The Knowledge
Why can’t it always be summer? It’s all about the Earth’s tilt
Earth’s axial tilt causes the seasons. As Earth orbits the Sun, different hemispheres tilt toward or away, creating summer and winter depending on location.
Last Updated on March 13, 2026 by Daily News Staff
Stephanie Spera, University of Richmond
Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.
Why can’t it always be summer? – Amanda, age 5, Chile
With its long days just itching to be spent by water doing nothing, summer really can be an enchanting season. As Jenny Han wrote in the young adult novel “The Summer I Turned Pretty”: “Everything good, everything magical happens between the months of June and August.”
But all good things must come to an end, and summer cannot last forever. There’s both a simple reason and a more complicated one. The simple reason is that it can’t always be summer because the Earth is tilted. The more complicated answer requires some geometry.
I’m a professor of geography and the environment who has studied seasonal changes on the landscape. Here’s what seasons have to do with our planet’s position as it moves through the solar system.
This animation shows why the Earth has seasons.
Closeness to the Sun doesn’t explain seasons
First, you need to know that the Earth is a sphere – technically, an oblate spheroid. That means Earth has a round shape a little wider than it is tall.
Every year, Earth travels in its orbit to make one revolution around the Sun. The Earth’s orbit is an ellipse, which is more like an oval than a circle. So there are times when Earth is closer to the Sun and times when it’s farther away.
A lot of people assume this distance is why we have seasons. But these people would be wrong. In the United States, the Earth is 3 million miles closer to the Sun during winter than in the summer.
Spinning like a top
Now picture an imaginary line across Earth, right in the middle, at 0° latitude. This line is called the equator. If you drew it on a globe, the equator would pass through countries including Brazil, Kenya, Indonesia and Ecuador.
Everything north of the equator, including the United States, is considered the Northern Hemisphere, and everything south of the equator is the Southern Hemisphere.
Now think of the Earth’s axis as another imaginary line that runs vertically through the middle of the Earth, going from the North Pole to the South Pole.
As it orbits, or revolves, around the Sun, the Earth also rotates. That means it spins on its axis, like a top. The Earth takes one full year to revolve around the Sun and takes 24 hours, or one day, to do one full rotation on its axis.
This axis is why we have day and night; during the day, we’re facing the Sun, and at night, we’re facing away.
But the Earth’s axis does not go directly up and down. Instead, its axis is always tilted at 23.5 degrees in the exact same direction, toward the North Star.
The Earth’s axis is tilted due to a giant object – perhaps an ancient planet – smashing into it billions of years ago. And it’s this tilt that causes seasons.
It’s all about the tilt
So that means in June, the Northern Hemisphere is tilted toward the Sun. That tilt means more sunlight, more solar energy, longer days – all the things that make summer, well, summer.
At the same time, the Southern Hemisphere is tilted away from the Sun. So countries such as Australia, Chile and Argentina are experiencing winter then.
To say it another way: As the Earth moves around the Sun throughout the year, the parts of the Earth getting the most sunlight are always changing.
Fast-forward to December, and Earth is on the exact opposite side of its orbit as where it was in June. It’s the Southern Hemisphere’s turn to be tilted toward the Sun, which means its summer happens in December, January and February.
If Earth were not tilted at all, there would be no seasons. If it were tilted more than it is, there would be even more extreme seasons and drastic swings in temperature. Summers would be hotter and winters would be colder.
Defining summer
Talk to a meteorologist, climate scientist or author Jenny Han, and they’ll tell you that for those of us in the Northern Hemisphere, summer is June, July and August, the warmest months of the year.
But there’s another way to define summer. Talk to astronomers, and they’ll tell you the first day of summer is the summer solstice – the day of the year with the longest amount of daylight and shortest amount of darkness.
The summer solstice occurs every year sometime between June 20 and June 22. And every day after, until the winter solstice in December, the Northern Hemisphere receives a little less daylight.
Summer officially ends on the autumnal equinox, the fall day when everywhere on Earth has an equal amount of daylight and night. The autumnal equinox happens every year on either September 22 or 23.
But whether you view summer like Jenny Han or like an astronomer, one thing is certain: Either way, summer must come to an end. But the season and the magic it brings with it will be back before you know it.
Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.
And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.
Stephanie Spera, Assistant Professor of Geography and the Environment, University of Richmond
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Forgotten Genius Fridays
Forgotten Genius Friday: Frederick McKinley Jones — The Inventor Who Changed How the World Keeps Food Fresh
Before fresh food could travel thousands of miles, before life-saving medicines could be shipped across long distances, and before grocery stores could offer products from around the world year-round, there was a major challenge: keeping things cold while they were on the move.
One inventor helped solve that problem.
His name was Frederick McKinley Jones—a brilliant engineer whose refrigeration technology transformed transportation, agriculture, healthcare, and modern supply chains.
