Last week I was writing about Goliath, the giant of biblical renown. The earliest records mark his height at 6 and a half feet, while later stories (including the Old Testament bible) report him being just shy of ten feet tall.
I had commented that the average height was shorter then, so being over 6 feet might very well be gigantic, relatively speaking. Well, now I’m doing the follow-up to that. Just how tall have humans been throughout history?
As it turns out, the answer is remarkably un-dramatic. Currently, the average height of men worldwide measures in at 5 feet, 9 inches. Turn the clock back 1000 years and the average height then was… [suspenseful organ sound] …5 feet, 8 inches. So in the last 1000 years we’ve grown an inch? Not quite. In around the 1600′s when our health and sanitation hadn’t yet caught up to the size of growing cities, human height was averaging 5 feet, 5 inches.
So we’re looking at a general fluctuation of maybe 5 inches per millennium. Not too exciting. Now let’s talk about some notable exceptions!
The tallest man… ever! Robert Wadlow was measured at 8 feet, 11 inches. He died in 1940, at the age of 22. Being ridiculously tall does seem to affect your lifespan. The average age of people over 8 feet is 43 years. (not counting two gentlemen still towering among us) Biologically, the human body runs into a lot of problems at that size, which seems to cast some doubt on Goliath pushing 10 feet and still being an able-bodied warrior.
Now, I find it rather amusing that there is a speck of physical evidence in support of the biblical height claim… but it comes from our ape ancestors. The Gigantopitecus blacki is an ancient species of ape discovered in southern China. All that has been found is a jaw bone and a few teeth, but they are huge! Some very smart people have been working on this, and by comparing the size of the jaw to its nearest related species the whole ape is speculated to be 10 feet tall. It’s a real-life sasquatch!
There are plenty of other stories of giants. Many claim “hearing about” giant skeletons found around the world, but in every case… every single case… the bones were either A) secreted away by some un-named government organization, or B) mysteriously lost. And for science, frankly, that just won’t do.
- Source: Historically Tall – The Height Site
- Source: Gigantopithecus blacki






Galileo Says Size Matters. Elephants and Jell-o Agree.
In 1638 Galileo Galilei, who is called the Father of Science, published the Square-Cube Law. Frankly, it’s not particularly clever as scientific discoveries go. It’s an observation that big things are bigger than small things. However, the particular way in which objects scale does create a few interesting implications.
I’m going to explain the concept using Jell-o. Alright, so imagine a perfect cube of that fruity lime-flavoured gelatin dessert sitting on a plate. Let’s say the cube is 1 inch in all directions. But, seeing as how there’s always room for Jell-o, you say you want “twice as much”. So, you would be expecting a cube that is two inches tall. Twice as much, right?
Not so! It may be twice as tall, and twice as wide, but the other measurements of size have more than doubled. The surface area has been squared, and the volume has been cubed. (hence Square-Cube Law) So, going by the volume, you actually have eight times more Jell-o in a 2-inch-sized serving as you do in a 1-inch-sized serving. A serving 4 inches across would contain 64 times as much Jell-o!
This exponential growth puts a hard limit on how big your Jell-o serving can get before it overwhelms the structural integrity of gelatin. As the volume increases, so does the weight of all that Jell-o pushing down on the bottom-most layer. (the mass is growing faster than the footprint, so the pressure increases) If you visualize this growing cube on your dinner table, you can picture it begin to bulge and eventually crush itself into a gooey mess.
This same law puts a limit on the size of land animals. It explains why ants can walk around on spindly little legs while lifting 50 times their body weight, compared to elephants with their tree-trunk sized feet who would strain to lift a quarter of their mass.
It also affects more than the size of animals. Elephants are practically naked (compared to most other fuzzy-haired mammals) because they have significantly more inside (volume) relative to their outside (surface area) and have a much harder time cooling down their body temperatures. Maximizing the surface area for cooling also explains the big floppy ears and wrinkly skin, which can expel more heat than a smooth surface.
It also explains why the Nazis failed when trying to build a massive tank, and why our giant friend Robert Wadlow needed leg braces to walk. Oh, and why an elephant might die if it could only jump, while a mouse could safely fall off a building. And lastly, if not to beat a dead horse, it explains why Goliath probably wasn’t ten feet tall.