Lithops is a genus of succulent plants native to southern Africa. They avoid being eaten by blending in with surrounding rocks. They are often known as pebble plants or living stones. The plants consist of one or more pairs of bulbous, almost fused leaves opposite to each other, with hardly any stem. The slit between the leaves produces flowers and new leaves.

The leaves are not green as in almost all higher plants, but various shades of cream, grey, and brown, patterned with darker windowed areas, dots, and red lines. The markings on the top surface disguise the plant in its surroundings. During winter a new leaf pair, or occasionally more than one, grows inside the existing fused leaf pair. In spring the old leaf pair parts to reveal the new leaves and the old leaves will then dry up.

Yellow or white flowers emerge from the fissure between the leaves after the new leaf pair has fully matured, one per leaf pair. Some species have flowers large enough to obscure the leaves. They open in the afternoon and close in the evening. In tropical climates, Lithops can be grown primarily in winter with a long summer dormancy.

Lithops are popular novelty house plants and many specialist succulent growers maintain collections. Seeds and plants are widely available in shops and over the Internet. They are relatively easy to grow if given sufficient sun and a suitable well drained-soil.


Alien abduction insurance is an insurance policy issued against alien abduction. The insurance policy is redeemed if the insured person is abducted by aliens. A policy normally costs around $150 per $1.5 million in coverage. Some companies offer policies for alien pregnancy, alien examinations and death caused by aliens. More recently the Alien Abduction Insurance Corporation has launched the idea of abduction insurance certificates as a unique gift for a lifetime premium and sells it for $9.95.

The first company to offer UFO abduction insurance was the St. Lawrence Agency in Altamonte Springs, Florida. The company says that it has paid out at least two claims. The company pays the claimant $1 per year until their death or for 1 million years, whichever comes first. Over 20,000 people have purchased the insurance.

The insurance company Goodfellow Rebecca Ingrams Pearson stopped offering alien abduction insurance after having sold the policy to about four thousand people. At a cost of roughly $155 a year the policy would pay about $160,000 to someone who could show that they had been abducted by a being who was not from Earth. The payment would double if the insured person was impregnated during the event. Men were also able to purchase the impregnation insurance for protection against the unknown capabilities of alien technology.


From Our Forests and National Parks, by John Muir, 1901

“The tendency nowadays to wander in the wilderness is delightful to see. Thousands of tired, nerve-shaken, overcivilized people are beginning to find out that going to the mountains is going home; that wildness is a necessity; and that mountain parks and reservations are useful not only as fountains of timber and irrigating rivers, but as fountains of life.

Awakening from the stupefying effects of the vice of over-industry and the deadly apathy of luxury, they are trying the best they can to mix and enrich their own ongoings with those of Nature, and to get rid of rust and disease. Briskly venturing and roaming, some are washing off sins and cobweb cares of the devil’s.

Spinning all-day storms on mountains; sauntering in rosiny pinewoods or in gentian meadows, brushing through chaparral, bending down and parting sweet, flowery sprays; tracing rivers to their sources, getting in touch with the nerves of Mother Earth.

Jumping from rock to rock, feeling the life of them, learning the songs of them, panting in whole-souled involvement, and rejoicing in deep, long-drawn breaths of pure wilderness. So also is the growing interest in the care and preservation of forests and wild places.”


A compass is a navigational instrument for determining direction relative to the Earth’s magnetic poles. It consists of a magnetized pointer, usually marked on the North end, free to align itself with the Earth’s magnetic field. The compass greatly improved the safety and efficiency of travel, especially ocean travel.

Compasses were initially used in mysticism in ancient China. The first known use of the Earth’s magnetic field in this way occurred in ancient China as a spectacle. Arrows were cast similarly to dice. These magnetized arrows aligned themselves pointing north, impressing the audience. Curiously, it took some time for this trick to get used by the Chinese for naval navigation, but by the 11th or early 12th century it had become common.

The earliest Chinese compasses were probably not designed for navigation, but rather to order and harmonize their environments and buildings in accordance with the geomantic principles of feng shui. These early compasses were made using lodestone, a special form of the mineral magnetite that aligns itself with the Earth’s magnetic field.

Since then, more accurate devices have been invented for determining north that do not depend on the Earth’s magnetic field for operation. A gyrocompass or astrocompass can be used to find true north, while being unaffected by stray magnetic fields, nearby electrical power circuits or masses of ferrous metals. A recent development is the electronic compass which detects the magnetic direction without potentially fallible moving parts. This device frequently appears as an optional subsystem built into GPS receivers. However, magnetic compasses remain popular, especially in remote areas, as they are cheap, durable, and require no electrical power supply.



The Black Oystercatcher is a conspicuous black bird found on the shoreline of western North America. It ranges from the Aleutian Islands of Alaska to the coast of the Baja California peninsula. It is a large, noisy bird with a massive long orange or red bill used for smashing or prying open mollusks.

