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Physics of Skipping Stones Could Make Bounceable Naval Weapons


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Physics of Skipping Stones Could Make Bounceable Naval Weapons

Skipping elastic balls off water is much easier to do than trying to make stones “hop” across the surface of a lake, but a new study of water-impact physics isn’t all fun and games — the research could improve everything from aquatic toys to naval weapons and inflatable rafts, scientists said.

Studying how objects ricochet across water has a wide range of applications. For example, during the Age of Sail, when sailing ships ruled the seas for trade and warfare, cannonballs were skipped over the water to bounce onto decks, killing enemy sailors and breaking masts.

“A text titled ‘The Art of Shooting [in] Great Ordnaunce’ by William Bourne was likely published in 1578, and is the first known account to mention that if cannonballs are fired at a sufficiently low angle they will ricochet across the water surface,” said study co-author Tadd Truscott, a fluid dynamicist at Utah State University in Logan. [The Mysterious Physics of 7 Everyday Things]

Furthermore, during World War II, British engineer Barnes Wallis developed a bomb that could bounce across water, which the Royal Air Force used against Germany in 1943. “This bomb was made to spin at a great rate before impact, enabling it to move along the water surface and avoid torpedo nets on its way to destroy key German dams,” Truscott told Live Science.

In addition, studying how the basilisk lizard can run across the water — a capability that earned these reptiles the moniker “Jesus lizard” — could one day help researchers build robots that can do the same. “Water impact has been heavily studied for the past 100 years, with motivations ranging from understanding the physics of seaplane landing to, more commonly, a simple desire to better understand the world in which we live,” Truscott said.

A stone can be coaxed to ricochet multiple times across the surface of water, provided it is the right, disk-like shape and is flicked with the right speed and trajectory. However, research suggests that elastic spheres are much easier to skip, even with only mediocre launches.

A toy known as the Water Bouncing Ball, or Waboba, inspired Truscott’s latest research into the physics of skipping spheres. The tennis- ball-size Waboba can’t bounce on land but is able to skip across water with relative ease.

“Our approach was playful at first,” Truscott said in a statement. “My son and nephew wanted to see the impact of the elastic spheres in slow motion, so that was also part of the initial motivation. We simply wondered why these toys skip so well. In general, I have always found that childish curiosity often leads to profound discovery.”

To learn more about how elastic objects skip, Truscott and his colleagues used high-speed cameras to capture images of elastic balls bouncing across tanks of water in a lab. The scientists discovered that elastic spheres can demonstrate superior ricocheting ability for a variety of reasons.

First, the act of elastic balls hitting water can deform them into disklike shapes resembling the kind of stones one might find on a shore. These shapes are ideal for multiple bounces off water; the liquid can exert more force on a flat saucer than a round ball.

In addition, elastic balls can deform into ideal disk shapes regardless of the angles at which they hit the water. This means they can hit the water at a greater range of angles than can rigid disks and still skip, Truscott said.

“I would estimate that a talented amateur stone-skipper might be able to achieve nearly 20 skips with a stone — the world record is 88, but it’s very difficult. This would involve years of practice, and [an] ideal stone, calm water and a lucky throw,” Truscott said. In contrast, “you could skip an elastic sphere 20 times in a matter of 10 minutes [of practice].”

All in all, the researchers found that elastic spheres can skip when hitting water at angles nearly three times greater than those predicted for rigid spheres. An elastic ball “would also skip at a much slower throwing speed than its rigid friend, if they were thrown at the same angle to the water surface,” Truscott said.

“It is still surprising to me when I throw one of these elastic balls at a lake or swimming pool and watch it effortlessly skip several times,” Truscott said. “To achieve the same feat with a stone takes considerable skill and velocity, while elastic balls can be skipped by my 5-year-old daughter.”

The researchers suggest their work could help improve “inflatable surface craft or skipping projectiles,” Truscott said.

The scientists detailed their findings online Feb. 4 in the journal Nature Communications.

Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

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The Bride: Basra’s ambitious vertical city to become world’s tallest building


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The Bride: Basra’s ambitious vertical city to become world’s tallest building

The Bride will cover an area of 1,550,000 sq m (16,700,000 sq ft)

The Bride will cover an area of 1,550,000 sq m (16,700,000 sq ft)

Basra, Iraq, is known as “the bride of the gulf” after its life-supporting fertile lands, and building vertically is one way to protect those lands. The planned Bride vertical city does just that. Covering 1,550,000 sq m and rising to a world record height of 1,152 m (3,789 ft), this vertical city designed by British-Iraqi architectural firm AMBS will have its own own neighborhoods, schools, clinics and transport system.

