She replied, “From my perspective, the absolute weight of this glass doesn’t matter. It all depends on how long I hold it. If I hold it for a minute or two, it’s fairly light. If I hold it for an hour straight, its weight might make my arm ache a little. If I hold it for a day straight, my arm will likely cramp up and feel completely numb and paralyzed, forcing me to drop the glass to the floor. In each case, the weight of the glass doesn’t change, but the longer I hold it, the heavier it feels to me.”