Pizza boxes are square for practical reasons

Detroit-style pizza's recipe nods to the Motor City

Legend has it that the rectangular pies were originally baked in blue steel pans intended to hold nuts and bolts in auto factories. The sauce poured across the top of the pies, meanwhile, is done so in straight lines called "tire tracks."

Taxicab geometry defines displacement as the sum of vertical and horizontal distances

In this mathematical system, pi is valued at four, and circles aren't round—they appear as diamonds with corners instead. The system simplifies pixel distances in digital imaging and helps engineers with robot navigation and chip design.

Are there any planets in the universe that aren’t round?

We think of all planets as spheres, but do they have to be spheres? To be classified as a planet, an object has to be sufficiently massive to reach a spherical shape through gravity. However, this doesn't mean they're perfectly round; for example, Earth has a slight equatorial bulge caused by centrifugal force from its rotation. Other observed planets feature tear-shaped formations while theorists posit donut-shaped planets. Read more here.

In 2001, Pizza Hut became the first company to deliver pizza to space

The chain paid the Russian space agency nearly $1M for the promotional stunt, which saw a Russian cosmonaut eat the pizza on video. Other unusual objects to make it to the International Space Station include a gorilla suit, an espresso machine, and several musical instruments.

The frozen pizza was invented in 1950

In 1950, some pizzerias were premaking pies, allowing customers to take them home and cook them at their convenience. That same year, Philadelphia's Joseph Bucci filed a patent for a "Method of Making Frozen Pizza." Soon, frozen pizzas were appearing in grocery store aisles.

The story of pizza in the United States

Pizza is a big deal in the US, and it has many proud regional iterations. From Chicago deep dish to New York thin crust, this video takes a slice out of US history to focus on this beloved entree. Begin with the documented first incidence of pizza in the US—believed to be by Gennaro Lombardi—and end with how old Pizza Huts are being converted around the country.

View a map of America's regional pizza styles

It may all be pizza, but it's not all the same. From California to New York and from Quad City-style to Old Forge, this interactive map of the US lets you see the country's different takes on the classic dish.

The world's largest pizza was 13,990 square feet

Pizza Hut teamed with YouTuber Eric Decker to create the massive, Guinness World Record-breaking pie. The 13,653-pound pizza was constructed at the Los Angeles Convention Center. It required 4,948 pounds of sauce, 8,800 pounds of cheese, and about 630,496 pepperoni slices.

Chicago deep-dish pizza arrived in 1943

Pizzeria Uno was the first establishment to sell the concoction, which turned more traditional pizza upside down, with cheese as the base and sauce as the topping. Soon, Uno employees went out on their own, sparking a citywide deep-dish phenomenon.

NASA funded research into creating pizza with a 3D printer

The agency awarded a contract for the development of devices that can create edible structures from long-lasting dry powders when mixed with liquids or pastes. By delaying this integration until the time of consumption, food could last longer than the current six-month expiration of freeze-dried meals for Mars expeditions.

Pizza is believed to have been invented in Naples

Flatbreads were eaten by ancient Egyptians, Romans, and Greeks, but historians trace pizza—flatbread with toppings, including present-day staples like tomatoes, cheese, garlic, oregano, and oil—back to 18th-century Naples, where the food was loved by its working poor, who appreciated a cheap, tasty meal. Naples formally became a part of Italy in 1861.

Pyramid or plate? Why nutrition guidelines change

Those who remember growing up with the age-old food pyramid may be resistant to dietary guidelines changing, but experts agree that the food pyramid recommendations held serious flaws. It suggested, for instance, that meat and junk food were meant...

Cardboard thieves are making millions

The global market for recycled cardboard is worth billions of dollars—and it's attracting criminals. Specifically, people are making a fortune from taking used cardboard that's been left outside to be recycled, then proceeding to sell it. As a result, legitimate recycling firms and local authorities are missing out on millions. Learn more here.

In 2023, the world consumed over 5 billion pizzas

Americans ate 3 billion of those, leading to sales that reached $43.3B, according to industry analysts at Gitnux. They estimated that Americans eat an average of 46 slices per person that year.

Pizza didn't take off in the US until after World War II, likely because of technological advancements and soldiers' exposure to it abroad.

Pizza became more popular in Italy after it took off in the US

Pizza was invented in Naples, though it wasn't particularly popular outside the region. As it grew more popular elsewhere—and as more American and European tourists visiting Italy began asking for it—restaurants across Italy adopted the cuisine. It's something anthropologist Agehananda Bharati calls "the pizza effect."

