‘‘KLM 867 we have flame out all engines and we are descending now!’’

The airspace over northern Europe has been virtually shut down to commercial air traffic because of volcanic ash spewing from Iceland.

We get to practice real-time science now. How much do we know about volcanic ash?

We can tell what's in it. (Iceland has initiated a huge involuntary fluoridation program.)

We can look at past anecdotal evidence at what has happened when commercial jets fly into ash. In 1989 a Boeing 747 flew into an ash cloud over Alaska, and temporarily lost all 4 engines. KLM is still using that particular aircraft, so there's at least one plane we know should avoid the ash.

We know that the Eyjafjallajokull volcano has spewed ash for over a year in the past, way back in 1821.

We're still new at this predicting business, and even newer at this flying business. If nothing else, Eyjafjallajokull reminds us how little we know, and how little we can control.

I bet I'm not the only science teacher tickled that the world still pokes holes into our hubris.

The photo by the Associated Press.

Update: various airlines are taking practice runs at different altitudes to assess the damage to their aircraft.
Science in action!