>Did Vikings navigate by polarized light?

>

A Viking legend tells of a glowing ‘sunstone’ that, when held up to the sky, revealed the position of the Sun even on a cloudy day. It sounds like magic, but scientists measuring the properties of light in the sky say that polarizing crystals — which function in the same way as the mythical sunstone — could have helped ancient sailors to cross the northern Atlantic. A review of their evidence is published today in Philosophical Transactions of the Royal Society B1.

The Vikings, seafarers from Scandinavia who travelled widely and settled in swathes of Northern Europe, the British Isles and the northern Atlantic from around 750 to 1050 AD, were skilled navigators, able to cross thousands of kilometres of open sea between Norway, Iceland and Greenland. Perpetual daylight during the summer sailing season in the far north would have prevented them from using the stars as a guide to their positions, and the magnetic compass had yet to be introduced in Europe — in any case, it would have been of limited use so close to the North Pole.

But Viking legends, including an Icelandic saga centring on the hero Sigurd, hint that these sailors had another navigational aid at their disposal: a sólarsteinn, or sunstone.

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”2. 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 Scandinavia2.

via Did Vikings navigate by polarized light? : Nature News.

>Lasers Control Nematode Worms Like Robots

>

Laura Sanders – scientists are using a dot of laser light. With it they can make a worm turn left, freeze or lay an egg. The researchers report their work online Jan. 16 in Nature Methods.

The new system, named CoLBeRT for “Controlling Locomotion and Behavior in Real Time,” doesn’t just create a mindless zombie-worm, though. It gives scientists the ability to pick apart complicated behaviors on a cell-by-cell basis.

“This system is really remarkable,” says biological physicist William Ryu of the University of Toronto, who was not involved in the research. “It’s a very important advance in pursuit of the goal of understanding behavior.”’

Transparent and small, the nematode Caenorhabditis elegans is particularly amenable to light-based mind control. Another benefit of the worm is that researchers know the precise location of all 302 of its nerve cells. But until now, there wasn’t a good way to study each cell by itself, especially in a wriggling animal.

“This tool allows us to go in and poke and prod at those neurons in an animal as it’s moving, and see exactly what each neuron does,” says study co-author Andrew Leifer of Harvard University.

The system is based on the emerging field of optogenetics, in which light is used to turn cells on or off. Leifer and his colleagues genetically engineered light-responsive molecules into particular groups of cells in the worm.

Then, a computer program that the team developed figures out where in the microscope’s field of view a target cell is. Once the cell is pinpointed, the program directs lasers so that a tiny beam of light hits the cell.

“When we’re shining light on a neuron, we’re hitting that neuron and nothing else,” Leifer says.

The whole process, from finding the cell to light hitting its target, takes about 20 milliseconds. As the worm’s position changes, that information is fed back into the computer program, and the laser is adjusted. If the worm crawls too far, a motorized microscope stage brings the animal back. …

via Lasers Control Nematode Worms Like Robots | Wired Science | Wired.com.

>Lasers Control Nematode Worms Like Robots

>

Laura Sanders – scientists are using a dot of laser light. With it they can make a worm turn left, freeze or lay an egg. The researchers report their work online Jan. 16 in Nature Methods.

The new system, named CoLBeRT for “Controlling Locomotion and Behavior in Real Time,” doesn’t just create a mindless zombie-worm, though. It gives scientists the ability to pick apart complicated behaviors on a cell-by-cell basis.

“This system is really remarkable,” says biological physicist William Ryu of the University of Toronto, who was not involved in the research. “It’s a very important advance in pursuit of the goal of understanding behavior.”’

Transparent and small, the nematode Caenorhabditis elegans is particularly amenable to light-based mind control. Another benefit of the worm is that researchers know the precise location of all 302 of its nerve cells. But until now, there wasn’t a good way to study each cell by itself, especially in a wriggling animal.

“This tool allows us to go in and poke and prod at those neurons in an animal as it’s moving, and see exactly what each neuron does,” says study co-author Andrew Leifer of Harvard University.

The system is based on the emerging field of optogenetics, in which light is used to turn cells on or off. Leifer and his colleagues genetically engineered light-responsive molecules into particular groups of cells in the worm.

Then, a computer program that the team developed figures out where in the microscope’s field of view a target cell is. Once the cell is pinpointed, the program directs lasers so that a tiny beam of light hits the cell.

“When we’re shining light on a neuron, we’re hitting that neuron and nothing else,” Leifer says.

The whole process, from finding the cell to light hitting its target, takes about 20 milliseconds. As the worm’s position changes, that information is fed back into the computer program, and the laser is adjusted. If the worm crawls too far, a motorized microscope stage brings the animal back. …

via Lasers Control Nematode Worms Like Robots | Wired Science | Wired.com.

>Churchill UFO ‘cover-up’ makes sense says expert

>

YouTube – Churchill UFO ‘cover-up’ makes sense says expert.

>A Bipedal Gorilla

>

21 year old Ambam, a Western Lowland Gorilla who sometimes walks upright on his two hind legs, is seen at Port Lympne Wild Animal Park in Kent, UK. – cryptomundo

>A Bipedal Gorilla

>

21 year old Ambam, a Western Lowland Gorilla who sometimes walks upright on his two hind legs, is seen at Port Lympne Wild Animal Park in Kent, UK. – cryptomundo