Plans2Reality

The third industrial revolution begins: The gentleman manufacturer | The Economist

3D printing is not that new, but it appears we are at, or even past, the stage where laser printers were int he late 1980s - leaving the corporate world and becoming personal

 

via www.economist.com

Fuel economy: Going along for the ride

The Economist throws a bit of cold water on fuel economy hype

IMAGINE you are stopped in the street by a clipboard-toting pollster, who asks whether health insurance should automatically cover all necessary procedures and medication, with no restrictions or co-payments? Nine out of ten people (if not all) would instantly answer yes. But had the respondents been warned beforehand that they would have to stump up an extra $10,000 for such coverage, the answer could easily have been a resounding no.

via www.economist.com

The Sixth Extinction Website - PeterMaas.nl

This web site has a great deal of information on more-recent animal extinctions, such as the passenger pigeon and the aurochs. Quite interesting!

via www.petermaas.nl

A Note on Digital Photography

This is from a recent issue of the Economist. It's as clear an explanation of digital camera sensor tradeoffs as I've read, and it contains some new information as well.

 

ON RARE and very special occasions, your correspondent digs out his ancient 120-format camera and loads a roll of colour-reversal film from a precious supply of Fujichrome Astia Professional he keeps stored in the fridge. He shoots off a dozen scenes painstakingly composed on the camera’s large ground-glass screen, carefully extracts the film-carrier and removes the exposed spool, wraps it in kitchen foil, and takes it to a lab across town that still knows how to process roll-film properly. Despite the palaver, the silver halide communion is hugely satisfying. Even after all the years of use, viewing the 120's big square transparencies under a loupe on a lightbox can still take the breath away.

In so far as it is possible to compare two entirely different ways of capturing photons, the Hasselblad's 6cm square frame is equivalent to a 70 megapixel digital sensor. The attraction of such a format is that it provides a large enough transparency for art editors to select the crop they like best, while still offering more than enough resolution (when the cropped area is enlarged) to cover losses incurred during plate-making and printing.

Creating a full-page bleed for a colour magazine using even 35mm film is far more challenging. Trying to do so with a compact digital camera or smartphone is out of the question. But, then, the vast majority of digital cameras have light-gathering sensors the size of tiny toe-nails—and are used largely for uploading images to Flickr or Facebook, or for making 3.5 inch by 5 inch (8.9cm by 12.7cm) prints for family albums.

That is not to say film beats digital any day. Not having to pay for and reload a fresh film every couple of dozen shots encourages digital photographers to experiment more. And there is the convenience of being able to see the result immediately, which allows users to delete inferior images and, if necessary, shoot additional ones. Meanwhile, the past decade has seen the light-processing power of silicon sensors become truly awesome.

Depending on the lens and the film speed, a frame of 35mm film has the digital equivalent of between 15 and 20 megapixels. The “full-frame” sensors (with the same 36mm by 24mm format of 35mm film) in digital single-lens reflex (D-SLR) cameras used by professionals can more than match that today. The Canon EOS 5D Mark II, for instance, uses a 21 megapixel sensor. 

With a decent lens, even the cheaper D-SLRs produced for the “prosumer” market can come close. Thanks mainly to their smaller sensors (typically 22mm by 15mm), these popular devices tend to be lighter, more compact and less than a third the price of full-frame models. Their sensors are based on the old APS film format, which promised to revolutionise photography but failed miserably. The cameras were barely any smaller than 35mm ones, yet had only 40% the frame size.

So, how come digital cameras that use so-called APS-C sensors, with less than half the sensor area of full-frame cameras, perform as well as they do? Even the so-called “micro four-thirds” D-SLRs, with sensors less than a third the size of a full-frame’s chip, seem more than passable. The answer is that while professional photographers using full-frame D-SLRs may blow up their images to poster size, the majority of camera users rarely make prints larger than 8 inches by 10 inches. Under normal lighting conditions, practically any 12 megapixel D-SLR will suffice.

In fact, 12 megapixels has become a kind of sweet spot in the digital-camera business. With smartphones incorporating eight-megapixel cameras these days, the number of basic digital cameras sold fell 17% during the first 11 months of 2011, according to NPD Group, a market research company based in Port Washington, New York. Meanwhile, unit sales of pricier point-and-shoot models with bigger sensors and zoom lenses grew by 16%, and prosumer D-SLRs were up 12%.

In theory, the more pixels a sensor chip has crammed onto it, the greater is the amount of detail that can be captured in a scene. That was certainly the case a decade or so ago, when Japanese camera-makers were engaged in a megapixel race. But there comes a point at which the pixels are too small and are packed too close together for further advantage to accrue.

At that point, the “shot noise”—caused when individual pixels are so tiny that too few photons strike them—replaces the steady shower of light falling on the sensor with a sporadic, hail-like drumming effect. Meanwhile, the close proximity of the pixels induces thermal and electrical noise. The result is an image that begins to fragment and develop artifacts, especially under conditions of low light.

