From another discussion, I realise my understanding of Event Horizons is quite lacking, but I am unable to find a definitive, reliable answer to fillbthe gaps. My issue is essentially that of trying to resolve the apparent conflict between an observer, Alice who remains motionless wrt a BH at 'safe' distance, whilst Bob heads towards the Hole. Now my current understanding is that using Schwarzchild coordinates, Bob will never reach the horizon, because the spacetime is distorted to singular extremes at that point, but this is a hint that that system is prrhaps insufficient/inadequate to describe the reality, so using a non-singular system, one can predict Bob accelerates towards and across the Horizon. However, this entails that Alice will never be able to observe this event. She might, if Bob flashes a gamma-ray torch towards her at regular intervals, detect somne flashesd at increasingly separated intervals, and ever-decreasing energy, but will not observe any event from the moment Bob reaches the Horizon. That is how I am lead to believe, is the current concensus. Almost all references to Bob's perspective suggest that from his perspective, the moment of crossing tyhe Horozon will be somewjat mundane and nothing noticably special will occur. But this stems from an assumption no other forces or effects come into plau. I am also under the impression, that the 'jury is still out' on precisely what occurs at the Horizon. If this is true, thern how can anyone be so absolutely certain that Bob actually crosses ther Horizon??? I still do not feel satisfied that there is any measuremernt that casn ber made to show Bob having crossed the EH. It was suggested that duer to therir own local time and acceleration, Bob must continue on, but fort anyoner other than Bob to experience this, must also be doomed - Alice can never see what's on Bob's wristwatch with the same interval. Bob can never tell he has been within the horizon, Alice will never observe Bob crossing the Horizon, so what readon is there to really believe Bob ever does? The only explanation is in non-singular coordinates in which Bob continuersd motion towards the Horizon and on through it. Yet this makes grand assumption that there is a real event horizon. If I am missing something, please explain it to me, because I cannot see how ideas such as Hawling's apparent horizon or the firewalls could even be put forth unless there was some unknowen quantity of what occurs- If there is this unknown quantity, how can anyone trust that Bob's motion continues as 'predicted'? Wouldnt't this be akin to assuming the predicting a ball thrown through a hoop will follow a parabolic path all the way even if there is something in the hoop?