Outdoor commencement exercises are moving and memorable. In the mid-1960s the school district where I taught science held its eighth grade graduation program outdoors. Students were the featured speakers, delivering themed addresses and recitations, including the invocation and benediction. Near the end of the ceremony one June evening, a young man was nearing the end of his recitation with a line beginning “This GREAT God…” Immediately a loud thunderclap pealed from overhead. Fortunately for the audience, the program was about to end.
The lightning which causes thunder commands prudent safety precautions and provokes many varied emotions. Charges of millions of volts of electricity are instantly released, generating brief temperatures of over 10,000 degrees C. The sound of thunder is caused as lightning produces a sudden wave of compressed air molecules. The thunder seems to roll for many seconds as sound arrives from more and more distant parts of the lightning bolt. Many people never overcome their fear of these phenomena. Others experience the thrill of excitement and overpowering wonder as they seek the best vantage points to watch and listen safely. Notwithstanding the unease thunderstorms produce in some people, they are a major source of beneficial rainfall in many locations. Scientists estimate that some 1800 thunderstorms are occurring on earth at any given moment. Surely it is one of nature’s most gripping events.
Scripture contains many references to thunder. The usual imagery is that thunder represents the power of God or the voice of God. That metaphor is appropriate as we contemplate the emotions it produces. The last few chapters of the Old Testament Book of Job are a treasury of meteorological metaphors and spiritual depth. These passages inspire us with scientific insights and a reverent sense of worship of the Creator.
At this my heart pounds and leaps from its place. Listen! Listen to the roar of his voice, to the rumbling that comes from his mouth. He unleashes his lightning beneath the whole heaven and sends it to the ends of the earth. After that comes the sound of his roar: he thunders with his majestic voice. When his voice resounds, he holds nothing back. God’s voice thunders in marvelous ways; he does great things beyond our understanding (Job 37:1-5 NIV).