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Posts Tagged ‘optics

“It’s fine to celebrate success, but it is more important to heed the lessons of failure”*…

 

If you ever wanted a glimpse into what dooms startups, look no further than autopsy.io, a website that lists the reasons why many newborn tech firms imploded. The website offers entrepreneurs the ability to self-explain why their startup didn’t quite make it; in a bid to separate real-life stories from entertaining fictions, the application form asks for a link to a blog post or medium article “that tells the story of the failure,” along with the founder(s) Twitter handle and Crunchbase or Angel.co profile. Some of the reasons listed for failure are maddeningly opaque, such as UniSport’s “for a number of reasons” or PlayCafe’s “we didn’t reach enough users.” Others are bleakly hilarious; as the founders of Zillionears, self-billed as a “creative pre-sale platform for musicians,” confessed: “People really didn’t really LIKE anything about our product.” If you’re thinking of launching your own company, or you work for a wet-behind-the-ears startup, it’s worth scanning the list to see if any of these potential crises are brewing in your setup.

Via Nerval’s Lobster at Slashdot.

* Bill Gates

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As we dust ourselves off, we might spare a thought for Roger Bacon; he died on this date in 1292.  A philosopher and Franciscan friar, Bacon was one of the first to propose mathematics and experimentation as appropriate methods of science.  Working in mathematics, astronomy, physics, alchemy, and languages, he was particularly impactful in optics: he elucidated the principles of refraction, reflection, and spherical aberration, and described spectacles, which soon thereafter came into use. He developed many mathematical results concerning lenses, proposed mechanically propelled ships, carriages, and flying machines, and used a camera obscura to observe eclipses of the Sun.  And he was the first European give a detailed description of the process of making gunpowder.

He began his career at Oxford, then lectured for a time at Paris, where his skills as a pedagogue earned him the title Doctor Mirabilis, or “wonderful teacher.”  He stopped teaching when he became a Franciscan.  But his scientific work continued, despite his Order’s restrictions on activity and publication, as Bacon enjoyed the protection and patronage of Pope Clement…  until, on Clement’s death, he was placed under house arrest in Oxford, where he continued his studies, but was unable to publish and communicate with fellow investigators.

Statue of Roger Bacon in the Oxford University Museum

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Written by LW

June 11, 2015 at 1:01 am

“Reality is merely an illusion, albeit a very persistent one”*…

 

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The Dynamic Ebbinghaus takes a classic, static size illusion and transforms it into a dynamic, moving display. A central circle, which stays the same size, appears to change size when it is surrounded by a set of circles that grow and shrink over time. Interestingly, this effect is relatively weak when looking directly at a stationary central circle. But if you look away from the central circle or move your eyes, or if the entire stimulus move across the screen, then the illusory effect is surprisingly strong – at least twice as large as the classic, static Ebbinghaus illusion.

Each year the visual illusion research community gathers in Naples, Florida for a meeting that culminates in a contest that names the Best Illusion of the Year.  This year’s grand prize winner is captured in the video above.

See all of the finalists here, read more about the contest (e.g., below) here— and check out the cool trophies here.

This is an anamorphic illusion. It begins as a normal photograph and then is tilted backwards and forwards to create opposite vanishing points. The tilting distorts the shape of the head and facial features to create the illusion of an actual age progression and regression. For the age progression the top half of the head narrows, and the bottom half expands creating a more mature look. For the age regression, the opposite happens. The head and ears enlarge and the lower face narrows giving them a smaller nose, chin and neck, which results in a realistic childlike appearance.

* Albert Einstein

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As we uncross our eyes, we might recall that it was on this date in 1758 that John Dollond filed for a patent (which he ultimately received) on achromatic lenses, and reported this to the Royal Society.   Isaac Newton had described the blurring effect due to chromatic aberration (the fact that different colored light wave have different focal lengths), which was important in the preparation of lenses for telescopes and microscopes; but could not solve the problem in simple lenses.  Indeed, the answer lay in compounding two lens.  In the event, Dollond had not invented the answer, but had learned it from another lens maker, George Bass, who prepared the first achromatic lens at the instruction of Chester Moore Hall, who actually deserves credit for the creation.

Chromatic aberration of a single lens causes different wavelengths of light to have differing focal lengths.

An achromatic doublet, like the one patented by Dollond, brings red and blue light to the same focus, and is the earliest example of an achromatic lens.

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It’s always Chile in Norway?…

 

When it comes to a country’s prospects, is morphology destiny?  Or is it simply the phrenology of geography? Strange Maps explores

Do Norwegians feel curiously at home in Chile, and vice versa? Do South Africans have a strange affinity with Italians? And Filipinos with Maldivians? They should, at least if they’re map nerds: each lives in a country with a territorial morphology that closely resembles the other’s.

Although they’re on opposite sides of the globe, Chile and Norway are each other’s type, morphologically speaking: elongated to the extreme…

The Five Types of Territorial Morphology [c.f., here] sounds like a fun parlour game, at least in cartophile circles (is Portugal compact or elongated? Is or isn’t Somalia prorupt? Does New Zealand qualify as fragmented?) But there is a serious, geopolitical concern behind this attempt at classification. For a country’s shape has a profound impact on its economic success, and even its political viability.