The Hawaiian pizza was popularized by a Canadian chef

Hawaii's tiki culture was popular in North America through the mid-20th century, with canned pineapple a household staple. Sam Panopoulos, a Greek immigrant who operated a diner in Ontario, experimented with outlandish pizza recipes until he stumbled upon the idea for topping a pie with canned pineapple and ham.

It took 70 years for computer scientists to determine how to cut a cake fairly

The cake-cutting problem explores how to divide something fairly, which is not solely about cutting evenly-sized pieces. A protocol that accounted for personal preferences (e.g., a corner piece) between just three people took 16 years to develop.

One food history professor says pizza is more American than Italian

Alberto Grandi, a professor at the University of Parma, argues that Italians who left the country developed the food now considered "traditional Italian cuisine," thanks to abundant ingredients and opportunities that were not available in the impoverished country they left behind.

Richard Cadbury invented the heart-shaped chocolate box in 1868

Richard's father, John Cadbury, founded the Cadbury Brothers chocolate company (now known simply as Cadbury) in 1824. Richard recognized the popularity of ornamental designs (especially for Valentine's Day gifts) and designed the heart-shaped box for the company's chocolates, which became a staple of the holiday.

Pizza's popularity has waned in the 2020s

The food remains popular, but it has lagged behind the growth of other fast food spots like coffee shops and Mexican restaurants. It ranked sixth in US food sales from restaurant chains in 2024; it was in the second slot throughout the 1990s. (Some readers may experience a paywall.)

All-you-can-eat buffets are a practical demonstration of economic ideas

Economists have noticed some restaurant goers prefer a flat pricing model despite it usually being more expensive than per-dish costs. The strategy behind endless servings includes concepts such as economy of scale, cross-subsidization, diminishing returns (of enjoyment of excess food), and more.

New Haven 'apizza' nods to Naples and New England

The thin pizza, called "apizza," is crispier than the typical slice from New York or a national chain, and much more like the thin-crust pizzas associated with pizza's birthplace. It's also got some inspired toppings, with one popular pie that speaks to New England's love of seafood: the white clam pie.

Are burritos sandwiches?

In this video, we trace the burrito's origins, explore the legal and culinary battles around its classification, and break down why this seemingly simple food raises such a complicated question.

Was the stone that sealed Jesus's tomb round or square?

Archaeologist Amos Kloner's survey of more than 900 Second Temple-era burial caves found only four with round, disk-shaped stones—all belonging to the very wealthy. The other 98-plus percent used square, cork-shaped stones, suggesting the popular image of a wheel rolled away from Jesus's tomb is probably a later artistic invention. The Greek verb translated as "rolled" can also mean "moved."

A fresco from ancient Pompeii featured an 'ancestor of modern pizza'

A team of archaeologists discovered a fresco from 79 CE featuring what appears to be a proto-pizza: a pita topped with fruit, spices, and other toppings. One archaeologist in the PBS documentary below calls it an "ancestor of modern pizza in the sense that it's a very simple, poor kind of food."

Scientists now know why wombats poop cubes

For years, scientists have been wondering why wombat poop is cube-shaped (yes, really). Now, they say they have got to the bottom of the mystery.

Why roller coaster loops are never circular

The beloved looped roller coaster rides used to be shapes as perfect circles and constructed with wood, resulting in wobbly machinery that gave people whiplash. After the invention of steel and further scientific understanding, Six Flags debuted The Great American Revolution—a modern, oval loop with steel that offered a safer and smoother experience.

Pizza Hut helped pioneer online food delivery in 1994 with PizzaNet, a website that allowed users in select areas of California to order pizzas online.

Figuring out how to get a sofa around a corner has been a math problem since 1966

A sofa with the largest possible area that can make a 90-degree turn is known as Gerver's sofa, named after the mathematician who determined the shape in 1992. In 2025, a 119-page paper provided the proof confirming this shape.

Spikes in pizza orders near US government buildings are thought to be signs of international crises

Theorists have long believed that sudden increases in pizza deliveries near the Pentagon signal a major event is about to occur. Historical examples include the CIA ordering 21 pizzas the day before the beginning of the Gulf War, and another surge of deliveries before former President Bill Clinton's impeachment hearings. Citizens have since begun monitoring food orders in the area. See a tracker of Pentagon pizza orders here.

