The Olympic Flag, which consists of five interlocking coloured rings, was created by Frenchman Pierre de Coubertin, the founder of the modern Olympic games, and unveiled in 1914.

Coubertin said that the five rings represent the five parts of the world embracing "Olympism" and competing against each other: Africa, The Americas, Asia, Europe and Oceania. The interlacing of the rings represents the unity and coming together of athletes from all parts of the world. Coubertin did not associate individual rings with individual continents.

The six colours of blue, dark yellow, black, green, red and white—the field on which the rings are set—"reproduce the colours of every country", and at least one is found on every national flag (I believe that’s still true).

I was thinking of including a sketch of each of the Olympic sports, but depending on how you count them, there are 32 sports and over 300 events.

You can learn more than you ever wanted to know about the history of the Olympic Flag in The Story of the Rings by Karl Lennartz (pdf). 

The Olympic flag and various other Olympic Properties (like the rings, torch and motto) are © IOC.

Great Britain, the British Isles, the United Kingdom - eh?

The Olympic Flag

Point Nemo is the furthest point in the ocean from any land.

Imagine falling overboard and needing to swim to the nearest shore; the longest possible swim would start at Point Nemo. This puzzle, known as the Longest Swim Problem, finds its solution far into the South Pacific Ocean at Point Nemo.

Where is Point Nemo? (Location & Coordinates)

Point Nemo, officially known as the Oceanic Pole of Inaccessibility, sits at 48°52.6′S 123°23.6′W, over 2,688 km from the nearest land. It is the single most remote location on Earth, entirely surrounded by open ocean.

The furthest point from land is a point with a maximum equal distance to three points of land. If you moved in any direction from Point Nemo, you'd be closer to one of the points than the others.

The three nearest landmasses to Point Nemo, each about 2,688 km away, are:

Moto Nui, a small islet off the coast of Rapa Nui (Easter Island)

Maher Island, off the coast of Antarctica

If you've ever been somewhere with only the sea in all directions, imagine what it would feel like to begin a 2,688 km swim (!) from there.

Croatian survey engineer Hrvoje Lukatela identified and named Point Nemo using computer calculations. Lukatela named it after Captain Nemo from Jules Verne's classic story Twenty Thousand Leagues Under the Sea. Nemo means nobody in Latin.

Lukatela faced challenges in determining its exact coordinates, such as choosing the edge of Ducie Atoll's tidal sandbar and Maher Island being beneath ice for most of the year.

One of the strangest facts about Point Nemo is that it is a designated spacecraft cemetery. Since the 1970s, NASA, the European Space Agency, and others have deorbited satellites and spacecraft over this remote spot. The lack of human activity and extreme remoteness make it the perfect safe crash site for space debris.

Over 250 spacecraft, including the Mir space station, have ended their journeys here in this region. The International Space Station itself is also planned to end here when it is retired.

At any given time, likely the closest people to Point Nemo are often those in the International Space Station passing overhead a mere 400km above.

The waters surrounding Point Nemo are part of the South Pacific Gyre, a massive current system that isolates it from nutrient-rich waters. As a result, marine life here is scarce, making it one of the least biologically active parts of the ocean.

The Oceanic and Continental Poles of Inaccessibility

Point Nemo is also known as the Oceanic Pole of Inaccessibility. In contrast, the Continental Pole of Inaccessibility—the point on land furthest from the ocean—is in northwestern China near Kazakhstan, a remarkable 2,645 km from the nearest shore.

And the antipode to Point Nemo, the point directly opposite it on Earth's surface, lies somewhere in Kazakhstan.

Point Nemo has a lovely spread in Simon Kuestenmacher's book Marvellous Maps.

Writing about Point Nemo makes me want to rewatch Life of Pi and listen to the captivating music.

Point Nemo: The Most Remote Place on Earth and the Spacecraft Graveyard

Nearly every iceberg you see in a picture or diagram is probably floating the wrong way. This was what I learned (from Megan Thompson-Munson) after sketching Biz Stone's brilliant saying about the myth of overnight success.

