Editing Square root of 2 (section)

===Physical sciences===
There are some interesting properties involving the square root of 2 in the [[physical sciences]]:
* The square root of two is the [[interval (music)#Frequency ratios|frequency ratio]] of a [[tritone]] interval in twelve-tone [[equal temperament]] music.
* The square root of two forms the relationship of [[F-number|f-stops]] in photographic lenses, which in turn means that the ratio of ''areas'' between two successive [[aperture]]s is 2.
* The celestial latitude (declination) of the Sun during a planet's astronomical [[cross-quarter day]] points equals the tilt of the planet's axis divided by <math>\sqrt{2}</math>.
{{distances_between_double_cube_corners.svg}}
* In the brain there are lattice cells, discovered in 2005 by a group led by May-Britt and Edvard Moser.  "The grid cells were found in the cortical area located right next to the hippocampus [...] At one end of this cortical area the mesh size is small and at the other it is very large. However, the increase in mesh size is not left to chance, but increases by the squareroot of two from one area to the next."<ref name="Hjernen er stjernen" >{{citation |title=The Book: Hjernen er sternen|last=Nordengen|first=Kaja|publisher=2016 Kagge Forlag AS|year=2016|isbn=978-82-489-2018-2|page=81}}</ref>