'Long shot' Laser 3-D Camera

A 'normal' camera takes flat pictures that have only two dimensions. As children many of us had come across 3D picture viewers that employed two pictures of the same object taken from slightly different angles to 'cheat' the eye into thinking that we are seeing a solid, three-dimensional object.

Now researchers have developed a new laser-driven camera system that creates high-resolution 3-D images of objects from up to a kilometre away. Mimicking radar, a laser beam is swept and bounced off the object, and the time for it to travel back to a detector is measured, from which the contours of the object are computed. The technique, called time-of-flight (ToF), is used in navigation systems for autonomous vehicles, but many current systems have a relatively short range and are virtually useless with objects that do not reflect laser light. The new system, however, has overcome these limitations.

The research team, led by Gerald Buller, professor at Heriot-Watt University in Edinburgh, Scotland, has perfected a ToF imaging system that can gather high-resolution, 3-D information of objects from up to a kilometre away. A low-power infrared laser beam is swept rapidly over an object and the round-trip flight time of the photons in the beam as they bounce off the object and arrive back at the source is recorded. The detector that can count individual photons can resolve depth on the millimetre scale over long distances. Also, the ability of the new system to image objects like items of clothing that do not easily reflect laser pulses makes it useful in a wider variety of field situations.

One of the key characteristics of the system is the long wavelength of laser light the researchers chose. The light has a wavelength of 1,560 nanometres, meaning it is longer, or "redder," than visible light. This long-wavelength light travels more easily through the atmosphere, is not drowned out by sunlight, and is safe for eyes at low power. Already the researchers are gunning for extending the range of the 3D 'scanning camera' to 10 kilometres.

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Jap Scientists in Dreamland

Dreams had always tantalized man from the ancient times to the Freudian and their interpretations had as many variations as there were practitioners. Psychology, we could easily see, inhabits that narrow borderline area between science and non-science. But whatever your take on dreams, be it Freudian or Jungian, or something more exotic, you just cannot hide your dreams from the Japanese scientists.

Scientists in Japan, using nothing more exotic than MRI (Magnetic Resonance Imaging) scanners commonly employed in diagnostics, have found a way to 'read' people's dreams, thus unlocking the secrets of the unconscious mind. According to researchers, this was "the world's first decoding" of night-time visions, the subject of centuries of speculation and study.

Scientists at the ATR Computational Neuroscience Laboratories (in Kyoto, western Japan) used EEG (Electroencephalography) and fMRI (funtional MRI) scans to map patterns of brain activity during the first (non-REM) phase of sleep. Once dream patterns were seen, the volunteer 'dreamers' were woken up and asked about the visual images that they had dreamed about. This was repeated for about 200 times for each of the volunteers. A computer algorithm correlated the resulting data of the dreamer's perceptions with the corresponding MRI patterns, with the result that soon the scientists could, with a fair amount of accuracy (sometimes as high as 70% !) predict what images the volunteers were dreaming about by looking at the MRI patterns. Specific items like men, words, books, cars etc could easily be identified, said the scientists. "We have concluded that we successfully decoded some kinds of dreams with a distinctively high success rate," said Yukiyasu Kamitani, a senior researcher at the laboratories and head of the study team.

US neuroscientist and dream expert Dr Robert Stickgold, from Harvard Medical School in Boston, said "...we are still far from having a machine that can fully read our dreams." But, despite this, he described the study as ‘stunning in its detail and success’ and added that "This is probably the first real demonstration of the brain basis of dream content".

At present, the system is apparently limited to detecting only very basic classes of objects which the dreamers visualise, and it would take a few bulky lab instruments and a team of boffins to open the doors to your dreamland. However, we can expect a further refinement of the 'dream-reader' algorithm, as well as an extension of the same to map smells, emotions and entire stories. That would mean plumbing the depths of REM sleep. So be careful about what you choose to say about your dreams. Sooner or later an app could even be available for the smartphone that could easily 'read' your secret dreams accurately!

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