Science

Gray, or white, is merely the base color of our hair. Pigment cells located at the base of each hair follicle produce the natural dominant color of our youth. However, as a person grows older and reaches middle age, more and more of these pigment cells die and color is lost from individual hairs. The … Read more

A similar situation arises when people wander in the forest or desert. Although they may intend to walk in a straight line, if they are lost and have no landmarks to guide them, most people will unconsciously walk slightly towards the left, making a big anticlockwise circle which brings them back to their starting point. … Read more

The tips of fingers and toes are covered by a tough, thick layer of skin which, when soaked for a prolonged period, absorbs water and expands. However, there is no room for this expansion on fingers and toes, so the skin buckles. Your whole body does not become crinkled as the skin has a layer … Read more

Chlorine is not the only member of the halogen group that can be used to disinfect water. Iodine and bromine will also do the job, though not fluorine because it is too reactive. Chlorine is often chosen simply because it is cheap, readily available, and relatively easy to handle. Disinfection relies on disrupting a harmful … Read more

How long a virus can live depends on the surface. Cool, moist glass in the shade, for instance, might retain many kinds of rhinovirus or coronavirus for days. Brass which is dry, sun-baked, and covered with verdigris and zinc compounds, on the other hand, might be germ-free within half an hour of being touched. Such … Read more

Accents and dialects develop and change for two distinct reasons, one phonetic, the other social. On the phonetic side, speech sounds change because of the way they are produced and perceived. Feel the position of your tongue against the roof of your mouth when you say the K sounds at the beginning of “key” and … Read more

The construction of a bagpipe allows a continuous supply of air to be maintained. A flexible bag is filled with air and acts as a reservoir. By squeezing the bag while a breath is taken, one can keep up the flow of air in both drone pipes and chanter. The fundamental frequency of a resonating … Read more

There are several phenomena involved when cast iron objects have been in the ocean for a while. One is that cast iron invariably contains small gas cavities or blowholes that are formed well beneath its surface. Another is that it has quite low ductility, and will fracture rather than deform. Thirdly, it is a very … Read more

It’s possible to move a large ship like Navy destroyer with your bare hands, by leaning against a stanchion on one ship, with both hands across the narrow gap to a similar stanchion on the ship, and pulling hard. For a while there may seem to be no result, but slowly the gap between them … Read more

There are only two physical requirements for a car tire tread pattern. It must provide traction for acceleration and braking and it must move surface water out of the way so that the tire can touch a wet road without aquaplaning, which is where a vehicle slides uncontrollably on a wet surface. A simple block … Read more

Hops contain a group of compounds called humulones or alpha-acids, that are very insoluble in water, but which undergo a chemical rearrangement during the wort boiling to form an isomeric group of compounds called isohumulones that are water soluble. The analogs of humulone, and isohumulone, also found in hops, cohumulone, adhumulone, and prehumulonediffer only in … Read more

Airline windows typically comprise three or more layers of glass, or acrylic, to provide insulation from the very cold atmosphere at altitude. The tiny silvery cylinder is really the edge of a small hole drilled in the middle layer to allow the pressure to equalize between the layers while minimizing convection. The condensation around the … Read more

Almost a century ago, a monthly journal, Country Queries and Notes, was first published. In it, it was asked if oak and fir trees were far more likely to be struck by lightning than pines, and if beech is the tree least likely to attract a lightning strike. This question attracted an enormous amount of … Read more

The wind-chill factors one commonly sees on earth are for turbulent flow, usually over exposed human skin, which loses heat by evaporation and convection. Laminar flow over smooth dry metal, which is what aircraft designers aim for, is much less efficient at transferring heat. At 29,500 feet, air density is about one-third of its value … Read more

Guttation is when drops of xylem sap appear on the tips of leaves of some vascular plants, such as grasses. On the surface of leaves there are stomata or pores through which water is lost by transpiration. At night, the stomata close, causing a reduction in transpiration. Drops of water are then forced out of … Read more

