> Gravity drops on linearly inside a planet, going to zero at the center. Anything dropping through a cored planet or asteroid will bounce up and down the shaft

> Gravity drops on linearly inside a planet, going to zero at the center. Anything dropping through a cored planet or asteroid will bounce up and down the shaft just like a kid on a swing or a pendulum […] …assuming the density distribution is homogeneous which is not fulfilled for Earth [1] and even more unreasonable for gas planets like Jupiter. > So actually you can’t reach the event horizon. As was already pointed out, this is not correct. > The closer you get, the faster the universe behind you moves. Stars are born and die in a tick of the clock, galaxies form and collide, galactic superclusters orbit super-superclusters and before the whole universe can die Gravity is a non-linear theory. Different solutions to the field equations cannot simply be superimposed, so aligning the time variable of a Schwarzschild spacetime (let alone of a falling observer) with the time variable of a Friedmann solution (which describes the evolution of the universe as a whole) is a priori very difficult. I would be very careful about trusting the above statement. > Imagine the lines on a ruler getting further apart the closer you get to a gravitational object. Oh god. This is wrong on so many levels. > Closer to the star, distances seem longer. Longer than where? This seems to assume that one could move a scale from one region of spacetime to another to see it grow or shrink. But this is wrong. Distances are tied to the spacetime by virtue of the metric which is a field and hence depends on where in spacetime you are. It makes absolutely no sense to compare the metric at two different points. > The more gravity, the slower time runs. Slower than where? Similar to above, distant observers cannot simply compare the hands on their clocks, so in general this statement makes no sense, either. The only thing one could compare are the lengths (eigentimes) of time-like curves starting and ending at the same spacetime events (like it was done in Interstellar: One person stayed in the orbit, the others went down towards the black hole and returned later). Also, in what geometry is all this supposed to happen? The author probably assumes a Schwarzschild geometry. But in a Friedmann universe, for instance, where gravity is strong as well, time keeps passing in the same way for all observers moving along with the matter, even as the universe might collapse (and gravity might intuitively become stronger). Conclusion: Gravity is not that simple that it can be broken down to a few easy facts. [1]: https://en.wikipedia.org/wiki/Structure_of_the_Earth#Structure https://en.wikipedia.org/wiki/Structure_of_the_Earth#Structu...