A General Facts You Need To know

Paper money isn't actually made of paper, which also disproves the belief that money grows on trees. Most banknotes are made of 25% linen and 75% cotton, which gives them a distinct look and feel in the 19th century. Back then, money was made out of parchment paper, which is why it was so easy to counterfeit.

The Eiffel Tower is currently almost 6 inches high. When the temperature rises, materials' particles move more actively and take up a bigger volume. This is called thermal expansion. When the temperature falls, the substances contract, causing an effect known as thermal contraction. This is more prominent in gases, but you can also see it in liquids and solids - even iron! Build bridges using expansion joints to allow a structure some flexibility in case of thermal expansion or contraction.

Bees land on flowers to collect sugary nectar, and then they transport it back to their hive and transfer it to other worker beams. These bees reduce the water content of the nectar by repeatedly drinking and regurgitating the liquid. Special enzymes in their stomachs break down nectar's glucose, making it acidic. Bees store this nectar in honeycombs and fan it with their wings to accelerate water evaporation. The resulting honey has high acidity and low water content, preventing spoilage and inhibiting bacterial growth.

In the past, people didn't elevate mattresses off the floor, but this practice originated in ancient Egypt and spread to other cultures when they discovered its benefits. People preferred to elevate their beds off the floor to stay warmer, especially in draughty houses where cold air seeped in from under the doors. As warm air rises, sleeping higher up provides better insulation compared to being on the cold floor. Additionally, raising beds made it easier to maintain cleanliness, as floors in simple homes used to be dirtier, and dirt would often find its way into beds. Speaking of cleanliness, do you think people are inherently tidy and clean?

Thousands of years ago, our ancestors already practiced hygiene, using latrines and combs to maintain cleanliness. Our natural inclination towards hygiene is driven by our sense of disgust, which protects us from infections. However, despite this, humans still have some untidy habits. In contrast, certain animals, like rattlesnakes, exhibit cleanliness by clearing their surroundings while hunting. Reptiles and songbirds also prioritise cleanliness to enhance their chances of finding food and reduce visibility to predators.

In space, shadows appear darker on the moon compared to our planet due to the Earth's atmosphere scattering more sunlight. If you were to visit the moon, you would encounter extremely dark shadows, making it difficult to see your way. Additionally, you would notice preserved footprints on the lunar surface. Despite no human presence in recent decades, these footprints remain intact as there is no water or wind on the moon to erase them. Consequently, they endure in their original form for millions of years. Hence, watch your step carefully!

The Earth's core possesses an abundant amount of gold, capable of covering the entire planet. If one were to undertake such an endeavor, the level of this precious metal would be knee-high for an extended period. Humans have been mining gold, platinum, and various other precious metals from beneath the Earth's surface for centuries, resulting in depleted mineral reserves in certain regions. However, Earth still harbours substantial deposits, particularly closer to its core, owing to numerous meteorite impacts during its formation. These meteorites carried diverse minerals, including gold, which sank into the core while the molten Earth was taking shape. The silicate mantle that encases the core currently holds vast amounts of gold and other minerals, although accessing them remains extremely challenging. These resources lie roughly 1800 miles below the surface, subjected to temperatures reaching thousands of degrees, rendering them inaccessible due to extreme heat.

In other words, if you were contemplating going into space, one of your first considerations would be a spacesuit. However, it's worth noting that it is technically possible to survive in space without any protective gear. But before you get too hopeful, the reality is that you would only last about 15 seconds. Within that short time frame, you would lose consciousness due to the lack of oxygen reaching your brain. An incident in 1965 involved a technician accidentally depressurizing his suit in a vacuum chamber, resulting in him losing consciousness after 12 to 15 seconds. Thankfully, his suit was repressurized 27 seconds later. The technician later recounted that he remembered the moisture on his tongue boiling, and he temporarily lost his sense of taste, which returned four days after the incident. It's important to note that holding your breath wouldn't save you either, as the air inside your lungs would expand, causing them to rupture. The oxygen in other parts of your body would also start to expand, resulting in your body swelling to nearly twice its normal size, albeit not exploding thanks to your elastic skin. Furthermore, the liquids in your body would rapidly vaporise. All in all, it's safe to say that the experience wouldn't be pleasant.

The distinct blue colour of the ocean is a result of sunlight. When the sun shines, water absorbs longer wavelengths of orange and red light and reflects shorter blue light waves. This phenomenon is more pronounced in areas with a greater volume of water, hence the deeper blue colour. As a result, the water you pour into a glass lacks the vibrant ocean blue hue. The ocean serves numerous vital functions. Notably, it produces 50 to 80 percent of the planet's oxygen, which sustains life. Additionally, it plays a crucial role in facilitating internet connectivity. So, when you enjoy a funny dog video or indulge in your favourite series online, you can thank the ocean. The majority of the internet's infrastructure relies on submarine communication cables, which span extensive distances across the ocean floor. Specially designed ships are used to lay these cables, ensuring their protection and preventing damage. They carefully select relatively flat areas of the ocean floor, avoiding old shipwrecks and large marine ecosystems. Some of these cables are coated to safeguard them from potential harm, ensuring that hungry sharks or curious fish don't disrupt the connectivity by munching on the wiring.

Trees communicate, albeit not in the same way humans do. They have a unique method of communication through their interconnected roots, facilitated by an underground fungal network known as the "wood wide web." Through this network, trees can share vital resources with each other, effectively engaging in conversation. They utilise these fungal connections to transmit nutrients and water from one tree to another. For instance, a dominant and older tree, often referred to as the "mother tree," generously shares its nutrients and sugars with neighbouring smaller trees. It's a remarkable display of mutual support within the forest community, akin to a nurturing parent.

On a pleasant sunny day, with insects buzzing around, one might wonder if they are susceptible to sunburn. Interestingly, most insects have dark exoskeletons rich in melanin, which effectively shields them from harmful UV rays. However, insects that reside underground, in water, or are active during the night possess paler and thinner skin. If these insects spend excessive time exposed to daylight, they can indeed experience sunburn or, in more severe cases, become prey for predators.

Squirrels have teeth that continuously grow, but they prevent them from becoming too long by constantly gnawing on nuts and hard foods. Interestingly, the front portion of their teeth is naturally orange due to a unique and resilient enamel coating. It's fortunate that humans don't have to contend with such dental challenges!

Certain bird species have no qualms about devouring chilli peppers since they are impervious to the fiery sensation. The burning sensation caused by peppers is due to the presence of capsaicin, a chemical compound. However, birds lack the necessary taste buds to perceive its effects, making them immune to the spice.

The horn of a rhinoceros is composed of hair, specifically the same protein called keratin that constitutes your hair and nails. This unique characteristic sets it apart from other animals whose horns typically have a bony core.