We usually blame the sun for aging materials.But have you ever noticed tiny cracks appearing on the sidewall of a tire, or on the rubber seal of a car door, even if the car is parked in a garage?The rubber looks like it is "rotting."This is Ozone Cracking.Ozone ($O_3$) is a gas present in the atmosphere (often generated by pollution or electrical sparks).While the ozone layer up high ... https://cometenvirons.com/