The Secret Life of Your House : A Look at the Everyday World Through a Tiny Keyhole

MORNING

FROM THE ALARM CLOCK, A SPHERICAL shock wave traveling at Mach 1 starts growing outward, spreading and spreading till it hits the wall. Some of the energy it carries causes the curtains over the window to heat up from the friction of the onslaught; much of the rest rebounds, enters the ears of two sleepers and finally rouses them awake.

There’s a rolling of eyes and a stirring of head, then a female hand gropes from under the security of the comforter, fumbles on the bedside table, finds the alarm clock and clacks down the button to turn it off.

The buzzing from the alarm clock stops, but the even-higher-frequency shriek from the quartz crystal inside takes over, spreading in a growing sphere from the clock as the sound wave did, striking the walls and heating the curtains, too. But this second room-filling shock wave is inaudible. The waker, desperate to fill the rigors of the morning with some soothing music, fumbles out from the covers again. The radio is found, switched on, listened to for a brief instant, then the tuning knob is furiously grasped. Some simpleton had left it on the news station last night. Now it must be moved to the haven of the classical music station.

The tuning knob quickly rolls, speeding across the megahertz to the new location. There’s a crackling as it moves between stations; a slight hiss and buzzing too. Some of the hissings are the cries of distant exploding galaxies, sending out massively powerful particle radiation across space and time in the process of obliteration. Other static comes from lightning strikes on distant continents, which send electromagnetic pulses through the upper atmosphere that travel across deserts and seas into the bedside radio; all are received, then passed over and ignored in the hunt for the right station.

The radio disturbs the other sleeper, and after some fruitless tugging of the comforter, a division of resources is ordained. The first waker lies back to savor the music, while the second one gets ready to emerge from bed.

Bam! The man’s foot extends out of bed and lands on the floor. The floorboards jam down, and their vibrations travel sideways like pond waves to the wall. The whole house compresses. Bricks where the floor fits into the wall shrink by 1/100,000 of an inch from the weight.

Any impact that doesn’t get lost in the walls stays quivering in the floor. The chest of drawers starts lifting up and down, as does the bed, the chair, the table with its plant on top, the stack of magazines and Sunday papers in the corner and even the old coffee cup left on the floor. All lift up and bounce down, rebound and crash down again, as the floor reverberates to get rid of its buzzing energy.

Then the second foot touches down, the waker stands up, and he steps to the double-glazed window to see what is happening outside.

It is, as usual, raining. Not water raindrops--that’s only on stormy days. This is an electric rain uncovered first thing in the morning, a rain of charged air particles that started as simple decay products from radioactive gas nearby. (House walls spray out radioactive gas--a lot if they are brick or concrete, less if they are wood or metal-clad--and front walks and street surfaces do the same.) The particles have been hovering in the lower atmosphere’s invisible electric field ever since. This electric rain spatters the lawn, the front walk, the roof, and now it sprays in through the open window. It’s a gentle rain--perhaps 200 volts per yard, but at a tiny amperage.

The window in its aluminum frame is slid closed; the invisible shower has not proven of captivating interest. As the window closes, long slivers of its aluminum frame come tearing off. On a steel window such tearing friction would provide a nice niche for future rust to sprout. But here the aluminum window quietly goes about repairing the scratch itself, as it always has. Before the culprit has even turned away, a new layer of aluminum oxide starts growing out sideways from the intact portion. It spreads across the microscopic gouge, covers it and seals it and only stops when it has formed a perfectly fitting replacement for the bit that was lost.

The waker is now on his way to the bathroom. As he steps, the floor continues to shake, and the dust continues to dance from the invisibly rebounding furniture. But there’s also something else that moves under his feet--some things rather, roused out of their sleep as the waker strides over them.

These are mites, thousands and thousands of tiny mites: male mites and female mites and baby mites and even, crunched to the side away from the main conglomerations, the mummified corpses of long-dead old great-grandparent mites. Brethren of theirs stir in the bed, too, where they have spent the night snuggling warm and cozy under our sleepers, and now, the great burden above them stirring, they are beginning to stir for the day, too.

