Editing Snowball (section)

==When and how==

When forming a snowball by packing, the pressure exerted by the hands on the snow is a determinant for the final result. Reduced pressure leads to a light and soft snowball. Compacting humid  or "packing" snow by applying a high pressure produces a harder snowball, sometimes called an ice ball, which can injure an opponent during a snowball fight.

Temperature is important for snowball formation. It is hard to make a good snowball if the snow is too cold.<ref name="schmitz"/> In addition, snowballs are difficult to form with dry powdery snow. In temperatures below {{Convert|0|°C|°F|0|abbr=on}}, there is little free water in the snow, which leads to crumbly snowballs. At {{Convert|0|°C|°F|0|abbr=on}} or above, melted water in the snow results in a better cohesion.<ref>{{cite conference |url=https://arc.lib.montana.edu/snow-science/objects/ISSW14_paper_P2.24.pdf |title=Granulation of Snow: Experiments and Discrete Element Modeling |first1=Walter |last1=Steinkogler |first2=Johan |last2=Gaume |first3=Henning |last3=Löwe |first4=Betty |last4=Sovilla |first5=Michael |last5=Lehning |date=2014 |conference=International Snow Science Workshop |archive-url=https://web.archive.org/web/20200328052228/https://arc.lib.montana.edu/snow-science/objects/ISSW14_paper_P2.24.pdf |archive-date=28 March 2020 |location=Banff |pages=733{{ndash}}737 |access-date=28 March 2020 }}</ref> Above a certain temperature, however, the snowball becomes [[slush]], which lacks mechanical strength and no longer sticks together.<ref>{{Cite book | author = Morag Challenor | chapter = No-Ball Snow | page = 157 | title = Does Anything Eat Wasps?: And 101 Other Unsettling, Witty Answers to Questions You Never Thought You Wanted to Ask
| editor = New Scientist
| publisher = Simon and Schuster
| year = 2006 
| isbn = 9780743299176 }}</ref> This effect is used in the rule that, in skiing areas, there is a high risk of avalanche if it is possible to squeeze water out of a snowball.<ref>{{Cite journal
 | title= Developing Interfacial Phase Diagrams for Applications in Activated Sintering and Beyond: Current Status and Future Directions
 | first = Jian 
 | last = Luo
 | journal = Journal of the American Ceramic Society
 | date = 2012-01-16
 | volume = 95 
 | issue = 8 
 | pages = 2358–2371 
 | doi = 10.1111/j.1551-2916.2011.05059.x}}</ref>