Shared posts

28 Nov 14:08

Doctor appeal

by PIDJIN.NET

384 doctor pidjin 6-01

384 doctor pidjin 6-01

384 doctor pidjin 6-01

384 doctor pidjin 6-01

384 doctor pidjin 6-01



12 Nov 16:00

TED: Ethan Nadelmann: Why we need to end the War on Drugs - Ethan Nadelmann (2014)

by TEDTalks
Is the War on Drugs doing more harm than good? In a bold talk, drug policy reformist Ethan Nadelmann makes an impassioned plea to end the "backward, heartless, disastrous" movement to stamp out the drug trade. He gives two big reasons we should focus on intelligent regulation instead.
14 Nov 20:05

Первый по фотошопу

1415982664-b8463f31539b197aeb8547aa7ff0dbb6
(большая картинка по ссылке)

Сегодня первый канал на всю страну выдал свою версию катастрофы малазийского боинга, произошедшей 17 июля. Тогда погибло 298 человек, и до сих пор не понятны точные обстоятельства произошедшего. Первый канал представил зрителям якобы снимки со спутника, на которых предположительно видно, как истребитель сбивает самолёт. При детальном рассмотрении выяснилось, что это очень грубо слепленная в фотошопе фальшивка, откопанная редакторами первого канала на форуме, где обсуждают заговоры.

Вот что конкретно тут не так:
— Снимок был сделал с гугл-карт в 2012 году, вот только одна из склеек
B2bMg3xIYAANkWP.png-large

— на фотографии предположительно СУ-27, но никак не МиГ, о котором говорят в репортаже. Вот сравнение, обратите внимание на хвост.
710238873_13051478507156534110

— размеры истребителя и самолета вызывают большие сомнения. Вот пример как показывается самолет на снимках со спутников.

Еще про размеры: длина северной кромки лесного массива, что находится под Мигом справа ~850 метров... Размах крыльев Мига составляет 11,36 м... Учитывая, что на "фотографии" перечисленные сущности визуально равны, эту "фотографию" должны были делать с высоты много меньше 10 км...

— на снимке показано место в 60 км от места крушения
HVOP82F9crM

— Время, указанное на снимке, не совпадает с временем, когда сбили самолет (его сбили около UTC 13:21). На снимке с таким временем должны была быть ночь.
B2bAjIoIAAAGQzW.jpg-large

— Навальный выяснил, что эксперт из репортажа не является никаким инженером и не получал технического образования.

— Первая картинка по поиску гугла "Боинг вид сверху" полностью совпадает с самолетом со снимка.

@max_katz http://t.co/fIvTAR38yy

— Nickolay (@interhalfer) 14 ноября 2014


— мало того, что картинка самолета взята из гугла, так еще и надпись на борту самолета, который сбили, расположена в другом месте
B2biw4jCQAAMKZv.jpg-large

— сторона, в которую должна была попасть ракета с картинки первого канала, не совпадает с местом попадания ракеты в боинг

— после выпуска ракеты истребителем за ним остается инверсионный след от выпускаемой ракеты, на картинке первого канала этого не видно

Комментарий Владимира Салуянова о подлинности снимка, руководитель аппарата Российского союза инженеров:
Снимок экрана 2014-11-15 в 0.39.37

Запись репортажа:


Детальный разбор:


СМИ, которые опубликовали эту "сенсацию":
Московский комсомолец — уже удалили.
Дни.ру
Вести.ру
НТВ
Лайфньюс
Говорит Москва
ТАСС
Лента.ру
Телеканал Звезда
Комсомольская правда


Это только один из эпизодов информационной войны. Держите свой мозг в чистоте, не смотрите телевизор.

07 Nov 20:20

New telescope array captures planet-forming disk orbiting distant star

by John Timmer

Yesterday, the European Southern Observatory released the first images taken with the upgraded version of its ALMA telescope. The images capture a disk of material orbiting the young star HL Tauri in exquisite detail, showing gaps in the disk that are likely to be created by the formation of larger, potentially planet-sized bodies.

ALMA stands for the Atacama Large Millimeter/submillimeter Array. As its name implies, it's located in the Atacama Desert, one of the driest regions on the planet. It's also placed at 5,000 meters above sea level; the combination limits the imaging complications posed by Earth's atmosphere. ALMA is an array of multiple individual telescopes, with the final image constructed by mathematically processing the input of each individual telescope.