The Bride will have a 600,000 sq m (6,500,000 sq ft) canopy or

The Bride will have a 600,000 sq m (6,500,000 sq ft) canopy or “veil” of its south facade to provide shade

Not only will vertical building help to minimize urban spread in Basra, but it will help to make efficient use of space in what AMBS Architects calls one of the fastest growing business centers in the world, and one where space is at a premium. This thinking is baked into a downtown masterplan commissioned by the Basra Governorate, which seeks to maximize the city’s capacity by 2025. The Bride will be the centerpiece of this masterplan.

The Bride will have its own rail system to transport people around the building

The Bride will have its own rail system to transport people around the building

The project began in 2014, but has been kept confidential until now for security purposes. It will cover an area of 1,550,000 sq m (16,700,000 sq ft) and the firm is at pains to make clear that, not only is it a vertical city rather than a tower, but its planned height of 1,152 m (3,789 ft) – which would make it the world’s tallest building by a substantial margin – should also not overshadow its other innovations.

AMBS says the design seeks to “break new ground in all disciplines of engineering, from structures to vertical transportation and services.” To begin with, it actually comprises four towers, ranging in height from 244 m (801 ft) to 964 m (3,163 ft), joined together by a series of “sky gardens” and “sky squares.” This gives the structure far more routes of access and escape than a conventional tower and makes it more stable.

The Bride is designed to make use of Basra’s vertical space and to limit urban sprawl

The Bride is designed for round the clock use, with offices, hotels, whole neighborhoods, commercial centers, sky-squares, parks, gardens and its own rail network. It will be open for use by all, not only those who live and work there. There will be shaded parks and promenades to walk in, for example, and places to shop and eat.

The Bride will comprise four towers, ranging in height from 244 m (801 ft) to 964 ...

The Bride will comprise four towers, ranging in height from 244 m (801 ft) to 964 m (3,163 ft), joined together by a series of “sky gardens” and “sky squares”

The Bride’s rail service will move people around the huge building. Each tower will have a three-story “sky avenue” containing amenities, services and a train station for its local community. The station will be served by fast double decker lifts, while smaller local shuttle lifts will serve the zones above and below.

The Bride's four-tower design means it has far more routes of access and escape than a ...

The Bride’s four-tower design means it has far more routes of access and escape than a conventional tower

The building is also aimed at being net-zero and at being the most environmentally-advanced development in the world. The towers are located in such a way as to shade each other, while the tallest and most exposed tower will be shaded by a 600,000 sq m (6,500,000 sq ft) canopy or “veil” of its south façade.

In addition to providing shade, the canopy will have integrated hybrid solar cooling photovoltaic-thermal panels. Water heated within these will be use to improve the performance of the panels and will them be used to drive a cooling cycle for the building.

The Bride is designed for “round the clock” use, with offices, hotels, whole neighbourhoods, commercial centres, sky-squares, parks and gardens

Director of AMBS Marcos De Andres tells Gizmag that the masterplan for Basra, with the Bride as its centerpiece, was approved last year. There is no start or completion date set for the project currently, but it is expected to move forward once economic conditions in the region are more favorable.

The video below provides an introduction to the Bride

Source: AMBS Architects

The kilometer-high club: World’s tallest skyscraper a step closer to completion


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The kilometer-high club: World’s tallest skyscraper a step closer to completion

Jeddah Tower will rise 1,007 m (3,303 ft), dwarfing even the Burj Khalifa – the world's ...

Jeddah Tower will rise 1,007 m (3,303 ft), dwarfing even the Burj Khalifa – the world’s current tallest skyscraper

(Credit: Jeddah Economic Company)

Saudi development group Jeddah Economic Company recently secured SAR8.4 billion (US$2.2 billion) additional funding to complete the Jeddah Tower. Under construction since 2013, the massive mixed-use skyscraper is on track to become the tallest building in the world.

Formerly known as both the Kingdom Tower and Mile-High Tower (the latter dropped once its height was reduced due to concerns the ground couldn’t support it), Jeddah Tower is set to be the first member of the kilometer-high club and will rise some 1,007 m (3,303 ft) over the Red Sea port city of Jeddah.

Its projected size is hard to get your head around. It will be over three times the height of the Eiffel Tower, over twice the height Empire State Building, and dwarf even the Burj Khalifa – the world’s current tallest tower, which is 828 m (2,716 ft). Interestingly, both skyscrapers are the brainchild of the same American architect, Adrian Smith (the former for SOM, the latter for Adrian Smith + Gordon Gill).