With some approximation, the density of ice is around 900 kg/m3, and seawater is around 1,000 kg/m3. Therefore, the fraction of an iceberg that's submerged is around ~900/1000 or 0.9. So, about 90% of an iceberg is below the surface and 10% above, which is partly why they can be so dangerous. While most iceberg pictures get this part more or less correct, most of these icebergs will be floating vertically. In reality, a tall, thin iceberg will likely topple, so most icebergs end up floating on their side, not their tips, even though we rarely draw them this way.

I remember learning about a fascinating experiment with children of different ages estimating which glass holds more water: a tall, slender one filled high or a wider glass filled to a lower level. Younger children almost always chose the glass with the higher water level as the most water, even when it was significantly less than the shorter and wider glass. I wonder if it's part of why we draw icebergs vertically, at least when we're using them as a metaphor. It's easier to grasp quantities vertically, and we commonly underestimate volume spread over a wider area.

We may still want to draw our icebergs tall and deep to make our point, but now, at least, we can do so with the knowledge that they're not like the real ones.

If you want to see it yourself, Joshua Tauberer made a brilliant draw-an-iceberg-and-see-how-it-will-float game. I recommend you give it a go so it sinks in forever (sorry).

Know your poles: penguins or polar bears, frozen ice or land

Iceberg orientation

While each volcano is unique they can largely be divided into red volcanoes and grey volcanoes.

Red volcanoes typically have effusive eruptions dominated by the classic red-glowing lava flow or lava lake. The constant mild eruptions of lava let gases escape reducing the chances of gas build-up and larger explosions. A classic red volcano is Kīlauea in Hawaii.

Grey volcanoes are known for explosive eruptions. Trapped gases and heat can build up within the volcano releasing explosive eruptions that can shoot ashes and rock high into the sky and cause fast-moving pyroclastic flows of solidified lava and ash. Grey volcanoes are typically much more destructive than red volcanoes and can exhibit some behaviours like their red counterparts. A classic grey volcano is Mt St Helens.

I learned this distinction from the remarkable film Fire of love.

Order of adjectives (came to mind as I wrote 'classic red-glowing lava flow' - try the adjectives in other orders =) )

Red volcano, grey volcano

How far away is the storm? The flash-to-bang method can help.

When lightning is made by a storm the rapid heating and expansion of the air create the thunderclap. But because sound travels slower than light, there's a gap between seeing the lightning and hearing the thunder it produced. Using Distance = speed x time, by counting the seconds from seeing the lightning you can easily estimate how far away it is.

Conveniently, the speed of sound in air is about 330 metres/second. So depending on your unit preference:

every 3s you wait the thunder travels about 1 km

every 5s you wait the thunder travels about 1 mile

Give it a try at a safe distance from your next lightning storm.

Also see: thunderclap or rumble, thunder clouds, dirty thunderstorm

Flash-to-bang method

Heat islands are urban areas that can have higher temperatures than surrounding rural areas with more greenery.

Heat islands are caused by several factors, including:

the types of materials we use in cities for buildings, pavement, and roads that can absorb more heat than natural surfaces such as leaves or grass

human additions to the sun's heat, such as air conditioning, vehicles, cooking, or machinery

the shapes of our cities that may restrict airflow to carry heat away

the mass of our buildings that can absorb heat and release it gradually, even through the night

More natural, often rural areas with greenery may reflect more light, release moisture and provide shade.

There are ways to help reduce the effect of heat islands, such as planting more urban trees or using green roofs.

Deciduous trees have the handy feature of providing shade for a house in the summer while letting light through in the winter when the leaves fall.

A study using 2015 data found that "doubling tree cover in European cities could cut the number of heat-related deaths during summer months by nearly 40 per cent." In Columbia's Medellín, creating 30 Green Corridors helped to reduce temperatures by 2°C in the first three years of the program.

Learn more about the heat island effect on the EPA site.

Heat islands

I like these common settlement patterns — look out for them.

Nucleated settlements, or clustered settlements, gather around one or more central hubs like a church or a square.

Linear settlements form alongside roads or landscape features like waterways or shoreline.

Dispersed settlements are common in agricultural areas where houses or farmsteads are spread out but form a loose settlement area.

Isolated settlements are the loners in the most magical and isolated wilderness by themselves.

