Shocking! (In a cool way.)

Via BABlog, here's a great set of photos from the SF Fleet Week airshow. My favorite (below), shows an F-18 flying LOW and FAAAAASTTT..... but how fast?



If you look underneath, you'll see a white V in the water under the plane. If you thought this was from the jet exhaust, you're a little off - it actually starts ahead of the tail. Instead, it the result of the shock wave caused by the plane as it passes through the air, perhaps at supersonic speed. Here's a closer look:

Notice the blurring in the air extending from the plane at an angle above and below. That's the shock front. It is actually a three dimensional cone extending in all directions that moves with the plane. When you hear a sonic boom, it is the effect of that wave crossing over your ears.

The author of the photo says that the plane isn't yet supersonic, but as an amateur appreciator of shock waves, I'm a bit skeptical. I'm baffled at the idea that anything would be able to create a V shaped shock front without being super sonic. Given certain assumptions and the angle of the cone, one (perhaps smarter than I) should be able to calculate just how fast this plane is going.

After I take my Patent Law exam tomorrow and my Business Associations exam Monday, I swear, the first thing I'm going to do (after maybe having a drink and a nap) is look into this thing further and report back here.

Even if I forget, which I might, trust me that it is a damn fascinating effect once you realize exactly what is happening in the air around this plane. But, like I said, for now, you'll just have to trust me (or look it up yourself).