The final resolution of these images depends on the distance among the telescopes, and ALMA has just received an upgrade that places them up to 15 kilometers apart. This is close to the planned final configuration (which will allow 16km separations) and much larger than previous telescopes that imaged at this wavelength, which were limited to separations of about 2km.

Read 5 remaining paragraphs | Comments

07 Nov 15:00

Dark matter: Devourer of stars

by Chris Lee

A type of star that I hold dear is the pulsar (a type of neutron star). Not just because the first one discovered was called LGM-1 (Little Green Men), but because they are a rich mixture of quantum physics, electromagnetism, and gravity, all in a single macroscopic object. For a young graduate student, being able to solve a set of equations and describe (at a simple level) the behavior of an entire freaking star is just mind-blowing.

But they are also a huge mystery, having a complex structure and possibly mountains. Another mystery that's not inherent to the objects themselves is that neutron stars of a certain type are conspicuous by their absence in the galactic center. There are many possible reasons for this absence—maybe there aren't any good schools in the neighborhood or it's too far to the local pub—but one of the most exciting possibilities is that the heaviest neutron stars are being hunted down and devoured by dark matter.

Neutron stars are essentially the corpses of stars. After burning through all their fuel and exploding in a last furious burst of energy, the remaining matter collapses in on itself. The temperature and pressure get so high that the electrons and protons fuse to form neutrons. However, their mass isn't sufficient for gravity to force the neutrons together—if it were, a black hole would form.

The pressure that prevents a neutron star from collapsing is called the Fermi pressure. Neutrons are fermions, which means they repel each other. Fermions cannot occupy the same quantum state, so at close range, they stack in energy and space themselves out. This unusual state also generates huge magnetic fields, which accelerates charged particles to enormous energies as the star spins. These particles emit beams of radiation that sweep around like the beam from a light house. When we happen to fall in the path of this beam, we record this as a regular blip of light.

Read 10 remaining paragraphs | Comments

10 Nov 05:00

Efficiency

I need an extension for my research project because I spent all month trying to figure out whether learning Dvorak would help me type it faster.
24 Oct 12:42

New Shopping Label

by DOGHOUSE DIARIES

New Shopping Label

This would drastically affect my shopping decisions. Comment on Facebook!

21 Oct 15:08

The north pole moved to the North Pole in a single human lifetime

by Scott K. Johnson

Geology rewards an active imagination. It gives us a lot of tantalizing clues about very different times and places in Earth’s history, leaving us to try to answer “Man, what would that be like?” One of the things that's tough to imagine involves changing something that most of us never give a second thought—the fact that compasses point north. That’s plainly true today, but it hasn’t always been.

What we call the “north” magnetic pole—the object of your compass’ affection—doesn’t need to be located in the Arctic (it noticeably wanders there, by the way). It feels equally at home in the Antarctic. The geologic record tells us that the north and south magnetic poles frequently trade places. In fact, the signal of this magnetic flip-flopping recorded in the seafloor was the final key to the discovery of plate tectonics, as it let us see how ocean crust forms and moves over time.

That the poles flip is interesting in itself, but “Man, what would that be like?” Does the magnetic pole slowly walk along the curve of the Earth over thousands of years, meaning your compass might have pointed to some part of the equator for long stretches of time? Do the poles weaken to nothing, disappearing for a while before re-emerging in the new configuration? Do they somehow flip in the blink of an eye? Given the number of species that use the Earth’s magnetic field to navigate—especially for seasonal migrations—this is more than an academic curiosity.

Read 9 remaining paragraphs | Comments

15 Oct 15:09

TED: Jorge Soto: The future of early cancer detection? - Jorge Soto (2014)

by TEDTalks
Along with a crew of technologists and scientists, Jorge Soto is developing a simple, noninvasive, open-source test that looks for early signs of multiple forms of cancer. Onstage at TEDGlobal 2014, he demonstrates a working prototype of the mobile platform for the first time.
13 Oct 17:43

Photo









13 Oct 19:10

The Math Behind the Rolling Shutter Phenomenon

by Jason Cole

3192314056_e0df39ed3c_z

I remember seeing the photo above on Flickr once, and having my brain melt slightly from trying to figure out what went wrong.

