Saturday, July 3, 2010

Lost at Sea exhibition : The Ocean in the English Imagination, 1550-1750

John Davis. The seamans secrets. London, 1626.

The Folger Shakespeare Library in Washington D.C., proposes an interesting free exhibition which runs until September 4 : Lost at Sea, the Ocean in the English Imagination, 1550-1750

On display are the tools early modern mariners used—from maps, astrolabes and compasses to books, symbols, and stories—to plot locations and understand their place in the world, both literally and figuratively.

Exhibition curator Steve Mentz (personal website) is Associate Professor of English at St. John’s University in New York City.


Mentz examined what the ocean takes away, what it gives back and its changing meaning in the world. Instead of sailors once strolling through Manhattan, there are now bankers and lawyers. Mentz said, "In New York, the ocean isn't the heart of the city anymore."

Often, the ocean provides instability, Mentz said, and gives back the natural vision of the world.
"The ocean represents our alien globe," Mentz said.
In Shakespeare's time, the bottom of the ocean could never be touched, but people could reach descriptions of the ocean through the use of the lead line, an early navigating device that measures the depth of the ocean.
"We never reach the bottom, but we see what's there," Mentz said.

There are also ocean phrases that have entered everyday language. Mentz referenced "the bitter end" and "by and large" as coming from sailors' terms. The word "fathom" also has both the definition of discerning a hidden meaning and a measure of underwater depth.

He talked to Shakespeare's use of the ocean in "The Tempest" and specifically, Ariel's song in the first act. With Ariel's song, "The ocean is everywhere and nowhere," It song insists that people look closer at the things at the bottom of the ocean and how the ocean changes them.
Ariel's song is narrative and metaphorical, since it draws Ferdinand away from death and transforms powers of the magic of the ocean. As Mentz said, "We never find the treasures that the song promises."

In "The Tempest," Prospero educates Miranda of the sea, discusses their exile by sea and the current sea storm that washes people upon their island. Unlike "King Lear", "The Tempest" never shows death by drowning. While "King Lear" addresses land division and fuels much of the plot, there are sea storms and oceanic references, including four places in the play where the earth gives way to the sea.

On the ecological aspect of the ocean, Mentz provided "The Five Rules of a Blue Cultural Studies" which include :
  • "The world is not our home",
  • "Ecology won't keep us dry",
  • "The ocean rules the weather",
  • "Our only inexhaustible resource is language" and
  • "Shakespeare isn't dead. He isn't even past."
Links :
  • 'At the Bottom of Shakespeare's Ocean' review

Friday, July 2, 2010

NASA demonstrates tsunami prediction system















Links :

Thursday, July 1, 2010

Earth's gravitational field mapped by researchers

Scientists have unveiled the most detailed map yet of the Earth's gravity
at a European Space Agency conference in Bergen, Norway this week.
It shows the difference between the regular ellipsoid shape that is used to represent the Earth’s shape
and the geoid, a hypothetical surface of the Earth on which the surface is perpendicular to the gravitational pull.
The map is based on just two months' worth of data generated by ESA's GOCE satellite
and shows the tiny differences in gravity that exist around the Earth.

From Wired & PlanetEarth



The satellite, which was launched in 2009, flies at an altitude of 254.9km -- the lowest orbit of any other research satellite.
As it flies so low, it's more subject to the pull of gravity -- which helps it to detect minuscule changes in the planet's gravitational field as it flies from pole to pole, but also means that it uses more fuel in its flight to keep it airborne.
Scanning the entire world took around two months.

The applications are numerous. Climate change researchers model ocean currents very carefully, and so will benefit greatly from knowing how gravity affects the huge masses of water in the oceans.
In fact, if there were no winds or currents, it's the shape that the ocean would take on the earth's surface, so comparing the geoid to the shape that the oceans actually take gives us some insight into what the other forces at work are.

Elsewhere, the information could be useful to geophysicists who want to know what's happening deep within the Earth, or engineers building a pipeline over a long distance and wanting to know what direction a fluid will naturally want to flow.

Prof. Reiner Rummel, the chairman of the GOCE mission advisory group, said: "The computed global gravity field looks very promising. We can already see that important new information will be obtained for large areas of South America, Africa, Himalaya, South-East Asia and Antarctica.

'The satellite is performing extremely well. In fact it's doing better than ESA expected,' says Dr Helen Snaith from the National Oceanography Centre in Southampton, who can't wait to get her hands on the data.

GOCE stands for Gravity field and Ocean Circulation Explorer and was the first of ESA's Earth Explorer missions to be launched. And as its name suggests, the satellite was designed to give scientists unprecedented information about the Earth's gravity field, which will tell them about ocean circulation patterns around the globe.

'It's doing so well that ESA has decided to scrap a planned hibernation phase and keep the satellite going until 2013,' says Snaith.

Its long operation means that by the end of the mission scientists may have an even more detailed map they expected.

'This map is based on just two months' data. As time goes on, it'll get revised and the resolution will just get better and better.' said Dr Helen Snaith, National Oceanography Centre
The satellite flies in the edge of the Earth's atmosphere and measures miniscule differences in gravity at many points around the Earth using three pairs of highly accurate gradiometers.

'These Earth Explorer missions are based on new concepts. Gradiometers are not quite a new concept, but it's an amazing bit of kit,' says Snaith.

