Canine agility champion

YouTube link.

Filmed at the 2015 Westminster Kennel Club dog show.  Wikipedia has a wonderfully comprehensive article on dog agility competitions.

Dogs run off leash with no food or toys as incentives, and the handler can touch neither dog nor obstacles. Consequently the handler's controls are limited to voice, movement, and various body signals, requiring exceptional training of the animal and coordination of the handler....

Because each course is different, handlers are allowed a short walk-through before the competition starts. During this time, all handlers competing in a particular class can walk or run around the course without their dogs...

Each dog and handler team gets one opportunity together to attempt to complete the course successfully...

Dogs are measured in height at the peak of their withers (shoulders). They are then divided into height groups... Dogs are further divided into their experience levels...Dogs are not separated by breed in agility competitions... 

Lots more details re the individual obstacles and the training techniques.

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Icebergs

Herewith three selections from a gallery of iceberg photos at The Telegraph.  Top photo credit to Steppes Travel. The beautifully-laminated one is by Hurtigruten/Dominic Barrington.  The bottom one, by Lizzie Williams, I include just for scale: those black dots are penguins.

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A Royal Flycatcher - before and after

Via Reddit.

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17 nude people

Body-painting artist Emma Hack piled 17 naked models up on the floor before arranging their arms, heads and legs into the shape of a small hatchback. She covered them in shades of blue, white, black and silver paint to highlight every detail, including the alloy wheels and number plate...and she even made it look like the car had been involved in a small shunt [?] by exposing the "engine" and leaving the front "bumper" hanging off. 

One of the photos at The Week in Pictures at The Telegraph.

Photo credit: MAC/Emma Hack/Jacqui Way/Solent

Addendum: Reposted from 2012 to add this "making of" video:

YouTube link.

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Otzi's copper axe

Readers of this blog should already be familiar with Ötzi the Iceman (his face) (his tattoos).  This is what his axe looked like.

Ötzi's copper axe was of particular interest. The axe's haft is 60 centimetres (24 in) long and made from carefully worked yew with a right-angled crook at the shoulder, leading to the blade. The 9.5 centimetres (3.7 in) long axe head is made of almost pure copper, produced by a combination of casting, cold forging, polishing, and sharpening. It was let into the forked end of the crook and fixed there using birch-tar and tight leather lashing. The blade part of the head extends out of the lashing and shows clear signs of having been used to chop and cut. At the time, such an axe would have been a valuable possession, important both as a tool and as a status symbol for the bearer.

Image cropped for emphasis from the original.  This is a replica; the original can be seen in this photo -

- from the Otzi website, where there are many more details about this tool.

The haft, i.e. the handle of the axe, was carved from the split wood of a yew tree. A nearly right-angled branch growing out of the trunk was used. The axe blade is held in a slit in the haft with birch tar. It was then bound in place with narrow strips of leather.  Using a replica of the axe, it took just over half an hour to fell a yew tree...

In Central Europe in the period around 3000 BC, a copper axe would have belonged to a man of high social status. This is confirmed by grave finds from this period. In the grave field at Remedello di Sotto southwest of Lake Garda, for example, only 17% of the axes placed in the men’s graves had a copper blade. The copper axe blades recovered from those graves are identical in shape and size to the Iceman’s.

If you would like to make one, someone else has posted a photo gallery of the steps required to craft the tool.

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Sigiriya

Sigiriya must be an awesome place, both in terms of geography and in the way it has been modified.  I first learned about it in an article at When On Earth.

In Sri Lanka, ruins of an ancient city can be seen lying on the steep slopes and summit of a 200-meter high peak. This awe-inspiring city is called Sigiriya and is located at the Matale district near Dambulla in the Central Province of Sri Lanka...

During the 11 years of staying in Sigiriya [in the 5th century], Kassapa transformed the rock into a magnificent complex.  The rock-turned-city possessed areas designed for its defenses but it didn’t forget to be a place of beauty and splendor. Ramparts and moats were built around it. Royal Pleasure Gardens Water Gardens, Fountain Gardens, and Boulder Gardens can be found within its inner city...

You’re almost at the rock’s entrance when you see a stone staircase that takes you to the fortress, but be better prepared, for it has 1200 steps.

In 1150 AD, it was abandoned but during the 16th and 17th century it served as temporary outpost for the Kingdom of Kandy. In 1831, it was discovered by Major Jonathan Forbes of the 78th Highlanders of the British Army that led to the beginning of its archaeological work in the 1890s.

