[Omnicron1]

just drop this in there real quick... the size of the sphere world as suggested by its graphic would be too small. Lets assume that the species building this sphere world lives at the "hot edge of life" just below the point at which matter breaks up into energy- 1000s of degrees celsius. This is fairly generous since only a few of the strongest chemical bonds would exist at this point and they would not be varied enough to provide the kind of complexities that sentients require...anyway- gravity would be the least of your problems. As i said the graphic suggests that the interior surface of the sphere world is inside the orbit of mercury now granted the species i described might like this right up until the MASSIVE amount of energy produced by the sun is trapped in this small area (we worry about global warming and we only get 1% maybe less of the suns energy, a sphere gets and traps 100%) and compounds like no other greenhouse in the galaxy until not them or their beloved planet can with stand it and the matter they're made up of goes nuclear just like the matter in the sun. All matter can be used for nuclear reactions at a certain temperature...anyway- besides this even at half the orbital radius of Mercury (toooo close to the sun) it would take the planets of many solar systems to build the actual sphere itself so that the amount of resources required is actually unimaginably tooo small.

my solution to all this- far larger graphic! lol seriously though i refuse to build the things because of thes scientific impossibilities and build ringworlds- the problems with them are in my opinion small enough to overlooked LOL

well i lied when i said this was gonna be quick but ill try and cut it off now by not going into the other ten problems i can think of off the top of my head for the sphere world...