The issue was the propeller was rotating as the camera detector ‘read out’, i.e. there was some motion during the exposure of the camera. This is an interesting thing to think about, lets have a look.

Many modern digital cameras use as their ‘sensing’ device a CMOS detector, also known as an active-pixel sensor, which works by accumulating electronic charge as light falls upon it. After a given amount of time, the exposure time, the charge is shifted row-by-row back to the camera for further processing. There is then a finite time where the camera scans down the image, saving rows of pixels at a time. If there is any motion over this timescale the image will be distorted.

To illustrate, consider photographing a spinning propeller. In the animations below the red line corresponds to the current readout position, and the propeller continues to spin as the readout proceeds. The portion below the red line is saved as the captured image.

First, a propeller which completes 1/10th of a rotation during the exposure:

Some distortion, but nothing crazy. Now a propeller moving 10 times quicker, which completes a full rotation during the exposure:

This is starting to look like the Flickr image at the beginning. 5 times per exposure:

This is a little too far, things have clearly gone mental. Just for fun, let’s see what some different objects look like at different rotation speeds, from 0 to 1 rotation per exposure.

The same propeller as above:

A fatter propeller:

A car tire:

We can think of the rolling shutter effect being some coordinate transformation from the ‘object space’ of the real-world object, to the ‘image space’ of the warped image. The animation below shows what happens to the Cartesian coordinate grid as the number of rotations is increased. For small rotations the deformation is slight, as the number increases to 1 each side of the grid is moved successively towards the right-hand side of the image. This is a fairly complicated transformation to look at, but simple to understand.

Let the image be denoted by I(r,\theta), and the real object (which is rotating) be denoted by f(r,\theta) where (r,\theta) are 2D polar coordinates. Polar coordinates are a natural choice for this problem due to the rotational motion of the objects.

The object is rotating at angular frequency \omega, and the shutter progresses across the image at speed v in the vertical direction. At position (r,\theta) in the image, the distance the shutter has moved since the start of exposure is y = r\sin\theta, and so the time elapsed is (r\sin\theta) /v. In this time the object has rotated a number of radians (\omega/v) r\sin\theta). Putting this together,

I(r,\theta) = f(r,\theta + (\omega/v)r\sin\theta)

which is the required transformation. The factor \omega/v is proportional to the number of rotations during the exposure, and parameterises the transformation.

To get some insight into the apparent shapes of the propellers, we can consider an object consisting of P propellers where f is non-zero only for \theta = 2\pi/P, 4\pi/P \dots 2\pi = 2p\pi/P for 1 < p < P. The image I is then non-zero for

\theta + (\omega/v)r\sin\theta = 2p\pi/P

or

r = \frac{v}{\omega}\frac{2p\pi - \theta}{\sin\theta}

In Cartesian coordinates this becomes

\text{atan}\left(\frac{y}{x}\right) + \frac{\omega}{v}y = 2p\pi

which helps to explain why the propellers get that S-shaped look – it’s just an inverse tangent function in the image space. Cool. I’ve plotted this function below for a set of 5 propeller blades at slightly different initial offsets, as might be observed during a video recording. They look pretty much like the shapes in the animations above.

Now we understand a little more about the process, can we do anything about these ruined photos? Taking one of the warped images above, I can take a line through it, rotate backwards the appropriate amount, then stick those pixels onto a new image. In the animation below I scan through the image on the left, marked by the red line, then rotate the pixels along that line onto a new image. This way we can build a picture of what the real object looks like even if a pesky rolling shutter ruined our original image.

Now if only my photoshop skills were better I could extract the propellers from the original Flickr image, un-warp them, and slap them back on the photo. Sounds like a plan for the future.


To figure out the real number of blades in the photo at the top of the post and the rotation velocity we can look to this excellent post at Daniel Walsh’s Tumblr blog, where he definitely has the edge on mathematical explanation.

