Herewith, some more shameless regurgitation of fantastic Lego creations I found on the excellent TechnicBricks.
Hybrid pneumatic/electric robotic arm:
Another feature-packed car (unfortunately, Lego do not make little rubber cones that'd make the suspension authentic):
Combination-lock safe:
And my favourite - a brick-sorter, which can only detect four sizes of brick, but which does it entirely mechanically, using a single motor!
I'm going to let you in on a little secret, here.
I don't use toothpaste.
Ever.
I was turned off the stuff by the dental-health people who came to my school when I was a wee 'un. They told me to brush my teeth with the ghastly gritty super-minty high-fluoride toothpaste they always brought with them, I begged them not to, they made me anyway, I vomited copiously, and that was the end of toothpaste for me.
Heck, for many years I didn't brush my teeth at all.
You may, at this juncture, be imagining the plausible results of this refusal, on my part, to allow society's frivolous protocols to take precedence over my personal values.
My mouth, you will be surmising, must be a steaming, mangrove-covered bayou, occasionally punctuated by by plopping mud-bubbles and shattered, gravestone-like, lichen-encrusted teeth.
I do not blame you for jumping to this conclusion, for it is perfectly reasonable. That was certainly the response of the dentist I visited, for the first time in at least ten years, a while ago.
But, as the dentist and her similarly terrified assistant immediately discovered, my teeth are actually just a bit yellower than the average.
Every one of 'em was there, not a one had a hole in it.
And my breath didn't, and doesn't, smell.
This is because, as that dentist cheerfully confirmed for me after she regained her composure, brushing your teeth is the least effective way of cleaning your mouth.
Brushing your teeth isn't useless, especially if you're thorough about it and do use fluoride toothpaste. But the danger spots in your mouth are between the teeth, where food particles accumulate and feed colonies of bacteria. And if you want sweet breath but only clean your teeth to get it, the similarly-flourishing colonies of bacteria on your tongue will start stinking up your exhalations again as soon as the masking smell of the toothpaste dissipates.
So what dark rituals was I performing, to escape what countless jaunty animated toothbrush mascots have insisted is the inevitable consequence of not scrubbing your teeth with minty froth?
Well, I floss pretty regularly, and also clean properly between my teeth very regularly. I do that now with Piksters "interdental brushes", which are, essentially, tiny tough pipe-cleaners for the gaps between your teeth.
And to avoid smelly breath, I clean the top surface of my tongue, every morning. There are many purpose-made doodads for scraping your tongue; plastic ones cost almost nothing, so you might as well give them a go. I've always found a straight scraper blade to be perfectly adequate, though; I use a little six-inch steel ruler.
Apparently if you use a tiny little scraper it can take three minutes to clean your tongue. My manly metal scraper would have pretty much removed my lower jaw by then. Yes, my taste-buds still work.
(When I stay the night at someone else's house, I have been known to use a butter knife. Not known by them, though, obviously.)
And... that's it. Keep the in-betweens clean, scrape the tongue, job done.
Not one filling, for 35 years.
I didn't avoid dentists because I had good reason to be terrified of them. I just didn't see the need.
And then I started taking a medication that reduces saliva production. And less than a year later...
...stuff was falling apart.
(That was my lower left first molar. I took the picture with the little USB endoscope which I reviewed some time ago, and which provided a surprising amount of later entertainment. Also, vaguely apropos of this, every kid who's starting to lose their baby teeth should be made aware of what a terrifying monster they now look like under the skin.)
Loss of saliva production is dangerous for teeth. Saliva actively protects teeth, and decay can progress much faster when you run out of spit.
This is part of the recipe for the "meth mouth" phenomenon, which can occur if you use any drug, like marijuana or the far-less-interesting medication that I'm on, which inhibits saliva production. All you have to do is habitually take such a drug, then treat your uncomfortable cotton-mouth with sugary and/or acidic fizzy drinks instead of something like milk or water (sugar-free chewing gum can also be helpful). Your teeth will then be rotting out of your head surprisingly soon. Especially if you also grind your teeth in classic tweaker style, and can think of a million very energetic things to do that are not cleaning said teeth.
