Leg length?

Question

Some people have long legs and some people have short legs. But whatever sort of legs a person has, they are always just long enough to reach the ground.
Is this some kind of optical illusion or can it be explianed by the theory of relativity

Answer 1

This observation has fascinated theoretical Biologists for centuries.

In 1726 Prof. Albert Femur postulated that this occurred because people with shorter legs always stood on higher ground, thereby enabling the ground to reach up to meet their legs (the so-called "short-guy on the hill" theory). This theory held sway for some considerable time until in 1804 Heinz Hindlegg conducted his famous "ten men in-a-ditch" experiment where he made 10 men of varying heights stand in a ditch at the same time and found that even the shortest remained in contact with the ground.

Accusations of cheating by the use of platform soles by the shorter men were made by the adherants of the "short-guy on the hill" theory and a major rift in the scientific community took place which lasted several decades.

The rift was finally resolved in 1865 when, in an elegant experiment, Dr. Hans Aneez forced 20 bare-footed men of varying heights into a large hole in the ground just outside Oslo and demonstrated that platform soles were not necessary in order to permit the shorter-legged individuals to still reach the ground (the "barefoot bigger hole experiment").

However, it devolved to the scientific genius of Professor Sir Anthony Legg to demonstrate what is now accepted as the true reason why even short people's legs reach the ground. In his Nobel Prize-winning experiment of 1909, Prof. Legg demonstrated that short people's legs reached the ground because their heads didn't start off so far up in the air, thereby keeping their entire bodies nearer to the ground and permitting their feet to remain in contact with the Earth's surface - The now well-known "Short@rses Law".

His experiment was as perfectly simple as it was cruel: Ten men (barefoot, of course) were dangled from a beam using ropes of the same length. The beam was then raised until all their feet had left the ground and their heads were all at the same height above the ground. [It might be worth noting that a first attempt at this experiment failed when elastic was used instead of rope and a second attempt on sloping ground was also found to be at fault after much re-calculation]. It was amply demonstrated that the shorter men died of hanging first, thereby demonstrating that their feet had left the ground first. A simple calculation using calculus, Newton's Law of Gravity and cup or two of coffee was then all that was needed to seal the issue once and for all.

Professor Legg received his Nobel Prize in Pentonville Prison shortly before his execution (ironically, by hanging) for mass murder and the unauthorised use of his neighbour's back yard (despite his protestations that it was the only nearby area of flat ground).

More recently, NASA has taken up the cause by conducting similar experiments at a secret installation at Leggup Lake Air Force Base, Nevada with a view to demonstrating that lifting a short astronaut's head so his feet dangle a foot above the ground reduces the thrust required to place him into Earth orbit. These experiments are mainly still classified as "Highly Secret" (although due to confusion some were originally marked "Shortly Secret") and the full results may not be made public for some time.

Answer 2

It's partly an optical illusion, if you look down at your own legs perspective foreshortens them and they look shorter and fatter than they really are (girls take note - this also applies to bums).

Mostly, as you have guessed it's down to relativity. If all your relatives have long legs then your own are more likely to be long. We can't predict exactly how long because of quantum indeterminacy, all we can give is a probabalistic prediction.

As for the legs being just long enough to touch the ground, have you considered that you might just have been very lucky? I have seen plenty of people wearing high heeled boots and the like to make up the difference and those circus stiltwalkers most have had a real problem in childhood.

Best of Luck

Answer 3

Reminds me of the Aggie who built a barn. But when he tried to get his mule in the barn, the mules ears hit the door, and it balked. So the Aggie started tearing out the barn door to rebuild it taller. His friend was watching the whole thing and said "Why don't you just dig a ditch beneath the door for the mule to walk in?"
The Aggie responded "Ya dang fool! It ain't his legs that'r too long. It's his ears!"

Answer 4

Leg length discrepancy
(also called anisomelia), may be functional or structural. Functional anisomelia is an apparent discrepancy in length due to joint contractures or other pathology. Structural anisomelia is genuine asymmetry in leg length due to unilateral shortening or lengthening for which there are numerous congenital and acquired causes.

Answer 5

no it's really true as long as you have a leg to stand on it'll reach the ground unless your suspended in the air of course

Answer 6

A good question, loved GLH's answer but Neil H, use the spell check