There are photos at the link, but for those interested I highly recommend the webpage of SriLankaView.  I opened a couple thumbnails and found myself clicking through scores of the several hundred photos, including these:

Access to the site is now provided by modern staircases, but note that adjacent to the stairs are hand-cut stone steps and cavities for ancient wooden railings and supports.

This is too far away to fit into the budget of my bucket list, so I was glad to be able to tour it online.  Amazing.

Here is the Wikipedia entry.

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An ant-mimicking treehopper

That's not an ant attacking an insect, as explained in an article entitled "Myrmecomorphomania" at Current Biology:

The insect was quickly identified to be a treehopper of the family Membracidae by the name of Cyphonia clavata — a species that lives in Middle and South America, and looks more like a creature from Greek mythology than a product of natural selection. At first, you see what looks like an ant; only on the second look, it becomes evident that the supposed ‘ant’ is actually not an ant at all, but an illusion created by a curious protrusion extending from the insect's pronotum. The main body of the treehopper is almost buried under the large ant-like shape and because of its pale colouration, much less obvious than the dark-coloured ‘ant’. The protrusion's general likeness to an ant is remarkably accurate, and, with the ‘propodeal spines’ found on the ant imitation, the similarity to the aggressive and stinging ants of the subfamily Myrmicinae is striking. Notably, the ant-mimicking structure seems to be inverted, with the imitated head facing towards the back of the treehopper. That way, as the treehopper moves forward, it probably creates a rather good impression of a reversing and agitated ant in erect defensive posture, deterring any would-be predators. To complete the illusion, the terminal segments of the treehopper's hindlegs, coloured like the ‘ant’, most likely serve as the ‘ant's’ forelegs, which provides the static protrusion with the illusion of movement.

More pix at the links.  Embedded photo by Andreas Kay, via The Ark in Space.

Previously on TYWKIWDBI:  Treehoppers and Thorn Treehoppers.

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This is not an in-utero photograph of a fetus

At least not a photograph in the conventional sense of an image recorded using light.  This is, to my understanding, a colorized three-dimensional ultrasound image.

The light is computer-generated "virtual illumination" which generates shadows and reflections just as available light would.

The purpose apparently is not just to satisfy the curiosity of expectant parents, but to improve diagnostic imaging of fetal abnormalities that might require medical intervention.

More at National Geographic Deutschland.

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Trees dead for 500 years - but not decayed

“We were gathering samples of dead trees to reconstruct summer temperatures in western Norway, when our dendrochronological dating showed the wood to be much older than expected”, says Terje Thun, an associate professor at the Norwegian University of Science and Technology’s (NTNU) Museum of Natural History and Archaeology...

Thun says that when a pine tree dies, it secretes a great deal of resin, which deters the microorganisms needed for decomposition. “Nevertheless, preventing the natural breakdown of the wood for centuries is quite a feat”, he says...

Resin was one of the ingredients used in Ancient Egypt for mummification, so its conservation abilities have been known for millennia. However, that trees could “self-mummify” in such a humid climate for centuries was new to the NTNU scientists.

“Many of the trunks we dated turned out to have seeded in the early 1200s, and had lived for more than 100 years at the time of the Black Death around 1350”, Thun says. “That means that the dead wood has ‘survived’ in nature for more than 800 years without breaking down.”

More at the link. The tree in the photo grew began growing in 1334, and died in 1513!  
Reposted from 2009.  Photo credit: Terje Thun, NTNU.

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Did a Darwin Award applicant pass through the propellor arc of this aircraft ??

YouTube link.

This [very] amateur footage of a serious Runway Incursion on a rural airstrip in Alaska shows our Fairchild C119 FlyingBoxcar taking off on a runway that is too short and too soft on a ferry flight. The plane had forced-landed there years ago to begin with...So this was the first takeoff after the plane had sat there for more than 13 years being vandalized etc. We had changed out one engine, windows and ball bearings and worked on it straight for over half a year. We have been given 7 videos of this takeoff by the locals and the FAA used the footage to teach about the feared "runway incursions". We have it on tape how our pilot preaches from the cockpit window to the assembled villagers that he will use every inch of available runway and THEN SOME beyond that, nevertheless we had a father and son standing in the way of the plane plus two others while a village schoolteacher and professional pilot was arguing with them about getting off the runway...Quite amazing, as said we have 7 camerapositions...Nobody died but the son did actually go through the Prop arc and had the luck to pass through the blades with no harm to him. R3350's run 2950 RPM on takeoff and the reduction gear reduces Prop RPM and at 94 knots it was some space between the 4 blades of the Prop. "

This video link was sent to me by my brother-in-law, who is an air traffic controller.  In the YouTube comment thread the OP responds to a question as to whether someone actually did "go through" the propellors:

From the 6 camera-positions & videotapes, as well as the still photos, That is what we have concluded, there is no other possibility. The 7th tape, being from the camera that the Kid held while he went through the prop-arc, I have never seen. Many people that saw it told me about it, there was no doubt !

