Slightly to the side

Did you know that Earth's tilt affects the school year?

We might refer to Planet Earth as ‘the globe’, but we know it is more like a slightly flattened sphere —experts would say it’s an oblate spheroid— that is also askew. These two details have major consequences for the climate, the night sky, the way we register locations, and even the way schools plan their academic year. How much does the Earth's being at an angle affect us? Let’s find out!

Why is Earth’s axis tilted? The most widely accepted theory is that, millions of years ago, a young planet Earth collided with another celestial body and was left permanently askew. Earth’s axis, supposedly straight before, now has a tilt of 23.5 degrees. It is also believed that the Moon is a product of this collision.

The Earth is permanently tilted, but it’s not static. The degree of the tilt varies slightly across a cycle of thousands of years, which would explain why seasons were harsher or milder across history. But what keeps the Earth from having a more extreme shift? The Moon. All celestial bodies have their own gravity, and they can affect each other. Moon’s gravity has a pull on the equatorial bulge (Earth’s widest part) and prevents it from being affected by other surrounding planets, while also keeping the axial tilt stable.

The different seasons are the first major consequence of the axial tilt. As the Earth orbits around the Sun, it remains tilted in the same direction, which means that, for half of the orbit, one pole is directly facing the Sun, while the other is directly away. For the next half of the orbit, the positions are reversed. The pole closer to the Sun experiences Summer, while the opposite pole goes through Winter (which means that yes, the Southern hemisphere celebrates Christmas during Summer).

When a compass signals North, what is it pointing towards? Spoiler: not the North Pole. The North Pole (also known as True North, or Geographic North) it is a fixed point in the Arctic Ocean intersected by the rotational axis. Maps and coordinates use this point as a reference for the North. A compass, however, points towards the North of the Earth’s magnetic field, which is constantly shifting. The difference between the two Norths is called declination, and is essential for navigation and map reading.

The Earth is a sphere, but most maps are flat. Something is not adding up, and it’s all the fault of a man called Gerardus Mercator, who, in the 16th century, mapped the Earth in a way that represented the meridians and parallels as straight lines. While this was excellent for navigation, it had its negatives: a size distortion. The farthest land masses are from the equator and closest to the poles, the most inflated in size they appear. For example, in the Mercator projection, Greenland appears close in size to the entire African continent, when in reality it is closer in size to the Democratic Republic of Congo.

We all know the difference between the Northern and the Southern hemispheres, but did you know the difference between the Eastern and Western ones? Unlike North and South (which are divided by the equator and experience opposite seasons), the Eastern and Western hemispheres are more of a cultural division, even though they are separated by the Prime meridian and antimeridian. The Eastern Hemisphere is commonly associated with "the Old World" (though it includes Australia), and the Western Hemisphere is "the New World".

Hemispheres split the world equally in size, but not in content. The Northern Hemisphere contains the majority of the Earth’s land mass (around 68%), while the Southern Hemisphere holds the majority of the water (around 80%). As the Northern side has more land, it also houses the majority of the world’s population, around 90%.

North and South experience opposite seasons, but what else is opposite? Storms and whirlpools spin depending on their location—clockwise in the South, counterclockwise in the North—, and the shape of the crescent moon is perceived inverted —a waxing crescent looks like a D from the North and a C from the South.

While bigger celestial objects, such as the Sun or Moon, are visible from any point on Earth, some can only be seen depending on your location. Constellations that are located closer to the Poles are only visible from that hemisphere, and have traditionally been used for navigation and orientation. In the Northern hemisphere, the main examples are Polaris (the north star), Ursa Major (a constellation that contains the Big Dipper), Ursa Minor, Cepheus, and Cassiopeia. For the Southern Hemisphere, the main examples are Crux (the Southern Cross), Centaurus, and Carina.

Most institutions plan their year around Summer, which means that in the Northern Hemisphere, the Academic year usually starts around September and ends in May or June of the following calendar year, while there’s a Winter break in time for Christmas and New Year. In the Southern Hemisphere, the calendar and academic years are matched: the academic year usually begins in March and ends mid-December, right before the Holidays, while Winter break usually falls in July.

BELIEVE IT OR NOT

Stranger Than Fiction: 10 Unbelievable Events That Actually Happened

Image: Diana van Ormondt

They say truth is stranger than fiction, and some of these historical events are living proof of this old adage.

Brace yourself for a rollercoaster ride through history, where the strange and unexpected take center stage in the theater of reality. From absurd battles to mysterious weather phenomena, these 10 astonishing tales will leave you thinking long and hard about the complexities of human history.

Image: Sharon Co Images

Wars are typically waged between nations, but in 1932, Australia faced an unusual adversary: emus. After large numbers of these flightless birds invaded crucial farmland within Western Australia’s Wheatbelt, the government decided to intervene by sending soldiers armed with machine guns to reduce the emu population in the area. However, most attempts were ineffective at most, killing very few birds and costing thousands of dollars in supplies and ammunition.

As soon as the first shot was fired, the seemingly tame emu dispersed way beyond the range of the machine guns, and apparently switched to guerrilla tactics of sorts, avoiding all further military ambushes and frontal attacks while still feasting on the farmer’s crops. The government’s futile attempts were ridiculed and physical barrier methods to manage wildlife were preferred from then on. Sadly, they give no medals for having endured the Great Emu War.

Image: Hannah Skelly

In 1518, the town of Strasbourg, France, was gripped by a strange and inexplicable phenomenon - people suddenly began dancing uncontrollably in the streets. The dancing madness persisted for weeks, with some of the affected succumbing to exhaustion or even death. The authorities at the time did not know how to react, and some people even joined the dancers voluntarily, as they feared it was a punishment from Saint Vitus (and presumably wanted to stay on the safe side).

