#light

#light

UK Based Company Creates Invisibility ShieldWe now have a chance to be invisible at will!Introducing the invisibility shield, an object that utilizes optics to create an illusion of invisibility. Created by a UK-based company of the same name, the product is currently on Kickstarter, with an aim of gathering $6,595 (₤5,000) to make them available for everyone. As of now, the company has obtained a total of $139,289 (₤105,598) from donations and pledges. The invisibility shield has an engineered lens array to manipulate the light from the subject away from the observer and refract the light from the background. This effectively smears the background light across the front face of the shield, over the area where the subject would ordinarily be seen. Cool, right? According to the company, the device performs best against uniform backgrounds such as foliage, grass, rendered walls, sand, sky, and asphalt. The shield is large enough to hide not just one, but multiple people! In addition, no power is required to use them, only space and the patience to assemble it when needed. Image credit: Invisibility Shield Co. #optics #lens #light #invisibilityshield

How Do We See Color?From light to object to our eyes to our brains, the process of perceiving color in our environment is pretty complex. This video from the American Museum of Natural History breaks the process down into its steps in a fairly thorough yet understandable way. Oh, and it's beautiful, too.

How Did Stone Age Humans Light Their Caves? Cave-dwelling humans in the Stone Age didn't have flashlights, but they didn't necessarily live in complete darkness. To shed light on how our ancestors lit up their Paleolithic caves, archaeologists in Spain recreated ancient lighting techniques: torches, grease lamps and fireplaces.Ars Technica explains:... measurements showed that the various lighting sources had very different characteristics and, thus, were probably used in different contexts. The wooden torches, for instance, emitted light in all directions, up to nearly six meters (19.6 feet), and lasted an average of 41 minutes. The torches exhibited uneven light intensity and often needed to be relit by waving them from side to side, and they produced a lot of smoke, so they worked best for exploring caves or crossing wide spaces. The team also found that adding resin intensified the flame, while adding animal fat extended its duration.By contrast, the grease lamps emitted weaker light akin to the intensity of a candle over a span of three meters (9.8 feet) or so. They burned consistently, and didn't smoke, for over an hour, but they had a dazzling effect if the person was moving and didn't illuminate the floor very well.Research paper at PLOS ONE#cave #stoneage #archaeology #light #lamp #firepit