It sounds unpleasant, but it is quite normal. Even if the room is well aired and the floor clean, the mites will still be there. Epidemiological studies show that nearly 100% of our houses are host to these creatures. The consolation is that these are not great visible mites that produce itching, let alone the all too visible and loathsome bedbug, but rather a special, ultra-tiny (so small they were only discovered in 1965) breed that lives in human carpets and beds and nowhere else.

Each one has eight legs, because at one time they were in the same evolutionary line as the spider. But that was more than 300 million years ago. The spiders went on to be great multi-eyed, hunting carnivores; the mites went a different way, and many have ended up as peaceful grazers, munching whatever is left over from the larger creatures they shelter near.

In the house, these leftover nibbles are skin: tiny rafts of human skin flakes. There’s plenty of it around. It’s rubbed off when you move in bed, and it’s brushed off when you dress. It falls off the body at a stupendous rate whenever you walk--tens of thousands of skin flakes per minute--and it tears off at slower rates when you stand perfectly still. To us the skin flakes are insignificant, noticeable only when they build up as dust, but to the waiting mites they are manna.

Hidden at the base of the carpets, these mites only have to wait for this perpetual haze of skin flakes to rain down. For the mites in the bed (an estimated 42,000 per ounce of mattress dust; 2 million in the average double bed) the floating skin rafts are even more accessible.

MIDDAY

THE CAR IS WAITING, the office beckons. A slammed door closes the house tight.

What’s in the empty house, so abruptly left behind? A world of strange things getting settled for the long haul through the day.

When the human beings rushed out to the car, their shoes scuffed through the outer layers of atoms on the carpet, like Dr. Zhivago and Lara trudging through the snowdrifts, sending sheets of carpet atoms a hundred layers thick flying like so much powder as they kicked along. Some of the atoms whirled up high enough to land on the exiters’ shirt and dress, peppering them with ultra-minute flakes of carpet Orlon, polyester and nylon; other of the drifting atoms stayed lower, gusting in miniature blizzards against trousers, leg cuffs, high heels and stockings.

The humans who did this damage also received a 400-volt electrical charge in the process, but that will have discharged the moment they touched the metal doorknob. The carpet, left behind, has no such outlet. For half an hour the electrostatic footprints carved out will remain clearly in place, marking the traveler’s path. (With the proper viewing scope the path would show a dim fluorescent green.)

Walls are rarely walked on in the morning, but they still suffer damage from the bustle before the humans leave. Water vapor starts it off, water that evaporated up from all the hand washing, teeth cleaning, face washing, tea making, plate rinsing, table wiping and showering: 1 1/2 pounds of the stuff on the average busy morning, all of which will have to come down.

If the air in the house were empty, the water would simply soak into the wooden floorboards and make them swell, an effect of no particular significance during the day, and worthy of comment later only to those of delicate constitution who take the creaks and groans produced by their drying out during the night as a sign of some ghostly visitation. But empty the air is not. There are skin flakes in the air, shiny cadmium blobs in the air, textile bits and sea salt and lost micro-insect limbs and also, hovering with all the rest, kept up by the pattering air molecules in every room and brought in by the suction pull from the slamming door, there are the fungus spores.

Spores are hardened containers that possess all the DNA instructions needed to create new fungus creatures--aerial eggs as it were. If they bump into dry walls they just rebound and go back to floating, but when they bump into wet walls they stick. Out of the broken open shell, a single fungus creature’s body appears, then a groping arm grows from that body, a leathery arm, albino and clear, and then from that arm grows another, and another, and then many, many others more. These are the fungal hyphae, and the reason they come out in such numbers, giving the appearance of something like a miniature and mutated octopus appearing from a micro-egg on your room walls, is that the newly arrived fungi need them to feed with. For some species it’s the sulfur grains in concrete that are sought; in others it’s the metals in paint, or the glue in wallpaper.

In the U.S. the spores can be blown from Texas to Minnesota within a week. They can last up to 40 years before hatching.

