Why There’s No Watermelon Juice in Stores

You can only cut a diamond using another diamond. It’s the hardest natural material on our planet. Between retrieving the stone from the Earth and the finished products you see in jewelry stores, a diamond goes through a complex process. Before they cut it, people need to consider which shape is best for the stone, so they don’t throw too much of it away.

One town in Norway, located north of the Arctic Circle, wants to become the first time-free zone in the world. The Sun doesn’t go down there at all between May 18 and July 26. The locals don’t want to follow the classical concept of time to get the most out of their 24 hours. Since they have constant daylight, they can’t act just like the rest of the world. You can sometimes see people playing soccer in the middle of the night there. Or mowing their lawns and painting their houses at 2 a.m.

The Leaning Tower of Pisa is tilted because the soil under the building’s surface is really soft. This was probably frustrating for the people who constructed it, but they eventually figured out the soft soil is part of the reason why the tower is safer from earthquakes. Because of the softness of the soil and the tower’s stiffness and height, the tower doesn’t resonate with earthquake vibrations. So the reason the tower is tilted is exactly why it’s still standing — even in such an unusual position.

You don’t actually see “pitch black” in a pitch-black room. It’s a specific phenomenon where you see “dark light”, or as people also refer to it, “brain grey.” It’s a dark gray background many people see in the absence of light. And some even call it “visual noise” since it’s like an ever-changing field of small black and white dots.

Watermelon is definitely one of the most refreshing and hydrating fruits, especially during hot summer days. But if you try some watermelon-flavored candies like gummy or hard candies, they’re usually either mouth-puckeringly sour or very, very sweet. They aren’t at all like the actual watermelon. It’s basically impossible to replicate the great taste in the overly acidic-tasting watermelon candy. That’s because its main chemical compounds are rare, and watermelon flavoring uses blends of cheap synthetic artificial flavors. Making high-quality realistic flavoring for candies and juices is possible but would cost businesses a lot. Some people love the “fake” watermelon flavor, but most stick to their perception of how that fruity taste should be and are not fans of it.

Why is there an expiration date on the water bottle? Of course, water doesn’t go bad, just like salt or sugar. But even though water doesn’t go bad, the plastic bottle does. When it starts expiring, it leaches chemicals into the water. It won’t make the water toxic, but it can change its taste, so you might not get the “mountain spring fresh” water you expected. Another reason for the expiration date on bottled water is there’s a rule all consumable food products — including water — need to have an expiration date. Also, many companies that produce these bottles use the same machines for bottling sodas and some other beverages. And these DO expire. So, it’s way easier to just put a stamp on all bottles, whether necessary or not, than to buy new special machines just for bottles of water.

How come identical twins don’t have identical fingerprints? The pattern of ridges on your fingers is unique and stays the same throughout your whole life, which is why fingerprints are a valid feature when it comes to identification. Two people could be sharing identical fingerprints, but the chances here are less than one in 64 billion. Identical twins have slightly different fingerprints because the patterns are affected by both environmental factors during prenatal development and genetics. Fingerprints are not just something that’s unique to humans. Gorillas and chimpanzees have fine ridges on their fingertips, too. They also seem to be unique to individuals. So we all probably inherited this from a common ancestor.

Why does a green screen come in green and not some other color? When you film someone in front of a green screen, it’s a technique known as chroma keying. The green color gets digitally filtered out so you can replace it with any footage you want to add. If the subject you’re filming is wearing something green, the background image fills that in as well. That’s why it gives the impression the person you’re filming has holes in them. And green is good for this since it resembles human skin tones the least.

Why do you feel dizzy after spinning? There are hairs lining the side of tiny tubes filled with fluids that are located in your inner ear. When you move your head, these hairs detect acceleration, which means a change in the speed of a certain object. If you spin for long enough, your brain can’t deal with the constant turn signals from your ear, and the way it adjusts is to zero them out.

At the moment you stop, your ears report zero turning correctly, but your brain is still in the mode where it actively cancels this out. It actually thinks you have now started spinning in the opposite direction. So, how can ice skaters do all those amazing things on the ice and not feel dizzy? When doing a pirouette, they lock their eyes on a fixed point and keep it that way. They whip their head around really fast when they’re not able to twist their neck further. Their spins are really fast, so they gradually train to overcome the feeling of dizziness and learn how to keep their eyes horizontal. That way, the view is spinning around one axis only.

Neutron stars aren’t that ’heavy’ - they’re just really ’dense’. So dense that just one teaspoon of a neutron star would weigh one billion tons. They are the densest and the smallest type of star we know of. Imagine squeezing 1.4 times the mass of our Sun into a sphere no bigger than 6 miles across. They’re dense because of the way they form. The balance between an outward pressure process in its core and the gravitational force that tries to contract a star hold it together. When a star loses its supply of fuel, gravity wins, contracts the star, and eventually makes it collapse.

When stars between 8 to 20 masses of the Sun collapse, this squeezes their core to be super-dense. Their outer layers rebound, and BAM, here’s a supernova. It leaves behind an extremely dense neutron star. If a star has 20 solar masses or even more, the core doesn’t collapse into a neutron star but into a black hole instead.

When you spend a day at the beach playing volleyball, swimming, or doing some other physical activities, you expect to be exhausted. But even when you spend a whole day just chilling around, you’ll probably end up just as sleepy. Your body still gets very tired because it’s doing a lot, even though you can’t see it. First, it’s always working to maintain your internal temperature. When it’s hot outside, it requires way more effort. And your body cools off in a way it dilates your blood vessels. This boosts blood flow and helps your blood get closer to your skin. Over there, it can offload excess heat. That’s also why some people blush when they’re hot. You sweat more when it’s hot outside — again, to cool down, and your metabolic and heart rate both increase. So, you lose a lot of energy even if you’re just lounging around at the beach.

Why do animals have differently-shaped pupils? The pupil is a hole in the iris of your eye that lets light pass through to the retina. The iris muscles change the size of the pupil, which affects the amount of light that passes through. Because our muscles are placed in a ring that contracts equally towards the center, our pupils are round. This brings certain benefits. It provides consistent focus over the whole field of view. But circular pupils are unable to constrict as tightly as some other shapes of pupils. Animals that hunt — or are prey to bigger animals — evolved to have big, sensitive eyes at night. Bright daylight is just overwhelming for them. That’s why they have an extra set of muscles that pull the pupil into a narrow slit shape in daily light.

Predatory animals often have vertical slit pupils, like many snakes and cats. Such pupils help them to have sharper focus across the horizontal field of view and determine better how far their prey actually is. Animals with horizontal slit pupils, like sheep and horses, don’t have sharp focus at the right and left edges, but they have wider peripheral vision. That way, they can spot predators coming after them better.