Black Holes. Don't let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City.
Determine Census Tract Codes Based on Address. â¢ Key in an address here to find codes/names based on address. Census tracts within a county are identified by a 4-digit basic code between 0001 and 9999, and may have a 2-digit suffix ranging from .01 to .98; for example, 6059.02. The decimal point separating the 4-digit basic tract code from the 2-digit suffix is shown in U.S. Census Bureau printed reports and maps.
1 Dynamic Tract/Block Maps. 2  Search by address, zip code or latitude and longitude. 3  Census 2000 PDF Maps. 4  Browse by area and use the index map (the first file - #000) for each area to find the relevant detailed maps.