Aside from the fungi and footprints, you might expect the house to just sit still and not make any trouble until you come home. But sitting still is about the only thing the empty house does not do.

One reason comes from outside. Sunlight is banging against the glass in the windows, and even though glass is quite impermeable to most solar rays--even though it is actually a liquid, continually molten--the very few rays that do squish through are piling up and will do a lot. They heat up any table they meet, splitting formaldehyde loose from the varnish, and when they get to the floor, they set that in motion, too. The little hollows in carpet fibers heat up and begin a slow-motion, Medusa-style writhing in the light. It’s not a total writhing, as wherever the light is blocked by the furniture there are infrared shadows that keep the carpet there cool, but it is enough to start the air currents going. The air rises, slithering along the walls and bouncing off the ceiling. A few of the neat piles of mite feces in the carpets are light enough to be pulled up with it, but most are just heaved in slow motion from one spot on the floor to another.

Where the sunlight hits the walls, it causes the heavier, color-giving metal particles floating in the paint to vibrate like pinball flippers on the loose. But since the paint that seems to cover your walls actually works as an optical illusion, with large gaps between the metal particles that we don’t see only because of limitations in our eyes, most of the light carries through to the underlying material, the brick or wood or concrete or whatever is there. This stretches the material, it yanks it up vertically, it pulls on every nail and screw in the wall, and as the roof overhead is tugging upward from the sunlight, too, the result is that the whole house begins to stretch. By the time you come home it will be several cubic inches larger--a solid addition that it will keep till night comes, when everything that was gained in the day sags away.

Even in rooms where there is no direct sunlight, there are still some curious goings-on. Sweaters stacked next to each other in the bedroom chest of drawers leach molecules into each other in a process that is actually a slow dripping, while hangers in the closet are sagging from the weight of the clothes on them and giving off a detectable ultra-low-frequency groan. On the dressing table top, rust is forming in thin water pools on a silver bracelet, and atoms from a gold earring are bubbling loose and rising to the ceiling. A certain amount of carbon monoxide from the morning’s cooking (carbon monoxide always emerges from a gas flame) will combine with the water film on the silver and on the aluminum window fitting to produce dilute carbonic acid, similar to the bicarb in indigestion tablets.

From radium impurities in the clay, stone or wood of the bedroom walls, a cloud of radioactive radon gas is wafting in, while quite likely helicoptering through all the hubbub are stony asbestos filaments, dropping down at regular intervals from the ceiling insulation and speeded up by any vibration in the house’s structure, such as the polyphonic chord sounds that a distant earthquake produces in the house’s frame. (There are several hundred earthquakes every hour somewhere on the globe strong enough to make your house shake.) Even better is the shaking of the house’s 200,000 or more pounds when a lone truck drives past in the distance. In all this jouncing, the hiss of the house’s air escaping through the holes in the wall will probably be minimal, but there are many trillion microscopically quivering capillaries in even the thickest brick walls, and out the air goes, replaced every 90 minutes by a new batch coming in through alternate holes.

For hours the empty house’s shaking, breathing, slithering and writhing can go on. But let the woman of the house slip home a bit early from work in the mid-afternoon, and all these miracles of the living house are ignored.

Our lady changes into comfortable jeans and moves into the back garden to rest. Several feet under the lawn over which she reclines are a vast number of little holes, or pores, and in each one there are many creatures. The amount of life is surprising: perhaps 10 pounds of living creatures in an average-size lawn. It’s an excellent setting for life, there being abundant moisture, food debris tumbling down from above, and a nice, constant temperature, moderated by the thickness of earth above.

There are two things these creatures do. First, they murder each other, with the smallest bacteria in the pores being eaten by slightly larger protozoans, those in turn being eaten by the again slightly larger nematodes--vile-looking, pencil-shaped microscopic creatures with no eyes and six great lolling lips--and so on in a chain of six or seven creatures before it comes to an end. This murderous chain would not be especially interesting except that to keep up their mutual assault the creatures in the holes under your lawn have to increase their respiration rate. They would run out of steam otherwise. In the process of breathing faster they incidentally dissolve certain sulfur and nitrogen compounds that the oxygen in our air has the unfortunate habit of getting stuck to; through their panting they release fumes that filter upward and indirectly but indispensably ensure that we surface dwellers do not suffocate.