One answer, of course, is to increase the size of the sensor chip, while making the pixels larger and spreading them out more. The point of using full-frame (and even larger) sensors in professional cameras is not just to increase the pixel count, but also to reduce their density—and thus the background noise. It is the low noise level that allows professionals to produce such detailed images in poor lighting conditions, and to enlarge them to such an extent.

The first rule in choosing a digital camera, then, is to place sensor size over pixel count. A second is to put sensor density and layout ahead of both of the above. Your correspondent has become intrigued of late by Fujifilm’s EXR sensor technology, which uses octagonal pixels instead of the usual square ones. Practically all digital cameras employ a square-grid arrangement of photosensors called a Bayer mosaic, which comprises rows of red and green filters alternating with rows of green and blue filters. This colour-filter array, patented by Bryce Bayer at Eastman Kodak in 1976, has proved extremely successful in capturing both the colour and the detail in a scene.

The use of twice as many green elements as red and blue ones mimics the physiology of the human eye. Because the eye can perceive finer detail in the green part of the spectrum, the abundance of green pixels produces an image that appears to be less noisy and to have greater resolution than would be the case if all three colours were treated equally.

Fujifilm’s EXR technology (originally called Super CCD when first introduced in 1999) produces a higher resolution than is possible with a conventional sensor of similar pixel count. It does this by allowing alternate rows of pixel sites to be read separately, rather like the scanning arrangement on an old-fashioned television set, making a 12 megapixel chip appear as though it were two interleaved six megapixel sensors.

Because the octagonal pixels are aligned diagonally along 45º axes, instead of being arranged in horizontal and vertical rows and columns, pairs of pixels of the same colour can be next to one another, which is impossible in a Bayer rectangular array. In low light, the sensor combines data from pairs of similarly coloured pixels next to one another, averaging out the noise between the two, to reduce the overall noise within the image.

To improve the camera’s dynamic range, the sensor reads alternate lines in the matrix and switches them off part way through the exposure process. This reduces their chance of causing overexposure while still retaining information about highlights in the picture. The underexposed highlight detail is then combined with information from the fully exposed other set of alternate lines, to produce a final image that reveals detail which might otherwise be lost in the shadows.

Fujifilm's recently launched $600 point-and-shoot camera known as the X10 encapsulates all these features and more. And while it will never replace your correspondent’s clunky old Hasselblad, it could well give his even older Leica IIIF a serious run for its money. (Cutting modern 35mm film to form a tongue that fits in the take-up spool of the old rangefinder camera is becoming too much of a chore.) While not quite as retro-looking as its X100 bigger brother, the X10 at least has a bright zoom lens, a faster auto-focus, and an old-fashioned (Leica-like) optical viewfinder. Your correspondent guiltily admits it was this last feature which finally swayed him to make the purchase. Happy New Year!

 

The stupidity of airline rules on electronics

This is worth the time to read. It's time we got the rules changed!

EVERY airline flight you are on has at least a handful of mobiles, laptops and other electronic kit left in a standby mode or actively on, rather than shut off as aviation regulators and airlines demand. Every flight, in other words, tests the proposition that hardware carried on board by passengers disrupts the aircraft or confuses the crew with false readings from cockpit instruments. And yet airplane electronics, or avionics to use the technical term, do not routinely squawk or fail. 

via www.economist.com

The Uses of Pessimism

Most of "The Uses of Pessimism" is given over to a fine analysis of the fallacies from which excessive optimism springs.

Roger Scruton identifies seven such. He devotes a chapter to each, drawing out the dire effects of each fallacy on politics, economics, and culture.

His principal target is the "unscrupulous optimist" waging "war against reality." He draws a clear distinction between this fellow and the "scrupulous optimist," who carefully consults evidence, experience, and authority before leaping.

Scruton similarly contrasts "judicious pessimism," which knows the difference between a constraint and an obstacle, or a setback and a catastrophe, with the more "systematic pessimism" of the fiercer kind of Old Testament prophet.

More people should read this book.

Ancient Mankind - 100,000 years ago in Oman

We don't usually post article on ancient mankind, but it is an interesting topic, one covered by one of the books we're reviewed. Here's more, a transcript of an interview with scientists who found some old stuff.

 

MARK COLVIN: An international team of researchers say it's found evidence of one of the first groups of humans to migrate out of Africa. 

They've dated a collection of stone tools they found in the Dhofar Mountains of southern Oman.

Remarkably, their measurements indicate that the toolmakers must have entered the area before 106,000 years ago. That's about 40,000 years earlier than palaeontologists have previously suggested. It's also the first time that tools of this type have been found outside the Nile region.

One of the researchers, Professor Bert Roberts from the University of Wollongong's Centre for Archaeological Science, spoke to Ashley Hall. 

BERT ROBERTS: We're definitely talking about humans, we're not talking about Neanderthals or some other species. And it's right close to the southern coast of Arabia so we think people came out of the Horn of Africa and spread across that way rather than going up through the Sinai.

ASHLEY HALL: And so the suggestion is that they used the rivers almost like highways. 

