The grid represents an ecosystem whose population grows
exponentially. Use the right and left arrow keys to step forward or
backward one time step. As the squares fill up, they turn from green
(zero population) to purple (doomsday—maximum population). The
population meter at the top gives the current population and the
amount of time before doomsday.

Making the grid size larger (looking for more resources) but keeping
the growth rate fixed “buys” little extra time. Reducing
the growth rate extends the system life more substatially.

In coping (as a society, as a species) with exponential growth
(population and resource consumption, for example), we must adjust our
intuition to the growth rate and the number of time steps
remaining, not to the current “population” relative
to the predicted maximum.