Anyway, now it's a few years later again, and I've got a couple of fillings. But only a couple, touch wood.
I brush my teeth now, with one of those fancy super-fast circle-jiggling electric toothbrushes, but I still don't use toothpaste. Everything seems to be going pretty well.
But wait, there's more.
My previous interaction with a dentist, before the mysterious alien-implant thing, had been many years before, when my wisdom teeth were coming through. A bridge of gum-flesh remained over the middle, from the back to the front, of at least of one of them.
This is an absolutely prime spot for gunk to accumulate and start destroying the "new" tooth before it's even finished erupting. The bridge will normally separate on one end as the tooth emerges, if like me you're lucky enough to have a jaw that in clear violation of God's plan actually has room for wisdom teeth. But you'll be left with a little flap of flesh over part of the tooth, and probably also a pocket down the side, which is almost as bad. It's basically impossible to keep these areas constantly clear of nasty-smelling... gunk.
So I'd been making damn sure the rotten-ness didn't have a chance to take hold, by digging and flicking and poking at the area with whatever small pointy object came to hand. The wire in the middle of twist-ties did a dandy job of getting some nice cleansing blood flowing.
I was, and still am, delighted to say that this dentist, also, endorsed and encouraged my bizarre oral-hygiene activities.
("Oh," I hear some of you ask, "on the subject of your hatred of the taste of toothpaste - do you, in far-off Australia, have in addition to your bizarre pink candies the things which we foreigners call 'Spearmint Leaves'?" Why yes, gentle reader, we do. "And do they taste exactly like numerous dental concoctions described as having a 'pleasant mint flavour', which statement is just as much of a... it can't be a lie, it's more of a cruel joke, really... as the similar statements made on cough-medicine bottles?" Yes, they do. "And do Spearmint Leaves, also, make you want to heave?" Yes, indeed they, also, do.)
A reader writes:
I love NASA's new "Blue Marble" images. I was a kid in the early 70s when they took the first Blue Marble picture, but now the young whippersnappers all have their Google Earths and such and can all pretend to be looking out the window of a UFO whenever they want to. The magic hasn't died for me though, and now there are newer, better, brighter Blue Marbles! Three of them, from different directions!
Except in the "Western Hemisphere" one (which I found on Astronomy Picture of the Day), the USA is HUGE! It looks almost as big as the whole of Europe, Russia and China. The one that shows Australia and a lot of clouds makes it look as if Australia's the only land mass in one whole hemisphere. Africa's way too big in the "Eastern Hemisphere" one, too.
You've written about map projections before; is this something related to that? But that can't be it, there's no "projection" at all when the map of the globe is still a globe, right?
Ulricke
The original 1972 Blue Marble, above (the Wikipedia article has information about the 2012 version too), is what it looks like. It's a single photo, taken from a spacecraft - Apollo 17, to be exact. The famous photo was taken from a distance of about 45,000 kilometres, which is a bit higher than geostationary-orbit-distance, but well under a tenth of the distance to the moon.
(There are a lot more Apollo 17 images; they're archived here.)
The distance is important, because the earth is about 12,750 kilometres in diameter.
If you're looking at the earth from an altitude of 45,000 kilometres, you're only three and a half earth-diameters away from the surface of the planet. (If you're 45,000km from the centre of the planet, the nearest point on the planet is less than 39,000km, about three diameters, away. Keep this in mind when reading about orbits; it's not always clear whether a given distance indicates how far it is from the centre of one object to the centre of another, or the distance between objects' surfaces, or even the distance between an orbiting object and the barycentre of the orbital system.)
Shrink everything until the earth is the size of a tennis ball, and the original Blue Marble viewpoint would only be about 23.6cm (9.3 inches) away from the surface of the ball.
