Hair

Hair refers to naturally growing, thread-like projections made from bundles of keratin – a protein also found in teeth and nails (which is why hair removal products can damage all three). Although organisms like insects and spiders sport similar filamentous structures, hair is unique to mammals. 

Hair is produced by follicles, narrow cavities found in the skin. Mammals express hair on all non-glabrous skin – the glabrous skin on lips, eyelids, palms, soles, back of the ears, and parts of the genitals lack follicles. Each follicle’s sebaceous glands produce oily sebum that lubricates and waterproofs the skin and hair. A hair matrix at the follicle's base generates hair through rapid cell division; cancer treatments such as chemotherapy specifically target rapidly dividing cells, causing hair loss side effects.

Déjà Vu

Déjà vu is a French expression meaning "already seen," coined by French parapsychologist ÉmileBoirac in 1876 to describe an inexplicable – and often unsettling – sensation of familiarity while experiencing something for the first time. Although déjà vu has become a blanket term for any experience of this feeling, it technically only applies to visual information. Later researchers further divided this sensation into déjà visite ("already visited"), déjà vecu ("already lived through"), déjà senit (“already felt”), and déjà entendu ("already heard").

Fruits and Vegetables

You may be privy to recent internet outrage over Congress declaring pizza a vegetable. In reality, Congress blocked a US Department of Agriculture proposal to increase the amount of tomato paste necessary to qualify as a school-lunch vegetable – for the past 20 years, two tablespoons has been sufficient.

Yet, to some, the true display of ignorance is calling tomato a vegetable, for – as even the most casual one-upper knows – they are really fruits. Which brings us to today’s post.

Zombies

What better way to mark learnalittle’s return from the dead than a short history of zombies?

Tales of the living dead abound in cultures across the world. The Norse draugar are the bodies of slain Vikings, said to inhabit their graves and jealously guard the treasures buried with their former selves. In Chinese folklore, jiang shi are reanimated corpses that hop around with their arms outstretched, sucking the life-force qi out of the living. And according to Medieval British accounts, deceased ne’er-do-wells may return as revenants – risen bodies bloated with blood – to terrorize their families and neighbors.

Daddy Long Legs

Sometimes, inspiration comes from the most unexpected places.

Endearing accent aside, this indignant German does bring up an excellent point: what exactly is the deal with daddy long legs?

As it turns out, the name "daddy long legs" is shared by three separate creatures, which all sport - you guessed it - notably long legs. The critters our Deutsch friend refers to are called Opiliones (or harvestmen). These eight-legged animals have two-segment oval bodies, have barely changed in the past 400 million years, and can be found across the globe. Though arachnids, harvestmen are not spiders, and lack both silk and venom glands; still, an erroneous urban legend contests harvestmen are the most venomous creatures on earth, yet lack fangs strong enough to pierce human skin.

Tides

Although tides are best appreciated from a comfortable beach chair, truly understanding the motion in the ocean requires a trip to the moon. As you may have noticed, the moon is Earth’s only natural satellite, locked in orbit by the Earth’s gravitational pull. But the moon has a gravitational pull of it’s own, which tugs on the planet’s oceans; the water on Earth’s moon-facing side – or sublunar point – bulges out slightly, while the water on the opposite side – or antipodal point – is pulled slightly “in,” towards the Earth’s core.

Marijuana

The story of marijuana is old indeed, and starts with one of the earliest domesticated crops: the Cannabis plant. Cannabis has been cultivated for millennia in Asia and the Middle East, as the fiber beneath its bark can be refined into soft, durable hemp. Though this fiber was the main selling point, ancient farmers soon discovered one could smoke Cannabis flowers and their attached leaves and stems for interesting psychological effects; archeological evidence shows intentional inhalation of cannabis smoke as early as the 3^rd millennium BCE.

Though these pioneers of pot most likely smoked unprocessed Cannabis, today’s stoners have additional options, like kief, a powder sifted from leaves and flowers; hashish, concentrated flower resin; and hash oil, extracted from cannabis leaves. These processed Cannabis variations offer benefits like ease of use when cooking weed-infused foods, or increased levels of Δ⁹-tetrahydrocannabinol (THC), marijuana’s main psychoactive ingredient.

Brain

Today, learnalittle has brains on the brain.

The brain is the central component of the nervous system, governing every thought and function in our body. This magnificent organ is enclosed in the cranium, protected by cerebrospinal fluid and a membrane system called the meninges. The brain itself is composed of two hemispheres that control opposite sides of the body (the left hemisphere governs the right side), joined in the middle by the corpus callosum – a thick bundle of fibers that allows the hemispheres to communicate.

Taste

Prepare your palettes for a taste of taste.

Taste – or gustation – is the one of the traditional five senses along with sight, hearing, touch, and smell. Taste usually refers to the ability to detect flavor, although smell, texture, temperature, and sight are also contributing factors. Humans experience taste through sensory organs called taste buds (or gustatory calyculi), located on the upper surface of the tongue on raised protrusions called papillae. Fungiform papillae are mushroom-shaped, and found on the tip and sides of the tongue; circumvallate papillae are the ten to fourteen dome-shaped dots at the back of the tongue; and foliate papillae appear on the sides of circumvallate papillae and the sides of the base of the tongue. Paintbrush-like filiform papillae are most common, but sense texture and touch rather than taste. Although the widely taught taste map implies taste is localized to certain parts of the tongue, taste-perception is evenly distrusted and all tasting papillae can sense every basic taste.

Photosynthesis

Today on learnalittle, learn how your food feeds itself with a look at photosynthesis.