A Self-Taught Mechanical Genius
Born in 1893 in Cincinnati, Jones faced challenges early in life. Orphaned at a young age, he developed an interest in mechanics and technology, teaching himself valuable skills through hands-on experience.
Rather than following a traditional educational path, Jones learned by repairing machines, studying engineering concepts, and experimenting with technology.
His natural ability eventually led him to work on inventions involving sound equipment, motion pictures, and electronics—but his greatest contribution would come from solving one of the world’s biggest transportation problems.
Solving the Cold Storage Challenge
Before Jones’ invention, transporting perishable goods over long distances was extremely difficult. Food, medicine, and other temperature-sensitive products could spoil before reaching their destinations.
Jones developed a portable refrigeration system that could be mounted on trucks and trailers, allowing goods to remain refrigerated while being transported.
His invention created the foundation for what is now known as the cold chain—the global network that keeps products at controlled temperatures from production to delivery.
The Birth of Modern Refrigerated Transport
Jones partnered with businessman Joseph Numero to create a company that would eventually become Thermo King.
Their refrigeration technology changed industries worldwide.
It allowed:
- Farmers to ship fresh produce farther than ever before
- Grocery stores to offer a wider variety of foods
- Hospitals to transport temperature-sensitive medical supplies
- The military to move food and medicine during wartime
A Life-Saving Innovation
During World War II, Jones’ refrigeration systems became especially important. His technology helped transport blood, medicine, and food safely to military locations.
His invention was not just about convenience—it helped save lives.
Recognition for a Forgotten Genius
Despite the enormous impact of his work, Jones remained relatively unknown to the public for many years.
In 1977, he was inducted into the National Inventors Hall of Fame, recognizing his groundbreaking contributions to refrigeration technology.
His inventions continue to influence the way the world moves essential goods today.
Why Frederick McKinley Jones Still Matters
Every time you buy fresh produce from another state, receive temperature-sensitive medicine, or enjoy foods transported across long distances, you are benefiting from technology that traces back to Jones’ innovation.
His story reminds us that some of the most important inventions are not always flashy. Sometimes, they are the systems working quietly behind the scenes that make modern life possible.
Final Word
As part of STM Daily News’ Forgotten Genius Friday series, the story of Frederick McKinley Jones highlights the power of problem-solving and persistence.
He didn’t just invent refrigeration for transportation—he helped create the modern world’s ability to share food, medicine, and resources across the globe.
Frederick McKinley Jones was the genius who kept the world moving—and kept it fresh.
Related Links for Further Information
- National Inventors Hall of Fame – Frederick McKinley Jones
- Google Patents – Frederick McKinley Jones Patent Records
- United States Patent and Trademark Office (USPTO) – Patent Search Database
- U.S. Energy Information Administration – Frederick M. Jones Biography
- Thermo King – The Legacy of Frederick McKinley Jones and Transport Refrigeration
- Frederick McKinley Jones – Biography and Inventions Overview
- U.S. Army – “The King of Cool”: How Jones’ Technology Supported Military Logistics
- Explore More Forgotten Genius Friday Episodes on STM Daily News
The Knowledge
Now You Know: Los Angeles Is One of America’s Great Art Deco Cities
Los Angeles is home to one of the nation’s most impressive collections of Art Deco architecture. Explore the iconic buildings, history, and legacy of this glamorous design movement.
Last Updated on June 21, 2026 by Rod Washington
When most people think of Art Deco architecture, cities like New York and Miami often come to mind first. But many Angelenos may be surprised to learn that Los Angeles is home to one of the largest and most impressive collections of Art Deco buildings in the United States.
The Art Deco movement flourished during the 1920s and 1930s, a period that coincided with Los Angeles’ rapid growth and transformation into a major American metropolis. As new theaters, office towers, department stores, and civic buildings were constructed, architects embraced the bold geometric designs, lavish materials, and futuristic styling that defined the Art Deco era.
Some of L.A.’s Most Famous Art Deco Landmarks
Eastern Columbia Building
Located in Downtown Los Angeles, the Eastern Columbia Building is often considered the crown jewel of the city’s Art Deco architecture. Its turquoise terra-cotta exterior and gold accents make it one of the most photographed buildings in Southern California.
Wiltern Theatre
The iconic Wiltern Theatre on Wilshire Boulevard is another masterpiece of the era. With its striking tower and ornate interior, it remains one of the finest surviving Art Deco theaters in America.
Bullocks Wilshire
Opened in 1929, Bullocks Wilshire was designed as a luxury shopping destination and is widely regarded as one of the best examples of Zigzag Moderne Art Deco architecture.
Los Angeles Central Library
The Los Angeles Central Library blends Art Deco styling with Egyptian-inspired motifs, featuring beautiful murals, mosaics, and decorative details throughout the building.
The Art Deco Buildings We Lost
Unfortunately, Los Angeles has also lost some legendary Art Deco landmarks.
Perhaps the most famous was the Richfield Tower, a stunning black-and-gold skyscraper that was demolished in 1969. Many preservationists still consider it one of the greatest architectural losses in the city’s history.