It takes a couple of seconds for the low-power, low-voltage fluorescent light fixture to supply enough energy to the tube to establish an arc across, or through, the gas used in the light fixture. This is because the small quantity of mercury that is used to create the arc needs to heat up just enough … Read more

What Causes a Persistent Sensation of Motion Boating All Day and How Do You Cure the Balance Disorder? A few unfortunate people experience persistent symptoms lasting months or even years. This is known as mal de debarquement syndrome. Exactly why their symptoms persist so long isn’t understood, but they can be treated. Sailing isn’t the … Read more

It is not true to say that nature hasn’t invented the wheel. Bacteria have been using it to get around for millions of years. It is the basis of the bacterial flagellum, which looks a bit like a corkscrew and which rotates continuously to drive the organism along. About half of all known bacteria have … Read more

Waves traveling in a fluid are not infinite. They lose energy because the passing of a wave causes an upwards and downwards displacement of the water, and hence there is always an associated dissipation of energy due to viscous forces. In addition, as the wave spreads, its energy gets distributed out over a greater and … Read more

Herman Melville’s assertion on the reverse magnetization of a compass is entirely plausible. Lightning involves very high currents with high associated magnetic fields. They remagnetize exposed outcrops of high-coercivity, high resistance to the effect of an applied magnetic field, rocks with ease. Currents exceeding 10,000 amperes have been deduced from rock magnetizations. The associated magnetic … Read more

No one from Canada or the northern United States would say that snow “normally” sticks together in a way suitable for making snowballs. All Canadian and many North American children know that sometimes snow is good for “packing” and sometimes it isn’t. The relevant variable for making snowballs is temperature. When the air temperature is … Read more

Waking up to frosty bedroom windows is quickly becoming a thing of the past, thanks to the insulating properties of double glazed windows and cozy central heating. But if you are still stuck with single glazed windows, on winter mornings your view will be obscured by fern-like patterns of frost. Panes of glass lose heat … Read more

Elongated stair rods are an illusion. Large raindrops actually tend to be flattened by air resistance. When they land they are called in Afrikaans, and I understand, in Welsh, “old women with clubs.” The circular sheet of splashing water suggests a wide skirt and the centrally rebounding droplet a cudgel. Droplet size is the main … Read more

The amount of water inside a cloud is not different from the amount of water in the clear air around it. However, while the clear air contains water vapor, inside the cloud the air is saturated with water vapor and it has condensed out to produce the cloud. The difference between the two states is … Read more

The calculation for this is not so simple duh. If we regard land masses as simple cones then the coastline initially grows longer as sea level falls. If we accept that actual topography is more complicated, then the answer becomes less clear. And finally, if we measure coastlines at progressively smaller scales, then we already … Read more

Just take an old surfboard, punch lots of holes through it, and connect them to a water tank placed on top of the board. Water escaping through the holes will create the same effect that you can observe when spitting on a hot iron plate. The droplets dance on the plate for quite a long … Read more

Much of the temperature difference between the two poles can be explained by their difference in elevation. The North Pole, with monthly average temperatures in winter of around -22°F, lies on sea ice on the surface of the Arctic Ocean while the South Pole, at around -76°F, is 9,100 feet above sea level on the … Read more

We first need to establish the scale factor we would have to shrink the Earth by in order to reduce it to the size of a squash ball. The Earth is 7,926 miles in diameter at the equator, and a regulation squash ball has a diameter of 1.7 inches. This means that to shrink the … Read more

Yes, it is true that South Britain is sinking. It’s the result of a process called isostatic rebound. Since the last ice age, a huge burden of ice has been removed from the north of Britain. Because the Earth’s crust is not rigid, as it appears to us over a human lifetime, but very slightly … Read more

NASA is indeed interested in the questions raised by brewing beer in a microgravity environment. Scientists who study the physics of gas-liquid mixtures would like to understand, for example, what happens when there is no buoyancy to bring the bubbles to the surface of a fizzy liquid, and the characteristics of fermentation in microgravity. Two … Read more

