This quote beautifully captures the profound presence and weight of silence in a moment shared between individuals. The author uses vivid imagery to make silence almost a physical entity, comparable in substance to the 'dark tree shadows' that lie across the characters' laps. This personification of silence not only heightens the sensory experience but also deepens the emotional resonance of the scene. It illustrates how silence can be so oppressive and significant that it feels as real and burdensome as a tangible object. The comparison to shadows also suggests a subtle darkness or foreboding, hinting that the silence might be a reflection of unspoken feelings, tension, or unresolved issues between the characters. In literature, such moments of silence often act as a powerful pause that invites reflection and reveals the complex dynamics of relationships without the need for words. It resonates with anyone who has experienced those heavy silences that communicate more than any dialogue possibly could. It reminds us that communication is not solely dependent on speech but can be conveyed through shared quiet, which carries its own language and meaning. The metaphor of silence having 'a measurable weight' metaphorically weighs down the narrative, emphasizing its significance in the moment and evoking empathy from the reader for the characters' internal states. This rich description from Madeleine L'Engle draws us deeply into the emotional landscape of her characters, showing her mastery in turning a simple moment into an immersive, almost tactile experience that defines human connection and emotional complexity.