Of course, the proposed Bride would be even taller still, but since there’s no immediate plans to build it, Jeddah Tower’s status as world’s tallest building looks assured for a while. For an informative rundown of the current and future state of skyscrapers, check out our video.

Towering over the Red Sea port city of Jeddah, the Jeddah Tower’s sheer size boggles the mind

(Credit: Jeddah Economic Company)

Rising over the Red Sea port city of Jeddah, the tower requires 59 elevators, will include some 5.7 million sq ft (530,000 sq m) of floorspace, and will boast the world’s highest observatory, a Four Seasons luxury hotel, office space, and many plush apartments.

Its triangular form, which is inspired by the folded leaves of a desert plant, is designed to withstand the strongest winds. In addition, its three sides sport notches that create pockets of shadow to shield areas of the building from the sun.

Jeddah Tower is expected to open by 2020.

It requires 59 elevators, includes some 5.7 million sq ft (530,000 sq m) of floorspace, and ...

It requires 59 elevators, includes some 5.7 million sq ft (530,000 sq m) of floorspace, and will be so high that you’d be able to see some 120 km (74.5 miles) to the horizon from the top

(Credit: Jeddah Economic Company)

Sources: AS+GG, Kingdom Holding Company

Carlo Ratti’s mile-high park in the sky would be world’s tallest building


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Carlo Ratti’s mile-high park in the sky would be world’s tallest building

On top of the world at The Mile observation tower

On top of the world at The Mile observation tower

If Carlo Ratti’s newly-announced observation tower comes to fruition (and it’s a big “if”), it will be as much a sight to behold as the views it provides. The proposed structure is a mile high, which would make it not only the tallest observation tower in the world, but also the world’s tallest building by some distance.

In order to achieve the height of the structure, it will be kept compressed and secured ...

In order to achieve the height of the structure, it will be kept compressed and secured through a net of pre-stressed cables

The tower will be covered by plants and greenery from bottom to top, providing a habitat ...

The tower will be covered by plants and greenery from bottom to top, providing a habitat for plants and animals

Aptly named, The Mile would reach 1,609 m (5,279 ft) into the sky, or one mile exactly. To put that into perspective, the world’s current tallest building, the Burj Khalifa, is just over half that height, at 830 m (2,723 ft). Even the Jeddah Tower, which is under construction and due to be completed in 2018, will only stretch to 1,000 m (3,281 ft), making it the world’s first kilometer-high building.

At the top, there will be a viewing deck, a

At the top, there will be a viewing deck, a “sky walkway” and a restaurant

Consequently, it is only reasonable to view The Mile with a degree of skepticism. Even if it’s a legitimate proposal, so many things can derail projects of such cinematic ambition that they can easily end up on the cutting room floor. But a legitimate proposal is exactly what Carlo Ratti Associati assures Gizmag this is. “The Mile is a real project, with a client, although it is only in the first phase now,” we are told.

At 20-m (66-ft) wide, the tower will have a height-to-width aspect ratio of around 80:1

At 20-m (66-ft) wide, the tower will have a height-to-width aspect ratio of around 80:1

Developed in partnership with German engineering firm Schlaich Bergermann und Partner and British digital design studio Atmos, The Mile will be a vertical park and publicly accessible observation deck. Visitors will ascend to the top in “sculptural capsules” that orbit the shaft of the tower. Once there, there will be a viewing deck, a “sky walkway” and a restaurant.

 

The capsules will be able to host meetings, dinners and concerts, and even, we are told, be home to pools. Visitors will be able to digitally interact with the surrounding views via augmented reality screens and experience the panorama in a variety of different ways.

The capsules will be able to host meetings, dinners and concerts

The capsules will be able to host meetings, dinners and concerts

At 20-m (66-ft) wide, the tower shaft will have a height-to-width aspect ratio of around 80:1, considerably larger than that of the British Airways i360 in Brighton, UK, which is currently recognized as the world’s most slender tower. An engineering study is said to have been carried out to develop a means of achieving this, with the structure to be kept in compression and secured using a net of pre-stressed cables.

“The structural concept for The Mile is technically feasible because of its consequent and uncompromised lightweight approach,” said associate and team leader at Schlaich Bergermann und Partner Boris Reyher. “The architectural form and the spatial equilibrium of forces become one and the same thing.”

There will be augmented reality screens via which visitors will be able to digitally interact with ...

There will be augmented reality screens via which visitors will be able to digitally interact with the surrounding views

In addition, it is envisaged that the tower will be covered by plants and greenery from bottom to top, providing a habitat for animals. Carlo Ratti likens the planned result to taking New York’s Central Park, standing it on its end, rolling it up and then twisting it.