BERT ROBERTS: That's right. I mean the popular notion was that people might have left Africa maybe 60, 70, 80,000 years ago. In fact we've pushed it back to about 106,000 years now, so it's earlier than people had thought, and that they'd stuck to the coast because that's what they were familiar with. 

But in fact this site is located inland it's not actually right on the coast at all. But it is in the river valley. So what we think they were actually doing is not spreading along the coast but going inland down the river valleys when they were lush, which they were 106,000 years ago.

Now it's all dry but back then it was waters, the waterways were flowing. So it would have been a great place to go inland all the way through Arabia.

ASHLEY HALL: What were they doing, hunting?

BERT ROBERTS: Definitely hunter gatherers at that point in time, yes. And these stone tools, I mean they're beautiful stone tools to look at. I'm not even a stone tool archaeologist but they're fantastically made. They're made in a very distinctive style and they're perfect for what people were needing at that particular point in time. 

ASHLEY HALL: Well describe some of them for me. What sort of tools were they? 

BERT ROBERTS: Well they're made out of a sort of beautiful kind of lustrous brown chert, it's like a flint, and they chipped them in a certain way so you get two flakes off and then you slip one right down the middle and you get these beautiful pointed little blades.

So these are going to be fantastic. They did all sorts of activities during the Stone Age, which was the way we were up until about 10,000 years ago, but these ones are amongst the earliest ever found on the Arabian Peninsula. 

ASHLEY HALL: You mentioned that your dating is at odds with the expectations of geneticists who argue that the migration out of Africa was a bit later than you're suggesting.

How significant is that? Are you essentially picking a fight with them?

BERT ROBERTS: I don't' think so. I think we might both be right in this particular instance. I don't think the geneticists are necessarily wrong because we have these stone tools which we call Nubian stone tools after a place in Africa where they were first found.

But we only find them in a limited part of Arabia. They don't seem to spread into the far east of Arabia. So we're wondering in fact people had spread into Arabia 106,000 years ago, got down these river valleys but in fact had died out. It wasn't a successful exit. It was the first of maybe one or the second or the third unsuccessful exit out of Africa into Arabia. 

But they never actually spread around the world from there, not until maybe 30 or 40,000 years later.

ASHLEY HALL: So what was your role in this research? 

BERT ROBERTS: So my role was to actually try and work out when some of these artefacts were dated; how old were they? And the reason it's been incredibly difficult to work out how old the artefacts are in Arabia, most of them just litter the surface, they're like cornflakes on the surface, now they're everywhere.

But that's very difficult to date, you really need something buried in the ground. They're much too old for radiocarbon. But we can use this method called luminescence dating, optically stimulated luminescence to actually date when those artefacts were buried in the ground.

ASHLEY HALL: And give me a sense of what optically stimulated luminescence is. 

BERT ROBERTS: Well we use quartz and grains of felspar and what we're actually doing is untrapping the electrons inside those grains and the more electrons we can untrap the longer they've been buried in the ground. 

And we measure those electrons by measuring the amount of light they then give off which we can measure with a very sensitive photomultiplier tube in the lab. 

ASHLEY HALL: This research changes our understanding about the migration of humans out of Africa; what does it mean for our broader understanding of how humankind developed?

BERT ROBERTS: Well it's adding to a sort of growing body of evidence that life in the past was a lot more complicated than we thought. We thought it was simply that we grew up as a species within Africa and with a single wave of migrations we sort of spread out of Africa, populated the rest of the world and kept moving around in the Americas and New Zealand were populated almost last of all.

But in fact it's got a little bit more complicated than that now with several new discoveries which seems to suggest at several waves of migration out of Africa. 

MARK COLVIN: The University of Wollongong archaeologist Bert Roberts, ending Ashley Hall's report. 

His research has been published in the journal PLoS One.

Support Wikipedia

Please go to Wikipedia and contribute some $$$. Wikipedia is not perfect, but it's darn close. And what do you know that is perfect, anyway?   ;-)

 

Argumentum ad Ignorantiam

Most of us are familiar with the ad hominum attack, the technique of discrediting an idea by attacking the person who expressed it. It's certainly common enough, even among folks who should know better. (Yes, I'm talkng about you, Scientific American)

But there is another, more pernicious argument - that of arguing from ignorance. This doesn't mean the arguer is ignorant, but rather that the necessary information is not known.

Another way of putting it is to say that absense of evidence is not evidence of absense.

Wikipedia says, "It asserts that a proposition is true because it has not yet been proven false, it is 'generally accepted' (or vice versa)."

This situation arise in business frequently, and in technology businesses very frequently. In the tech sector, we often deal with many unknowns, including not know what will go wrong. We know, from experience, that we are likely to encounter suprises and setbacks along the way, but because we don't know what they will be, we discount them.

The most obvious case is when creating a schedule for a major development project. We don't know what will go wrong, so management tends to ignore the possibility of anything going wrong.

Sadly, this is all too common.

Khan Academy: A Game-Changer

Khan Academy offers online classes, of high quality, to anyone, anywhere, for free.

This is a game-changer. Not every subject can be taught this way, but a very large number can. Check it out!