Fundamentals of Physics

In short, what causes sprites?

The answer is in this chapter.

For decades, pilots flying near a thunderstorm at night occasionally reported seeing huge flashes far above the storm’s clouds just after seeing lightning below the clouds. However, the high-altitude flashes were so brief and so dim that most pilots figured they were just illusions. Then in the 1990s, the flashes were captured on video and given the name sprites. If sprites are associated with lightning that occurs between ground and clouds, why do they appear only very high above the clouds and not immediately above them?

22-1   What Is Physics?

The physics of the preceding chapter tells us how to find the electric force on a particle 1 of charge +q₁ when the particle is placed near a particle 2 of charge +q₂. A nagging question remains: How does particle 1 “know” of the presence of particle 2? That is, since the particles do not touch, how can particle 2 push on particle 1—how can there be such an action at a distance with no visible connection between the particles?

One purpose of physics is to record observations about our world, such as the magnitude and direction of the push on particle 1. Another purpose is to provide a deeper explanation of what is recorded. One purpose of this chapter is to provide such a deeper ...