On top of the world at The Mile observation tower

On top of the world at The Mile observation tower

The client for whom the project is being developed, a planned location and any construction dates remain undisclosed. More information will no doubt be forthcoming when the project is presented at the MIPIM property show on March 16, though, at which point we may get a better idea of its feasibility.

The Mile is said to be feasible due to its lightweight design

The Mile is said to be feasible due to its lightweight design

Source: Carlo Ratti Associati

UPDATE (Feb. 25/16): Carlo Ratti Associati tells us the following:

“The project has been developed as a concept for a client, including not only the design, but also advanced feasibility studies from a financial and engineering points of view. We are now dialoguing with a series of further subjects to define an ideal schedule for the realization. We hope we can disclose all the operative details in the next months.”

This is the Most Beat Up Dinosaur Ever Discovered


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This is the Most Beat Up Dinosaur Ever Discovered

Today 1:51pm

 http://gizmodo.com/this-is-the-most-beat-up-dinosaur-ever-discovered-1761281186
This is the Most Beat Up Dinosaur Ever Discovered
Dilophosaurus wetherilli (Royal Ontario Museum, Toronto)

Injuries are common in the fossilized remains of dinosaurs, but the recent discovery of a severely roughed-up skeleton in Arizona establishes a new record for the most bone injuries sustained by a single theropod. This guy got wrecked.

The dinosaur in question belongs to a species of theropod called Dilophosaurus wetherilli. These creatures lived about 193 million years ago during the early Jurassic Period, and were among the largest carnivores of their time. A fully mature adult measured around 20 feet (6 meters) long and weighed as much as 1,100 pounds (500 kg). In addition to their impressive size, dilophosaurus were known for a pair of cranial crests and a notch behind the first row of teeth, giving the beasts a crocodile-like appearance.

This is the Most Beat Up Dinosaur Ever Discovered
A reconstruction of Dilophosaurus wetherilli at the Geological Museum of the Polish Geological Institute, Warsaw

In a recent PLOS One study, paleontologists Phil Senter and Sara Juengst from Fayetteville State University analyzed the remains of a specimen recently uncovered in Arizona. This dilophosaurus appears to have been roughed up in an encounter, but it somehow managed to survive.

This is the Most Beat Up Dinosaur Ever Discovered
Credit: Senter and Juengst/PLOS ONE, 2016

On its left side, the dinosaur suffered a fractured shoulder blade and several fractures and fibriscesses (like an abscess in mammals) in its ulna (the thinner, longer bone in its forearm) and hand. On its right, it had abnormal twisting in its upper arm, bony tumors on its forearm, messed-up metacarpal hand bones, and severe deformities in its third finger. In all, eight distinct injuries were detected in the skeleton. That’s a new record. What’s more, many of these wounds had healed, suggesting the animal was able to live for months, and possibly years, after these injuries appeared. The deformity in its third finger, however, may have occurred at birth.

So what happened?

Senter and Juengst aren’t entirely sure, but they say the injuries could have been the result of a single, high-energy encounter with a tree or a rock wall during a fight. During the battle, a rival dinosaur could have caused the puncture wounds to the hand and toe claws. The dilophosaurus may have survived the encounter, but the injuries “must have severely compromised the use of the forelimbs in prey capture,” wrote the researchers.

To survive during the healing period, the dinosaur likely fed on small prey that it was able to catch with its mouth or feet, or with its one good forelimb. It must have been a pathetic sight. But as the researchers conclude, this dilophosaurus is “a testament to the hardiness of an animal that doubtlessly experienced an agonizingly long duration of high degrees of pain” across its body.

[PLOS ONE]

Email the author at george@gizmodo.com and follow him @dvorsky.

Stunning Underwater Photography Contest Winners (Photos)


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Stunning Underwater Photography Contest Winners (Photos)

Fired Up

Credit: Marty Engels Dunmore/UPY 2016
On top of taking Runner Up in the Up & Coming Worldwide Category, photographer Marty Engels Dunmore garnered the “Most Promising British Underwater Photographer, 2016″ with this image of the USS Kittiwake in the Grand Caymans. By doing the research beforehand, this photographer captured this unique image from a well-known wreck.”It takes a lot to impress an old wreck photographer lag like me but here is a quite superb example of how, with a comparatively simple touch, a straightforward technical shot has been so effectively elevated to the eye,” said one of the judges Peter Rowlands, in a statement.

