I wish I had the patience that this gentleman has to wait out the results of a sealed bottle plant environment, but maybe I could get a few years in.
I would be curious of actual measurements within and without the environment. One such measurement would just be the temperature variation. I'm sure it had to be a bit of a swing given his location and movement into sunlight at various angles to provide a more uniform dispersion of light.
So sensors sealed in the bottle to provide readings of all sorts could provide valuable data, or just keep some data analyst busy for decades.
Considering so much of what plants do is opposite of what animals & people do in processing air, water and food, combining the two is very interesting to me, especially in our DIY/Maker era with the abilities to use a free app on a smart phone to do so much of it.
I presently can measure noise levels in db, generate a variety of audio tones, and even modulate them with other tones and wave forms,