Photosynthesis is a chemical process that uses sunlight to convert carbon dioxide and water into sugars, usually releasing oxygen as a byproduct. Land plants are the most widely known photoautotrophs (they produce energy from sunlight), along with algae and certain bacteria. Though only a handful of organisms use photosynthesis, all life on earth depends on this process. Cyanobacteria first appeared 3,000,000,000 years ago, and gradually oxygenated the planet, allowing complex aerobic (oxygen-breathing) organisms to evolve. Likewise, photoautotrophs serve as the basic terrestrial food source.

Moon Landing

Continuing learnalittle’s WEEK OF SPACE, we explore the exploration of the moon.

Before getting to getting to the moon, let’s consider the context behind one of man’s coolest accomplishments. Lunar exploration was the ultimate goal of the Space Race, an unofficial – yet high stakes – competition between the US and Soviet Union to be the world leader in technology. The Space Race itself is one of the most visible aspects of the Cold War, a fifty-year period of governmental, cultural and military tension between the two above-mentioned nations.

Stars

To kick off learnalittle's WEEK OF SPACE, we look to the stars.

A star is a massive, luminous ball of ionized gas (or plasma) that form in giant, slowly rotating clouds of dust called stellar nurseries. A cloud’s gravity gradually causes it to condense into a sphere; as it collapses, this ball becomes hotter and denser, eventually forming a protostar. Under incredibly high pressure, atoms that normally repel each other begin to collide and combine in a process called nuclear fusion. In the case of a new star, molecules of hydrogen collide to form helium. When the protostar’s heat and pressure hit 1 million °C, fusion begins and the star ignites.

Cicadas

Today on learnalittle, find out what all the buzz is about with rundown of the cicada.

Cicadas are winged insects of the superfamily Cicadoidea. There are over 2,500 species of cicada, native to temperate and tropical regions across the globe. While most cicadas are an inch or two long, members of the Pomponia and Tacua genera can be over half a foot with an 8inch wingspan. Cicadas live on tree sap, sucking up the sweet stuff by puncturing the bark with their straw-like proboscis; as they have no defenses, the only way a cicada might hurt a human is by mistaking them for a tree and going in for drink.

Octopuses

Are two arms just not enough? Learn how the other half lives with a look at octopuses.

Octopuses (or octopodes) are mollusks in the Cephelopoda (literally “head-feet”) Class, along with squids, cuttlefish, and nautilus. Unlike their relatives, most octopuses lack an external or internal shell; their squishy bodies can easily squeeze through small spaces. These creatures sport eight muscular arms used for swimming, usually lined with suction cups for walking, climbing, and grasping prey. At the center point of its arms, there’s a hard beak used to crush and eat.

Batteries

Make sure your laptop is fully charged, because today’s learnalittle is all about batteries.

A battery reacts two different kinds of metal to convert stored chemical energy into electricity through a series of ionic reactions. Batteries produce a strong, consistent current of electricity, ideal for powering electronic devices in a closed electrical circuit.

Bees

They say beauty is in the eye of the bee holder. Well, learnalittle… holds… um. Today’s post is about bees.

Bees are flying insects, closely related to ants and likely descended from wasps. Some bees are highly eusocial: one queen breeds for the entire colony, while female workers guard the hive, collect resources, produce honey, and tend to the queen and her young. A handful of male drones – which hatch from unfertilized eggs – exist primarily to mate with the queen. To raise new queens, workers feed select larvae protein-rich royal jelly, making them larger than the average bee and sexually mature.  These new queens may leave the hive with a swarm entourage to form a new colony.

Sleep

Do you have that 2:30 feeling? Forgo the energy drink and learn a little about sleep.

Sleep is a restful state of reduced or absent consciousness that occurs in all mammals, all birds, and most reptiles, amphibians, and fish. The sleep cycle is divided into two broad categories: REM (rapid eye movement) and Non-REM (or NREM) sleep; NREM sleep is further divided into three stages. In Stage 1 sleep (N1), breathing slows and the brain’s electrical activity transitions from bursts to regular brains waves. Individuals in N1 are easily woken, and may not realize they’ve been asleep. This stage is sometimes accompanied by a “falling” sensation, that may cause a hypnic jerk or sleep start – an involuntary twitching of the muscles that might wake the sleeper.

Blood

Readers beware: today’s post is not for the faint of heart. If you don’t mind a little blood, then why not learn a little more about it.

Blood is a bodily fluid that plays several vital functions in animals. While humans have several types of blood cells, more than half is plasma – a solution primarily composed of water that also contains floating proteins. In addition to circulating the body’s blood cells, Plasma also distributes sugars and hormones, and removes waste such as carbon dioxide, urea, and lactic acid. Plasma also contains platelets (or thrombocytes), which form blood clots at wounds and cuts to preventive excessive bleeding.

Ginkgo Trees

Embrace your inner tree hugger and learn a little about the one-of-a-kind Ginkgo tree.

The Ginkgo biloba is a non-flowering plant species with no close living relatives, easily recognizable by uniquely fan-shaped leaves. When grown in sunny, well watered, and well-drained locations, ginkgoes can grow over 100 feet; some Chinese specimens are over 150 feet tall!

Horseshoe Crabs

In observance of beach season, today’s post honors one of the sea shore’s oldest inhabitants: the horseshoe crab.

Horseshoe crabs date back to the Ordovician Period, and haven’t really changed in the intervening 450 million years; these ancient origins have earned them living fossil status. With their hard, dome-shaped shells, horseshoe crabs look like fossils; they molt this armor about 18 times over their life to keep growing. Under the shell, they have five pairs of clawed legs that converge at a central mouth. Instead of teeth, their mouths sport stiff bristles for eating mussels and worms.