Living in a universe where antimatter predominates would be akin to living in our mirror image. We wouldn’t actually notice anything different. occurred All the positive charges would be negative and vice versa, but to someone studying physics in an antimatter universe the idea of positrons orbiting negatively charged nuclei would be as natural as … Read more

Subduction zone insertion was one idea proposed for the disposal of radioactive waste during the early history of atomic energy. Other ideas included a serious proposal to dump canisters of waste on the Antarctic snow and leave them to melt their way to the bottom of the ice sheet. In fact, subduction zone insertion is … Read more

Seawater appears blue because it is a very good absorber of all wavelengths of light, except for the shorter blue wavelengths, which are scattered effectively. The light attenuation is caused by the combined absorption and scattering properties of everything in the water, along with the water itself. Changes in the sea’s color are primarily due … Read more

The ocean floor is mapped using satellite measurements of gravity anomalies. The ocean floor is static, so the measurements can be averaged over a long period to give quite a high level of precision, though unfortunately not to the nearest inch. In any case, knowing the average depth of the ocean is not really important … Read more

The spring and autumn equinoxes are defined as the point in time when the sun is overhead at midday local time on the equator, in astronomical terms, the time at which the sun crosses the celestial equator. On the equinoxes there is an equal length of day and night everywhere in the world. The precise … Read more

Galaxies can collide because the expansion of the universe is the expansion of space itself, not the movement of matter through space. Local movement is independent of this overall expansion. The Andromeda galaxy is actually moving towards us. The big bang was not like a normal explosion, in which fragments of a lump of matter … Read more

The answer to why beer goes flat when it gets warm lies in the behavior of gases, and their solubility in water. Most beers are dilute solutions of sugars, gases, organic acids, and other complex compounds, and, hopefully, alcohols. The gas which gives fizzy drinks their distinctive fizz is carbon dioxide. In the case of … Read more

Navigation requires that you know where you are relative to your destination, and how to negotiate the route. To do this in space, knowing your attitude is as crucial as knowing your position, so the first thing to do is find and track the sun and a known, conspicuous, distant star. Sirius is a good … Read more

The magnetic field of the Earth looks like a dipole, the shape formed by iron filings around a bar magnet, although the Earth’s is rotated about the field’s axis to form a three-dimensional shape. This extends to about 40,000 miles into space. On the ground we use a compass in two dimensions. In space you … Read more

If the moon suddenly disappeared, it would unleash a devastating chain of events that would ultimately spell the end for life on Earth. The most immediate difference would be the disappearance of the tides. Both the sun and moon influence the tides on Earth, but the moon is the dominant force. Remove the moon and … Read more

Old bottles of Madeira wine don’t have to be stored in an upright position, but unlike other wines, it won’t do them much harm. Once wines have been bottled, oxygen becomes the enemy. It oxidizes the wine, resulting in an unpleasant odor and taste. The purpose of the cork is to keep out all oxygen … Read more

The simple answer to why black tea changes color is that adding lemon juice alters the acidity of the tea and the color change is an indication of this. The color change is the same way that litmus paper changes color. A similar effect can be observed by substituting the tea with some cooked red … Read more

If you applied an absolute vacuum above a nonvolatile liquid, then the maximum height you could suck it up a vertical pipe would be reached when the hydrostatic head pressure of the column of liquid equals one atmosphere (101,325 pascals). This pressure is given by p x g x h, where p is the fluid … Read more

The earliest fabric softeners were developed during early 20th century and were based on a water emulsion of soap and olive oil, corn oil, or tallow oil. Static build-up in clothing is caused by fiber-to-fiber, fiber-to person and even fiber-to-air friction, and depends on the type of fiber from which the garment is made. The … Read more

Many folks have assured us that their bread doesn’t have time to go concave when spread with honey. However, for those folk who chomp their honeyed bread in a more leisurely fashion, there is a simple explanation. Bread is approximately 40 percent water while honey is a strong solution containing approximately 80 percent sugar. This … Read more

The graying of the inner surfaces of incandescent bulbs is the result of gradual evaporation of tungsten from the filament while the light is on. This evaporation eventually makes the filament so thin it burns out. Various methods have been developed to reduce graying. Filaments of the first incandescent lamps burnt in a vacuum, but … Read more