Settlement patterns

It might seem straightforward to pull out a map and measure the distance between two distant points, however, the larger the distance the bigger the distortion caused by traveling on the curved surface of the Earth as opposed to flat 2D space. So while the distance you measure to your neighbouring town won't be too bad, if you're measuring between London and Rio the curvature of the Earth will make a big difference to the distance that you'll travel. To help figure out the correct distance there's the haversine formula.

The haversine formula allows you to calculate the shortest distance between two points on a sphere using their latitudes and longitudes — this will be the arc between them on the great circle that includes both points. A great circle is a circle on a sphere with the same centre as the sphere, like the Equator. The haversine formula isn't perfect in practice, as Earth isn't a perfect sphere — see the 3 tallest mountains.

It was invented around two hundred years ago, together with tables to speed any calculations, to help sailors navigate.

The haversine formula

Jared Diamond’s classic book Guns, Germs and Steel, proposes some remarkable hypotheses about how the pattern of history played out, notably trying to answer the question of why it was generally the Europeans that invaded much of the rest of the world rather than the other way around. One hypothesis, striking in its simplicity if you’ve ever looked at a world map, is the significant contribution of the general orientation of the major continents.

The Americas are largely lined up north–south, while Europe and Asia (Eurasia) are largely lined up east-west. An east-west alignment means the land generally has a more similar climate, day-length and seasonal variations. The general logic of the hypothesis is that the similar latitude of an east–west alignment means animals, crops, as well as travel and trade, more easily spread across the continents than across those with a north–south alignment — of the Americas and Africa — which naturally encounter more different climatic zones.

As a simplified example, horses and other large animals and crops spread throughout the shared temperate latitudes of Eurasia. In contrast, South America’s only large domesticated animal, the thick-coated llama (and related species like the alpaca), couldn’t easily spread to North America through the impassable tropical barrier of the isthmus of Panama. They just aren’t built for it.

There are a lot of viewpoints on the theory, and Diamond includes many more factors of geography and others — like never being able to domesticate the zebra — that go towards answering his question of why Spain invaded the Americas and not vice-versa. But ever since reading his simple hypothesis, available to anyone with a world map, I’ve found it hugely intriguing.

The continental axis hypothesis

The coastline paradox is the fascinating observation that it’s not straightforward to say how long a coastline is. If you were to measure the coastline of a country by using a ruler on a globe, you would come out with a vastly different number than if you were to pace around the edge. The closer you look, the more wiggles and squiggliness you come across, and instead of converging to a more accurate length, the coastline just keeps getting longer. The smaller your ruler, the longer it gets.

This was originally spotted, incredibly, in the 1950s by an Englishman, Lewis Richardson, when trying to check a theory he had that the likelihood of war between countries depended on the length of their shared borders. Remarkably, he found that the quoted lengths of borders varied significantly. While measuring on maps at different scales, he saw that the smaller scale map he used, or the smaller the width of his callipers he measured with, the length systematically increased. When looking at coastlines, instead of borders, some countries had wigglier coasts, and so the length increased at a faster rate with the scale — for instance, Norway’s coastline, with it’s crinkly fjords, increases faster than Britain’s, which in turn increases faster than South Africa’s, as he zoomed in. The rate of this increase later became known as its fractal dimension.

Long after Richardson’s research, Benoit Mandelbrot published a paper How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension that discussed how the wiggliness of something like a coastline at one scale can be repeated at smaller and smaller scales. The work led to the later term fractals. Many other things exhibit fractal-like behaviour, such as river networks, borders, brains, frequencies, lightning, and even the stock market.

There’s a super section on this in Scale, by Geoffrey West.

The difference between Great Britain, the UK and the British Isles

The coastline paradox

I grew up with the idea that there are developed countries and developing countries, the “rich” world and the “poor” world. I didn’t actively consider this teaching. It’s just always been there. And it’s wrong.

In his excellent book Factfulness, Hans Rosling shows that wealthier countries tend to have smaller families and a low child mortality rate. In contrast, poorer countries are more likely to have larger families and a high child mortality rate.

Plotting the spread of countries in the 1960s gives a reasonable approximation of a cluster of “developed” countries with small families where most children survive and a cluster of “developing” countries with larger families where more children die. But that was in the ’60s.

The world has changed a lot since then, and that model of dividing the world into two buckets no longer fits the data. Most people in the world are somewhere in the middle.

