Sometimes people describe 10^9 as a "thousand million" and use "billion" to refer to 10^12. In that way of speaking, you can have a number like "one thousand two billion three thousand four million five thousand six." I'm leaving out the interesting but inconsistent hundreds to make the job easier for the Martian in the next paragraph. A Martian might infer that our number system was based on 10^3, 10^6, 10^12... and possibly extrapolate 10^24, 10^48, etc. Strange system, but maybe we have a population of a million families, each with a million members, each with a thousand tentacles, each with a thousand suction cups, or something gloriously rational and expansive like that. Here is a minimal system starting with base two. Counting: 1, 12, 121, 13, 131, 1312, 13121, 123, The number 123 (eight) is analogous to "one thousand million"--the first with two power numbers in a row. 1231, 12312, 123121, 1213, 12131, 121312, 1213121, 14... So, 1=1, 12=2, 13=4, 14=16, 15=256, 16=65536, 17=2^32, and so forth. Notice that '0' hasn't shown up. Let's say that 0 means zero, just like in our own number word system, where "zero" only shows up by itself. 18 = the size of the address space of a 64-bit processor, still less than Avogadro's number. 19 = 2^128, about 3x10^38 123456789 = 2^255, about 6x10^76, more than the diameter or age of our universe in Planck units, but less than the volume (about 10^184 Planck volumes(?)), or a googol, of course. The holographic principle puts the number of bits in the universe at something like 4 x the area of an enclosing sphere in Planck areas, about 4x10^58(??), 2^195, or 181219. Who needs a number greater than 123456789 then, since, as every Martian schoolchild knows, it could only be used in a question if asked the answer to which could not be contained in the Whole. Martians might speculate that, due to some evolutionary accident, humans started with base five, then progressed towards enlightenment by multiplying by two, then again by squaring to get 100. It's hard to guess why we took the detour to 10^3, perhaps it had something to do with the nearness of 2^10. But then we got back on track with a squaring trend. Lately we've been mentioning "memories" in sizes 16, 17 and 18, which must be gratifying for Martians to hear. (Martian adolescents have a rude rhyme: 1213121412131215121312141213121612131214121312151213121412131217 1213121412131215121312141213121612131214121312151213121412131218 1213121412131215121312141213121612131214121312151213121412131217 1213121412131215121312141213121612131214121312151213121412131219 1213121412131215121312141213121612131214121312151213121412131217 1213121412131215121312141213121612131214121312151213121412131218 1213121412131215121312141213121612131214121312151213121412131217 121312141213121512131214121312161213121412131215121312141213121 --!!) --Steve And remember, "Zero means zero."