I now know that an area is 256 meters square.
How big each way is the whole SL world?
Sometimes when flying I run into an area that looks like deep sea with no visible seabed, and it will not let me enter, and there is no barrier with NO ENTRY in red on it. Is that a region with no server to run it?
How high into the air do the various sorts of entry-restricted areas extend?
On Thunderbird Island at [25,237,312] Star Wars X-wing and Tie fighters can be bought; but where in SL is enough 3-dimensional empty space to fly them adequately?
I found that normal maximum unaided flying speed seems to be about 26 mph or 43 kph. What is maximum walking speed? How can I get my avatar to run (i.e. like a man runs)?