Along with this useful breathing, the creatures of our deep lawn holes are busy synthesizing fluid dribbles that can be squirted out as defenses against other pore creatures. Since such dribbles will be fatal to unwanted microbes on the surface, too, it is from this source that we get most of our antibiotics. The satisfying smell of fresh soil the woman gets when sitting in the garden is due to the gases released by streptomycetes--the same creatures used to make the streptomycin and tetracycline antibiotics that hospitals stock.

In this backyard setting--the house writhing and breathing invisibly behind, the garden swarming invisibly below--the woman might well find herself succumbing to mid-afternoon hunger pangs and return to the home to retrieve a snack.

LATE AFTERNOON

THE RETURNING DRIVER IS IN A skid. All cars are in skids, because all car tires melt as you drive on them. The rubber drips out into molten pools less than one-thousandth of an inch thick, and the car slides on them. Evaporating as soon as the wheel leaves them behind, more than 50 tons of rubber get into the air this way daily in a city the size of London or New York. The car is also shaking and, in time with each shake, is blasting out radiation from the jolting spark plugs, which whacks into the trees in the garden, (where an inserted probe would light up to detect their arrival), bears down on the brass doorknob of the house’s front door, the watch of a passer-by two streets away, all other loose bits of metal in range and, skedaddling outward at 670 million m.p.h., reaches the orbit of the moon a bare 1 seconds after release.

All of which is as nothing compared to what happens when the man enters the house to greet his spouse.

If it’s a summer evening and the window is open, there is quite likely to be another creature inside. It is one of the most agile flying beings in the animal kingdom, even if it was next to last in evolving this skill, following the beetle (300 million BC), pterosaur (150 million BC) and bird (130 million BC), and preceding only the bat (an arriviste 15 million BC). It carries on-board gyroscopes, has spring-release clasps to unhinge its wings, a catapulting undercarriage, and can even generate its own high-octane fuel. What makes it even more impressive is that this creature, Musca domestica , commonly known as the housefly, does not look out of its swollen giant eyes at any world we would recognize.

For the fly sitting there on the kitchen table, reflexively stroking its front legs to clean them and regurgitating some of the nice liquefied dog excrement it lapped up earlier outside, the fluorescent light fixture in the kitchen is doing some very odd things. The bulb shines over the kitchen for a while as bulbs are supposed to, but then it suddenly cuts out, leaving the kitchen and everything in it in total darkness for a long interval until it just as suddenly lights back up again. To the human occupant of the kitchen, fussing over the food now being readied for display, no such stroboscopic flashes are taking place. The reason is that we can only tell two events apart if there is more than 1/20 of a second between them. That’s why movies are called movies, even though they’re just a series of still shots projected a bit faster than that key 1/20-second interval. A fly in a movie theater would suffer no such delusion. Its nervous system operates so fast that it can detect distinct events happening only 1/200 of a second apart. That would make a projection of Indiana Jones and his derring-do appear to be a tedious travelogue slide show, with long intervals of dark while the frames were advanced. The light in your kitchen goes on and off 60 times a second--that’s how the power station pumps it in--whence the fly’s moments of dark and light we started with. It’s like what we might see in a curiously distorted disco, where the overhead strobes are slowly blazing on, then off, and sometimes you see the other dancers caught in strange poses halfway between steps by the light, and sometimes you see nothing at all. For the fly, it’s the final dragging of the stew tureen to a free counter that it sees in these disco stroboscopic blasts: strange and disturbing tableaux of grimacing face, slipping of potholder, nursing of burned fingers and soundless but deeply felt curses being emitted.