The way in which the unique Aero bubbles are added is a top-secret process closely guarded by Nestle Rowntree. We can tell you, however, that there are approximately 2,200 bubbles in one Aero chunky bar. Secret details may be absent but the broad answer is in Rowntree’s British patent GB 459583 from 1935. The chocolate … Read more

Tia Maria is a coffee liqueur made originally in Jamaica using Jamaican coffee beans. It is beautiful to watch patterns form on the layer of cream on a Tia Maria, and how different patterns form in layers of cream of different thickness. This is all caused by convection. Convection is the bulk movement of fluid, … Read more

Water flowing from an inverted bottle has no free surface. So the water coming out has to be replaced by something else because liquids do not expand or contract very much when the pressure changes. In the case of a thin-walled plastic bottle, the volume can be replaced by the walls of the bottle being … Read more

Unopened jars of honey that have remained clear for years can, over the space of a couple of weeks, change into solid sugar while the jar remains motionless on its shelf. Temperature does not seem to be a factor, the process can occur in winter or summer. Beekeepers argue about this, as honeys from different … Read more

Monosodium glutamate is a common flavor enhancer that is used particularly in Chinese and Japanese cooking. Monosodium glutamate, or MSG, is presumably most commonly used in oriental cooking for traditional reasons. For thousands of years the Japanese have incorporated a type of seaweed known as kombu in their cooking to make food taste better. It … Read more

Dyes used in toilet paper or paper towels are not very ecologically harmful or destructive. Chemically active groups on the dye molecules cling to the cellulose; that is why the colors don’t run and leave you fundamentally decorative after you apply them. The dyes are like a mousetrap that has caught a mouse: the trap, … Read more

Gnocchi is a variety of thick, Italian dumplings made from semolina, wheat flour, potato, or bread crumbs. Gnocchi is yummy when it is soft, airy, light, and “fluffy”. The word gnocchi means “lumps”, and is a traditional Italian pasta type introduced by the Roman Legions during the expansion of the empire into the European continent. … Read more

There is no known inventor of the pickle, because pickling has been around for a very long time. Pickling was a way to preserve food for out of season use and for long journeys, especially by sea. Pickles and chutneys were originally a means of preserving fruit and vegetables using a combination of heat processing … Read more

Natural rubber is made of polyisoprene chains that slip past each other when the material is stretched. When raw, the substance is too sticky and soft to be of much use, so it is toughened with the addition of chemicals such as sulphur that create cross-links between the chains, making the rubber stiffer and less … Read more

Here’s why some fruit and plant tissues go brown when cut. Plant cells have various compartments, including vacuoles and plastids, which are separated from each other by membranes. The vacuoles contain phenolic compounds, which are sometimes colored but usually colorless, while other compartments of the cell house enzymes called phenol oxidases. In a healthy plant … Read more

In the interest of science a Guinness was poured in a glass until the rising bubbles had formed a creamy head. Some of this was put in a dish and examined it through a low-powered microscope. Unlike bath foam, which has many semi-coalesced bubbles, Guinness foam is made mainly of uniformly sized, spherical bubbles of … Read more

Being stung by a nettle is painful because the sting contains an acid. Rubbing the sting with a dock leaf can relieve the pain because dock leaves contain an alkali that will neutralize the acid and therefore reduce the sting. Bees and ants also have acidic stings, so dock leaves should help, but other alkalis, … Read more

The lowly wasp certainly has its place in the food chain. Many animals feed, in one way or another, on this lowly and potentially dangerous insect. Here are a few creatures that do eat wasps, the first list being invertebrates. Several species of dragonflies (Odonata); robber and hoverflies (Diptera); wasps (Hymenoptera), usually the larger species … Read more

The United States Department of Agriculture states that a 180 g serving of boiled spinach contains 6.43 mg of iron. The reason you should you always use a stainless steel knife to cut your spinach is intriguing and is a major stumbling block to the fortification of food with iron. Remember that a lack of … Read more