He works out that we can calculate the number of blades by subtracting the ‘lower’ blades from the ‘upper’ blades, so in this picture we know there should be 3. We also know the propeller is rotating approximately 2 times during the exposure, so if we try ‘undoing’ the rotation with a few different speeds around that we get something like this:

I’ve had to guess where the centre of the propeller is, and I’ve drawn a circle to guide the eye. Looking at that, the centre shouldn’t be too far off. There is unfortunately a missing blade, but there’s still enough information to make an image.

There is a sweet spot where everything overlaps the most, so picking this rotation speed (2.39 rotations per exposure), the original image and blades look like this:

It’s still a bit of a mess unfortunately, but at least looks something like the real object.


About the author: Jason Cole is a PhD student from London with a passion for math, physics, and data visualization. Visit his website here. This article originally appeared here.

22 Sep 22:40

Gravitational wave evidence disappears into dust

by John Timmer
Planck, and the image of the sky that it has given us.
ESA

Earlier this year, researchers who used a telescope based at the South Pole called BICEP announced that they obtained evidence for gravity waves caused by the Big Bang itself. The results would provide direct evidence that a model of the Universe's origin called inflation had left its mark on the present-day Universe.

But in reporting on the results, our own Matthew Francis suggested that the discovery was not as definitive as it might be, writing "the story of BICEP2, inflation, and primordial gravitational radiation is just beginning." And since then, it became clear that there was a complicating factor—dusty material in our own galaxy—and that the BICEP team's way of controlling for it left a little something to be desired (it involved using processed data obtained from a PDF used in a conference presentation).

Yesterday, the team that put the PDF together in the first place released its own analysis. And they've determined that BICEP was probably staring at dust, rather than the earliest moments of the Universe.

Read 11 remaining paragraphs | Comments

24 Sep 04:00

Tasks

In the 60s, Marvin Minsky assigned a couple of undergrads to spend the summer programming a computer to use a camera to identify objects in a scene. He figured they'd have the problem solved by the end of the summer. Half a century later, we're still working on it.
09 Sep 13:30

Tasmanian depths may have been hiding unknown animal phylum

by John Timmer
D. enigmata on the right, with the three larger samples on the left representing D. discoides.

Over the past few years, studies of genomes have confused what we thought we knew about the origin of animal life. Instead of the simple sponges being the earliest branch off the animal tree, a group of relatively complex organisms, the ctenophores, seem to be the earliest branch. That finding has some serious implications, as it suggests that a nervous system evolved twice.

Now, some more traditional biology may upset the family tree even further. Old samples taken from the seabed near Tasmania contain examples of two different species that may belong to a phylum entirely unknown to us—one that split off near the base of the animal tree. The strange creatures also have features that suggest they may be related to remains from the Ediacaran, a period in which the first animal life appears in the fossil record.

The samples actually date from a research cruise taken nearly 30 years ago, where a "sled" was dragged along the ocean floor and samples returned to the surface. The new species weren't recognized as interesting when they were first found, so they were left mixed in with the rest of the collection, which was fixed with formaldehyde and then dumped in 80 percent ethanol. The samples suffered a bit of further abuse when one of the authors wanted to refresh the alcohol and was given 100 percent ethanol instead. (The paper actually notes, "Unfortunately absolute alcohol was provided without comment instead of the requested 80 percent ethanol.")

Read 10 remaining paragraphs | Comments

15 Sep 16:15

The Basics of Recording Audio for Digital Video

by FilmmakerIQ.com

We now turn our attention to the audio signal chain as John P. Hess defines the different components needed when recording on set for digital video.

We are still working on the new iteration of FilmmakerIQ, but we wanted to get this third part of our Audio Series out to you. Great things are coming stay tuned.

This lesson is proudly sponsored by RØDE Microphones:
rodemic.com/

The other videos in this Series:

The History of Sound at the Movies
vimeo.com/103099450

The Science and Engineering of Sound
vimeo.com/103862254.