It is restricted in its range, never straying far from shores, in particular favoring rocky shorelines. It has been suggested that this bird is seen mostly on coastal stretches which have some quieter embayments, such as jetty protected areas. It forages in the intertidal zone, feeding on marine invertebrates, particularly mollusks such as mussels, limpets and chitons. It hunts through the intertidal area, searching for food visually, often so close to the water’s edge it has to fly up to avoid crashing surf.

The diet of oystercatchers varies with location. Species occurring inland feed upon earthworms and insect larvae. The diet of coastal oystercatchers is more varied, although dependent upon coast type; on estuaries bivalves, gastropods and polychaet worms are the most important part of the diet, where rocky shore oystercatchers prey upon limpets, mussels, gastropos and chitons. Other prey items include echinoderms, fish, and crabs.

The Black Oystercatcher is a territorial bird during the nesting season, defending a foraging and nesting area in one territory. Some pairs have been recorded staying together for many years. Nests are small bowls or depressions close to the shore in which small pebbles and shell fragments are tossed in with a sideward or backard flick of the bill.


In the Indian Hindu calendar, Tithi is the lunar date. A tithi is the time taken for the longitudinal angle between the moon and the sun to increase by twelve degrees. Tithis begin at varying times of day and vary in duration. As the moon rotates around the earth, the angular distance between the sun and the moon as seen from the earth increases from 0 degrees to 360 degrees. A lunar month consists of 30 tithis, whose start time and duration vary.

The lunar date, however, varies approximately between 22 to 26 hours based on the angular rotation of moon around the earth in its elliptical orbit. It takes one lunar month or about 29.5 solar days for the angular distance between the sun and the moon to change from 0 to 360 degrees. When the angular distance reaches zero, the next lunar month begins. Thus, at the new moon a lunar month begins; at full moon, the angular distance between the sun and the moon as seen from the earth becomes exactly 180 degrees.

Since the angular distance between the moon and the sun is always relative to the entire earth, a lunar day or tithi starts the same time everywhere in the world, but not necessarily on the same day. Thus, when a certain tithi starts at 10:30pm in India, it also begins in New York at the same time, which is 12:00pm on the same day. Since the length of a tithi can vary between 20 to 28 hours, its correspondence to a weekday becomes a little confusing.

Tithi is one of the most important aspects of the Indian Almanac, or Panchang, and therefore many Hindu festivals and ceremonies are based on the Tithi Calendar. Most Indians celebrate Kartik Shudha Prathama (the first day of the Indian lunar month Kartik) as their New Year’s day. Indians living in India, Europe, and the eastern part of the United States thus celebrate their New Year on that Monday, while regions west of Chicago do so on the preceding day, Sunday.


The 2007 Siberian orange snow was an anomalous phenomenon that happened on February 2, 2007 when an orange-tinted snow fell across an area of 580 square miles in the Siberian Federal District in Russia, as well as into the neighbouring oblasts of Tomsk and Tyumen. It was most likely caused by a heavy sandstorm in neighbouring Kazakhstan.

This orange snow was malodorous, oily to the touch, and reported to contain four times the normal level of iron. Though mostly orange, some of the snow was red or yellow. It affected an area with about 27,000 residents. It was originally speculated that it was caused by industrial pollution, a rocket launch or even a nuclear accident. It was later determined that the snow was non-toxic. However, people in the region were advised not to use the snow or allow animals to feed upon it. Coloured snow is uncommon in Russia but not unheard of, as there have been many cases of black, blue, green and red snowfall.

The phenomenon was most likely caused by a heavy sandstorm in neighbouring Kazakhstan. Tests on the snow revealed numerous sand and clay dust particles, which were blown into Russia in the upper stratosphere. The speculation that the colouration was caused by a rocket launch from Baikonur in Kazakhstan was later dismissed, as the last launch before the event took place on January 18th.

Russia’s environmental watchdog originally claimed that the coloured snowfall was caused by industrial pollution. It stated that the snow contained four times the normal quantities of acids, nitrates, and iron. However, it would be nearly impossible to pinpoint a culprit if pollution were the cause, as there are various industries nearby, such as the city of Omsk, which is a centre of the oil industry in Russia.


Tides are the rising of Earth’s ocean surface caused by the tidal forces of the Moon and the Sun acting on the oceans.Tides cause changes in the depth of the marine and estuarine water bodies and produce oscillating currents known as tidal streams, making prediction of tides important for coastal navigation. The strip of seashore that is submerged at high tide and exposed at low tide, the intertidal zone, is an important ecological product of ocean tides.

The changing tide produced at a given location is the result of the changing positions of the Moon and Sun relative to the Earth coupled with the effects of Earth rotation and the bathymetry of oceans, seas and estuaries. Besides the ocean, tidal phenomena can occur in other systems whenever a gravitational field that varies in time and space is present.

