Every second, around 28 million litres (700,000 gallons) of water flow down Niagara Falls. It is believed to be the fastest-moving waterfall in the world. With a height of 188 feet (57 meters) and a depth of 170 feet (52 meters), Horseshoe Falls is the tallest waterfall. Glacier action caused Niagara Falls to develop some 12,000 years ago.

How much melanin, or pigment, is present in the eye affects the color of the eye The color of the eyes will be darker if there is a lot of melanin present. 

Most people know that anxiety causes difficulty focusing and concentrating, restlessness, irritability, and frustration. However, few people realize that anxiety causes serious physical problems like weakness, shortness of breath, rapid heart rate, nausea, hot flashes, and dizziness. People experiencing a panic attack often end up in the ER believing they are having a heart attack.
 

Before that, people used flattened animal horns to create windows.

13 frames per second is the minimum speed required by the human brain to process consecutive images as movement. Anything less, and the human brain will treat each frame as a separate image. Because 16 FPS is so close to 13, old movies appear choppy and unnatural.

You are reducing air pollution for everyone by keeping your automobile at home. By avoiding congested main routes when you're walking, you can make it safer for yourself. If you can't avoid a big road, however, move as far away from the kerb as you can because even a few meters can reduce your exposure to pollution.

True. The Greeks of old would bring a cake with candles on it. To the temple of Artemis, the Goddess of the Hunt and the Moon stood in for the glistening moon. 
As each candle stood for a year that had passed, it wasn't until the 1700s that it started to become a birthday custom.

With over 500 million copies sold, Don Quixote is the best-selling novel of all time. The novel by Miguel de Cervantes, about a man who becomes obsessed with tales of knights and decides to become one, is the one that gave us the phrase "tilting at Windmills" to describe a noble but futile endeavour. Since its publication in 1612, Don Quixote's misadventures as he travels across the Spanish countryside seeking to right wrongs and uplift downtrodden peoples have entertained generations of readers. Don Quixote is also regarded as one of the first novels ever written.

In 1958, organized searches for yetis were launched by both American and Soviet teams. Cryptozoologist Gerald Russell, who headed up the American effort, claimed that "the yeti race is now an international one."

The best graphite in the nineteenth century came from China. Yellow is associated with royalty and respect in China. American manufacturers began painting their pencils yellow to convey a luxurious, high-quality vibe.

The fundamental technology behind windmills was undoubtedly derived from the wind sails that were used to steer ships. However, the first instance of wind energy being used to help automate routine manual tasks, such as pumping water or grinding grain, was most likely in Persia. Last but not least, the first vertical axis windmill design that has been historically recorded is the Persian panemone windmill, with records of the technology dating back as far as 1,500 years. The vertical sail on this particular specimen was made of bundles of reeds or wood, which were then fastened to the central vertical shaft with the aid of horizontal struts.

Make sure you're getting enough vitamin D to maintain your immune system operating at its peak.

We often get attracted towards the smell of the earth when it rains but have you have thought that rain too can have smell? But it does! Petrichor is the word that describes the scent of the rain. The reason behind it is that some plants secrete oild during dry periods & when it rains these oil get released into the air. And the aromatic compounds combine to create the pleasant scent of rain.

This one from Amazing Facts About Hindi is one that practically everyone is familiar with. Simply put, Hindi is the simplest and most evolved form of Sanskrit.

The typical dust mite produces 1,000 allergen waste particles during its 80-day lifespan.

The pan shot, also known as the panorama shot, was invented in 1987, when panning cameras were first used in film production. Cameras used to be stationary, so you had to move the entire camera and tripod to get any movement. This was a significant step forward in filmmaking and cinematography as an art form.

When it came to popular medicine in the 1830s, ketchup was all the rage. An Ohio physician called John Cook advertised it as a treatment for dyspepsia in 1834. It wasn't popular as a condiment until the late 1800s. 

Except for one character, it appears that one of the most intriguing parts of the program is that the people go by the names of major cities throughout the world. The Professor is a completely separate and distinct persona, yet many fans are unaware that he, too, has an unofficial city name - Vatican City. Vatican City, a well-protected, secretive, and knowledge-filled city, is the ideal name for the figure played by Alvaro Morte. Another intriguing detail about this actor is that he has great eyesight in real life and it took him a long time to get used to wearing glasses, but the appearance was preserved in the program.

Did you know that there are more types of mosquitos on the earth than there are humans? There are over 3,500 different mosquito species ready to suck your blood. To give you an idea of how big that number is, imagine stacking 100 trillion mosquitos on a football field. The mound would be more than three miles tall.

The risk of heart disease and stroke can rise when one breathes in contaminated air. It aggravates asthma symptoms and even has been linked to lung cancer. We are urging the government to phase out diesel vehicles by 2025 as a starting step in addressing this. The human costs of both indoor and outdoor air pollution are horrendous; air pollution is a factor in millions of preventable deaths each year.

In the southeast of Europe is the Republic of Bulgaria. The Balkan Peninsula includes it. In addition to the Black Sea on its eastern border, Bulgaria is bordered by Serbia and Macedonia to the west, Romania to the north, and Turkey, and Greece to the south.

In Tunisia, Islam is a major religion. The majority of residents are Sunni Muslims, with minority of Christianity and Judaism. It is easy to observe how Islam has made a presence in Tunisia. One of the most obvious features is a call to prayer that may be heard five times a day: at dawn, lunchtime, mid-afternoon, sunset, and evening. In Tunisia, there are around 5000 mosques. The way people dress differs greatly depending on where you are. It is normal to see more western style attire in tourist locations, however in traditional places such as southern Tunisia and smaller villages, a more respectable form of dressed is recommended.

A female shrimp will give birth to an insane number of eggs that will hatch in two weeks during a single season. As long as there is food, they can also thrive in any.

Too many comic book enthusiasts believe that Marc Spector was developed by Marvel as a deliberate retaliation to Bruce Wayne. For those who wish to connect the dots, the parallels are there. While they are both monsters of the night who terrorize villains, there are some significant distinctions. The most noticeable change is Moon Knight's outfit. Batman usually wears an all-black outfit with a few yellow or gold accents. Moon Knight's all-white attire appears to be a near-identical negative of Batman's black costume. The hero wears white because he wants his adversaries to see him coming — and fear the sight of him, according to Warren Ellis' 2014 run on Moon Knight.

The love partnerships revealed in the story's epilogue were one of the most contentious aspects of the Harry Potter series' ending. Rowling chose Ron and Hermione in a controversial choice, despite many fans' desire to see Harry and Hermione get their happily ever after. It almost goes without saying that Rowling regrets matching Harry with Ginny Weasley, believing that Harry and Hermione should have ended up together. Rowling confessed in an interview with The Sunday Times that these narrative decisions were "chosen for very personal reasons, not for grounds of veracity."