My two-year-old, Yaakov, shouts whenever there is a thunderstorm, and there are many in the U.S. during the summer. I guess lots of kids shout scared, as they run into their parents' arms or beds. But what Yaakov shouts always gives me and my wife a laugh. "It's a wunda!"

No one taught him to say the word ‘wonder' when hearing thunder. But somehow, through a divine twist of fate, when Yaakov hears the word ‘thunder,' he repeats it as ‘wonder'. Though he doesn't quite mean it this way, he's right; thunder is indeed a wonder.

Yaakov's thunder/wonder comment got me thinking: what is this loud crash of thunder and why did God create such a disturbing sound to appear smack in the middle of a heavy rainstorm?

Let's first explain what thunder is. (My apologies to the more knowledgeable reader, but this writer was pretty ignorant about thunder until recently.)

Thunder occurs when a flash of lightning heats up the air around it making the air expand very rapidly, or explosively. In fact, it is thought that the air around a lightning bolt heats up to five times hotter than the air on the sun's surface.

Heat causes things to expand, thus, the air expands when the lightning heats it. Because the rate of expansion is so fast, the air actually vibrates, causing waves. These sound waves comprise the crash of thunder that we hear.

That's how it works scientifically, but why did God make thunder?

The Talmud actually asks this question and says: Thunder was created to straighten out the crookedness of the heart (Brachot 59a). What does this mean? And how is the heart crooked?

If there's one area of life that man cannot control, it's the weather.

We tend to place much confidence in human wisdom and accomplishment. Technological advancements make us beam with pride as we look back upon ‘ancient' generations, some of them a mere decade or two ago, that didn't have the palm pilot, internet, not to mention the many significant medical breakthroughs. But sometimes, we place too much confidence in human wisdom and we forget that God still runs the world.

If there's one area of life that man cannot control, it's the weather. Ever wonder why all the news services spend so much time and emphasis on the weather? There's even a TV channel singularly dedicated to weather! I think it is because weather is one part of life that terrifies man, so we obsess over it. We can do nothing to stop or alter weather. From deadly hurricanes and tornadoes, to the rainstorm that cancels the outdoor picnic and BBQ, man is at the mercy of weather.

God created weather and designed the system of the rain cycle. Since we tend to forget that it is He who is in charge, He devised a mechanism to make us remember: thunder. Who isn't frightened from that first crash of thunder in a storm? Who feels totally secure that no harm will come to him as a result of the thunderstorm? We lull and distract ourselves away from such thoughts but in the back of our minds, they are there. Thunder makes us realize that we are not in true control of our lives; we exist only because God wants us to. This is why the Talmud (ibid.) states that upon hearing thunder, we must make the blessing, ‘His (God's) strength and power fills the world.' In this way, the ‘crookedness' of the heart is straightened.

But why does God make thunder occur specifically in the middle of a rainstorm? Why not ‘straighten the crookedness', at a different time using a different phenomenon?

Rain brings productivity, making things grow and providing material nourishment for the world. We tend to think that we provide our own paychecks, that we can independently sustain our physical selves, that we ‘bring the rain' to produce the flowers in our lives. But this is not true and this is why we need the lesson of the thunder. God is in control and He delivers the rain. We must recognize this and ascribe proper gratitude toward Him.

God did not make a quiet, delicate appearance at Sinai. The mountain shook, lightning lit up the sky, thunder crashed and the Divine voice reverberated through the galaxies. The world was shocked into silence. The Torah was given through an earth-shattering event, literally, and the message is for us to shatter our own sense of invincibility, to recognize the true source of our well-being, and to allow the wonder of thunder to penetrate our souls.