In addition to oceanic tides, there are atmospheric tides as well as earth tides. All of these are continuum mechanical phenomena, the first two being fluids and the third being essentially the thin solid Earth’s crust on top of the semi-liquid Earth’s interior.

Atmospheric tides are negligible from ground level and aviation altitudes, drowned by the much more important effects of weather. Atmospheric tides are both gravitational and thermal in origin and are the dominant dynamics from about 80 km to 120 km where the molecular density becomes too small to behave as a fluid.

Earth tides or terrestrial tides affect the entire mass of the Earth, which can be viewed as a liquid gyro with a very thin crust. The Earth’s crust shifts in response to the Moon’s and Sun’s gravitation, ocean tides, and atmospheric loading. While negligible for most human activities, the semidiurnal amplitude of terrestrial tides can reach about 55 cm at the equator which is important in GPS calibration.

When oscillating tidal currents in the stratified ocean flow over uneven bottom topography, they generate internal waves with tidal frequencies. Such waves are called internal tides. The galactic tide is the tidal force exerted by galaxies on stars within them and satellite galaxies orbiting them. The effects of the galactic tide on the Solar System’s Oort cloud are believed to be the cause of 90 percent of all observed long-period comets.


Magnetoception is the ability to detect a magnetic field to perceive direction, altitude or location. This sense plays a role in the navigational abilities of several animal species and has been postulated as a method for animals to develop regional maps.

It is most commonly observed in birds, where sensing of the Earth’s magnetic field is important to the navigational abilities during migration. In pigeons and other birds, researchers have identified a small heavily innervated region of the upper beak which contains biological magnetite and is believed to be involved in magnetoception.

Evidence has also been found that the light-sensitive molecule cryptochrome in the photoreceptor cells of the eyes is involved in magnetoception. According to one model, cryptochrome when exposed to blue light gets activated and forms a pair of two radicals where the spins of the two unpaired electrons are correlated. The surrounding magnetic field affects the type of correlation (parallel or anti-parallel), and this in turn affects the length of time cryptochrome remains in its activated state. Activation of cryptochrome may affect the light-sensitivity of retinal neurons, with the overall result that the bird can “see” the magnetic field. Cryptochromes are also essential for the light-dependent ability of the fruit fly Drosophila melanogaster to sense magnetic fields.

It is believed that birds use both the magnetite-based and the radical pair-based approach, with the radical pair mechanism in the eyes providing directional information and a magnetite-based mechanism in the upper beak providing information on position as component of the ‘map’.

In bees, it has been observed that magnetite is embedded across the cellular membrane of a small group of neurons. It is thought that when the magnetite aligns with the Earth’s magnetic field, induction causes a current to cross the membrane which depolarizes the cell.

Crocodiles are believed to have magnetoception, which allows them to find their native area even after being moved hundreds of miles away. Some have been strapped with magnets to disorient them and keep them out of residential areas.

In 2008, a researcher team led by Hynek Burda using Google Earth accidentally discovered that magnetic fields affect the body orientation of cows and deer during grazing or resting. In a followup study in 2009, Burda and Sabine Begall observed that magnetic fields generated by power lines disrupted the orientation of cows from the Earth’s magnetic field.

Humans have magnetite deposits in the bones of the nose, specifically the sphenoidal/ethmoid sinuses. Beginning in the late 1970s the group of Robin Baker at the University of Manchester began to conduct experiments that purported to exhibit magnetoception in humans. People were purposely disoriented and then asked about directions to a specific place. Their answers were more accurate if there was no magnet attached to their head. These results could not be reproduced by other groups and the evidence remains ambiguous. Recently, other evidence for human magnetoception has been put forward as low-frequency magnetic fields can produce an evoked response in the brains of human subjects.

Certain types of bacteria and fungi are also known to sense the magnetic flux direction. They have organelles known as magnetosomes containing magnetic crystals for this purpose.


A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. The Ancient Romans called volcanoes Vulcano, after Vulcan, their fire god.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart. The Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth’s crust, such as in the African Rift Valley, the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

Volcanoes can be caused by mantle plumes. These so-called hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.

The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit. This describes just one of many types of volcano, and the features of volcanoes are much more complicated. The structure and behavior of volcanoes depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic lava and gases can be located anywhere on a landform.

Other types of volcano include cryovolcanoes or ice volcanoes, particularly on some moons of Jupiter, Saturn and Neptune. Mud volcanoes are formations often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano.

Many ancient accounts ascribe volcanic eruptions to supernatural causes, such as the actions of gods or demigods. To the ancient Greeks, volcanoes’ capricious power could only be explained as acts of the gods, while the 16th German astronomer Johannes Kepler believed they were ducts for the Earth’s tears.

Various explanations were proposed for volcano behavior before the modern understanding of the Earth’s mantle structure as a semisolid material was developed. For decades after awareness that compression and radioactive materials may be heat sources, their contributions were specifically discounted. Volcanic action was often attributed to chemical reactions and a thin layer of molten rock near the surface.