1

If it’s not in use, turn it off

Image: Chris Haws

We start the list with this well-known advice: turn off the lights when nobody is in the room .

Additionally, switch off appliances completely rather than leaving them on standby, as standby mode continues to consume electricity. Most computers have energy-saving settings that automatically turn off the computer and screen after a period of inactivity.

2

Keep the temperature where you need it

Image: Natalia Y.

Whenever you are heating or cooling a room, remember to close the doors and windows that connect to other unoccupied parts of the building . This way, the heating or cooling equipment you are using will not require more energy than is necessary to maintain the desired temperature where you are.

During cooler months, ensure your curtains or blinds are properly sealed to keep the cold out. In warmer months, keep your curtains closed during the day to prevent heat from entering.

3

Wash and dry clothes once the basket is full

Image: engin akyurt

Avoid using your washing machine when your laundry basket is only half full; instead, use it when you have accumulated a full charge. Also, remember to select the appropriate washing cycle to optimize energy use.

On a related note, clothes dryers consume a significant amount of energy, so consider hanging clothes outside to dry or using a fan to help dry them indoors.

4

Save energy in the kitchen

Image: Jason Briscoe

Your kitchen offers many energy-saving opportunities. The fridge, one of the most energy-intensive appliances, runs 24/7 for obvious reasons but measures can be taken to make it a more efficient device. The ideal fridge temperature for the fridge is between 35° and 38°F. Make sure the door seal is tight, with no gaps or cracks that allow cold air to escape.

As for cooking, always put frozen food in your fridge in the morning to thaw out and reduce cooking time in the evening. Whenever possible, use a microwave, as it consumes significantly less energy than an electric oven. Plan to cook more and have leftover meals for the next day or the week ahead. Keep leftover meals in the freezer for convenience and minimal waste.

5

Smart heating and cooling

Image: Everett Pachmann

It may be tempting to adjust the thermostat a degree or two above or below the recommended settings depending on the season, but there is good reason to avoid doing that. Every degree above 20 can increase your heating bill by up to 10%. In winter, set your thermostat between 18 and 20 degrees. In summer, aim for 26 degrees or higher.

Additionally, some ducted systems allow you to disable heating or cooling in unoccupied rooms, which can help save energy.

6

Use energy-saving LED lights

Image: Anton Belashov

LED lighting has been around for a while and can save up to 80% on lighting costs. LED bulbs consume less power and last longer, which means that users spend less money and time replacing them.

Another perk, LEDs generate very little heat compared to incandescent and halogen bulbs, which convert much of their energy into heat. This can reduce cooling costs, especially in warm climates.

7

Solar energy

Image: Andreas Gücklhorn

The energy given to us by the sun can be harvested in solar panels that reduce the amount of energy we need to buy from the electricity company . Similarly, solar hot water systems can minimize gas usage, reducing reliance on gas-fired water heaters.

Solar panels and solar hot water systems used to be very expensive and had to be replaced much more often but, their costs have dropped significantly in recent years, making them more accessible.

8

TV settings

Image: Jonas Leupe

Today's high-definition televisions use around 60% less energy than earlier models. However, some Internet-ready models consume extra power even when turned off due to a "quick start" feature that enables faster boot-up . You can disable that option in your television's settings .

While perusing through the settings, you can also see if your model has an automatic brightness control, which will adjust the picture brightness to the level of light in the room. This can make a big difference in energy consumption.

9

Efficient appliances

Image: Vlad Zaytsev

Most of today's new appliances use half the energy of those from a couple of decades ago. If you're thinking of buying a new one, look for products with the Energy Star label, as they typically use 10 to 40 percent less energy than other models.

If you are going to buy a new computer, keep in mind that laptops use significantly less energy than desktop versions.

10

Insulate your roof

Image: Erik Mclean

Temperature affects air in different ways: heat rises, while cool air sinks. This means that if a house's roof is not properly insulated, heat will escape in the winter, and the cold from outside will seep in through the roof.

An insulated ceiling can make a big difference to your energy bills . Effective ceiling insulation can save up to 20% on cooling and heating costs.

1

What are bills made of?

