, is geodesically complete is investigated. This space–time is an exact solution of certain extensions of general relativity coupled to Maxwell's electrodynamics and, roughly speaking, consists of two Reissner–Nordström (or Schwarzschild or Minkowski) geometries connected by a spherical wormhole near the center. We find that, despite the existence of infinite tidal forces, causal contact is never lost among the elements making up the observer. This suggests that curvature divergences may not be as pathological as traditionally thought.