When you're looking at a sphere, you can never see a whole half of it at once. If you're very close to the sphere - an ant on the tennis ball - you can see a quite small circle around you, before the curvature of the sphere cuts off your view. (Actually, the fluff on the tennis ball would block your ant's-eye view much closer, but let's presume someone has shaved these balls.)
Go a bit higher up from the surface, and you can see a bigger circle. Higher, bigger, higher, bigger; eventually you're so far away that you can see 99.9999% of one half of the sphere, but you'll never quite make it to seeing a whole half.
(See also, the previously discussed optical geometry of eclipses. Shadows cast by spherical bodies are conical, and more or less blurred around the edges, depending on the size of the light source.)
If you're eight inches away from a tennis ball, you can see pretty close to a half of it, and if you're 45,000 kilometres from the earth, you can see pretty close to a half of the planet. Which is why, in the original Blue Marble, Africa looks pretty darn big, but not disproportionately so.
Now let's look at the 2012 Blue Marble.
(Note that there's also, confusingly, an unrelated other NASA thing called "Blue Marble Next Generation"; that's a series of composite pictures of the earth covering every month of 2004.)
The 2012 Blue Marble was stitched together from pictures taken over four orbits by the satellite Suomi NPP, previously known as "National Polar-orbiting Operational Environmental Satellite System Preparatory Project", which was just begging for that Daily Show acronym joke.
Suomi NPP is in a sun-synchronous orbit (which, just to keep things confusing, is a type of orbit that can only exist around a planet that is not quite spherical...), only 824 kilometres up. So Suomi NPP can't see very much of the globe at any one time. But if you're compositing pictures of a planet together, you can use your composite to render an image apparently taken from any altitude you like. Provided you've got enough patchwork photos to cover the whole planet, you just have to warp and stitch them until you've covered the whole sphere. Then, you can render that sphere however you like.
For the 2012 Blue Marble images, NASA chose to render the sphere from a much closer viewpoint than the 1972 image was taken from - they say the altitude is 7,918 miles (about 12,743 kilometers). That distance is, no doubt not accidentally, about the diameter of the planet - so the virtual "camera" for the new pictures is only one tennis-ball diameter away from the surface of the tennis ball it's "photographing".
As a result, Blue Marble 2012 shows rather less than half of the sphere. But this is not immediately apparent. At first glance, it just looks as if whatever you can see is bigger than it should be.
You can experiment with this in Google Earth or any other virtual globe, or of course with one of those actual physical globes that people used to use in the 1950s or during the Assyrian Empire or something before we had computers.
Anyway, look at the real or on-screen globe from a long distance and a given feature, like for instance Australia or North America, looks as if it takes up as much space as it ought to. Zoom in and whatever's in the middle of your view takes up proportionally more of the face of the planet, as things on the edges creep away over the horizon.
So the close viewpoint of the 2012 Blue Marbles doesn't give them away as "synthetic", stitched-together images. Something else does, though.
The feature image of the new Blue Marbles - the one that showed up on APOD, and countless other sites - is the one that shows the USA. I think NASA may not have chosen that one just for patriotic reasons, though. Rather, I think it may be because the America image is the only one of the three that doesn't have noticeable parallel pale stripes on the ocean.
The stripes - most visible in the Eastern Hemisphere image of Africa (4000-pixel-square version) - are from sunlight reflecting off the water, which the Suomi NPP satellite saw on each of its orbits, and which therefore show up multiple times in the composited image. A real observer sitting in the location of the virtual camera of the new Blue Marble would only see sun-reflection on one spot on the earth, if the appropriate spot was on the water.
The 1972 Blue Marble photo was taken with the sun pretty much behind the spacecraft, so it has this one reflective highlight in the middle of the image, off the coast of Mozambique.
Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.
And then commenters will, I hope, correct at least the most obvious flaws in my answer.
A reader writes:
What are those little LED-like, but flickery, orange lights, seen in nightlights, electric-blanket power lights, etc? I've seen them in antique radios and as indicator lights in other ancient gear, so I presume they're not actually LEDs.