Unlike other currencies, dollar bills are not made of paper or plastic. U.S. dollar bills are made from a special fabric blend composed of 75% cotton and 25% linen. This mix makes the bills extremely durable and resistant, and they can be folded about 4000 times before tearing.

2

What bills are valid?

Any U.S. dollar bill that was legally printed is valid, no matter how old, as American currency does not have an expiration date. While some bills might not be accepted by businesses of foreign exchange services due to their condition or if they are a discontinued version of the bill, the bills themselves are still valid, and American banks will accept them, though they might take them out of circulation.

3

American leaders

Five bills have a depiction of an American president. The exceptions are the $10 bill, with Alexander Hamilton on the front, and the $100 bill, with Benjamin Franklin. The $1 bill, depicting George Washington, is extremely symbolic: several elements are repeated 13 times as a nod to the thirteen colonies, and it showcases the Bald Eagle and the Eye of Providence as a sign of God watching over America.

4

A change in size

Did you know that dollar bills used to be so big that they were nicknamed "horse blankets"? Original dollar bills were 7.4 × 3.1 inches. In 1929, the Treasury Department reduced the size of bills to 6.14 × 2.61 inches to reduce production costs and materials. Old bills, though still valid, are worth much more as collector items.

5

Uniformity

Besides their value and design, all dollar bills have the same size (6.14 × 2.61 inches), color, and weight (1 gram) , which sets American currency apart from other countries where bills of different values are differentiated by size, color, or both. Why doesn’t the U.S. implement differences among bills? The cost of adapting vending machines, bank drawers, and ATMs to new bill sizes would cost billions of dollars.

6

Hard to copy

Originally, dollars were not green, but black. As time passed, green ink was favored, as it was cheap and did not fade as much as black. The new color also prevented people from using black-and-white cameras to create counterfeit money. Currently, dollar bills are predominantly green, but newer versions also include extra colors, such as pink, orange, or purple.

7

A $100,000 bill?

Have you ever seen a $500 or 1,000 dollar bill? What about a $100,000? Up until 1945, the U.S. Treasury printed $500, $1,000, $5,000, $10,000, and $100,000 notes , in addition to the values currently in use. These higher-value notes were mainly intended for bank and government use, but were sought by criminals as they made it easier to hide large amounts of money. Even though they were officially discontinued in 1969, these notes are still valid, though rare, and they have a high worth as collector's items.

8

No numbers

Unlike bills, American coins have different sizes and colors related to their value. Originally, gold, silver, and copper were used for coins, but modern coins are made of copper, zinc, or nickel. Besides their size and design, the value of each coin is printed in letters, not in numbers , alongside depictions of American presidents.

9

Liberty for all (the coins)

By law, all American coins must include six specific details : the word ‘Liberty’, the name of our country, the national motto "In God We Trust", the oldest American motto "E Pluribus Unum", the value of the coin, and the year. Each coin also includes a mint mark that shows where it was made: "P" for Philadelphia, "D" for Denver, "S" for San Francisco, and "W" for West Point.

10

A global currency

The American dollar is one of the most powerful currencies in the world, acting as a backbone for international trade and finances. It is estimated that two-thirds of the physical dollars in circulation are outside American territory. Besides the U.S. and its territories, eight sovereign nations have the U.S. dollar as their official currency, with several more accepting it as legal tender.

1

There's an unexplained billion-year gap

Look closely at the canyon walls, and you'll notice something strange: a clean, sharp line where ancient rock simply stops, and a much younger layer begins directly above it.

This geological puzzle is called the "Great Unconformity," and it represents over a billion years of rock layers that are simply absent , as though that stretch of time never happened. In some spots, rock dated 1.8 billion years old sits directly beneath rock that is only 520 million years old. Where did the missing billion years go?

The leading theory involves the violent breakup of an ancient supercontinent, but scientists are still piecing it together.

2

During the Cold War, it hid a nuclear fallout shelter

During the Cuban Missile Crisis in 1962, the U.S. government converted part of the Grand Canyon Caverns into a fallout shelter. This dry cave system, more than 200 feet underground, was stocked with enough food and water to sustain 2,000 people. Naturally, it was never occupied, and the supplies were never used.