And more helpful than dismantling a worldview is providing a new model to replace it: a model with four income levels instead of two. The numbers reflect most people’s reality, with most of us somewhere in the middle.

Related Ideas to A world of Four Income Levels

For more, check out the Factfulness book, or Gapminder. And you could do much worse than watch Hans’ entertaining TED talk: the best stats you’ve ever seen.

A world of 4 income levels

Everyone knows Everest is the highest mountain at a colossal 8,848m above sea level. But, depending on how you’re measuring, there are two other candidates for tallest mountain.

Mauna Kea is a volcano on the big island of Hawaii. In fact the whole island is made from volcano, so as a peak it rises from the base of the Pacific ocean to over 4,200m above sea level. Including the part of the mountain that rises from the sea bed it is over 10,000m tall.

Mt Chimborazo can also lay a claim to the tallest mountain. The Earth is not a perfect sphere — it bulges around the Equator meaning that points on the Equator are several kilometres further from the centre of the Earth than points further North or South. A bulging around the centre is a common shape for a spinning sphere due to the force exerted by the spinning. Sitting almost exactly on the Equator means that Chimborazo’s already enormous 6,263m from sea level makes its summit the furthest point on the Earth’s surface from the centre of the Earth.

I’m not totally sure if that means that at some point Chimborazo’s summit makes it the closest point to the sun, but it definitely sounds plausible! 

The 3 tallest mountains

In the UK and certain temperate latitudes there’s a period where the weather gets warmer and the season late for the winter crops, while the temperatures can still be too low for the Summer crops to get going. This period is known as the Hungry Gap — from late April, through May and a little of early June — as it’s hard to pick enough crops locally at that time of year to live off.

Ellen Warrell at Riverford Organic Farmers explains the Hungry Gap, including ways to manage it. For example, did you know that “Trucking tomatoes over from Spain uses just a tenth of the carbon compared with growing them in the UK using heat.”

The Hungry Gap

All maps involve decisions. Whenever you compress real life onto something smaller and less detailed you have to choose what to keep in and what to leave out. And in the case of printing a map of the Earth, you have to figure out how to get something that is curved onto something that is flat, and this involves trade-offs and decisions as well. 3 dimensional space just doesn’t flatten to 2 dimensional paper without choices.

In 1569 Gerardus Mercator created a map that brilliantly solved a pressing problem — that of being able to follow a straight line while sailing and it correspond to a straight line on the map. His map also did a good job of preserving the shape of countries. But to do this you have to stretch the areas at the top and bottom of the Earth. Because most of the land on Earth is in the Northern hemisphere, and because that land is generally further north than the land in the southern hemisphere is south, it has the effect of enlarging Northern countries such as Europe, the US and Canada, Scandinavia and Russia as compared to countries closer to the equator and in the Southern hemisphere.

Most world maps you see are still similar to Mercator’s projection. In fact Google Maps desktop used it until just recently. It could well be that this distorts our worldview by emphasizing Northern countries in size and therefore importance. When I see a more size accurate Gall-Peters projection I have to say it’s hard to argue.

The Mercator projection

The Earth’s tilt causes the changing seasons. As the Earth revolves around the sun, the tilt of its axis—23.5 degrees—causes the two hemispheres, North and South, to be either tilted towards the sun or away from it at different times of the year.

In Winter, because light from the sun hits at a greater angle and closer to the poles, the solar energy gets spread over a larger area. This makes it weaker and cooler and gives rise to colder weather (aka winter).

In summer, the sun's light hits more directly and is closer to the equator, so it’s concentrated on a smaller area, leading to hotter days.

Because of the tile of the earth, seasons are reversed in the two hemispheres, so if it’s winter in the Northern Hemisphere, it’s summer in the Southern and vice-versa. The further from the equator you go, the bigger the effect of the seasons. As an example, temperatures in Ecuador stay relatively constant throughout the year, while the poles experience extremes of 24-hour daylight or 24-hour night and great freezes and thaws.

A version of this sketch, along with a number of other planetary and seasonal ideas, features in my book Big Ideas Little Pictures

Seasons

Lake Effect Snow is a phenomenon where crazy amounts of snow can fall in massive storms on a lake’s downwind—leeward—side. Where the effect is pronounced, to the east of some of the Great Lakes in the U.S. (think Buffalo), it’s responsible for the regions known as the snow belt.

