Once upon a time, I was in college messing around in microbiology  labs, where we boiled up smelly gelatinous broths and poured them into shallow glass petri dishes.  Then we inoculated the nutritious media with various bacterial strains – just one or two bacteria per dish was all we needed.  Don’t ask where we obtained some of the bacteria.  Next, we placed the petri dishes in incubators, with the temperature not too warm and not too cold,  and sat back to watch disaster TV.

After days of incubation a tiny bump appeared on the surface of the medium, then another and another.  These were little colonies of bacteria that finally were becoming visible to the naked eye.

Days might go by, and the tiny bumps grew and became little islands, which then linked together.

Finally, after days of watching in fascination, I came into the lab one morning, reached into the incubator, and removed the petri dish, to discover …. a gooey mess with no viable bacteria remaining.

The tiny one-celled organisms had multiplied, using the nutritious medium as an energy source, until there was simply not enough medium left to sustain bacterial life. The colonies had collapsed, sometimes in a matter of hours. That’s what exponential growth does. Everything looks great for weeks, as one organism doubles, then two double, then four double, then eight double, then 16, then 32, then 64, then 128 ….  You get the picture.

And picture us, on our petri dish …. I mean, planet ….

Then watch this short film. You’ll find out about the grains of rice.