This is a well known experiment, but I began wondering if anything can be applied to tektites.

The experiment basics are:

1) Take two cans of coke and shake vigorously.

2) Tap one of the cans.

3) Open the cans up and the un-tapped one erupts violently, whereas the tapped one doesn't.

The explanation: Fizzy drinks contain carbon dioxide gas under pressure. When you shake the can up the bubbles of gas form. These bubbles cling to the side of the can. When the can is opened the pressure in the can is suddenly decreased. The gas bubbles expand and erupt out of the can. If the can is tapped, however, the bubbles are released and go back to the top of the can. Therefore fewer bubbles (that expand and create froth) are in the liquid. This is better explained here.

An example in nature: In nature a similar thing happens with explosive volcanic activity. As the magma rises towards the surface the pressure decreases. Dissolved gases come out of the magma, forming bubbles. If the gases separate rapidly as the magma rises and cannot escape, then the pressure builds up. When this pressure exceeds the strength of the overlying rock, the overlying rock fails catastrphically in an explosion.

So, what has this got to do with tektites? Well, tektites start at ground level, which for all intents and purposes we can assume to be roughly sea level. They are then blasted into sub-space. At least 40 km above sea level. As you go up, the atmosphere thins exponentially (three-quarters of the Earths Atmosphere is within 11 km of the surface- Wikipedia), the pressure decreases and any liquids or gases will expand.

This is very interesting as one of the problems with tektite formation by impact, that is often quoted by those favouring the lunar hypothesis, is that bubble-free glass cannot be made that quickly (in a minute or two). I am not a physicists and so am out of my depth here, but I always thought that projecting the tektite at 10 km/sec (+/-) would be sufficient to separate the liquids and gases in the same manner as a centrifuge. I imagine though, by creating a pressure differentiaition between the gas in the tektite and that on the outside (in a matter of seconds) would also help things along. Like releasing the pressure in a coke can, perhaps the rapidly expanding bubbles rush to the lower pressure on the exterior of the tektite.

Are impactites and trinitites bubbly simply because they where ejected at lower velocities and did not attain any great altitude?

If you are a physicist maybe you can enlighten me - are my assumptions correct. What happens to the bubbles in a liquid if you shoot the liquid/gas mixture at hypervelocities - will they separate? What happens to the bubbles in the liquid when the pressure outside is suddenly decreased?

In time I will read more around this subject area and report back!