It works like this: Cold air blows over a lake. As the cold air passes over the warmer lake, it picks up water vapor from the water, which warms the air. This causes the air to rise and, in turn, cool, such that when it reaches the downwind side of the lake, it has become cold and moist. This simple change can lead to some incredible snowstorms dumping 2 to 3 inches of snow per hour. Satellite pictures show it in action pretty clearly.

If there is a rise in land elevation along the path of the cold air, the air can cool faster and increase the effect — and also cause a rain shadow. And if there’s a lot of convection and the air rises quickly, you can even get what’s called thundersnow—a thunderstorm in a snowstorm.

Find the weather interesting? Me too. Also see:

Yesterday’s weather (applying weather forecasting to productivity forecasting)

Know your cirrostratus from your altocumulus

For everyday weather-related phenomena explained, see Dennis Mersereau’s The Skies Above: Storm Clouds, Blood Moons, and Other Everyday Phenomena, Mountaineers Books (2022). Dennis is also the source of the lovely phrase Nature’s greatest snow machine.

Lake-effect snow

Growing up on the island of Great Britain, I took for granted that after a few hours of travel in most directions, I'd be looking out to sea. But that's not the case for many people.

If you were born in a landlocked country, there's no coastline, and you'd need to cross at least one other country to reach the ocean.

And there's a much rarer situation: being double-landlocked. Only two countries in the world have this unique distinction: Uzbekistan and Liechtenstein.

To be double-landlocked, a country must be surrounded entirely by landlocked neighbours. In other words, not only does the country itself lack access to the sea, but every country bordering it is also landlocked.

If you live in a double-landlocked country, you must cross at least two national borders before reaching a coastline connected to the oceans.

The World's Only Double-Landlocked Countries

There are just two double-landlocked countries in the world:

Located in Central Asia, Uzbekistan is surrounded entirely by other landlocked nations: Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, and Turkmenistan. To reach the ocean, you'd need to cross at least one of these countries and then go through another country to its coastline.

For instance, you could cross through Kazakhstan (landlocked) and on through Russia to reach the Arctic Ocean. Or perhaps through Afghanistan and then Pakistan to reach the Indian Ocean.

Although Turkmenistan borders the Caspian Sea, the Caspian Sea isn't connected to the open oceans.

The tiny principality of Liechtenstein, sandwiched between Switzerland and Austria, is the other double-landlocked country.

Because Switzerland and Austria are landlocked, reaching the ocean involves crossing at least one of these countries and then travelling through a third—perhaps heading south through Switzerland to the Italian coastline for a nice trip.

Being double-landlocked adds complexity to trade and transport and a particular reliance on neighbours.

Are There Double-Landlocked States in the United States?

Landlocked and double-landlocked also applies to states in the US. 27 US States are considered landlocked to some degree.

16 states are singly landlocked—crossing one state boundary would give them access to the ocean.

10 states are double-landlocked because reaching the coastline requires crossing at least two other states. These are:

And Nebraska is the only triple-landlocked state. To reach the ocean, Nebraskans must first cross a double-landlocked state, then a landlocked state.

Double-landlocked countries, along with other fascinating facts about the world, features in my book Big Ideas Little Pictures.

Double-landlocked countries

From the prefix iso meaning equal and khronos meaning time it literally means equal times. And whereas maps are usually put together with lines of equal distance you can either construct maps, or overlay maps as here, with lines of equal time. The overlay view gives you time contours rather than, say, altitude contours. Handy for checking things like commuting distance. I like how you find little islands where there is fast transport in and out like trains or planes.

You can explore time maps of London at mapumental.

Isochrones

Strahler stream order is a smart way of categorizing the size of rivers by tracking where tributaries join. 

Each time two tributaries of the same order join together, the river rises in order.

So, the start of a stream from a spring is the outermost branch—it's first order. When two first-order tributaries join together, the river is classified as second-order, and so on.

The largest river by Strahler stream order classification is the Amazon, which is an incredible 12th-order river. This means that at least two 11th-order rivers had to merge together before the river emptied into the sea. Huge.

