Two weeks ago 164 skydivers, flying at 20,000 feet and falling at 240 miles an hour, set the “head-down” world record in Illinois. The international jump team joined hands for a few seconds, in a pre-designed formation resembling a giant flower, before they broke away and deployed their parachutes.
I was intrigued by the design of the formation. I have found many qualities in ten petal (or star) designs and, of course, I look for continuous lines in all sorts of designs that I find and in particular the possibility of a Single Continuous Line.
Here is my sketch of the skydivers formation. It is made up of many linked circles, starting with a central ring of ten circles which radiate out to ten “petals”. The plan seemed to involve six skydivers forming each circle by holding hands. Some extra skydivers started links between petals. I checked to see if I had included all the skydivers, which made my sketch look like a prickly cactus.
This was such a tremendous achievement by very brave men and women. My only experience of heights is abseiling 150 feet down a cliff in the Lake District. I realise that the jump would have been very carefully planned using the latest science and involved a lot of training, etc. but I am particularly interested in the part that the formation design played.
The hexagon appears to be an essential element so that hands can be joined at 3 way junctions. A core circle of hexagons would naturally be 6, but more would be required for this jump. The next highest near fit would be 10, which is fine given the variations in human proportions. This also naturally allows linking between middle circles in the petals to complete a second ring of circles, which was partly done in this jump.
Every participant would need to know exactly where their place would be in the design and yet it is so symmetrical that I struggle to get my sketch the right way up. Also with the short time involved co-ordination of planned stages would be difficult. This made me think of a flock (or murmuration) of starlings performing their remarkable patterns in the sky and how they manage to co-ordinate. Apparently each bird relates and reacts to the nearest birds around it. Absolute simplicity and ruthless efficiency with no critical path.
If the skydivers have adopted a similar approach then the design is ideal. The design is basically 30 circles in sets of 3 in a row making up 10 petals. The process is fluid and adaptable, building outwards from the centre. Think 10 individuals linking hands to start off with, which then recognisably evolves into 10 petals, and think 6 individuals in each of the 30 circles. Everyone is dropped (there were 7 aircraft I think) in an order which anticipates being able to take up a place a certain distance from the centre of the structure and within a specific circle. As they approach they can recognise the progress and assess whether they can link in as expected or whether a modified position may need to be taken up (and being guided by the people already in place). The last individuals to be dropped will not have a planned position in any circle but will form the start of the links between the central of the 3 circles in the petals. They need to be prepared to become part of an outer circle which has not been completed.
I have done a sketch of how this may work, with the numbers indicating my thoughts on the expected order of arrival in the building of the formation.
I hope this was a useful exercise, in trying to work out how the formation worked, and not total tosh (if so my apologies to all concerned).
To help my attempt to apply my continuous lines to the design I have completed the links between middle circles, which was partially done this time and I suppose will be considered for the next larger attempt at the record (say 180 skydivers). The Continuous Lines are intended to pass through every three handed junction once only (I normally would say three legged ! ).
The method I use to complete the overdraw was developed in the early 1970’s when I was working on trying to prove the Four Colour Theorem. A single continuous overdraw throughout a map would split it into two chains of alternate colours which would demonstrate that only four colours were needed. I will explain how this is done in a future post.
This overdraw has resulted in several continuous lines and no alternative would produce a Single Continuous Line. This is due to the lack of width going around the structure.
Consequently, I have extended the design further by adding linking lines between all outer petals and succeeded in drawing a Single Continuous Line on that. A future Skydiver jump completely assembling this design would require about 220 participants (I am not suggesting that this be attempted) !