Technically speaking the map shows the Earth's 'geoid' - or which parts of our planet have a greater gravitational pull than other parts because of the different rocks it's made of.
Stronger gravitational pull is depicted by red, while a weaker pull is depicted by blue.

If you turned this map into a globe, it would look like a partially blown-up football, where peaks represent strong gravity and the troughs show slightly weaker gravity.
If you placed a much smaller ball anywhere on this squashy football, it wouldn't move – even if it was on a slope – because gravity would be exactly the same all over it.

Although during school physics, you probably learnt that acceleration due to gravity at the Earth's surface is 9.8 meters per second squared, this is not strictly true. In fact, gravity differs very slightly all around the planet.
For example, because the Earth is the shape of a squashed ball, gravity is stronger at the poles than at the equator.

Before GOCE was launched, scientists knew that gravity is stronger around Greenland than around the Indian Ocean for example.
But the new map is telling them much more than they ever knew about the Himalayas, the Andes and Antarctica, all traditionally very difficult places to do research.

'The current geoid models are largely based on ground measurements, which of course is difficult in inaccessible parts of the planet,' adds Snaith.

This includes the oceans.
The geoid model that GOCE has generated is the shape the world's seas would be if there were no winds, tides or currents.
Scientists can then subtract the geoid from real measurements of sea surface height to work out how winds, tides and currents affect ocean circulation.

'Until now, the best maps we had were on the 400 to 500 kilometre scale. GOCE's resolution is focussed down to 150 kilometres.
Most ocean current are around this width or smaller, so we're going to get a lot more detail about currents with this map,' explains Snaith.

'This map is based on just two months' data. As time goes on, it'll get revised and the resolution will just get better and better,' she adds.

Links :
  • ESA : GOCE giving new insights into Earth’s gravity
  • BBC News : Goce satellite views Earth's gravity in high definition
  • ScienceDaily : European Space Agency makes first GOCE dataset available

Wednesday, June 30, 2010

Robo-Baywatch: Autonomously patrolling robot lifeguard swims at 28 MPH

Meet EMILY, a robot lifeguard that can operate six times faster than a human lifeguard.


The hottest, fastest lifeguard on the beach is named EMILY, a kind of robot version of Pamela...

You’re caught by the ocean’s riptide, exhausted and barely keeping your head above water. Then your unlikely hero appears: a four-foot-long talking buoy.
It’s EMILY, the robot lifeguard. Grab on, and it can bring you safely back to shore.



How It Works
  1. Ready for action : EMILY patrols solo or is thrown into the sea from the beach, a helicopter or a ship.
  2. Search and rescue : EMILY’s sonar finds a distressed swimmer, and it jets toward him at 28 mph.
  3. Mission accomplished : A swimmer holds onto EMILY as it gently brings him to shore or waits for a lifeguard. The robot can travel up to 80 miles on a single battery charge.

Tuesday, June 29, 2010

"Recycled Island" turns ocean plastic into a paradise

From Stephen Messenger (Treehugger)

Ever dreamed of living on a giant island of plastic?

Well, with all the plastic that floats around in the ocean as a toxic soup threatening all manner of marine life, one architecture firm has a bold vision to create an eco-paradise called "Recycled Island" in the Pacific Ocean with sustainability at its core.
It's a bold plan, but not only would the project help clean the oceans, the firm claims, it might just be a perfect home for climate refugees--and a way to turn those toxic patches of ocean plastic into an island that may do the planet some good.

The idea for the massive Recycled Island was developed by WHIM architecture as a way to clean the oceans and create a new floating habitat dedicated to sustainable living, complete with beaches, farms, and buildings.
Ideally placed in the Pacific, between San Francisco and Hawaii, the island would be some 4 thousand square miles of plastic 'land' upon which plastic communities would be built.

According the project's plan, the plastics used to build the island will come from the giant North Pacific Gyre. Once collected and cleaned, the material could then be reformed into floating platforms of recycled plastic.
"This will clean our Oceans intensely and it will change the character of the plastic waste from garbage to building material," says WHIM. "The gathering of the plastic waste will become a lot more attractive."

With the land mass built, the firm believes a sustainable island paradise will flourish, according to the project's Web site:
An important component in making Recycled Island sustainable comes from the cultivation of seaweed, which would provide food, fuel, and medicine, as well absorb CO2 and offer a habitat to fish.

While the plan to build an island by recycling the plastic that pollutes our oceans is certainly a bold one, if not downright impossible, it is in line with a number of ambitious recycling projects that have indeed come to fruition.
Certainly, the planet has no pressing need for a new island, sustainable or otherwise, but it would be a huge improvement on the toxic masses of ocean plastic inadvertently in place already. And who knows, maybe Radiohead could write a song about it.

Links :

Monday, June 28, 2010

Crocodiles ride ocean currents to travel long distances

From LiveScience



These scaly monsters have been known to devour sharks, and even attack things they can't eat, often assaulting boats in the mistaken belief they are rivals or prey, biting down with nearly 2 tons of pressure - powerful enough to crush bone or punch through aluminum hulls.




Crocodile river travel

Riding ocean currents







Links :
  • TheRegister : Steve Irwin surveillance-crocodiles travel across oceans

Sunday, June 27, 2010

Tuna fishing in South Pacific

