

One of the earliest yet most difficult challenges to date has been that of world domination. From an arbitrary start, such asYstart, is it possible to clear the board leaving the bluecell the last and only cell left alive? 

World domination is possible, but it took a computer search to prove it, find out more below. Alternatively discover world domination for yourself using this minichallenge:
Load: SS<U<D>U<SSSU/D
Find: worlddomination in 4 moves
Note: this challenge has been preloaded for you, just
click on the grid to move the blue cell.
Controls Movement Keys 
For many months world domination remained an unsolved challange, but in March 2001 Jacco Compier proved by computer search that world domination was possible, in as little as 15 moves. A convincing vindication that world domination is probably possible from almost any startstate that the bluecell can 'escape' from. Here is a selection of the shortest known solutions for worlddomination from Ystart. x,y indicates the final resting place of the bluecell.
Solution  Length  x,y 
USS\D\UD/SSS>SD  15  4,3 
SS<U<D>U<SSSU/D>\UD  19  3,6 
SS<U<DS/D/</S<UL\/R  19  3,3 
SS<U<DURSLSRS//D\>D  19  5,5 
SS<U<DURURRD\URR/SL  19  6,2 
SS<U<DURUR/<LS>\SD  18  3,5 
And here are some slightly longer solutions that all end with the bluecell back in the centre (4,4).
SS<U<D>US>/UL\SUSD</>U
SS<U<D>/D\/SSLD\>/\</R
SS<U<DU>>SUULSSS\RRLR
All these solutions are of course edgedependent, which is true for many of the challenges posed and solved so far, but having proved worlddomination is possible in as few as 15 moves, it is particularly tempting to ask... is worlddomination also possible on an infinite board? And if so, what is the minimum size board?
We have shown it is possible for the bluecell to manouvre itself into the tiniest onecell state, but onecell is never going to survive by itself. What is the smallest, indefinitely survivable, state for the bluecell? Is it those two 4cell stablestates 4a and 4b we've already seen? No. If the bluecell is prepared to retire to an oscillator, rather than a stablestate, the minimum is actually 3 cells. If you a familiar with Game of Life, you probably know the 3cell, 2step, oscillator I refer too, but can the bluecell retire to it from Ystart? I feel sure the answer is yes  but I do not know the shortest solution.
Carl Hoff stumbled on several oscillators in his early search for stablestates and we began to collect examples of a brand new type of oscillator which is unique to intelligentcell life. To find out more see the page on active oscillators.