Written By Aubrey Whymark 2007-2017

Bubbles in Indochinites

The proximal indochinites are by far the most bubble-rich of the true tektites. Many fragments with smooth concave surfaces represent broken bubbles.
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 catastrophically 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 Earth’s 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 physicist and so I 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 differentiation 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 were ejected at lower velocities and did not attain any great altitude? Probably the lower temperature and high viscosity of the melt is an important factor.​

Largest tektites

Very large tektites in excess of a kilo should not exist as thermal stresses should ensure their destruction. This is why the very largest true tektites from the Philippines always contain large bubbles. This results in a thinner glass wall (instead of a solid body), thus making them more stable.