In Ray Kurzweil’s example, lily pads that double daily fill the pond on day 30 after covering half of it on day 29, and cannot grow further on day 31 because the pond is full.

“he has the lily pad example to give an idea of of how exponential growth works. He says, you know, the if the lily pads double every day and on day twenty nine they cover one half of the pond,”

“well,”

“then on day 30,”

“the pond is full.”

“And then on day 31,”

“the lily pads don't grow anymore because they filled the pond.”

“There's no more pond.”