So it has had water and presumably some atmosphere was exchanged when it was watered in 1972, 40 years ago. The title is somewhat misleading but 40 years is still a long time.
The stopper doesn't look like its particularly well fastened and could potentially pop up and allow leaks. Impressive but without closer inspection it looks like a slightly flawed execution to me. Maybe I'm just being pedantic. A picture of the starting point would be nice.
"[he] has only watered the plant twice, the last time in 1972 when he oiled the plastic stopper so that it wedged so tightly it hasn't been out since."
Well its not a hard experiment to reproduce and just needs time.
maybe there is gap in our knowledge here and would expect scientists to have had many versions of these already.
The stopper doesn't look like its particularly well fastened and could potentially pop up and allow leaks. Impressive but without closer inspection it looks like a slightly flawed execution to me. Maybe I'm just being pedantic. A picture of the starting point would be nice.