The Fundamentals of Sound in Post Production
vimeo.com/108069304

Introduction to Automated Dialogue Replacement
vimeo.com/108440800

Introduction to Foley and Sound Effects for Film
vimeo.com/112006972

Cast: FilmmakerIQ.com

Tags: John P. Hess, Sound, Filmmaking, Digital Audio, Recording Audio and Signal Chain

11 Sep 15:30

TED: Hans and Ola Rosling: How not to be ignorant about the world - Hans Rosling / Ola Rosling (2014)

by TEDTalks
How much do you know about the world? Hans Rosling, with his famous charts of global population, health and income data (and an extra-extra-long pointer), demonstrates that you have a high statistical chance of being quite wrong about what you think you know. Play along with his audience quiz — then, from Hans’ son Ola, learn 4 ways to quickly get less ignorant.
10 Sep 13:15

A big chunk of the Sierra Nevada caught fracturing on video

by Scott K. Johnson

If you like geology, you’re used to relying on an active imagination. Most geologic processes occur too slowly to see them play out for yourself. Many of the exceptions are dangerous enough that you might not want a front row seat or are rare enough that the odds of being there to witness them are disheartening. Sometimes, though, the Earth throws us a bone—or in this case, a gigantic slab of granite.

One interesting way that rocks weather and crumble apart is called “exfoliation.” Like the skin-scrubbing technique, this involves the outermost layers of exposed igneous or metamorphic bedrock sloughing off in a sheet. Over time, this tends to smooth and round the outcrop—Yosemite’s Half Dome providing a spectacular example.

We’re not entirely sure just what drives the peeling of an outcrop’s skin like this, but the classic explanation is that it’s the result of bringing rocks that formed at great pressure up to the surface. Once there, the outer layers can expand slightly, creating a physical mismatch with the layers below them.

Read 2 remaining paragraphs | Comments

02 Sep 21:00

Death Valley’s famous moving stones, caught in the act

by Scott K. Johnson

Mario is just a video game, and rocks don’t have legs. Both of these things are true. Yet, like the Mario ghosts that advance only when your back is turned, there are rocks that we know have been moving—even though no one has ever seen them do it.

The rocks in question occupy a spot called Racetrack Playa in Death Valley. Playas are desert mudflats that sometimes host shallow lakes when enough water is around. Racetrack Playa gets its name from long furrows extending from large rocks sitting on the playa bed—tracks that make it look as if the rocks had been dragged through the mud. The tracks of the various rocks run parallel to each other, sometimes suggesting that the rocks had made sharp turns in unison, like dehydrated synchronize swimmers.

Many potential explanations have been offered up (some going back to the 1940s) for this bizarre situation, as the rocks seem to only move occasionally and had never been caught in the act. One thing everyone could agree on was that it must occur when the playa is wet and the muddy bottom is slick. At first, suggestions revolved around especially strong winds. One geologist went as far as to bring out a propeller airplane to see how much wind it would take.

Read 9 remaining paragraphs | Comments

01 Sep 16:44

I'm not sure if this or the the shirt folding impresses me more

27 Aug 18:50

Quantum mechanics lets you image an object with photons that never hit it

by John Timmer
Constructive and destructive interference make this cat out of photons that never actually went through a cat-shaped transparency.
Gabriela Barreto Lemos

One item on the long list of strange facts about quantum mechanics is that the mere possibility of something happening is often just as good as it actually happening. For example, the fact that a photon could potentially travel down a given path can be enough to create an interference pattern that requires the photon to take that path.

Something similar is true regarding a phenomenon called quantum interference. A team of researchers from the University of Vienna has now taken advantage of this idea to create a bizarre imaging technique where the photons that actually strike the object being imaged are discarded. The image itself is then built other with photons that were entangled with the discarded ones.

Interference is the ability of two waves, such as photons, to interact either additively or destructively. In the quantum world, whether or not interference occurs depends on the ability to distinguish the two things that are interfering. If they are distinguishable, interference cannot occur. But you don't have to actually distinguish between them in order to block interference. As the authors of the new paper write, "The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference."

Read 6 remaining paragraphs | Comments

26 Aug 14:48

TED: Rose Goslinga: Crop insurance, an idea worth seeding - Rose Goslinga (2014)

by TEDTalks
Across sub-Saharan Africa, small farmers are the bedrock of national and regional economies—unless the weather proves unpredictable and their crops fail. The solution is insurance, at a vast, continental scale, and at a very low, affordable cost. Rose Goslinga and the Syngenta Foundation for Sustainable Agriculture pioneered an unconventional way to give farmers whose crops fail early a second chance at a growing season.
19 Aug 23:26

Motorcyclist crashes, flips and sticks a perfect landing on a car's roof

by Casey Chan on Sploid, shared by Casey Chan to Gizmodo

Motorcyclist crashes, flips and sticks a perfect landing on a car's roof

If there is such thing as a perfect motorcycle accident, this might be it: a motorcyclist crashes full speed into a car that's changing lanes. That's bad. The crash launches his body into a spinning mess in the air. That's definitely bad. But yet somehow he manages to flip and land standing up on the car's roof.