Another beloved structure was the Pan Pacific Auditorium, a Streamline Moderne icon that was destroyed by fire in 1989.
A Hidden Part of Everyday L.A. History
Many longtime residents have passed these buildings countless times without realizing they were looking at pieces of architectural history. Downtown Los Angeles, Wilshire Boulevard, Hollywood, and other historic neighborhoods still contain numerous Art Deco gems that reflect the optimism and ambition of the city’s boom years.
For railfans and transportation enthusiasts, the era is especially significant. Many civic structures, stations, theaters, and commercial buildings constructed during the expansion of Los Angeles in the early 20th century incorporated Art Deco design elements that remain visible today.
Why Art Deco Still Matters
Art Deco represented more than just a style—it symbolized modernity, progress, and confidence in the future. Nearly a century later, these buildings continue to give Los Angeles a distinctive character that sets it apart from other American cities.
So the next time you’re driving down Wilshire Boulevard or walking through Downtown Los Angeles, take a closer look. You may be standing in the middle of one of the nation’s greatest open-air Art Deco museums.
Now You Know
Los Angeles isn’t just a city of movie studios and palm trees—it’s also one of America’s premier Art Deco destinations.
Related External Links for Further Reading
- Art Deco Society of Los Angeles
- Los Angeles Conservancy – Art Deco Architecture
- Los Angeles Public Library Photo Collection
- National Trust for Historic Preservation
- The Getty Research Institute – Architecture Resources
- Library of Congress Digital Collections
For more stories about history, architecture, transportation, and fascinating facts from around the world, visit STM Daily News at https://stmdailynews.com. Don’t forget to leave a comment and subscribe to our newsletter for more “Now You Know” stories!
Forgotten Genius Fridays
Forgotten Genius Friday: The Legacy of Thomas Jennings — America’s First Black Patent Holder
Discover how Thomas Jennings, the first African American to receive a U.S. patent, revolutionized garment care with his dry-cleaning invention and supported abolitionist causes.
Last Updated on June 19, 2026 by Daily News Staff
In the early 19th century, long before modern dry cleaners lined city streets, one man quietly transformed how Americans cared for their clothing. His name was Thomas Jennings—a tailor, entrepreneur, and trailblazer whose innovation would earn him a historic place in U.S. history.
Breaking Barriers in a Divided America
Born in 1791 in New York City, Jennings lived in an era when opportunities for African Americans were severely limited. Yet he built a successful tailoring business, gaining a reputation for craftsmanship and attention to detail.
At the time, cleaning delicate garments—especially wool—was a persistent challenge. Traditional washing methods often damaged fabrics, leaving customers frustrated and tailors searching for better solutions.
Jennings saw not just a problem, but an opportunity.
The Invention of “Dry Scouring”
In 1821, Jennings developed a cleaning method he called “dry scouring,” a precursor to modern dry cleaning. Unlike water-based washing, his technique used chemical solvents to remove dirt and stains without harming fabric fibers.
That same year, he achieved a groundbreaking milestone: Jennings became the first African American to receive a U.S. patent.
This was no small feat. Patent laws at the time largely excluded enslaved individuals, and systemic racism made legal recognition difficult even for free Black citizens. Jennings’ success marked a rare and powerful breakthrough.
“His achievement stands in stark contrast to what followed—when laws would deny many Black innovators the right to claim their own ideas.”
Innovation With Purpose
Jennings didn’t just profit from his invention—he used his success to support a broader cause. The income generated from his patent helped fund abolitionist efforts, contributing to the fight against slavery in the United States.
His work intersected with the growing abolitionist movement decades before the American Civil War, demonstrating how innovation and activism often went hand in hand.
Lasting Impact on Modern Life
Today, dry cleaning is a global industry, essential to fashion, hospitality, and everyday life. While technologies have evolved, the core concept Jennings pioneered remains intact.
His legacy can be seen in:
- The modern dry-cleaning industry
- Textile preservation techniques
- The broader recognition of Black inventors in American history
Why Thomas Jennings Still Matters
Jennings’ story is not just about an invention—it’s about access, perseverance, and impact. At a time when the odds were stacked against him, he secured intellectual property rights, built a business, and used his platform to support social change.
For today’s innovators, his journey underscores a powerful truth: meaningful breakthroughs often come from those willing to challenge both technical problems and societal barriers.
Final Word
As part of STM Daily News’ Forgotten Genius Friday series, the story of Thomas Jennings serves as a reminder that some of the most influential figures in American innovation history are still waiting to be fully recognized.
His invention didn’t just clean clothes—it helped clear a path for future generations of inventors.
Related Articles & Further Reading
External Sources
- Thomas Jennings – Wikipedia Overview
- National Park Service: Thomas Jennings Biography
- BlackPast.org – Thomas Jennings Profile
- USPTO – African American Inventors and Innovation History
- Smithsonian Institution – Thomas Jennings Feature