The caverns have since been transformed into a tourist attraction, with organized tours winding through the same underground chambers that were once intended as a refuge from nuclear war. You can even book a night's stay there.

3

The Federal Aviation Administration was founded after a crash over the canyon

In 1956, two commercial passenger planes collided in midair over the eastern Grand Canyon, killing all 128 people on board both crafts. Rescue teams struggled to reach the wreckage deep inside the canyon, and the extreme heat of the crash had caused the planes' aluminum to fuse with the bedrock. There were no survivors.

The disaster exposed a terrifying truth: the U.S. air traffic control system was dangerously outdated, relying on pilots' visual estimates and rough guesswork from controllers , with no way to separate fast-moving aircraft from slow ones, or instrument-flying planes from those navigating by sight. Congress responded by passing legislation that created both the Federal Aviation Administration (FAA) and the National Transportation Safety Board.

4

A hoax suggested that an Egyptian civilization had lived there

In 1909, the Arizona Gazette reported that an explorer named G. E. Kinkaid had discovered a vast underground citadel inside the canyon, filled with artifacts linked to ancient Egyptian civilization. He even claimed the expedition had been funded by the Smithsonian.

This story described hieroglyphics on the walls, mummies in the chambers, and relics pointing to a direct connection with the Egypt of the pharaohs. It was incredibly detailed, and it was, of course, a hoax. No evidence for any of Kinkaid's claims ever surfaced.

5

Fewer than 100 people have ever hiked its full length

Among the few people who have completed the through-hike of the Grand Canyon is Jen Hogan, the first woman to accomplish it, finishing her journey in 2021–2022.

It’s a full 800-mile length below the rim. The route involves extreme heat, flash floods, near-impassable areas, and stretches with no water or trail whatsoever. Around 60 or 70 people have reportedly accomplished it. This makes it one of the most exclusive feats on Earth.

6

The Grand Canyon's rocks predate dinosaurs entirely

Visitors scanning the canyon walls for fossils are often surprised to learn they won't find any dinosaur bones here. The rock layers of the Grand Canyon are simply older than dinosaurs. This fact alone can be shocking: staring at its walls means staring at marine fossils from as far back as 1.2 billion years ago. Some of its caves hold the remains of ancient mammals. The canyon is a window into a world that existed long before the dinosaurs, when the land that is now Arizona lay beneath a shallow sea.

7

The park is bigger than Rhode Island

Numbers alone rarely capture the Grand Canyon's scale, so here's a different approach. Rhode Island covers about 1,214 square miles, and the Grand Canyon National Park spans 1,904 square miles.

The canyon's depth exceeds four Empire State Buildings (which is 1,454 feet) stacked on top of one another. That’s 6,093 feet at its deepest point.

8

But it's not the deepest canyon on Earth

For all its grandeur, the Grand Canyon does not hold the depth record. Pictured above, the Yarlung Tsangpo Grand Canyon in Tibet, China, plunges to 17,567 feet, which is nearly three times deeper. Carved by the Yarlung Tsangpo River as it cuts through the eastern Himalayas, that canyon is so remote and extreme that it remained largely uncharted until the late 20th century.

9

It is home to a pink rattlesnake found nowhere else on Earth

The Grand Canyon Pink Rattlesnake has a pinkish-red coloring that matches the canyon's own distinctive rock walls so closely that it's nearly invisible. It is found nowhere else in the world. Officially classified as Crotalus oreganus abyssus , it has darker diamond-shaped markings along its back that deepen the camouflage further.

10

There's a village at the bottom: Supai Village

For over 1,000 years, the remote village of Supai has been home to the Havasupai Tribe, the People of the Blue-Green Waters. It is located an eight-mile hike from the rim, but sits roughly 3,000 feet deep inside the Grand Canyon.

The U.S. Department of Agriculture has called it the most remote community in the contiguous United States, and it has no automobiles and no road access. The only ways in are on foot, by mule, or by helicopter. It is also the only place in the United States where the postal service still delivers mail by mule train.