Minnie
They're neon bulbs. One giveaway is the colour; a plain neon tube, just low-pressure neon in a glass envelope, glows naturally with that orange-red colour when you put enough volts across it.
("Neon lights" that aren't orange-red may still contain neon, but have a phosphor coating on the inside of the glass that turns the light another colour. White fluorescent lights are all actually mercury-vapour tubes with a phosphor coating. The amount of mercury in even a large fluorescent lamp is very small.)
For a large neon tube, the voltage from end to end has to be up in the kilovolts. But if you make a little teeny neon bulb with electrodes only a few millimetres apart, you only need a bit more than a hundred volts to get it to glow.
This makes teeny neon bulbs a natural fit for indicator-light duty in countries with 115V-ish mains power. You still need to use a current-limiting resistor in series to discourage the lamp from zipping up past the C on this graph and burning up, but that's all you need. In countries with 230V-ish mains, you just need a larger resistor value.
If you run a neon lamp directly from 50 or 60Hz AC mains power like this, the bulb flickers at twice the mains frequency, because the two electrodes light up in turn, but only when the mains waveform is giving the bulb enough voltage to light. (From DC, the lamp won't flicker, but only one electrode will light up.) The older the lamp, the more flickery it will become, until eventually it doesn't light up at all. Little neon lamps ought to last 20,000 hours or more, but many modern ones seem to be of lousier quality.
(Incandescent bulbs don't visibly flicker when run from AC, because a tungsten filament has enough thermal inertia to keep glowing at very close to full brightness even when the mains waveform is crossing the zero-volts mark. A fluorescent tube driven almost-as-directly as a neon bulb from mains power will also flicker, which a lot of people hate. Modern high-frequency electronic ballasts solve this problem, for fluorescent tubes and compact-fluorescent lamps.)
Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.
And then commenters will, I hope, correct at least the most obvious flaws in my answer.
A reader writes:
When I was visiting my mother the other day, I dropped her glass casserole baking dish... thing... (I'm not much of a cook), and it broke, and so of course I said I'd get her a new one. The old one was "Pyrex" brand, but she told me I should just buy whatever similar sized glass dish is cheapest, because, and I quote "Pyrex isn't made from Pyrex any more".
The philosophical implications of that statement aside, were Pyrex products made from special glass, and now they're not? All I know about Pyrex is that I've seen that word written on laboratory glassware.
Harry
In the olden days, the "Pyrex" brand, wherever you saw it, meant borosilicate glass. Borosilicate glass doesn't change size much in response to temperature (it has a low "coefficient of thermal expansion"), so if you heat or cool it suddenly, it's unlikely to shatter.
("Pyrex" wasn't actually the first borosilicate glass; Otto Schott invented it, and the Schott company still sells it under the "Duran" brand. But Pyrex became the genericised trademark for borosilicate glass. Lab glassware that's intended to be used on heat is pretty much all borosilicate, under one name or another.)
Ordinary "soda-lime" glass expands and contracts more with temperature. So if, for instance, you suddenly cool a hot plain-glass baking dish by putting it the sink and turning on the tap, the inside surface of the dish contracts as it cools, the outside surface stays expanded, and stress between the two encourages the glass to break.
This can also happen when a glass object is originally manufactured. After forming the object, if you don't "anneal" the glass by slowly cooling it (a special kiln for doing this to glass that's been made somewhere else is called a lehr), a brand-new glass object can break spontaneously as it cools, or be right on the edge of breaking from the slightest shock.
There are numerous tricky ways to make glass objects more sturdy, the most common of which takes advantage of soda-lime glass's thermal expansion and contraction, to "temper", or "toughen", the glass and force the outside of the glass object to be under great compressive stress, which glass tolerates very well.
The simplest way of tempering glass is by rapidly cooling the outside of molten glass, so it solidifies and contracts quickly, and is then pulled into compression when the core of the glass cools later. Now, any insult suffered by the object will have to overcome the compression built into the outer layers before it can get the glass into tension and get a crack going. And if a crack does start, the whole glass object will collapse into zillions of distinctive little lumps of glass with quite safe large-angled edges, rather than dagger-like shards.