Strahler stream order: Streams, rivers, the Amazon and how to organise them.

If you were to dig straight down from where you’re standing and pass straight through the centre of the Earth and keep on digging — you’d now be tunnelling up I guess — where you come out would be your antipode. Though most of them would first have you springing a leak at the bottom of the ocean, so be careful.

Antipodes

The Union Jack, one of the most recognizable flags in the world, is a combination of three historic flags. It represents the union of nations within the United Kingdom at the time the Union Jack flag design was created and is made up of:

The Saltire of St Andrew for Scotland: a white diagonal cross on a blue background. The term “saltire” refers to this specific diagonal cross shape in heraldry.

The Cross of St Patrick for Ireland: a red diagonal cross on a white background. Though Ireland is no longer part of the United Kingdom, it is still represented in the design.

The Cross of St George for England: a red cross on a white background.

You may notice that Wales, which is part of the United Kingdom, is not represented on the Union Jack flag. This absence is because Wales was considered a principality under the Kingdom of England, not a separate kingdom, when the flag was created.

The Union Jack we know today didn’t always look this way. The first version, known as the Union Flag of 1606, only combined the crosses of St George and St Andrew, representing England and Scotland. It wasn't until 1801, with the Act of Union between Great Britain and Ireland, that the Cross of St Patrick was added, resulting in the modern Union Flag, often referred to as the Union Jack.

The term “Union Jack” comes from naval usage. A “jack” is a flag flown from the bow of a ship. Originally referred to as the Union Flag, it became more commonly known as the Union Jack when flown at sea. Over time, this name has become standard, even on land.

According to the Flag Institute, the terms are often used interchangeably. However, some argue we should only call it a “Union Jack” when flown on a ship.

By representing the United Kingdom, the Union Jack appears on other flags. For example, the Union Jack flag is part of Australia's flag, which also includes the Southern Cross, and New Zealand's flag. It's also part of the flags of several Commonwealth countries and British Overseas Territories. It is often used symbolically to represent the UK in popular culture and events worldwide.

Sometimes, people refer to it as the Great Britain flag, though this is not technically accurate, as Great Britain refers only to the island, not the full union.

If you're interested in flags, you might already know someone studying flags is called a vexillologist. Vexillology is the study of the history, symbolism, and usage of flags. Like the history of the Union Jack here, flags are both a symbol and a product of the history and culture of a country or institution. The history and construction of the Olympic Flag is a good example.

Curious about the difference between Great Britain and the United Kingdom?

The Union Jack

This is generally the source of much confusion, even amongst those who live over here.

If you look carefully at the description of the United Kingdom (on a passport say), you’ll see it’s the "United Kingdom of Great Britain and Northern Ireland". So the UK is both of those.

Great Britain is the largest island in the British Isles and includes the three countries: England, Scotland and Wales.

The British Isles is the group of islands as a whole, including all of Ireland.

The British Isles also include several significant islands that are part of Scotland, such as the Hebrides (Inner and Outer), and the Northern Isles of both Orkney and Shetland. It also encloses the Isle of Man, which sits in the Irish Sea between England and Northern Island and is actually a self-governing British Crown Dependency with its own parliament and government.

For a little more subtlety, there's the term the British Islands (as opposed to Isles), which includes the UK, the Isle of Man and the Channel Islands, which sit closer to France.

For much further confusion, think for a moment why there’s a UK passport, Great Britain in the Olympic games, and in football, we compete as England, Wales, Scotland and N. Ireland separately. 🤔

Great Britain and the United Kingdom: What’s the difference?

How do you remember the difference between stalactites and stalagmites in a cave? And how do you spell them?

A simple mnemonic that’s helped me is this:

For Stalactite, the "-tite" and "tight" remind you of the ceiling connection, and the letter “C” in stalactite fits perfectly with “ceiling.”

For Stalagmite, once you’ve got stalactite, stalagmites naturally become the ones that grow up from the ground, with their cheeky “G” matching “ground.” Easy, right?

With this trick, you’ll never mix them up again, whether you’re exploring caves or acing a quiz. Sorted.

Stalactites, Stalagmites

And, let’s face it, most of us are more likely to encounter camels in the Middle East and Africa than trekking around the Gobi Desert. The wild bactrian camel is sadly on the critically endangered list.

