Jasmine: Hi, I'm Jasmine.
Chrissy: I'm Chrissy.
Jasmine: We're from NIU STEAM and...
Chrissy: You're listening to The Sound of Science on WNIJ.
JJ [pre-recorded]: My name is JJ and my question is how does lightning form?
Jasmine: We might be moving full STEAM into Winter, but this is still a great question! Especially since we've seen some thunderstorm action this month.
Chrissy: In science class, you may have learned about sub-atomic particles: negatively charged electrons, positively charged protons, and neutral neutrons. You may remember that like-charges repel, while opposite-charges attract. In this Sound of Science, we are going to be focusing on electrons and their movement between objects. For instance, when you walk across a carpeted room in Winter, your body can pick up extra electrons from the carpet. When you then touch a conductive object, like a metal doorknob, the excess electrons quickly flow from your body to the knob to balance out the charge. This rapid movement of electrons is what we perceive as a shock.
Jasmine: Lightning works in much the same way. Usually when lightning occurs, there is a mixture of water droplets and ice crystals within a cloud. As the crystals and droplets move around in the cloud, they collide causing a separation of positive and negative charges to occur. Usually, the positive charges can be found at the top of the cloud and the negative charges are found at the bottom of the cloud. When the difference in charges is great enough, electrons will quickly flow to balance out the charge and this is seen as lightning.
Chrissy: Jasmine is describing cloud-to-cloud lightning, but cloud-to-ground lightning works in the same way: an imbalance of electrons between the cloud and the ground. In 5-10% of lightning strokes, a particularly dangerous condition can occur: positive lightning strikes. During extreme weather events, the top of a cloud and the ground can interact. This type of lightning typically carries more electrical current and energy and is more branched than negative lightning.
Jasmine: You have been listening to The Sound of Science on WNIJ, where you learn something new everyday.