The forces involved in tempering glass are the same as the forces that make unevenly-cooled, unannealed glassware fragile; they're just tightly marshalled to make the material more durable, in the same way that prestressing "tendons" can make concrete far stronger.
(The most extreme version of the tempering process is Prince Rupert's Drops...
...which you can make at home, while wearing suitable protective clothing, by dripping molten glass into a bucket of water. Internal tensions make the body of each drop amazingly strong, but if you snap the thread-like tail - which is also very strong, but so thin that it can easily be bent or sheared past its limits - the whole drop instantly explodes into tiny particles.)
(Oh, and again, if you'd like to have the above explained much more clearly, try J.E. Gordon's classic "The New Science of Strong Materials, or Why You Don't Fall through the Floor", which is one of my favourite books, along with "Structures, Or Why Things Don't Fall Down".)
A fancier kind of tempered glass is "Corelle", which is laminated tempered glass, but doesn't look or feel much like glass at all. This is partly because it's opaque (though I don't think there's anything about the manufacturing process that says it has to be), and partly because it's so strong that plates and bowls made from the stuff can be very thin and lightweight.
Which brings us back to Pyrex, because the Pyrex and Corelle brands are now both held by World Kitchen, LLC. World Kitchen would really like people to stop saying that Pyrex kitchenware isn't made from borosilicate glass any more, because although this statement is actually correct, it wasn't World Kitchen that changed it. World Kitchen say the change happened "more than 60 years" ago; other sources can't put an exact figure on it, but it seems pretty clear that it's not a recent development.
In any case, what World Kitchen sell today as "Pyrex" bakeware isn't plain soda-lime glass, but "heat strengthened" soda-lime, which presumably means the usual kind of tempered glass. Tempered glass resists breaking from temperature changes pretty well, and resists breaking from mechanical insults very well, so it's a good choice for bakeware, which is bumped by other bakeware much more often than it has to tolerate large temperature shocks.
Well, it's a good choice for bakeware as long as your oven doesn't get hot enough to anneal the glass, which I think it definitely doesn't.
This is despite the additives in soda-lime glass, which are there to make the stuff melt at a reasonable temperature. Silica, also known as quartz, makes up the bulk of all normal glass compositions, and could be used to do anything ordinary glass does. But quartz's melting point is way up around 1700 degrees Centigrade. This is higher than the melting point of iron, and makes quartz unreasonably difficult to use for glassware, unless you're making furnace windows or something.
To make soda-lime glass from scratch you need a furnace that burns hot enough to melt silica - which is why recycling glass is so popular - but once the ingredients are mixed, the melting point of the mixed material plummets to less than 600°C.
Annealing happens significantly below the melting point, but you still need a temperature of more than 500°C to anneal soda-lime glass, even if you're willing to wait for hours, and no household oven goes that high. Actually, I don't think any food oven goes that high. The hottest are probably coal-fired pizza ovens (the great problem of making "authentic" pizza at home is getting the oven hot enough); I think those top out at around the 1000°F/540°C mark, but they usually run rather cooler.
I'm sure there are many companies that make tempered, or toughened, glass kitchenware, and I'm also sure that other companies again make plain soda-glass kitchenware, which may not even be properly annealed, much less properly tempered. So your mum may be right that Pyrex-brand glassware is not particularly good - but you also shouldn't buy the cheapest glass casserole dish you can find, unless you've good reason to believe it's made from tempered glass. Which may or may not be clearly, or honestly, indicated on the box.
I think the best way to authoritatively tell the difference is by bopping any dish you're planning to buy with a ball-peen hammer. I leave the formulation of techniques by which one could get away with this as an exercise for the reader.
Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.
And then commenters will, I hope, correct at least the most obvious flaws in my answer.
A reader writes:
I know that when you look up at a clear sky, the dark things you see floating around inside your eyeballs are called... "floaters". Someone worked hard on that name, huh.