Underwater Fisherman

Credit: Mike Korostelev/UPY 2016
With plans to capture a bear fishing in Kuril Lake in Russia, photographer Mike Korostelev crafted an underwater cage to keep himself safe. The effort landed him this image of a bear planning, waiting and capturing multiple fish and winning Korostelev first place in the International Wide Angle category.One of the judges Alex Mustard called the photo “unforgettable,” saying it was more than just an amazing portrait of a brown bear under the water. “It is a precisely timed behavioral portrait, capturing the peak of the action as the bear leaps for a meal and swishes his claw through the stones to snag his food. It is a great composition, taken in a split second in frigid waters of Kamchatka.” [Read the full story on the underwater photo contest]

Mangrove Sunset

Credit: Fabio Galbiati/UPY 2016
Due to inclement weather, photographer Fabio Galbiati’s plan to dive in the open ocean was canceled. A decision to excplore the pristine mangrove ended with this image of mangrove, root to sky, with a nudibranch looking for a snack — not to mention a Runner Up place in the International Wide Angle category.

Octopus at Night

Credit: Helen Brierley/UPY 2016
Floating in the pitch-black open ocean many strange and amazing creatures drifted by photographer Helen Brierley. She snapped this image of a juvenileoctopus, snatching the Runner Up place in the International Macro category of the Underwater Photographer of the Year 2016 contest.”It is not easy to shoot macro portraits of tiny, semi-transparent critters while suspended in the darkness of inner-space: an open ocean black water dive,” Mustard said in the statement. “Capturing such a pleasing composition of such an attractive species in these conditions is a great achievement.”

A Family Affair

Credit: Thomas Heckmann/UPY 2016
While swimming with his snorkeling 5-year-old daughter, photographer Thomas Heckmann collected this splendid image of a tugboat wreck just off Curacao. Though it took several tries to get it perfect, the image indeed worked, winning him first place in the International Wrecks category.

Truck Parking

Credit: Anders Nyberg/UPY 2016
In the SS Thistlegorm, using off camera strobes, photographer Anders Nyberg and his friend created a stunning image evoking a sense of history and intrigue.The old Ford trucks, the repetition of the lit windows and the smattering of color from the native fish meld mysteriously with the gentle blue light in the background.

Turtle eating Jellyfish

Credit: Richard Carey/UPY 2016
Photographer Richard Carey breakfasted with a Green Turtle near the Similan Islands in Thailand. The reptile came upon a Mosaid Jellyfish and snacked on the creature, resulting in a winning photo in the Behavior category of the Underwater Photographer of the Year 2016 Contest.”The turtle obviously wanted to keep the jelly close to the surface so every time it swam deeper the turtle would bite onto it and drag it back upwards. I spent a few minutes watching it and taking photos, and then left the turtle to finish his meal in peace,” Carey said.

Part of the Illusion

Credit: Marcus Blatchford/UPY 2016
During an exploration dive at the deep end of a UK dive center, photographer Marcus Blatchford captured this dark and moody image with no artificial lighting, landing himself first place in the British Waters Wide Angle category.

Shocked Shark

Credit: Will Clark/UPY 2016
Teasing a toothy shark isn’t usually advised but it gave a phenomenal result in this instance. After a long hour of chumming the waters of Penzance, Cornwall, this young Blue shark made a showing and, when his snack was jerked from his mouth, he was clearly surprised, as seen in this image captured by photographer Will Clark.

Planktonic Predator

Credit: George Stoyle/UPY 2016
At the end of a long dive surveilling a cave in North Rona off Scotland, photographer George Stoyle captured this image of an other-worldly looking creature — a juvenile monkfish — grabbing a snack.”The most remarkable looking creature I have seen photographed in British waters. This juvenile monkfish doesn’t even look like it comes from our planet, let alone our shores,” Mustard said. “An amazing subject photographed flawlessly, it is definitely one of the most memorable pictures in this year’s collection.”

What Feeds Beneath

Credit: Alejandro Prieto/UPY 2016
When plans to capture a humpback whale pair were cut short, photographer Alejandro Prieto was in the right place at the right time to snap this image of an endangered Hawaiian petrel noshing on sea creatures in Todos Santos, Mexico.

Hello Ducky!

Credit: Paul Colley/UPY 2016
What began as an interruption turned into an opportunity to be creative and produced this image. A flock of Mallard ducks barged in on a project focusedon photographing trout at River Test, Hampshire and, with a load of patience, photographer captured this intriguing view of both animals as well as winning first prize in the category.

Tompot Looking Out

Credit: Trevor Rees/UPY 2016
This charming little fish peaks out from its hiding place under a sea peir. The Tompot blenny posed curiously for photographer Trevor Rees to capture this image, in the British Waters Compact Category.

Photos: A Medieval Trade Ship Revealed


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Photos: A Medieval Trade Ship Revealed