President's Letter: Virtual photonics
Action-at-a-distance is a concept deeply embedded in physics, as indeed it has been since the earliest scientific accounts of magnetism. The later emergence of a more comprehensive science of electrodynamics laid to rest, finally, any idea that vision itself could require tangible interaction between an object and the eye of the beholder—contrary to arguments once advocated by ancient Greek schools of philosophy.
Strangely enough, the most consistent modern understanding of seemingly noncontact interaction has echoes of those earlier notions. Particles, even though massless, are indeed at work between observer and the observed. And just as vision requires the propagation of light in the form of photons, so too, we now understand the forces that operate over nanoscale distances to be mediated by so-called virtual photons—those not directly observed. As Feynman, Casimir, and others have shown, the forces between electrical charges, and even between electrically neutral bodies, are mediated by these virtual particles.
Of course, as a descriptor the word virtual now finds many more applications. In optics and photonics, virtual reality, along with augmented and mediated reality, are at the cutting edge of transformative technologies as witnessed by the spectacular growth of these subjects at SPIE conferences. But the past 18 months have accelerated other connotations, as virtual or digital meetings have sustained society connections at every level, from one-to-one videocalls between friends and family members, to the highly sophisticated teleconferencing platforms deployed for scientific meetings.
The challenges of lockdowns and restrictions, imposed on us all in times of global pandemic, have resurfaced the landscape of human connections. Harnessing modern IT and communication channels, ingenious new ways have been found for scientific symposia and meetings to stay alive. In-house expertise has put SPIE at the forefront of innovations for hosting high-quality meetings, and the experience gained will assuredly be a legacy that informs future events. And yet, the very term virtual reminds us that even our finest digital symposia lack direct human contact.
Sociologists and mental health experts increasingly emphasize just how much we need direct contact with one another. Most of us also know that in-person contacts, either planned or serendipitous, can lead to career-enhancing changes in our professional lives. And so, it is a pleasure, and a relief, to see the first fruits of a return to in-person SPIE meetings. It will take a while for the reset to have full effect, but you can be sure that as we go forward together, our Society will be energetically waving the banner at the front.
2021 SPIE President