With the Christmas holidays in full swing, you may by now be sick of the sentence ‘Do you want to build a snowman?’. Snowmen building is a delicate art and there are plenty of different ways of building one. In this article, we are going to investigate ways of engineering the perfect snowman, to make sure you impress this Christmas.
Optimal Snowman Dimensions
A good, well-built snowman requires appropriate body dimensions. The classic shape consists of 3 spherical balls of snow. As well as being simple and stable, spherical snowman parts increase its lifetime. Spheres have the smallest surface area to volume ratio of any shape; at higher temperatures they provide more heat transfer resistance meaning they will melt slower. When building these balls, you should stick to a ‘large, medium, small’ arrangement for the stacking. This ensures it won’t fall over. The centre of mass needs to be as low as possible, this is achieved by a wide base relative to the rest of the snowman. An optimal diameter ratio is 3:2:1 from the base to the top. This ensures stability as well as the required strength of the base to support the rest of the structure.
There is some suggestion that an inverted construction (i.e. large snowball on the top, small on the bottom) could work but is not particularly sustainable. Perfect snowmen also require appropriate snowball size. As the snowball size increases, the relative stability of the structure decreases. It is more difficult to apply the required pressure to sufficiently pack the snowball at larger sphere size. This upper limit of snowball formation is also related to water content of the snow.
Other Parameters
When it comes to building the perfect snowman, temperature of the snow can be as important as anything. The optimal temperature for snow has been reported at around -1°C, which represents a balance between snow strength and moisture content. This is due to how ‘wet’ the snow is. This is defined in terms of amount of free water relative to ice crystals in the snow. Free water acts as adhesive, keeping snow particles together. If the snow is too dry the particles won’t stick, making it hard to build anything. Too much water however is counterproductive as it would not form a solid structure. The optimum moisture content for snowmen building is around 3%.
Another key parameter is where to build it. A snowman needs a good, sturdy base; try using a foundation with at least two inches of snow. It’s best to use ground level, but keep the snowman away from driveways as the ground material better absorbs the sun’s rays. It’s also best to keep the snowman in the shade for obvious reasons. And definitely don’t build it on a sledding path (unless you don’t like it very much I guess…)
The Perfect Snowman Equation
In January 2016, Dr James Hind of Nottingham Trent University presented his formula for the perfect snowman. It uses measures of a number of the parameters already spoken about in this article: height, diameter of tiers, snow quality, temperature. It also assess the golden ratio (noted as φ), which you may have heard of before. This ratio pops up in nature time and time again and is considered as a naturally occurring determination of beauty.
According to this formula, the snowman needs to be 1.62m tall with three snowball tiers of 30cm, 50cm and 80cm. The snow should be freshly fallen and be below 0°C. Snowman’s eyes need to be no more than 5cm apart, and it should have a carrot nose of exactly 4cm in length. Only 3 accessories are needed, a hat, scarf and gloves. It should also have 3 buttons of equal space apart. It is a cool little formula which you could use to score your snowman. But as us engineers know, practical experience mostly trumps theoretical studies.
SEE ALSO: Can Santa Realistically Bring so Many Gifts for Christmas?
Originally published at ilmm.co.uk on December 27, 2016.