When water vapor condenses on a dry mirror, it does so as separate droplets, a process known as dropwise condensation. The numerous drops effectively screen the mirror so that it appears opaque. When you draw on the surface with your finger, the droplets coalesce into a thin film of transparent water, so the mirror becomes … Read more

Shandy, also known as shandygaff, is beer flavored with carbonated lemonade or ginger ale. If you pour lemonade and beer into separate glasses you will notice that only the beer forms a head. That is because beer contains surfactants, proteins, and other long-chain molecules that help liquid films to form and stabilize bubbles. Lemonade bubbles, … Read more

The best way to whisk egg whites is with large continuous strokes and conviction in a clean copper bowl with a large whisk with very thin wires made of stainless steel. We regularly whisk organic free-range egg whites without any problem, and bearing in mind that in culinary history all eggs could once have been … Read more

A study in 1987 examined injuries and mortality rates in cats that had been brought to their hospital following falls ranging from between two and 32 stories. Overall mortality rates were low, with 90 percent of the cats surviving, a fact that supports many ailurophobics. However, the study unexpectedly found that the incidence of injuries … Read more

Pineapples aren’t eaten in the state that we normally see them but are eaten after they have ripened much further and fallen to the forest floor. The pineapple, Ananas comosus, was originally found in south Brazil and Paraguay and indigenous peoples spread it throughout South and Central America and to the West Indies. The plant … Read more

Many elementary school boys have a great interest in all aspects of the decomposition side of the food chain. It is difficult to predict precisely how fast a guinea pig or any other animal will decompose. Farmers, especially those who raise livestock, bury a lot of small animals over the years. They also prepare many … Read more

When the lead bird completes a flap of its wings two vortices are shed, one from each wing tip. These vortices consist of a rolling tube of air, the upper portion of which is moving forward and the lower part rearward. Should a following bird complete a downward stroke into the top of a vortex, … Read more

The reason dogs yowl when emergency services go by may be that to the dogs, the siren sounds like other dogs howling and they respond by howling back. This goes back to the time when they hunted in packs and signaled to one another when searching for prey. Even if the screaming siren does not … Read more

Snails both fertilize and carry their eggs internally. When snails are being prepared before being eaten, the snails are scooped out of their shells; usually mixed with butter, parsley, and garlic; then cooked. After cooking they are reinserted into their shells and served. The shells themselves are not cooked, so sometimes baby snails will later … Read more

Potatoes are a member of the Solanaceae family of plants, which includes tomatoes, peppers, eggplants, tobacco, and deadly nightshade. They are characterized by their ability to produce toxic alkaloids such as solanine in their leaves, roots, and fruit. Unfortunately, solanine does not dissolve, so it cannot be removed by soaking the potato and it is … Read more

The absence of trees in most chimneys shows that a very favorable site is required for growth. Damaged brickwork can provide a crevice for a seed to lodge in and send down a root, usually during a particularly wet year. The extra wetness permits the roots to go deep enough into the brickwork to survive … Read more

The depth and extent of the tunnel system of a mole, also known as Talpa europaea, will vary considerably depending on a number of factors such as the type of soil and the height of the local water table. Earthworms and other invertebrates that enter the tunnel system are the moles’ main source of food, … Read more

Giraffes and camels have long legs, relatively short bodies, and large feet. A common explanation for their unusual gaits is that the gait prevents fore and hind feet from getting in each other’s way. If you refer to feet by their initials, LF for left fore, RH for right hind, and so on, you can … Read more

Beheading hurts. How much it hurts depends on the executioner’s skill, or lack of it. When Mary, Queen of Scots, was executed at Fotheringay Castle in 1587, a clumsy headsman gave her three strokes without quite managing to sever her head. The headsman then had to saw though the skin and gristle with his sheath … Read more

The reason that we can’t see clearly underwater is the same reason a spoon looks bent when you immerse it in a glass of water. Light travels more slowly through water than it does through air. When light moves from one medium to another, it changes speed, and as a result the beam is bent, … Read more