After many efforts to fight the strange epidemic, the dancing eventually subsided and people in the town could resume their normal lives. While theories range from mass hysteria to hallucinogenic substances and neurological disorders like Sydenham's chorea, the event remains a historical enigma that challenges our understanding of the human mind and collective behavior.

Image: Nima Sarram

In 1908, a massive explosion flattened over 80 million trees in the remote Tunguska region of Siberia. The cause? A mysterious airburst, likely caused by the explosion of a meteoroid or comet in Earth's atmosphere. It is now estimated that the event had an explosive energy of 3 to 5 megatons, equivalent to over a thousand Hiroshima bombs. The resulting shockwave broke windows, and knocked people down hundreds of miles away, reaching an equivalent of an earthquake of 5.0 on the Richter scale in some areas.

A bright glow was observed in night skies in Asia and Europe for days after the event due to high-altitude ice particles that formed as a result of the explosion. For all its magnitude, the explosion left no visible crater and minimal debris beside the devastated forest. The Tunguska Event serves as a stark reminder of the potential cosmic threats that lurk in the darkness of space.

Image: British Library

Miscommunication can often lead to chaos, but rarely on the scale witnessed in the Battle of Karánsebes in 1788. The Austrian army, at the time facing the Ottoman Empire, descended into total anarchy when two different scouting parties mistook one another for the enemy, fired on each other, and raised the alarm.

Making matters worse, the Austrian army was made of men of different nationalities who more often than not could not understand each other. All attempts to end confusion and the ensuing friendly fire on the part of the Austrian emperor himself were in vain, and after a while - deeply demoralized - he was forced to give the order of retreat. When the Ottoman army arrived two days later, they found an empty battlefield and were able to take the city of Karánsebes without any resistance.

Image: Aswathy N

In 1807, eight years before Waterloo, Napoleon Bonaparte had a humiliating defeat at the hands of a strange opponent - a horde of rabbits. During the celebrations that followed the Treaties of Tilsit - which effectively ended the war between the French and Imperial Russia - Napoleon’s chief of staff Alexandre Berthier had the idea of organizing a rabbit hunt to entertain its guests.

So far, nothing out of the ordinary for the time, but when the rabbits were simultaneously freed along the edges of a grassy field, instead of scattering as expected, all these fluffy beasts began running toward their amused hunters. But the fits of laughter didn’t last long, as the now-hunted hunters realized that there was nothing they could do to stop the relentless animals as they swarmed their positions and had no other choice than to flee. Some accounts state that Berthier had gathered around 3000 rabbits, so not even mighty Napoleon was a match for this unexpected army.

Apparently, the chief of staff's mistake was buying tame rabbits from local farmers, accustomed to being fed by humans, instead of trapping wild hares for the hunt. If we learned anything from the Great Emu War, the lesson is clear: never underestimate animals!

Image: Mitsuo Komoriya

In the aftermath of the eruption of Mount Tambora in Indonesia - the largest in at least 1,300 years - 1816 became known as the "Year Without a Summer." The volcanic ash floating in the atmosphere led to climate abnormalities worldwide, resulting in crop failures and widespread famine in the most affected areas.

In Europe and North America temperatures plummeted, and most crops suffered irreparable damage due to the persistent frost. In the United States, a "dry fog" was observed in the eastern regions, dimming sunlight so much that sunspots were visible to the naked eye. Also, the high level of volcanic particles present in the atmosphere caused strange optical effects in the following years, such as strong red hues during sunsets, which can be observed in many paintings produced at the time.

Image: Tiana Attride

It seems that wars against unusual adversaries are a fashionable trend in human history because the Roman Emperor Caligula declared war in the year 40 AD on no one other than the god Neptune himself, king of the raging seas.

Known for his eccentricity, Caligula allegedly ordered his legionnaires to "attack" the sea with swords and spears, after which he declared victory against the powerful god and told the men to gather seashells as trophies of war. One can only imagine that the soldiers had a fun -albeit puzzling- day.

Image: Tim Mossholder

In the late 1980s, Pepsi briefly possessed the sixth-largest navy in the world. In exchange for commercializing Pepsi products in the Soviet Union, the company received 17 submarines, a cruiser, a frigate, and a destroyer.

However, the fleet was composed of obsolete and unseaworthy vessels that were destined to be turned into scrap almost immediately. The payment was made in the only resources the USSR could gather easily at the time, and it provided a way to establish profitable international relations - and open up to the world.

Image: Garry T

The American Civil War started and concluded with a curious connection to Wilmer McLean, an American wholesale grocer from Virginia. The conflict's first major battle, the First Battle of Bull Run, took place in McLean's farm in 1861. A cannonball fell directly through the kitchen fireplace of the McLean’s house, which was being used as headquarters for the Confederate Army, destroying the dinner that was being prepared by the stationed officers - something that was noted not without humor by the Brigadier General P. G. T. Beauregard.

The McLean family moved to Appomattox, Virginia trying to escape the war, but just four years later, General Robert E. Lee surrendered to General Ulysses S. Grant in McLean's parlor, marking the conclusion of the Civil War. Unintentionally, McLean was a prime witness of one of America’s most defining conflicts. Later, he said of this: "The war began in my front yard and ended in my front parlor."

Image: Snowscat

Genghis Khan's vast empire and brutal military campaigns had an unexpected impact on the Earth's climate. A recent study suggests that the Mongol invasions in the 13th century led to a significant reduction in global carbon dioxide levels, as large areas of cultivated land returned to forests.

This had the unintentional effect of scrubbing as much as 700 million tonnes of carbon from the atmosphere, roughly equivalent to the global annual consumption of gasoline today. This drastic ecological shift highlights the effect that land use, and particularly deforestation can have on our planet at a large scale.