The square-cube law describes the relationship between surface area and volume as an object grows or shrinks in size.
Media
Small Is Might: the Square-Cube Law (5:09 – watch from 0:59 to 2:51)
3-Minute Explanation – Square-Cube Law Explained (Why Kids Are Better At Monkey Bars Than Adults?) (3:17)
In what activities does the square-cube law benefit children over adults?
In what activities does the square-cube law benefit adults over children?
Where else in the world can you find the square-cube law?
Kurzgesagt – In a Nutshell – What Happens If We Throw an Elephant From a Skyscraper? Life & Size 1 (6:39)
Vsauce – How Big Can a Person Get? (15:43 – stop at 5:46)
In a vacuum chamber, there is no drag. The only force is gravity pulling down proportionally to the object’s mass (which is proportional to volume). With no drag, the square-cube law no longer applies to falling objects and objects fall at the same rate regardless of size and shape.
Brian Cox Visits the World’s Biggest Vacuum Chamber (4:41) David Scott does the feather hammer experiment on the moon (0:51) Baby Grip Strength
Newborn babies (and older) often have very strong grip strength relative to their weight.
rokwood1 – Baby hanging from bar (0:22)
Chung Arthurr – Sons first try hanging on pull up bar (0:17)
In “Popular Science Monthly” (March, 1892), Louis Robinson wrote an article titled “Darwinism in the Nursery“. He wrote:
Finding myself placed in a position in which material was abundant, and available for reasonable experiment, I commenced a series of systematic observations with the purpose of finding out what proportion of young infants had a noticeable power of grip, and what was the extent of the power. I have now records of upward of sixty cases in which the children were under a month old, and in at least half of these the experiment was tried within an hour of birth. The results as given below are, as I have already indicated, both curious and unexpected.
In every instance, with only two exceptions, the child was able to hang on to the finger or a small stick three quarters of an inch in diameter by its hands, like an acrobat from a horizontal bar, and sustain the whole weight of its body for at least ten seconds. In twelve cases, in infants under an hour old, half a minute passed before the grasp relaxed, and in three or four nearly a minute. When about four days old I found that the strength had increased, and that nearly all, when tried at this age, could sustain their weight for half a minute. At about a fortnight or three weeks after birth the faculty appeared to have maintained its maximum, for several at this period succeeded in hanging for over a minute and a half, two for just over two minutes, and one infant of three weeks old for two minutes thirty-five seconds! As, however, in a well-nourished child there is usually a rapid accumulation of fat after the first fortnight, the apparently diminished strength subsequently may result partly from the increased disproportion of the weight of the body and the muscular strength of the arms, and partly from the neglect to cultivate this curious endowment. In one instance, in which the performer had less than one hour’s experience of life, he hung by both hands to my forefinger for ten seconds, and then deliberately let go with his right hand (as if to seek a better hold) and maintained his position for five seconds more by the left hand only. A curious point is, that in many cases no sign of distress is evinced, and no cry uttered, until the grasp begins to give way. In order to satisfy some skeptical friends I had a series of photographs taken of infants clinging to a finger or to a walking-stick, and these show the position adopted excellently. Invariably the thighs are bent nearly at right angles to the body, and in no case did the lower limbs hang down and take the attitude of the erect position. This attitude and the disproportionately large development of the arms compared with the legs, give the photographs a striking resemblance to a well-known picture of the celebrated chimpanzee “Sally” at the Zoölogical Gardens. Of this flexed position of the thighs, so characteristic of young babies, and of the small size of the lower extremities as compared with the upper, I must speak further later on; for it appears to me that the explanation hitherto given by physiologists of these peculiarities is not altogether satisfactory.
I think it will be acknowledged that the remarkable strength shown in the flexor muscles of the forearm in these young infants, especially when compared with the flaccid and feeble state of the muscular system generally, is a sufficiently striking phenomenon to provoke inquiry as to its cause and origin. The fact that a three-weeks-old baby can perform a feat of muscular strength that would tax the powers of many a healthy adult—if any of my readers doubt this let them try hanging by their hands from a horizontal bar for three minutes—is enough to set one wondering.
He later wrote “Infantile Atavism – Being Some Further Notes on Darwinism in the Nursery“, where he explained how he had access to so many newborn babies. He included pictures of babies hanging as evidence of his previous article. There is another picture of uncertain provenance claiming to show the same thing.
