Erin Noteboom's A knife so sharp its edge cannot be seen takes exact and exquisite measurement of what carries a voice through illness, grief, loss, and through the failures and triumphs of work and love. Various theories and hypotheses are tested in these poems: sadness is knowledge and science "is only half a turn from love." Whether Noteboom is examining the life and work of physicist Marie Curie or compressing imagistic gems from plaintive, important questions like "What lasts?", there is everywhere in these poems a shadow-scratching curiosity, vital research, and an acknowledgement of the long waits in a life between discoveries. An essential marriage between the arts and science, A knife so sharp its edge cannot be seen is full of poems that readers will savour long after closing their eyes and raising the vial.