Theory 147/Glass tempering/Ratio lens
Strength Is Flaw Against Stress
The claim
Glass strength is set by the ratio of flaw size to applied stress, so a single deep scratch negates any tempering.
01Mechanism
Failure initiates at flaws; the ratio determines whether the stress intensity exceeds the toughness.
02Prediction
Strength should track the ratio.
03Refutation
Strength tracking temper level would remove flaws.