But what are the much smaller pale scooty things? You know what I'm talking about, right? I'm not the only one who sees them, am I? Are they bacteria or something? Oh god, they're bacteria, aren't they?
Presuming I'm not about to die of pale-scooty-eye-thing-itis, why do I only see these things when I'm looking at the sky?
Noel
The pale scooty things are white blood cells.
The blood vessels that feed your retina are located, thanks either to the blind forces of evolution or to the carelessness of a really incompetent intelligent designer, on top of the retina, so light has to pass through the blood vessels before it can get to the retina, and the blood vessels can cast shadows on the retina.
A really big red blood cell has about the same diameter as a really small white blood cell, and white cells are roughly spherical blobs instead of the doughnut-ish shape of the red cells. The result of this is that red cells zipping through the blood vessels over your retina are invisible, but the much less numerous white cells do show up, as little pale scooty things.
(Because floaters really are floating in the goop inside your eye, they move around even when you don't move your eyes. Blood cells are - with any luck - constrained to the vessels over your retina, so the paths of the little scooty things track precisely with your eyes, no matter where you look.)
There are two reasons why you see these things when you're looking at a blue sky, or daytime fog, or a white area on an over-bright computer monitor, for that matter.
The minor reason is that floater-shadows on your retina are pretty low in contrast, and white blood cell shadows are even lower, so they're hard to see if you're looking at something rich in detail. For the same reason, it's hard to notice minor dirt-spots on a computer monitor unless the image being displayed is pretty uniform.
The major reason why floaters and zippy leucocytes show up when you look at the daytime sky, though, is that the sky is bright.
Update: As Bernard points out below, the explanation I originally had here was wrong.
Bright light causes your pupils to contract, and contracted pupils give the eye a higher f-number, and a deeper depth of field. Floaters and blood cells are far from the eye's focal distance no matter what you're focussing on, but with a smaller aperture, they become sharp enough to be noticeable, against a uniform background.
The contracted pupil, as Bernard says, is closer to a point source of light inside the eye, and casts sharper shadows of whatever's in there onto the retina.
Many photographers are familiar with this effect. There can be all sorts of dust and crud on and even in a lens, and dust on the sensor too if you've got an interchangeable-lens camera, without any obvious problems for large-aperture pictures. Faint fuzzy circles may be visible if you look really closely, especially, again, in areas of uniform colour, but even things that you'd think would be totally obvious, like raindrops on the lens, can have surprisingly little effect on a large-aperture photo.
Stop your lens down, though, and the crud-shadows will be much closer to sharply focussed, and much easier to see and obsess over.
A reader writes:
I'm getting older, which is better than the only alternative, but reading small print started to get difficult, so I bought reading glasses on eBay for $3 delivered and... problem solved!
Except now I think I may be slowly blinding myself by using $3 glasses. Especially after what you said the other day about eye damage often not being noticeable until it's really bad.
Are cheap reading glasses dangerous?
Andre
You're not blinding yourself. Cheap reading glasses are a perfectly acceptable treatment for hyperopia (longsightedness).
You won't be able to focus far away while wearing even weak reading glasses (for the same reason that adding filter-thread magnifiers or extension tubes to camera lenses prevents infinity focus), but the only danger this poses is if you decide to go driving with the reading glasses still on.
It's actually pretty much impossible to damage your eyes by wearing the wrong glasses, although you certainly can give yourself a headache. There are all sorts of folk legends about how you can damage your eyesight by sitting to close to the TV or cure your myopia by doing eye exercises or massaging your eyeballs, possibly with some gadget or other, but it's all claptrap.
(It'd be nice if you could focus close and then far away and then close and then far away at some sort of eye gym and thereby cure the optical shortcomings of your particular set of eyeballs, but there's no good evidence to suggest that this is possible. Fortunately, spectacles and contact lenses are now very mature technology, and the various forms of refractive surgery are getting better and better.)
