You’ve seen holograms before: they’re images that seem to jump out of a flat surface, full of depth that you can experience through perspective changes and parallax cues. The three-dimensional effect that a hologram creates comes from the three dimensional light field that’s created when photons diffract through the interference pattern on a holographic plate. It’s essentially a structure made of light that gets projected out into space when the seemingly random pattern of features on the plate interact with each other.
Light isn’t the only wave that can be manipulated to create structures in space; the same thing goes for sound waves. The structures generated by constructively and destructively interfering with ultrasonic waves are tangible things that can exert force on objects. Researchers at the Public University of Navarre in Spain have used ultrasonic acoustic holograms to manipulate things just like the tractor beam used by the crew of the USS Enterprise on the TV show Star Trek.
Acoustic levitation is usually accomplished with a pair of ultrasound emitter arrays, or with one array aimed at a reflector. A standing wave of ultrasound is formed between these two elements,
Today’s technology makes a 1-exaflop supercomputer capable of performing 1 million trillion floating-point operations per second almost inevitable. But pushing supercomputing beyond that point to 10 exaflops or more will require major changes in both computing technologies and computer architectures.
Health care providers and insurance companies are increasingly relying on smartphone and wearable activity trackers to reward active individuals for healthy behavior or to monitor patients.
Once you have bought an expensive smartphone, it is worth thinking about protecting it from different undesirable scratches so that this useful gadget could serve you longer.