The microorganisms that inhabit the body of a healthy human being are known as the normal microbial fauna and they come in two different types, those that are permanently resident and those that are transient. Of course, any number of fascinating and nasty parasites can join this microbial community and make the human body their … Read more

Millipedes and earthworms have similar lifestyles. Both burrow in soil, eating dead and decaying vegetation, but they have evolved very different methods for forcing their way through the soil. Worms use the strong muscles in their body walls to build up pressure in the body cavity, and so develop the forces needed to push forward … Read more

Some of us have birdbaths in our garden with a large plastic receptacle fashioned from a plant-pot saucer to hold the water. Many birds use it each day, but it is common to have algae build up very quickly on the surface covered by the water. This can happen even if the plastic receptacle was … Read more

Flies are often a nuisance while sitting on the hotel balcony when you’re on vacation. But when the winds pick up, the flies disappear. There is indeed a maximum wind speed above which they will not fly, but it also depends on temperature, humidity, and the sex and age of the fly, as well as … Read more

In the nineteenth century, bromide salts were used widely as sedatives to treat everything from epilepsy to sleeplessness. The bromide salts were said to “reduce the excitability of the brain.” The normal dose was between 5 and 30 grains and was taken several times a day, there are about 437 grains per ounce. In the … Read more

Miraculous claims of cellulite removal are characteristic of quackery, one of the biggest parasitic industries on the planet, ranking with politics, recreational drugs, and bad-faith litigation. The word “cellulite” was coined to exploit rich innocents. It has no clear definition, and that is why quacks say so little about what it is. Cellulite amounts to … Read more

Your butt does look smaller when you dress in black, at least if viewed from behind. The reason is that we can perceive shapes only if what we see appears in different shades or colors. If you wore white trousers the shape of your behind could be inferred from the slight shadows cast by its … Read more

There are many situations in which a wiping or rubbing action becomes converted to a high-frequency vibration, and the usual reason is the stick-slip nature of friction. When you start to push one surface over another, friction resists the movement. But if the pushing force is increased, it eventually reaches the threshold at which friction … Read more

Umbilical cords consist of three blood vessels and a surrounding medium called Wharton’s jelly, the whole lot enclosed by a sheath. This makes the cord too thick to be tied in a knot. Today, where medical supplies are readily available, a plastic clamp is used to compress the cord and cut off the blood supply. … Read more

One of the major functions of the colon is to absorb water and produce plasticine-like poop or feces which can be voided readily and at will. Feces consist of 75 percent water; bacteria make up half the dry weight; and the rest is unfermented fiber and excreted biliary compounds. The range of fecal weights produced … Read more

The scientific term for the yellowish crystalline substance sometimes found encrusted on eyelids when you wake up is “Rheum”, or gound. It is also commonly referred to as “sand” or “sleep”. Some amount of dry mucus forming in the corners of the eyes is common even among healthy individuals, especially children. The substance collects around … Read more

About 2,000 sebum-producing sebaceous glands and specialized sweat-like apocrine glands in the outer third of the ear canal produce mildly acidic secretions, called cerumen. Earwax is a mixture of cerumen, skin cells, and hair fragments from the ear canal, plus bacteria and other substances caught in this waxy matrix. Earwax normally moves out of the … Read more

Athlete’s foot, also known as ringworm of the foot, is a fungal infection of the skin that causes flaking, scaling, and sometimes severe itching of affected areas. The Infection is commonly transmitted in moist areas where people walk barefoot, such as showers or bathhouses. It can also be transmitted by sharing footwear and even towels … Read more

Measuring the weight of your head involves effectively isolating it from the rest of your body. Decapitation has the obvious disadvantage of your not being alive to see the results. However, there is a solution. Your neck vertebrae are responsible for holding your head’s weight. If you hang upside down from your feet the vertebrae … Read more

The equivalent of the true appendix in most animals is known as the cecum and is at the junction of the small and large intestines. In general, carnivorous mammals have a small cecum that serves the same purpose as it does in humans. However, in many herbivorous mammals the cecum is greatly enlarged to create … Read more