Case in point: Lesotho. Being completely surrounded by another country does your economy no good. Four out of 10 Lesothans live on less than $1 a day, and the country ranks 160th (out of 187) on the UNDP’s  Human Development Index. Even compared with the wildly unequal society that is South Africa, Lesotho stands out as a pocket of deprivation…

Another morphology, another set of problems. Fragmented states often experience great centrifugal pressures, with separatism affecting their outlying fragments. This is true of the Philippines, the central government of which only last October concluded a peace deal with the Moro Islamic Liberation Front, which had waged a separatist guerilla on the southern island of Mindanao. Something similar has been endemic in Aceh, at the western tip of Sumatra, where both the Dutch colonisers and the Indonesian central government have battled insurrections and rebellions.

Indonesia has had to contend with a few other centrifugal forces, one of which actually succeeded (and seceded): East Timor, which in 2002 became the 21st century’s first independent state. In the process, East Timor changed from being a fragment of a fragmented state to being the solid core of a compact state.

The implicit message of the Five Types is that compact is best, avoiding the logistical problems posed by the elongated, fragmented, perforated and protruded types. But is that really so? Cambodia, vaguely resembling a sea shell, is a fairly compact nation. That didn’t stop it descending into murderous anarchy when the Khmer Rouge took power in the mid-1970s, installing a regime that took its cue from the crazier aspects of Maoist Communism. China itself, morphologically compact, is torn between its high-performing coastal zone, an underdeveloped hinterland, and a far west forever rumbling with the distant thunder of separatism.

Perhaps these morphologies are the star signs of geopolitics: a fairly random way to categorise states and territories, which may or may not behave like the categories they’re placed in predict they will. Maybe the Five Types are a parlour game after all…

Read the whole story at Strange Maps.

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As we agree with Virgil that we should “trust not too much in appearances,” we might send clearly-magnified birthday greetings to Alexis-Marie de Rochon; he was born on this date in 1741. An astronomer, physicist, and inveterate traveller, de Rochon worked extensively in optics and lens design– and is probably best remembered as the inventor of the retractable telescope, the spyglass.

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Written by LW

February 21, 2013 at 1:01 am

Looking closely. Very closely…

 

Designer Adam Saynuk is a detail guy… and a very fine photographer.  Consider the photographs that he took for The Taco Truck (restaurant/store/food truck in Hoboken, NJ) last year, in which he minutely examined each of 35 ingredients

Tomatoes

Corn Tortillas

See them all here.  And see some of Adam’s other work here.

[TotH to Good]

 

As we resolve to leave our glasses on while eating, we might recall that it was on this date in 1609 that Galileo first demonstrated his telescope.  Earlier that year, while in Venice, he’d heard of “Dutch perspective glass,” which made distant objects appear closer and larger.  He reports that he returned to Padua, made a prototype, then an improved telescope, and returned to Venice– where he presented his invention to the Doge Leonardo Donato, who was sitting in full council. The Doge and Senate were so impressed that they awarded him life tenure for his lectureship at Padua and doubled his salary.

Later that same year, Galileo turned his invention around, and created the precursor of Adam’s favorite optical tool, a compound microscope with a convex and a concave lens.

19th Century painting of Galileo displaying his telescope to Leonardo Donato (source)

 

 

Pictures worth a million words…

In his great opus De Revolutionibus Orbium Coelestium published shortly before his death in 1543, Copernicus takes 405 pages of words, numbers and equations to explain his heliocentric theory. But it is the diagram that he draws at the beginning of the book that captures in a simple image his revolutionary new idea: it is the Sun that is at the centre of the Solar System, not the Earth.

A diagram has the power to create a whole new visual language to navigate a scientific idea. Isaac Newton’s optics diagrams [Opticks, 1704] for example transform light into geometry. By representing light as lines, Newton is able to use mathematics and geometry to predict the behaviour of light. It was a revolutionary idea.

Mathematicians had been struggling with the idea of the square root of minus one. There seemed to be no number on the number line whose square was negative. Experts knew that if such a number existed it would transform their subject. But where was this number? It was a picture drawn independently by three mathematicians at the beginning of the 19th Century that brought these numbers to life. Called the Argand diagram after one of its creators, this picture… was a potent tool in manipulating these new numbers [Imaginary Numbers] since the geometry of the diagram reflected the underlying algebra of the numbers they depicted.

Although better known for her contributions to nursing, Florence Nightingale’s greatest achievements were mathematical. She was the first to use the idea of a pie chart to represent data.  Nightingale’s diagrams were designed to highlight deaths in the Crimea. She had discovered that the majority of deaths in the Crimea were due to poor sanitation rather than casualties in battle. She wanted to persuade government of the need for better hygiene in hospitals. She realised though that just looking at the numbers was unlikely to impress ministers. But once those numbers were translated into a picture – her “Diagram of the Causes of Mortality in the Army in the East” – the message could not be ignored.

Read more (and find links to enlarged versions of the images above) at BBC.com, in “Diagrams that Changed the World,” a teaser for new BBC TV series, Marcus du Sautoy’s six-part The Beauty of Diagrams (on air now, and available via iPlayer to readers in the U.K… and readers with VPNs that can terminate in the U.K.)

As we marvel at the power of pictures, we might recall that it was on this date in 1997 that eight planets in our Solar System lined up from West to East– beginning with Pluto, followed by Mercury, Mars, Venus, Uranus, Neptune, Saturn and Jupiter, with a crescent moon alongside– in a rare alignment visible from Earth.  Mercury, Mars, Venus, Jupiter and Saturn were visible to the naked eye; the small blue dots that are Uranus and Neptune, with binoculars.  Pluto was visible only by telescope (but has subsequently been demoted from “planet” anyway…). The planets also aligned in May 2000, but too close to the sun to be visible from Earth.

Readers who missed it have a long wait for the reprise: it will be at least another 100 years before so many planets will be so close and so visible.

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