The perfectly rolled burrito depends on the tortilla

Experts recommend warming a tortilla before wrapping it around the filling. Once warm, you should distribute the ingredients evenly on the back half of the tortilla for a uniform shape.

Frisbees earned their name from a pie company that made tins that college students used to throw around campus.

Uncrustables' reinvention of the PB&J

In the 1990s, David Geske and Len Kretchman came up with the ingenious idea to package and mass-produce a crustless version of the peanut butter and jelly sandwich. This makeover to an American childhood staple resulted in a $1B business. Read this article in Mental Floss to learn more about the origins of the brand Uncrustables and its extraordinary success.

Watch the iterative process of successfully printing a slice of vegan cheesecake

3D printing food requires integrating ingredients with a variety of properties, which may not all resist the physical stress of stacking. This means successful 3D printing of food may require rethinking how ingredients are layered and modifying ratios of each, potentially sacrificing taste for structural integrity.

Aristotle discovered that Earth was spherical by observing the round shadow it cast on the moon during lunar eclipses and by noting that different constellations were visible from different latitudes.

Cookies were originally used as low-stakes ways to test the temperature of an oven

In 7th century Persia, bakers used small mounds of dough to test the heat in ovens before baking larger cakes. Afterward, they'd add honey, nuts, and other items to the small mounds, creating early cookies.

'Neapolitan pizza' is a highly specific (and tightly regulated) distinction

The Associazione Verace Pizza Napoletana claims to protect the tradition of Naples' pizzamaking and has codified precise requirements for what constitutes a "Neapolitan pizza," specifying ingredients, preparation, fermentation, condiments, and more.

The solar system's planets orbit in the same direction in a nearly flat disc because the particles that made up the gas cloud from which the system formed had an initial, overall plane of rotation.

This flat map is still wrong, but it's the least wrong of all flat maps

While flat maps can never be as perfectly scaled as a globe, they're far more practical than carrying around a sphere. Researchers set out to minimize six major errors of flat maps, including boundary cuts and skewed proportions, by simply squashing...

Two Papa John's pizzas were the first real-world transaction involving cryptocurrency.

One baker is likely responsible for several of New York's earliest pizzerias

Filippo Milone established at least six pizzerias in New York, including one that would later be called Lombardi's, widely considered to be the city's (and the country's) first pizza establishment. Milone died in 1924, leaving no children to tell his story. Researcher Peter Regas unearthed a 1903 advertisement, pictured below, from an Italian-language New York newspaper.

Explore fun facts from the USPS, including unique post office buildings, a stamp that traveled past Pluto, and more.

A solar eclipse viewer can be made from everyday objects, such as a cereal box, aluminum foil, tape, and paper, to safely view the cosmic event.

Great circles provide the shortest path between two points on a sphere

On Earth, a great circle is formed by slicing through the planet, such that one cuts through the center alongside the two locations from which the shortest distance needs to be found. The resulting arc along the Earth's surface is responsible for curved routes on flight maps, rather than straight trajectories.

The bizarre 1920 proposal to form a pizza-shaped central European state

In light of the challenges of the Treaty of Versailles, which concluded the Great War, a mostly unknown author, and son of the map's printer, PA Maas suggested central Europe be integrated into a single state. With a central capital in Vienna, 24 Kantons, or regions, would radiate outward in pie-slice shapes.

Delivery apps have realigned the restaurant industry

As delivery apps like Grubhub and DoorDash became popularity, traditional dine-in restaurants have adapted to become more accommodating. In this thinkpiece for the Atlantic, Ellen Cushing argues that it's both changed the kind of food being made and realigned our very notion of a restaurant. (Some readers may experience a paywall.)

What Costco does with its unsold baked items

Ever wonder what Costco does with its seemingly endless supply of muffins and other baked goods? Rather than mark down the items or toss them in the trash, the big-box retailer donates the perishable food to Feeding America, a network of food banks and other programs that help feed those in need.

Is Domino’s pizza inflation-proof?

A Big Mac Extra Value Meal is nearly $11 in 2025, compared to $4.59 in 1993. A Taco Bell crunchy taco costs $1.79 today, but was only 59 cents in 1990. Inflation impacts the price of many fast-food items—but the price of a Domino's pizza hasn't changed much at all in the past two decades.

Why cartoons only have four fingers

Ever notice cartoon characters only have four fingers? There’s a surprising reason why and it goes back to the first Mickey Mouse cartoons. From saving money to cultural taboos, here’s why animators draw hands this way.