The fly would be content to stand on the table for ages, stroking and dribbling and watching this surreal slow-motion show. But when the evening’s chef spots the fly on the table, when he decides to take out all his aggrieved feelings and obliterate the cursed fly, then everything changes. Then the fly has to depart. It doesn’t do this immediately, however. For the fly’s vision, though channeled through 4,000 crystalline little eyes, is not really good enough to make out fine details of movement over a distance. It’s only when the human has stalked up quietly to the table, raised his hand and started bringing it down in a furious, murderous sweep that the fly gets a clear enough impression that its presence is no longer recommended. It can usually get away with its poor vision because it is fast. But can a fly really be fast enough when a fist has already started on its way?

A human’s hand swinging down at top speed will take at least 1/60 of a second to cover the last three inches--the measured speed of a jab by Sugar Ray Leonard in his prime--and more likely 1/30 of a second or even more. This the fly clearly sees coming, flashed into bright light by the slowly churning overhead fluorescent bulb, and without undue haste sets about preparing for takeoff. A fighter pilot scrambling for his jet has nothing on the simple housefly, whose technique has evolved over 80 million years. First, its brain works out the trigonometry of the descending hand so it can tell in which direction survival lies. Then starter muscles on the outside of its chest get their first signals to start pulling in the hard sheet of fiberglass-like material that forms the point of attachment for the wings. These wing fasteners click inward, and the wings are ready to be moved. That requires fuel, of course, and so the fly--still in the interval while the furious hand is crashing the last two inches tableward--neatly opens its fuel valves. Not gasoline, but high-octane sugar streams into the muscles holding the wings, and great blasts of oxygen to help ignite it come pumping in through silvery air hoses. Only when the air and fuel are properly under way does the fly send a stronger hit to its starter muscles. The wings are pulled all the way down, like a propeller plane still on its chocks getting its first engine-spluttering rev.

There’s no time for a running start, so the fly just tightens its thigh muscles, crouches slightly, then pushes straight up, thus catapulting itself into the air. The ungainly bug-eyed creature floats at first, like a helicopter hovering above an aircraft carrier deck, until its wings pick up enough speed to carry the whole weight. Then it turns sideways, retracts its landing-carriage legs to reduce air resistance, and accelerates fast, upward and away. The descending hand smashes onto the table, the burned fingers get bruised again, and a strange cry sweeps out of the human’s mouth. The sound catches up to the fly (sound traveling at 760 m.p.h., the fly, though faster than us, doing no better than 25 or 30 m.p.h.), rocking it like a burst of air turbulence jolting a fighter, but otherwise doing no harm.

So far the fly has catapulted, evaded, controlled its fuel supply and accelerated away. It has never buzzed, and that’s only fair. The buzz we hear from a fly is quite likely never heard by the creature itself. Flies flap their wings at about 300 times per second, and a sound with a basic frequency of 300 cycles is what we consider a standard mid-range sound. It buzzes. But to the fly, which samples and assesses simple incoming events 10 times faster than us, that 300-cycle vibration is equivalent to only a 30-cycle fundamental tone. Now, 30 cycles is nowhere near a standard piano or telephone buzzing sound. It’s rather at the lower limits of our hearing, the sort of sound we hear when heavy machinery is clanking and rumbling nearby. If the fly makes the same transformation, then its wings sound to it like heavy girders or boilers clanking slowly away, too.

Because of its overspeeded vision, half of its flying time--even with the kitchen light brightly on--is spent in what it perceives as utter darkness. And as any pilot knows, navigating in the dark is no easy task. (In the living room this won’t be a problem, for the glowing filaments in the ordinary light bulbs there will keep light going even in the intervals when the power station cuts out.) The cruising fly manages to get through its cycles of night in the fluorescent-lit kitchen with the help of two gyrocompasses sticking out from behind its wings. If it accidentally yaws, pitches, rolls, or just gets dizzy when it can’t see anything, the gyros inform the brain, and a course correction is computed and sent along to the flight muscles. With all this help it can easily work out where it wants to go, and so the navigating fly cruises into the living room and ascends to the ceiling, there to perform the most impressive feat of its journey: landing upside down.

