All of the rain this Saturday was crazy! Our soccer beach run was cancelled (shucks ;) and instead I spent the day giving admissions tours, going to the movies, and celebrating my friend’s 18th birthday. But the rain reminded me of a huge storm my family and I got caught in this summer. Apparently freak thunderstorms are common in Chicago and the rest of the Midwest, but it definitely was an experience for us. Thunder and lightning is caused by, “the difference in charge between the thunder cloud and the foreign surface, such as a different layer of the cloud or the ground.” Normally the cloud gains a positive or negative charge and when the difference between the two regions reaches a certain point, the air between the charges breaks down, allowing the two surfaces to form a circuit and discharge. The first step in formation of lightning is the gathering of charge in the clouds (Physics of Electromagnetism). As the negative charges collect at the bottom of the cloud, the negative forces in the ground move away from the surface. The negative charges from the cloud then connect with the positive forces on the ground, creating a streamer of light…LIGHTNING! The heat created in the air then quickly expands, forming thunder; which is why you see lightning before you hear the thunder. Taller objects generally lead to a more condensed electrical field, making them more susceptible to lightning. In fact, during this storm, the Sears Tower, the tallest building in the Chicago skyline (and North America!) was hit by lightning. The Sears Tower actually gets hit by lightning quite often, thousands of times each year, which is why it has a lightning protection system. Here is a video and picture I took from my hotel room during the fabulous lightning display. The lightning went on all night, even when the rain stopped—embodying perfect physics the entire time.
