where was benjamin franklin invention effective?
1) its a Hole in that things fall into it and never get out. Its Black because even light falls in. 2) Gravity is not a ray of force that the black hole lets free but is rather a side effect of what all that stuff in the hole is doing to the spacetime all around it. 3) its not a hole that fills up, its a hole that gets bigger the more that falls into it. (so its the worst/scariest type of hole)
1: Because not even light escapes the gravitational singularity. In a very real sense, it seems to be a hole in the fabric of spacetime. 2: It seems to be the only fundamental force that works over infinite distances. We're working on the Grand Unified Theory - check back later. 3: No. It continues eating - the event horizon gets bigger as the black hole gets more massive. Arguably, Hawking radiation will evaporate the black hole if and when the universe goes to a heat death (flat universe theory), but that's so far off in the future it isn't even funny.
A full face helmet have good ventilation systems that keep plenty of air to enter the helmet. I wear glasses when I ride and I use a full face helmet, I've never had any fogging issues. I have not ridden much in the rain, but you can always keep the visor of the helmet slightly open to get more air movement.
1) the black hole is the region around a singularity from which light cannot escape. as such if it is stationary (not spinning) then the limits of the even horizon would create a big ball as you said, although it would be invisible. it is called a black hole because nothing can come out of it. hawking described it like the cheshire cat in alice in wonderland (or was it through the looking glass?). it's a star that collapses until only its gravity is left, much like the cat would disappear until only its smile was left. 2) gravity is carried on imaginary particles called gravitons, of course gravity cannot affect gravity so subsequently it cannot hold itself in and so gravity is felt outside of the black hole. this is usually represented 2 dimensionally as a weight on a rubber sheet, where the weight creates a cone shape in the material, just a singularity creates a 3 dimensional cone in space time. gravity is a property of mass in space time, it cannot be restrained. 3) black holes never get full, they just continue growing there could potentially be a limit but it would have to be many billions of times heavier than our sun and so far there is no real evidence of such a limit