If a fly could travel upside down, landing on the ceiling would be easy. It would just have to put its feet out. But flies, like most airplanes, lose their lift when they try to go through the air bottom-side up. How does a fly get around this problem? Proceeding at altitude high in the living room, the fly lifts up two of its front legs as high as they will go in front of it. It’s the position Superman takes when exiting phone booths, and it’s ideal for what’s to come. As soon as these two front legs contact the ceiling, the fly will aerobatically tuck up the rest of its body and let momentum rotate it to the ceiling. From there it can vaguely detect the television screen flashing on and off below, and perhaps hope that the man in the half-discarded apron won’t be able to find him up there, hugging the ceiling, to attack again.

DINNER

IN THE DINING ROOM THERE’S A sight to see. As the eaters sit fidgeting gently around the table, a jet of carpet dust, pollen and fungus spores is being sucked up from the floor and shot at high speed into their noses.

The cause is hot air. Human bodies produce heat, 98.6 degrees Fahrenheit on the inside, a little bit less than that but still a pretty high temperature on the outside. This heat acts on the air just beyond the skin, and in heating the air makes it less dense. About two gallons of air trapped between clothes and skin (1.6 square meters of clothed area times five millimeters of air caught underneath) are heated this way. Being less dense, the heated air becomes buoyant, and, just like the great quantities of air heated by a propane torch in a hot-air balloon, it has a tendency to float up.

Down on the toes the heated air separates off from the shoe and rises in individual capsules, like the spray from an upside-down miniature rainfall. That’s an effect perhaps of aeronautical interest, but it doesn’t amount to much, as the heated air capsules float away from each other and break apart even before they reach the level of the table. What’s more important is what happens to the heated air produced at the ankles. As it wobbles up, it doesn’t spread out into the cool general room air, but finds itself in another gust of warm air, this time produced by the hairy calf, under its synthetic stockings, a little further up the leg. The ankle-produced air joins with the calf air, and, wrapping tight around the leg, the two join forces to continue their journey up.

Since they get joined by regular pulses of hot air as they move up the leg, the initial slithering airstream at the ankles turns into a higher-speed gush by the time the level of the knee is reached. A stray amount puffs off blindly at the bend there, but most stays, and the steadily growing stream trundles along the thigh--under skirt or over trouser makes little difference--takes the second bend at the waist, and then is ready for the real sprint. The speed down at the heel and ankles had been 11 centimeters per second; here at the waist it’s 25 centimeters per second and rising. The belly-circling ring of air accelerates, whipping over vests, corsets, petticoats or bare midriffs, and makes it up to the level of the chest. Once again there’s a certain separation--some pushing off horizontally and gliding out over the table; the rest, the majority, continuing straight up.

Two points are worth observing about what comes next. Up till now there have been no blunt obstacles to stop the upward-bobbing hot airstream. Even a sprawling belly could be circumnavigated. But once the chest is reached there are some obstacles in store. The part of the stream that floats into the armpits gets blocked there, as does whatever portion rushes up to the earlobes. These are called stagnation points, and as a reconsideration of human sculpture will make clear, there’s only one more protruding obstacle in addition to armpit and earlobe to create another stagnation point. In some members of our species this protrusion is of more noble proportions than in others, but in all cases it is there, and the air piles into it. This is the nose, and the reason we singled it out is that while armpits and earlobes don’t do anything more with their heated arrivals than block them, the noble nose is also going to breathe them in.

Whence our second addendum. When the first air flow began at the heel and ankle, its disappearance upward produced a partial vacuum, and partial vacuums an inch above the floor are ideal for picking up dust. Into the staging area by the ankles the dirt gets lifted up, and with the next puff of heated air, it goes into the enveloping stream and travels up the body. Everything that was on the floor goes up: grit, pollen, fungus spores, asbestos particles, mite feces, mite corpses, sweat residues, food crumb fragments--the lot. It’s a mighty journey for those small items, akin on their scale to a large brick house being rolled all the way across America by a storm. The same happens to a minor extent whenever you put your hand out. Because of the heat it produces, it acts like a snorkel tube. Dust on the table, spores from the cheese, salt fragments: All roll upward, in this case along the fingers, hand and arm, and arrive seconds later at the neck to join the main stream. The portion that goes to the ears sticks in place there, giving justice to the eternal calls by observant mothers to wash in that apparently out-of-the-way place. The part that goes to the stagnation point of the nose piles on in there--an estimated 10% of the air you breathe when sitting or standing still has come bobbing and rolling up your body from the floor this way. But most of the floor-originating air flows up past the face--streaming within an inch of the eyeball--without stopping. It rises in the air till it’s two feet over the head of each person sitting at the table, and there it spreads: an invisible, geysering halo, for each and every one.