I did some rough calculations this morning.  The plane's velocity at the end of the runway was reported at 94 knots = 108 mph = 158 fps.  The "reduction gear" ratio for the propellors is not defined; let's say the RPM were reduced from 2950 to 2400 (anyone know/guess?)  It's a 4-blade propellor, so 2400 RPM results in 9600 blade-passes per minute, or one blade coming by every 1/9600 minute.  Divide by 60 = 160 passes per second.

160 passes per second in a plane moving forward 158 fps would give a space of about 1 foot for the head to pass through.    The person who pulled this stunt probably had a small head to begin with.

A standard, unquestioned rule of airport safety is that nobody should walk through the propellor arc - even if the engine is turned off.

If you never walk through a stationary prop arc due to a conscious decision to avoid it, when you hurry across the flight deck it is less likely that you will walk through a turning prop arc.  FACT: People who have been killed by prop arcs were familiar with the aircraft and flight deck around them, but a momentary lapse of concentration caused them to stray into a turning propeller. 

I suppose there is one possible lesson to be learned here.  If one finds oneself in a real-life action-movie scenario with a propellor blade coming toward you, and if there is no way to stop it and no way to avoid it and a physical encounter is unavoidable, then one's chances are statistically improved by rushing toward the spinning blades as fast as possible.

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Nature finds a way

From an assemblage of nine similar photos at Curiosités de Titam.

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The first "mulitiple-image gravitationally-lensed supernova"

The four dots centered on the bright elliptical galaxy at top are multiple images of supernova SN Refsdal taken with the Hubble Space Telescope between November 10-20, 2014. In the bottom image, the galaxy has been digitally removed to show only the supernova images, labeled S1 through S4. The line segments are diffraction spikes from a nearby star. Credit: P.L. Kelly/GLASS/Hubble Frontier Fields

A fascinating discovery explained at Universe Today:

Using the Hubble Space Telescope, Dr. Patrick Kelly of the University of California-Berkeley along with the GLASS (Grism Lens Amplified Survey from Space) and Hubble Frontier Fields teams discovered a remote supernova lensed into four copies of itself by the powerful gravity of a foreground galaxy cluster... It’s the first multiply-lensed supernova ever discovered and one of nature’s most exotic mirages...

In effect, the [galaxy] acts as a lens, bending and refocusing the light from the distant source into either a brighter image or multiple and distorted images. Also known as the deflection of starlight, nowadays we call it gravitational lensing...

Rich galaxy clusters act like telescopes – their enormous mass and powerful gravity magnify and intensify the light of galaxies billions of light years beyond, making visible what would otherwise never be seen...

To create such neat symmetry, [the supernova] must be precisely aligned behind the galaxy’s center.

More details, images, and discussion at the link.   I understand the "lensing" principle, but perhaps some reader can further explain why the lens would create four discrete images rather than a circular "halo" around the galaxy.

I'm also pleased to note that the lead author of the study is the son of my old debate partner from high school.  Kudos!

Addendum:  One of the joys of writing this blog is having an audience of readers who are able to answer many of my questions - often within just a couple hours of my posting a query.  So, a tip of the blogging hat to reader Jeff, who provided a link to a relevant AskScience subreddit thread.

The circular "halo" lensing effect I postulated above is well known, and is called an Einstein ring.  It forms around spherical masses (think black hole).   A galaxy, however, is not typically spherical - when light from a quasar traverses an ellipsoidal galaxy, the result is an Einstein Cross, with the four foci corresponding to the major and minor axes of the mass distribution of the galaxy.  Easy as pie.

Update March 5:  The findings above were featured in a New York Times article today -

...the explosion is expected to appear again in another part of the sky in the next 10 years. Timing the delays between its appearances, he explained, will allow astronomers to refine measurements of how fast the universe is expanding... Dr. Kelly and his colleagues suspect that Supernova Refsdal has appeared before, around 1964 and 1995, in other lensed images of the spiral galaxy.

The link has a well-done informative video explaining gravitational lensing.

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A potential treatment for multiple sclerosis

Excerpts from the report at JAMA Neurology (the new name for the Archives of Neurology):

High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic cell transplant (HCT) may.. induce sustained remissions in early MS.

