Invisible Bike Helmet

A pair of Swedes has developed a clever "invisible bike helmet" (hat tip: Zach Yeager). I won't spoil how they did it, so please watch the video. I hope their new design prompts more people to wear helmets.
That being said, there is a lot more to being safe than merely wearing a helmet. Some observations:
  • Helmets certainly can't prevent broken limbs; it also seems unlikely that they would reduce neck and spinal injuries.
  • Rotational acceleration is a major contributor to brain injury. Ongoing research on football concussions suggest that helmets do little to reduce rotational acceleration.
  • Styrofoam helmets may not even be that good at reducing linear acceleration, either. They are supposed to reduce acceleration through compression, but it is fairly common for them to fracture instead. Fracturing reduces acceleration less than compression does. (I expect the invisible Swedish helmet to be far superior on this front. Watch the video!)
If you don't like styrofoam helmets, please buy and wear the invisible bike helmet. Despite the limitations above, helmets surely reduce the severity of injuries in the event of a crash. 
Please remember, however, that injury risk is the product of the probability of a collision with the severity of injuries. As important as helmets are, I believe it is even more effective to reduce collision probability. Use safe cycling practices: be observant of traffic and potential road hazards, communicate with other road users, use lights and bright colors, and campaign for safe cycling facilities. Helmet use might not be enough to keep you safe.