But is it art?

Blipper SeriousFrolic introduced me to the esoteric world of 'Thomasson art': "a preserved architectural relic which serves no purpose" according to the definition on the linked site, though I think it's also important that some people at least should find artistic meaning in the thing

I'm not sure if this qualifies. Certainly SeriousFrolic has the final judgment on that. It is a relic of a lost architectural feature, created by water - which may admit it as a "hydrogen bomb" type of Thomasson - but it's not the actual outline of a building, so that may disqualify it. Either way, it's biologically interesting and, for me at least, more cheering than any of the real art we went to Oxford to see

The Ashmolean has an exhibition of the relationship beteeen money, art, society and power. I was amused by the "Banksy of England" £10 note, described as "Di-faced", because it bears the head of Diana Spencer. Also by finding out about the 1950s "Devil's Head Controversy", when the first image of Elisabeth II on a $100 (Canadian) bill was said to include a 'secret' image of the face of the devil, hidden in her permanent wave (the hair, not the hand). This is an example of both another blippers' favourite word - pareidolia - and a pre-internet conspiracy theory. 

So, occasionally amusing or intriguing, but nothing to make me sigh or cry or dream

A brief dip into a different room left me puzzling over the depiction of infants in medieval art. A 14th century depiction of the Madonna and Child, in which the infant Jesus looks like, not a baby, but a fully-grown adult on a different scale. This was a serious work designed for personal religious devotion, but all I could see was a Lilliputian rock-climber, scaling Mary's chest, Pythonesque in its comedy. Were artists somehow culturally blind to what babies look like, or did male artists never see real infants, or would it have been blasphemous to depict the Christ-child accurately as a human baby?

So, in the end, Thomasson or not, I'll take the ghost-green downspout (MrsM's eyes finding a blip for the second day in succession) as the best artistic experience of a thought-provoking day