Read more...








16 Aug 04:00

August 16, 2014


Kerpow!
11 Aug 03:24

The History of Sound at the Movies

by FilmmakerIQ.com

THIS IS A SNEAK PEAK AT A NEW AUDIO COURSE SERIES!!

FilmmakerIQ.com and RØDE Microphones are proud to give you a sneak peak at the first lesson in our six part course which will cover science/microphones, recording, editing, foley, and ADR. We are also hard at work behind the scenes updating the site to include even more interaction which should be live in the coming weeks. Until then - enjoy this lesson on the history of sound at the movies.

The inclusion of sound at the movies was one of the most dramatic changes in all of film history. Dive into the early experiments of Edison trying to incorporate sound from film's inception, through the experiments in the early 1920s, the Jazz Singer and the industry sound overhaul, and finally the multi-channel surround and modern movie sound technologies.

This video is proudly sponsors by RØDE Microphones.
rodemic.com/

The other videos in this Series:

The Science and Engineering of Sound
vimeo.com/103862254.

The Basics of Recording Audio for Digital Video
vimeo.com/106193328

The Fundamentals of Sound in Post Production
vimeo.com/108069304

Introduction to Automated Dialogue Replacement
vimeo.com/108440800

Introduction to Foley and Sound Effects for Film
vimeo.com/112006972

Cast: FilmmakerIQ.com

Tags: FilmmakerIQ, Sound, History, Jazz Singer, Edison and John P. Hess

07 Aug 15:34

TED: Janet Iwasa: How animations can help scientists test a hypothesis - Janet Iwasa (2014)

by TEDTalks
3D animation can bring scientific hypotheses to life. Molecular biologist (and TED Fellow) Janet Iwasa introduces a new open-source animation software designed just for scientists.
25 Jul 15:00

Restaurant Research Shows That the Customer Isn't Always Right

22 Jul 20:40

Mankind’s greatest invention. [video]





Mankind’s greatest invention. [video]

17 Jul 19:15

Detailed imaging of Mount Rainier shows subduction zone in glorious detail

by Scott K. Johnson
A cross section of Washington's Cascade Range from west to east (left to right) passing near Mt. Rainier, indicated by a red triangle. The colors represent electrical resistivity, with red being low. Contour lines show temperature in degrees Celsius. Small red circles show the centers of earthquakes.
McGary et al/Nature

Most people know that the Pacific Ring of Fire is related to boundaries between tectonic plates, but there’s a common misconception about where the magma comes from to fuel those volcanoes. At those boundaries, called subduction zones, a plate made of denser oceanic crust dives beneath a continent (or another oceanic plate). It’s not that the diving plate heats up and melts as it sinks downward, though.

Actually, the minerals in the diving plate contain lots of water, and that water migrates upward as the plate slowly warms up. The addition of water to hot mantle rocks lowers the melting point of the rock, and this effect is enough to convert some mantle rock into magma. Since magma is less dense than solid rock, it works its way upward toward the surface, resulting in the arcs of volcanoes we see along subduction zones.

Within this simplified picture, however, there are complexities and open questions. Does the water simply rise directly into the mantle rocks above, or does it take a more tortuous path? Is that water the cause of all the magma production in an area, or does some magma form because the flow of mantle rock brings some up to lower pressures where it can melt?

Read 10 remaining paragraphs | Comments

18 Jul 12:00

Beverage Logic

by DOGHOUSE DIARIES

Beverage Logic

Okay I’m pretty sure McDonalds Coke is way different from normally bottled Coke. Next time you have it, close your eyes and think of apple pie, and taste the interesting resemblance. Or am I crazy. Comments here.

15 Jul 22:07

La mejor reflexión sobre el Mundial que va a ver

by Carlos Valladolid
La mejor reflexión sobre el Mundial que va a ver