Blue is the color of the sky and sea. It is often associated with depth and stability. It symbolizes trust, loyalty, wisdom, confidence, intelligence, faith, truth, and heaven. Blue is considered beneficial to the mind and body. It slows human metabolism and produces a calming effect.
1 Backlash (sociology), an adverse reaction to something that has gained prominence.  Backlash (pressure group), a UK group opposing the 2008 law criminalising possession of extreme pornography.
most often occurs in gears with small numbers of teeth and low pressure angles. Circular Tooth Thickness is the distance from a point on one side of a gear tooth to a corresponding point on the opposite side of the same tooth, measured along the pitch circle. Backlash is the amount by which the width of a tooth space exceeds the thickness of the engaging gear tooth. Backlash is achieved either by decreasing tooth thickness slightly (increasing tooth space) on one or both