Tag: light

An Entirely Possible Legend: Vikings Steered Ships Using “Sunstones”

By Patrick Morgan | January 31, 2011 10:59 am

You might think seafaring Vikings–who traveled hundreds of miles on rough seas between 750 and 1050 AD–would be adrift on cloudy days: not only did they lack compasses, but they were often traveling so far north that the sun never set, and thus couldn’t use stars to navigate. But scientists are finding new evidence to support the existence of what was once considered a mythical navigational tool: the sólarsteinn, or sunstone.

It all starts with an Icelandic legend about a man named Sigurd. As Nature News reports:

The saga describes how, during cloudy, snowy weather, King Olaf consulted Sigurd on the location of the Sun. To check Sigurd’s answer, Olaf “grabbed a sunstone, looked at the sky and saw from where the light came, from which he guessed the position of the invisible Sun.” In 1967, Thorkild Ramskou, a Danish archaeologist, suggested that this stone could have been a polarizing crystal such as Icelandic spar, a transparent form of calcite, which is common in Scandinavia.

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In the Light of a Streetlamp, Young Blue Tits Get More Action

By Jennifer Welsh | September 16, 2010 4:46 pm

slutty-titIt can be hard to sleep with a light shining in your window, but for the male blue tit, this night-lighting gives him a sexual advantage. Researchers have found that male tits that live near streetlights wake up and start to sing on average three minutes earlier than the rest of the gang.

These birds are more likely to be chosen as mates because under normal conditions, early risers are the strongest fully grown birds. When adventurous lady-birds go looking for extramarital affairs in the morning light they are attracted to early risers because they assume they are the macho, macho men of the group.

As a result, any male blue tit–even a young and scrawny fellow–that lives within 50 feet of a streetlight gets about twice as much extramarital action, and has more offspring than male tits that live in other parts of the neighborhood.

Study author Bart Kempenaers told Science News that they don’t know what effect this might have on the population:

From an otherwise unattractive male’s point of view, streetlights must be great. But Kempenaers says he doesn’t have data on the consequences for the blue tit population as a whole if artificial light inspires many females to mate with males that they would normally shun.

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Genetically Engineered Bugs Can Smell Blue Light

By Joseph Calamia | May 27, 2010 5:24 pm

blue-bananaDo I smell a banana? Nope. It’s a blue light I’m smelling.

Fruit fly larvae made this mistake while participating in a study recently published in Frontiers in Neuroscience Behavior. By adding a light-sensitive protein to certain smell receptors in the larvae, German scientists allowed the genetically engineered bugs to essentially smell light.

The team, under the guidance of Klemens Störtkuhl at Ruhr University Bochum, is attempting to understand “olfactory coding”–how the brain transforms chemical signals into perceptible smells. Normally, a fly’s olfactory receptor neurons only send an electrical signal to its brain when the fly smells something, but by adding a protein the researchers caused a neuron to fire when the one-millimeter bug was basking in blue light.

The fly brain uses some of its 28 olfactory neurons to detect bad smells, and others for good ones. Protein puppeteers, the researchers could pick which neuron to add the light-sensing protein to. The good-smelling neurons respond to a smorgasbord of fly-friendly scents: like banana, marzipan, and glue (apparently rotting fruit gives off these scents). By attaching the light-sensitive protein to one of these neurons, researchers caused the typically light-fearing insects to crawl straight towards the blue glow.

According to a ScienceDaily article, given their successful mapping of these larvae olfactory neurons, the researchers next hope to make adult fruit flies go bananas.

Related content:
Discoblog: Neuroscientist Says We Perceive “Smounds”—Half Sound, Half Smell
80beats: A Life-Extending Coup: Flies That Can’t Smell Food Live 30 Percent Longer
Not Exactly Rocket Science: Smell a lady, shrug off flu – how female odours give male mice an immune boost
Not Exactly Rocket Science: Elephants smell the difference between human ethnic groups
DISCOVER: The Brain: The First Yardstick for Measuring Smells

Image: flickr / Jason Gulledge

Will Glowing Wallpaper Make Light Bulbs Obsolete?

By Brett Israel | December 30, 2009 4:05 pm

cfl-bulb-webFor those tired of changing light bulbs, we’ve got some good news. A light-emitting wallpaper may replace light bulbs as soon as 2012, according to The Times:

A chemical coating on the walls will illuminate all parts of the room with an even glow, which mimics sunlight and avoids the shadows and glare of conventional bulbs.

Apply a low voltage current to the wallpaper and bam!—no more light bulbs. The organic LED wallpaper, under development by the Welsh company Lomax, will be at least twice as efficient as current energy saving bulbs. And no, the glowing wallpaper will not create an electric fence in your living room—Lomax says their electric wallpaper will be safe to touch.

Related Content:
Discoblog: Suits Revolting: Bangladesh PM Bans Suits, Ties to Conserve Energy
Discoblog: Color-Changing Solar Tiles Will Blow Your Mind, Heat Your House
Discoblog: Monitor Your Daily Energy Use With Google’s PowerMeter

Image: flickr / nodomain1

CATEGORIZED UNDER: Technology Attacks!
MORE ABOUT: electronics, energy, light

The Deep Sea is a Red Light District After All

By Andrew Moseman | September 16, 2008 3:43 pm

red fishNow that they know some fish can see red, ichthyologists might be a little red in the face.

Because water tends to absorb long wavelengths of visible light, long-wavelength red photons don’t penetrate much past the top 30 feet of ocean. So fish experts had assumed that red just wasn’t part of the underwater world, and fish probably couldn’t see it. But a new study led by German researcher Nico Michiels concluded quite the contrary—numerous species of fish can produce their own red light through luminescence.

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MORE ABOUT: fish, light, Ocean

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