Was Einstein wrong about gravity? Einstein said gravity and acceleration are indistinguishable, and therefore identical.

Is he right about that?

Astrophysicists theorize that near the event horizon of a black hole, physical matter would undergo gravitational "spaghettification".
That means matter would get stretched out; because the exceptionally powerful gravitation would be very strong, but stronger on the portion of the matter closest to the black hole; weakest on the other end.

Thus, the matter would be stretched apart, or at least elongated.

But in acceleration, rather than stretching things out, matter tends to get compressed.

Or phrased another way; gravity has a gradient. Acceleration does not.

So what's the deal Einstein?

A little booboo perhaps?

I've read that some of Einstein's theories were later proven wrong, in theory.

I think, when applying this theory to earth alone, it maybe correct. I agree it probably doesn't hold water when applied to a black hole.

Acceleration can cause either effect, depending on the orientation. Think of the difference you feel going over the top of a roller coaster compared to the squeeze you feel going thru the dip at the bottom. One's a squeeze, the other's a stretch, but both are accelerations - only the direction changed.

Acceleration certainly CAN have a gradient. And that would be due to a varying force. By Newton's 2nd Law, F = m x a. And by the universal law of gravitation, force is inversely proportional to the square of the distance. So, near an intense gravitational source like a black hole, a small variation in distance would result in a significant difference in force, causing acceleration to vary from one side of an object to the other. Remember, Einstein's work in no way negated Newton's. He put a finer point on it, and that point has some rather astoundig implications that would not have been observable in Newton's time.

I hope my explanation has been clear enough.