Results  Grafts were collected from 25 patients, and 24 of these individuals received HDIT/HCT. The median follow-up period was 186 weeks (interquartile range, 176-250) weeks). Overall event-free survival was 78.4% (90% CI, 60.1%-89.0%) at 3 years. Progression-free survival and clinical relapse-free survival were 90.9% (90% CI, 73.7%-97.1%) and 86.3% (90% CI, 68.1%-94.5%), respectively, at 3 years. Adverse events were consistent with expected toxic effects associated with HDIT/HCT, and no acute treatment-related neurologic adverse events were observed. Improvements were noted in neurologic disability, quality-of-life, and functional scores.


Conclusions and Relevance  At 3 years, HDIT/HCT without maintenance therapy was effective for inducing sustained remission of active RRMS and was associated with improvements in neurologic function. Treatment was associated with few serious early complications or unexpected adverse events.

In the present study, HDIT/HCT induced remission of MS disease activity for up to 3 years in most participants. It may therefore represent a potential therapeutic option for patients with MS in whom conventional immunotherapy fails, as well as for other severe immune-mediated diseases of the central nervous system. Most early toxic effects were hematologic and gastrointestinal and were expected and reversible. Longer follow-up is needed to determine the durability of the response... We have presented the 3-year interim analysis of the HALT-MS trial; the prespecified full duration of observation is 5 years, after which the final report on the study will be prepared.

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The escape from Eastern State Penitentary

Excerpts from the original post at Life Without Buildings:

With its hub-and-spoke design of long blocks containing individual prison cells, ESP could be considered the first modern prison. There are many, many stories told about the prisoners that have been incarcerated here over its nearly 150 years of operation–some inspiring, some horrible, some about Al Capone–but none of them have captivated the public more than the 1945 “Willie Sutton” tunnel escape...

Working in two-man teams of 30 minute shifts, the tunnel crew, using spoons and flattened cans as shovels and picks, slowly dug a 31-inch opening through the wall of cell 68, then dug twelve feet straight down into the ground, and another 100 feet out beyond the walls of the prison. They removed dirt by concealing it in their pockets and scattering it in the yard a la The Great Escape. Also like The Great Escape, the ESP tunnel was shored up with scaffolding, illuminated, and even ventilated...

More details, photos, diagrams, and information about the fate of the escapees and the current state of the tunnel here.

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Negative pressure in the xylem tubes of trees

YouTube link.

"Trees create immense negative pressures of 10's of atmospheres by evaporating water from nanoscale pores, sucking water up 100m in a state where it should be boiling but can't because the perfect xylem tubes contain no air bubbles, just so that most of it can evaporate in the process of absorbing a couple molecules of carbon dioxide."

I can't quite wrap my mind around the concept of such immensely negative pressures inside trees, but then I was an English major...

A tip of the blogging hat to reader Dan Noland, who found the video.

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"9 darter" explained

YouTube link.

It's a perfect darts game:

Although other combinations are possible, the traditional nine-dart finish requires a score of 60 (treble 20) with each of the first six throws, that is, with the first two shots of three. This leaves 141 to score on the final shot (of three darts), known as the outshot.
This outshot is traditionally performed in one of three ways:

• treble 20 (60), treble 19 (57) and double 12 (24)
• treble 20 (60), treble 15 (45) and double 18 (36)

Another way is to score 167 with each set of three darts, scoring a perfect 501 total, in the following way:

• treble 20 (60), treble 19 (57) and bullseye (50)

This eliminates the chance of any dart being deflected by an already thrown dart into the wrong scoring area by throwing each dart at a different location on the board. It is only usually seen in exhibition matches, as in tournaments, players are inclined to aim for the triple 20, only switching to the triple 19 for a cover shot.
Arguably the most difficult nine dart finish would be 180 (3xT20), 171 (3xT19), and 150 (3xBULL) – owing to the difficulty of getting all three darts in the bullseye: it is the smallest double on the board.

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Grizzly bear paw

Sad that this bear paws are considered a delicacy in Cantonese culture.

Via Neatorama.  Photo credit Sean Sparling.

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Impress your kids (and friends) with magnets, a battery, and copper wire

YouTube link.

Via Neatorama.

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Snake climbing a brick wall

Using a technique evolved over the millennia to climb rough-barked trees.

Photo cropped for size from the original at imgur.

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Flexible paper sculptures

The pretty lady stands behind a sculpted bust.  Then she does something incredible (click on the instagram gif at the link to animate it).

To make his sculptures Li uses a stencil to paste glue in narrow strips across large pieces of paper that he then sticks together to form blocks of 500.

He stacks the blocks to the desired height -- an average bust is over ten blocks or 5,000 sheets of paper high -- then cuts, chisels and sands the large block just as if it were a piece of soft stone.

The process is explained and illustrated in this video:

YouTube link.

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