For your information, the sonic booms are back this summer as expected. I learned from the (Ken) Burns Civil War movie series that localized sonic booms were heard during the Civil War during cannon fire; the same thing that happens in the summer here due to high-speed jets crossing paths in the Sonora region, as verified by FlightRadar backtracking. So this explains the localized periodic sonic booms that seem so mysterious to people across the nation.

Every summer we get these sonic booms. It is an atmospheric, ground terrain (as in Burns’ Civil war movie), and, of course, aircraft moving at about 500-plus mph and intersecting paths with other aircraft traveling just as fast.

As you might know, there can be thermal layers in the atmosphere, etc., with different densities of air, etc. Likewise, with radio wave propagation, a similar phenomenon occurs, but this is more an ionization of the air, temperatures, etc. The sound waves are skipping, just like radio waves can sometimes. When conditions are right, strong radio waves can be received many thousands of miles away from their source. This is not explained by the power of the transmitter.

The sheriff’s department and local rock quarries get all kinds of phone calls when this happens.

I am done figuring this one out. I am convinced of this phenomenon, by careful observations. The sound always comes from the Sonora, Yosemite, direction. It drives some people nuts, but once you know what it is, you can ignore it. I have seen some ridiculous national news stories about this phenomenon.

It is just wave theory; the same thing can happen with radio waves, etc. Sleeper waves in the ocean are a good example.

Alvin P. Lamore Jr.

San Andreas