BEDTIME

JUST AS WE ARE FALLING OFF TO sleep, there is a chance, an unfortunately good chance, that a certain repetitive and intrusive noise will be heard--the splat of a dripping bathroom tap.

Dripping taps have no pity, but just grow louder and louder, reverberating inside the attempted sleeper’s head until he gives up, jams feet into slippers, and storms into the bathroom to deal with the culprit. If he is lucky, the encounter with the tap will be a brief one, no bicep-straining battle with rusted metal, but a simple flick, a twist, and so a quick return. But if he is not lucky, there will be war.

The water droplet can work its way through even a tightly closed tap because it doesn’t simply fall out in one glob, but rather dangles, stretches, pulls, tugs and only then snaps loose from the tap. This makes turning off a tap difficult. It is also why drops descend not in regular intervals but in uneven gaps of teasing agony. Even once they come out, the drops continue their contortions. The first thing they do when free from the tap is stretch out into something like an overextended rubber band. But then, since water has a certain amount of internal cohesion, it snaps back to the form of a wadded-up rubber band, before rebounding again for another stretch. It’s like a high diver doing a series of tucks and stretches as he’s in free fall. Only after a few cycles of stretch and snapping does the drop settle down to its ultimate appearance, which, due to all this unaerodynamic buffeting, is not the drop-shaped contour we might imagine but something resembling the profile of a hamburger bun.

When the water drop hits the sink it makes two separate sounds. To us the impact seems a brief, almost jerkily fast event, lasting as it does only one-hundredth of a second. But to the water droplet, whose inner molecules are used to bumping and interacting on a scale of mere billionths of a second, that impact movement is equivalent to many hours of slow shattering. There’s time for writhing, bouncing, wiggling and even a quick shimmy, before the inevitable happens and the droplet explodes. If the explosion sent water fragments out at 180 m.p.h., all the energy of falling would be used up in those mini-shrapnel displays, and there would be none left over to vibrate the sink and make a noise. But alas, falling water droplets in your sink have the bad grace to pop apart at a mere 140 m.p.h., and at that speed there’s plenty of extra impact energy to send the sink twanging. If the basin were sculpted to resemble the inside of a cello, the resultant sound would be perhaps as delicate as a bass chord from a master. But as the sink your unimaginative architect specified is probably a hackneyed thing, merely sink-shaped in design--the acoustic equivalent of a deformed banjo--then all that the shrapneling droplet produces for the first part of its note is a discordant ping when it strikes.

The 140-m.p.h. leftover fragments are what produce the second half of the sound. These fragments from the dismembering droplet create shock waves in the air in front of them as they float sideways away from the point of impact. Such shock waves on a larger scale are what thunder comes from; here in the sink the sound they produce is equally discordant, only softer. Combine the two effects and the full ping-thunk of a dripping tap is there.

This is what the homeowner has emerged from his bed to stop. He lunges at the tap and begins to squeeze, squeezing in wild, primitive jerks, ignoring the shearing of flesh from palm and squeezing till the last drop inside is severed, till there’s not even the tiniest exit for others to seep out of, till he’s sure there will be no more ping , no more thunk ; he squeezes till the torture is over and the tranquility of his home is assured. Only then can he return to bed, where all is warm, and cozy, and quiet. Only then is the day, for our household, finally done.

Copyright 1986 by David Bodanis. From the forthcoming book, “The Secret House,” by David Bodanis, to be published by Simon and Schuster. Printed by permission.