And, there is this simpler way to remember the difference that a reader passed on to me: dromedary is one hump like a D on its side, and bactrian is two humps like a B on its side. Simples.

Camel identification: 1 hump dromedary, 2 humps bactrian

There’s stiff competition for the original and the most authentic British cream teas between Devon and Cornwall and the Southwest of England. And you may have, like me, wondered if when having scones with clotted cream and jam in what order should you put them. However, you can tell each apart by the preference on your scone to go for jam on top of the clotted cream, or under the cream. Cream on top = Cornwall. Jam on top = Devon. If you haven’t had one on location, I recommend you give it a try.

Cream tea: Cornwall vs Devon

Divergent (Mid-Atlantic ridge, The Rift Valley), Convergent (The Andes, The Himalayas) and Transform (San Andreas fault, Dead Sea Transform). There are some sub-varieties but these are the main ones. This makes natural sense, so there’s no remembering to do, when you have two contacting plates: they can either be pushing together, pulling apart or rubbing past each other.

Incidentally, the idea that the giant continents move around all the time, enough to pull apart South America and Africa, and thrust up the Himalayas, obvious as it may seem now, was once not at all obvious. And if you stand on the ground in a big landscape, it’s kind of amazing to think of just what an amazing notion it was to propose.

I read about it in Bill Bryson’s, A Short History of Nearly Everything for which I found a relevant excerpt online - The Earth Moves (pdf) - should you be interested in the characters that had the courage to seriously propose it.

Tectonic plate interaction boundaries

Where the Northern Hemisphere simply allows you to find the North Star, around which all the stars will rotate, finding your way in the Southern Hemisphere is a little more involved. Unlike in the North, there’s no obvious star due south in the Southern Hemisphere. Instead, you have to use two handy indicators: the Southern Cross — easily spotted, fortunately — and two stars known as The Pointers. Find where these intersect, as in the sketch, and you’ve found due south.

Or, if you prefer, you can follow the direction the Southern Cross is pointing for a distance equal to 4.5x the length of the Southern Cross to arrive at the spot.

Incidentally, I wondered about reliable methods of finding south in the Northern Hemisphere and north in the Southern Hemisphere. And I think the answer is to find north or south and turn around.

Use the Southern Cross to find South

From various sources I have learned that mandarins are the original, from China, and were rather fancy and therefore only suitable for high society, which included mandarins (bureaucrats).

Satsumas are a type of mandarin cultivated in the Japanese district of Satsuma.

Clementines are named after Father Clément Rodier who may have cultivated the variety himself.

And tangerines are so named as being from Tangiers in Morocco, one of the places where mandarins were first imported into Europe.

Origins of mandarins

Know your poles

Surfing is all about catching the perfect wave, and the type of surf break plays a big role in shaping those waves. Surf breaks are influenced by the seabed, coastline, and water depth. While no two waves are the same, surf breaks can generally be grouped into three main types: beach breaks, reef breaks, and point breaks.

Beach breaks occur where waves form over sandy bottoms near the shore. These are often the go-to for beginner surfers because the sand offers a softer, more forgiving landing compared to reefs or rocks. Another advantage is that you usually don’t have to paddle far to catch waves at a beach break. However, the wave conditions can vary frequently as shifting sands reshape the underwater landscape.

Reef breaks are formed where waves break over a coral reef or rocky seabed. These can be located close to shore or further out at sea, depending on the reef’s position. Reef breaks are known for producing highly consistent and well-shaped waves, making them a favourite among experienced surfers. But be warned—wipeouts can be dangerous due to the shallow and sharp nature of the reef.

Point breaks form when waves wrap around a headland or rocky outcrop and peel along the coast. These breaks can create some of the longest, most rideable waves, often extending into a sheltered bay. The downside? Navigating rocks can be tricky, and the waves might require a bit more paddling effort. For surfers chasing long, clean rides, though, point breaks are hard to beat.

I updated this sketch from the original hand-drawn version for my book Big Ideas Little Pictures

The 3 Main Types of Surf Breaks Explained

California is a nice example both stitching up the Central Valley and Nevada. And in Washington State if you need a bit more sunshine, just try driving East.

Geography sketches