Time to Stop Telling Biophysics Students that Light Is Primarily a Wave

Abstract

Standard pedagogy introduces optics as though it were a consequence of Maxwell's equations and only grudgingly admits, usually in a rushed aside, that light has a particulate character that can somehow be reconciled with the wave picture. Recent revolutionary advances in optical imaging, however, make this approach more and more unhelpful: How are we to describe two-photon imaging, FRET, localization microscopy, and a host of related techniques to students who think of light primarily as a wave? I was surprised to find that everything I wanted my biophysics students to know about light, including image formation, x-ray diffraction, and even Bessel beams, could be expressed as well (or better) from the quantum viewpoint pioneered by Richard Feynman. Even my undergraduate students grasp this viewpoint as well as (or better than) the traditional one, and by mid-semester they are already well positioned to integrate the latest advances into their understanding. Moreover, I have found that this approach clarifies my own understanding of new techniques.

Avaliação dos efeitos de um emissor de ondas ultrassônicas no tratamento do envelhecimento facial / Evaluation of the effects of an ultrasonic waves issuer on facial aging treatment

“…Especificamente, as ondas sonoras são mecânicas e longitudinais (se propagam na mesma direção de sua trajetória) e podem atravessar meios sólidos, líquidos e gasosos (POLANSKA et al, 2017). Sob este quesito, é valido mencionar que a capacidade audível do ser humano tem frequência média entre 20 a 20.000 Hz; portanto, ondas sonoras que possuem frequência acima do audível, ou seja mais de 20 KHz, são conhecidas como ultrassom (NELSON, 2018). Na área da saúde, aparelhos de ultrassom tendem a ser mais usados que os aparelhos sonoros, devido ao não comprometimento da frequência audível do ser humano (KIM, et al, 2021).…”