Like I've been saying, once you understand one thing in physics it’s easy to understand the next. Once you understand that time travel is science fiction, you understand why Einstein said the speed of light is not constant. After that you understand how gravity works: light curves because the speed of light varies with position, and matter falls down because of the wave nature of matter. And after that, you can understand black holes. Straight up. Yes, straight up. Because imagine you’re standing on a planet shining a laser beam straight up into space. The light goes straight up. It doesn’t curve. Now imagine it’s a denser more massive planet. The light still goes straight up. It still doesn’t curve. Let’s make it really massive. That light still goes straight up. It still doesn’t curve. But when we make it so massive that it’s a black hole, all of a sudden light can’t escape. Why not? Some will tell you that the light curves back down into the black hole. When you challenge that by saying the light didn’t start curving on the massive planet, they’ll change tack. They’ll say it’s because spacetime is curved. Then when you challenge that by saying spacetime is an abstract mathematical space, they’ll change tack again and tell you about the waterfall analogy. That’s where space is falling inwards so the light beam doesn’t make any progress. That’s garbage. In no sense is space falling inwards in a gravitational field. A gravitational field alters the motion of light through space, but it doesn’t suck space in. Because it’s a region of inhomogeneous space, like Einstein said. Like this: Please Register or Log in to view the hidden image! Optical clocks go slower when they’re lower because the space down there is different to the space up here. They call it gravitational time dilation, but it’s just the light going slower when it’s lower, so the clocks go slower too. How much slower? Have a google on infinite gravitational time dilation. What pops up time and time again? Yes, black holes. Remember those parallel-mirror light-clocks at different elevations? Gravitational time dilation is said to go infinite at the black hole event horizon. So an optical clock at the event horizon doesn’t tick at all. And if it doesn’t tick, it can only be because the light isn’t moving. Because the speed of light at the event horizon is zero. That’s why your laser beam doesn’t get out of the black hole. Not because of some mystic curvature, or because the sky’s falling in, but because at that location the speed of light is zero, zip, zilch. The light isn’t moving, so it doesn’t go up and it doesn’t get out because it is effectively “frozen”. Did you know that black holes were originally called frozen stars? If you google on frozen star Oppenheimer you can find references to this. However if you google on frozen star and follow the links, what comes up is black hole along with a point singularity. It’s like history has been rewritten. It’s like the original “frozen star” has been airbrushed away, and replaced with something else. Something stupid. See the picture below? Please Register or Log in to view the hidden image! Image credit: W H Freeman, publishers My mate Jesse put it up on the internet. It’s a screenshot from Misner/Thorne/Wheeler, the “bible” of gravitation. It depicts Schwarzschild coordinates for a body falling into a black hole. See the dashed line up the middle? That’s the event horizon. See how to the right of it the curve goes up? Do you know where that’s headed? It’s headed to the end of time. Only it’s cut off vertically, and then it comes back down. Yes, according to MTW if you fall into a black hole, you go to the end of time and back in no time flat. That’s why you read about the elephant and the event horizon, where the elephant is in two places at once. Sadly there’s even an echo of this in Kevin Brown’s the formation and growth of black holes. He refers to the frozen star, but doesn’t favour it, and talks about “future infinity” instead. Fall into a black hole and that’s where you go. And back again. It’s crap. The truth is that when you fall into a black hole, everything goes slower and slower until it stops. Your clocks go slower and slower, and so do you. Some people think you can cancel out a stopped clock with a stopped observer, who somehow sees the clock ticking normally. But he doesn’t. He’s stopped. He doesn’t see anything. Ever. At the black hole event horizon the speed of light is zero, so he can’t see. His light is stopped, and because of the wave nature of matter, he’s stopped too. And because light can’t go slower than stopped, light isn’t going to curve any more, and he isn’t going to fall any further. So the frozen-star black hole grows like a hailstone. Which is apt. Only there’s something I forgot to mention. If you fall towards a black hole you fall faster and faster. And all the while the speed of light is getting slower and slower. So, is there some crossover point where you end up going faster than the local speed of light? Relativity says no, the wave nature of matter says no, and The Man from Del Monte says no. So it stands to reason that something bad is going to happen. Like you get ionised and annihilated. Hence gamma-ray bursters. Hence Friedwardt Winterberg’s firewall, which is “very different to Hawking radiation”. There’s other things different too. For example you’ll have heard of gravitational blue shift. But remember your conservation of energy. When you drop a 511kev photon into a black hole, the black hole mass increases by 511keV. So whilst people talk about blue-shifted photons, those photons don’t actually gain any energy or increase in frequency as they descend. All that happens is that clocks go slower when they’re lower, so you measure a higher frequency when you’re lower. That’s relativity for you. You understand time, then the speed of light, then gravity, then black holes, and then you realise just how much nonsense is out there. Because you realise just how simple it all is.