Babies grow like weeds, especially in their first 6 months of life when they grow a staggering inch (2.5cm) per month. If we carried on growing at that rate, based on an average birth length of 20 inches or 51cm, these are the milestones we’d hit:
At three years old we’d be over 4.5 feet (1.5m)!
At five years we’d be taller than most adults at 6 feet 7 inches (2m)!
As we headed into our teens at thirteen we’d be taller than a double decker bus at 14 feet 7inches ( over 4.4m).
By the time we hit our 18th birthday we’d be 19 feet 7 inches (over 5.9m). At this point, we would have surpassed the tallest ever recorded male giraffe, called George, who reached 19 feet 3 inches (5.88m) tall.
Upon turning 21, we’d become the tallest land animal ever recorded at 22 feet 7 inches (6.81m) tall. At that height, we’d be able to stare down at even the largest T-rex and have taken the record from the tallest ever land animal, a female giraffe, called Shackie, who came in at 22 feet (6.7m).
As amazing as this may be, as human beings, we would never manage to achieve those great heights because of a little something called the square-cube law (or cube-square law). What this essentially points out is that our bones would be too thin to support our own weight and our hearts would be unable to pump blood around our bodies. Breathing would become impossible and even if we were able to keep our airways open, the incredible airflow needed would mean we’d experience tornado-force winds throughout our airways.
Luckily for us, although upsetting to a few, we don’t grow at the rate of a baby. We will have bursts and spurts and eventually, most of us will reach the optimal size for humans somewhere between 5 feet (1.52m) and 6 feet 3 inches (1.9m).