A good old-fashioned wooden pointer, that would be my choice, or better still, no slides at which to point and just a charismatic and engaging speaker. However, it seems that everything has to be gadgetified these days, which is good news for materials scientists, of course, as gadgets need novel materials.

But, the lecturer's laser pointer has always struck me (not literally) as a step too forward. All that coherent light flashing about with none of the control of the lighting desk at a Pink Floyd gig, surely it was always an accident waiting to happen. And, "pranksters" have caused problems with aircraft playing with these devices outdoors, allegedly. It wasn't with much shock that I read a study from the US National Institute of Standards and Technology (NIST) in which they lay bare their safety studies of 122 laser pointers readily available to lecturers.

They used an inexpensive test kit that others could use elsewhere to see whether these devices were in compliance with safety standards. Unfortunately, it turns out that of those 122 pointers, 90% of the green lasers and 44% of red pointers were not. Some of the devices were in breach of the US Code of Federal Regulations (CFR) and some green pointers were emitting hazardous levels of infrared light. The NIST tests investigated commercial devices labelled as Class IIIa or 3R lasers, which are purportedly safe for use in lecture theatres, classrooms and other public spaces. The CFS limits them to 5 milliwatts in the visible and less than 2 mW in the IR. Some of the devices tested had a power output of more than 66 mW, which does represent a risk to vision for anyone caught in the firing line of such a laser.

An emerging trend in technology are glasses that have a built in camera, internet access and display so that you can get heads up data wherever you are based on what you're looking at. That will certainly be a useful tool for many students and conference delegates, but given the NIST research, I'd suggest buying a set with fast-response laser blocking too…just in case. Of course, materials scientists could help in that regard too, with the development of non-linear optical (NLO) materials.

Further reading




David Bradley blogs at http://www.sciencebase.com and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".