In the olden days, mail-order spectacles were exceedingly likely to be a scam, on account of how the notion of an eyeglass prescription didn't yet exist, so it was impossible for even an honest mail-order glasses dealer to actually know what glasses you needed. This didn't, of course, stop mail-order outfits from making the usual pre-consumer-protection outrageous claims about their wonderful products, and separating countless suckers from their money.
A significant portion of the mail-order hucksters' business, though, was simple mild-magnification reading glasses optically much the same as the ones you bought on eBay, As long as the people who bought those glasses really were longsighted, many of them were probably perfectly happy with their purchase (although it's likely that they were still paying more than they needed to).
Should your need to see stuff close up move beyond "reading books" and into "working with small objects, and wanting to look as much as possible like a mad scientist while I do it", allow me to recommend the Donegan Optical Optivisor. The Optivisor works very well (it's comfortable, you can easily flip it up when you don't need it, and interchangeable lenses are available for different magnifications), it looks pretty hilarious, and it isn't very expensive.
A while ago, I reviewed a book with a lot of fictional death in it. I didn't like that book much.
Today, a book with a lot of factual death in it. I like this book a lot.
Over The Edge: Death In Grand Canyon, by Michael P. Ghiglieri and Thomas M. Myers, is accurately titled. It chronicles the numerous ways in which people can end, and have ended, their lives in Arizona's Grand Canyon and its environs.
There are a lot of deaths in this book. A lot of deaths. The means of death that sprang first to my mind when I discovered the book existed was people larking around pretending to step off the edge, and then not pretending quite so much. And yes, those people are in there. But so are underprepared hikers, plane crashes, an awful lot of people in boats, and gruelling tales of historical exploration.
Every now and then a tale in Over The Edge ends with someone surviving. But that's really not the way to bet.
Absolutely the worst thing about this book is the cover. It clearly depicts a rainbow-farting unicorn plunging to certain doom, so that's good, but it's got that weird "undesigned" look typical of self-published crank-screeds. (And, yes, it's also got Papyrus, again.)
And, while I'm whinging, the editing and proofing isn't everything it might have been. There are occasional typoes, like two different renditions of someone's name, not to mention uninventive prose like "a deadly game of Russian roulette" - as opposed, presumably, to Russian roulette played with a Nerf revolver.
And, if I'm honest, the middle of the book's not as fascinating as the beginning. The middle's where you'll find numerous deaths in modern river-runs, usually because of lousy steering by boatmen, and other stuff that could pretty much happen anywhere - air accidents, freak accidents, (a surprisingly small number of) suicides, and murders.
(I did find an unfortunate interaction between a low-flying helicopter and an environmental sediment-transport study to be blackly hilarious.)
But perhaps I'm being too demanding. People wind up dead at a regular pace throughout the book, which really should be good enough for me. And there's quite a bit of variety; it's not all "If you choose to play a practical joke on your young daughter by pretending, with great theatricality, to fall off the edge of a canyon and hundreds of feet to your death, it is a good idea to make sure that the ledge just below the edge on which you intend to land is not covered with loose pebbles forming a slope at their critical angle of repose."
To extract maximum entertainment from this volume, you may by this point have figured out that you need a somewhat morbid sense of humour. Watching Dad leap off the edge may be a horror beyond imagining for the onlooking mum and kids, but if, like me, your first thought on seeing that the man in question actually did have kids was "darn, not eligible for a Darwin Award, then", you're all set to enjoy the rest of the volume.
All this is not to say that this is one of those schlocky publications aimed at People Who Like Football, and Porno, and Books About War. Over The Edge isn't relentlessly po-faced, but neither is it buckets-of-blood-narrated-by-Jeremy-Clarkson. It does help if, like me, you decided to download the coroner's report linked from here specifically because of the warning about the photos it contains (and then, like me, decided that the term "extensively morselized" made the document a must-read all by itself...), but Over The Edge is really a collection of true stories of people in horrible situations, and the noble, venal, foolish and/or altruistic things they then do.
It also, definitely, has educational value. I now, for instance, know some more of the wonderful panoply of ways in which whitewater can murder you, whether the flow rate is high or low.
