Research reported in TechSac about the physics behind toast falling butterside down:
The cause:
• The buttered side is up after we butter the toast.
• Kitchen counters are waist-high
• When buttered toast falls from that height, it rotates half a rotation on its way to the floor.
• So it lands butterside down.
Solutions:
• Use a higher counter when buttering toast.
• Or toast smaller slices of bread, small enough to rotate a full rotation before hitting the floor.
Read more about this in TechSac: http://techsac.blogspot.com/2011/07/why-buttered-toast-falls-butter-side.html