Amazing things — height seen during revolutionary flower power (9)
I believe the answer is:
phenomena
'amazing things' is the definition.
'phenomena' can be an answer for 'things' (I have seen 'Wonderful things' mean 'phenomena' so perhaps 'things' could also mean 'phenomena'). I'm not sure about the 'amazing' bit.
'height seen during revolutionary flower power' is the wordplay.
'height' becomes 'h' (abbreviation in geometry).
'seen during' is an insertion indicator.
'revolutionary' shows that the letters should be reversed in order.
'flower' becomes 'anemone' (anemone is a kind of flower).
'power' becomes 'p'.
'anemone'+'p'='anemonep'
'anemonep' backwards is 'penomena'.
'h' put into 'penomena' is 'PHENOMENA'.
Can you help me to learn more?
(Other definitions for phenomena that I've seen before include "extraordinary things" , "Unusual developments" , "Happenings" , "Events that may be observed" , "remarkable people" .)