High rates give deeper, and possibly also faster, water, which in the case of the Colorado River may be startlingly cold (Over The Edge's co-author thinks this may be because of the Glen Canyon Dam, which releases water from its ice-cold depths, not its warmer surface). Low flow rates are still often plenty to whip your feet out unexpectedly from under you (people keep forgetting that a cubic metre of water weighs a tonne, and even a mere cubic foot of water weighs more than 28 kilograms {62 pounds}...), and they also make rapids much rockier, and thus more likely to break your boat and then your body.
Many of the deaths in Over The Edge are quite improbable. Horsing around on the rim of a canyon, or going for a hike in the heat equipped with a Snickers bar and a 591-millilitre bottle of Dasani (and not even telling anyone you're going...), are both dangerous activities. But people do these sorts of dumb things all the time, and the overwhelming majority of them survive. Often without even having to involve rescue staff (also known as the TNS, or Thwarting Natural Selection, Squad).
Over The Edge can be quite educational, though, in showing you how to avoid taking less obvious risks, even if you're never going to visit the Grand Canyon. Much of the advice is highly applicable to any backcountry adventuring, especially in gully country.
For instance: Yes, lost people really do have a strong tendency to walk in circles, even when they should be able to get their bearings from their surroundings.
Oh, and if you're going out on the water, or just wading into the water, or possibly even just fishing in the water from the shore, WEAR A LIFE JACKET.
And, advice almost as important, if more specialised: If you have a history of sleepwalking, don't camp right next to a river.
(The poor kid starring in that particular story was meant to be camped miles away from the river, but the adult leading the trip got the group stranded next to the river for the night, when they got there too late and the one flashlight the adult brought didn't work.)
You also, it turns out, can't count on arid country having the traditional desert climate where it's hot during the day and freezing cold at night. The Canyon manages to stay hot right through the night! Enjoy!
And young, fit people - especially children - can become severely dehydrated while they're still running around and looking chirpy enough. Then they suddenly crash, and five minutes later their heart is still beating, but there's windblown sand accumulating on their unblinking eyes.
And, remember, kids: Just Say No to jimsonweed. Seriously.
And then there are the historic stories, featuring numerous explorers who figured that God would not have made a place so dismal and lethal as this without putting at least one damn good vein of silver in there somewhere.
(This reminds me of the fact that for a lot of people in the olden days, forests, canyons and mountains were not "beautiful". Ships, bridges, castles, cathedrals and geometrically landscaped gardens were beautiful. It was only when we started to have the luxury of not having to look at nature all the time that we started finding it appealing.)
The central theme of this book is that wilderness does still exist, and does not automatically come with handrails and warning signs.
I'm quite close to some wilderness myself. I live in Katoomba, New South Wales, and my house is a lazy ten-minute walk from Echo Point. At Echo Point itself and most of the cliff walks around it, you do get a pretty good supply of handrails and warning signs, and people almost never die, except occasionally on purpose.
Tromp on down the Giant Stairway into the rainforest-y valley, though, and things change. The valley barely qualifies as a pothole compared with the Grand Canyon, and most tourists just toddle along the wood-paved walkways and catch a cable car back up. But if you strike out south you're instantly in a heavily-forested National Park. People can and do get life-threateningly lost down there, even after so little wandering that if the land were magically flattened they could walk to a place that serves a really good latte in about an hour.
I thought Over The Edge would just be morbid, shading to morbidly-hilarious, which would be good enough for me. But it isn't. Yes, it's basically just a long list of people who died, almost died and/or really should have died (serious Survival Bonus Points, for example, go to the immobilised-by-injury woman who managed to catch the attention of people hundreds of feet away by shouting, even though she had two collapsed lungs...). But it's frequently fascinating.
And, of course, if you're actually going to the Grand Canyon, to do anything more than stand 30 yards from the edge under a parasol, there is no better book to read beforehand. And to be seen reading while you're there.
Recommended.
(Buy it at Amazon, and I'll get a cut!)
