We, here at STS, are inquisitive people, and we often ask questions about the world around us. This list has ten explanations of common, every-day things that you probably did not understand. And if you did understand them you’re far cooler than us. Using this knowledge you can impress your friends, family, or romantic interests, because nothing is more attractive to the other sex than knowing how random things work. 

1.) Falling Sensation:

Have you ever woken up to a falling sensation and a strong muscle twitch as you are simply lying in bed? This phenomenon is known as hypnagogic myoclonic twitch or “Hypnic Jerk,” and studies have shown that roughly 70% of people have experienced it. There is no definitive answer on why this happens, but most scientists have agreed on the following explanation. When you are falling asleep your muscles become very relaxed and enter what is essentially a state of temporary paralysis. While your body is making this transition the brain can misinterpret the sudden relaxation of the muscles and instead think that you are falling. Instincts kick in and send signals to your muscles to jerk you upright which leads to a rude awakening. Studies have found that “Hypnic Jerks” occur more frequently with people who suffer from sleep anxiety, fatigue and discomfort because the brain is more easily confused. Either way, it is a normal part of the sleep process and poses no real danger.

Source: failedsuccess

2.) Cracking Joints:

You may not be a knuckle cracker yourself, but chances are you have heard someone doing it. This noise is caused by pockets of gas that are escaping from the joints in the hand. There is something called synovial fluid that lubricates joints and contains nitrogen, oxygen, and carbon dioxide gas. When the joint is put in an abnormal position, bubbles of these gasses are rapidly released which causes the cracking noise. The reason a knuckle can rarely be cracked twice is because it takes time for the gases to build up again. Some claim that cracking knuckles leads to arthritis, but the studies claim that it only causes minor damage to soft joint tissue. A similar cracking noise can be produced with the knee or the ankle but it is not due to escaping gas. Tendons can be pushed out of place as joints move, and when they return to their original position they can create cracking noises. Because gas does not have to build up like it does in the knuckles, this noise can often be made repeatedly.

Source: everydaymysteries

3.) Goose Bumps

Goose bumps are the dots that form on the skin when a person is cold, afraid, or experiencing strong emotions. The reflex that causes goose bumps is known as horripilation and it occurs in other mammals as well. The goose bumps are caused when individual muscles at the base of each hair contract which make the hair stand straight up. This reflex is linked to the sympathetic nervous system which is responsible for most fight-or-flight responses. Goose bumps provide no known benefits for humans, but the reflex makes sense for animals. When humans are cold, horripilation causes their hair stand up, but humans in general do not have much body hair. For animals with fur, air pockets are trapped between the hairs which create an extra layer of insulation. In response to fear or anger, raised hair would make an animal seem larger and more intimidating. The best example of this is the porcupine whose spikes stand up when threatened. It seems that horripilation is simply a reflex left over from the evolutionary process, a constant reminder that humans were not always as they are now.

Source: wikipedia

4.) Wrinkled Fingertips

If you have ever spent time in a hot tub for too long then you most likely emerged with wrinkly fingertips. They go away soon after you dry off, but what causes them to get that way? The body has three layers of skin, the subcutaneous tissue (fats, nerves, large blood vessels), the dermis (small blood vessels, nerves, hair roots, sweat glands), and the epidermis (protects the skin beneath and keeps water inside the body from evaporating). These layers are tightly connected, and biologists have found that when the skin is submerged for a long time the epidermis begins absorbing water. Because it is so tightly connected to the dermis underneath, the skin warps which leads to the wrinkles. The reason this mostly occurs on the fingers and toes is because the epidermis in those areas has calluses which take in more water.

Source: everydaymysteries

5.) Eyebrows

Many people see eyebrows as just another facial feature to be self conscious about. Some spend a great deal of time plucking, waxing, trimming, preening, shaving (frat parties), penciling, or essentially worrying about their appearance, but have they ever thought why humans have them in the first place? Evolution has removed hair from most of our bodies so why would two little strips above our eyes remain? Eyelashes and eyelids work to keep dust and other debris out of the eye, but they can not do all of the work. The eyebrows divert sweat and rain around the eyes which makes it much easier to see. If you have ever had saltwater in your eyes you know how irritating it is, and it was just annoying enough for natural selection to create eyebrows.

Source: howstuffworks

6.) Chopping Onions

No matter how manly you think you are, cutting onions will make you tear up. Onions release an enzyme known as Lachrymatory-factor synthase into the air when they are cut open. The enzyme converts the sulfoxides (amino acids) in the onion into the unstable compound sulfenic acid which rearranges itself into something called syn-ropanethial-S-oxide. Syn-ropanethial-S-oxide is a chemical irritant which causes the lachrymal glands to release tears when it comes in contact. If you have never cut onions yourself than you may not be so convinced, but shortly after the knife cuts the onion you are sure to notice. Three ways to help prevent this is to run water near to where you are cutting the onion, to put the onion in the fridge half an hour before cutting it, or to avoid cutting the root. If you still tear up while cutting onions, and have nothing better to spend your money on, you can always purchase the incredibly useful Onion Goggles for $19.95 (available in black, white, or pink!).

Source: everydaymysteries

7.) Freckles

Freckles are flat tan, brown, or black spots that can appear on skin that has been exposed to the sun. These spots are abnormal collections of melanin, a pigment that is produced by cells in the skin called melanocytes. The melanocytes create freckles to protect the skin from sunlight, and therefore they occur more often on those with lighter skin that burns more easily. Freckles are more common on the face, arms, and shoulders because those areas get the most sun. For many people freckles fade during the winter only to return during the spring and summer months. In some cases too much sun exposure can cause certain cells to become cancerous, so any suspicious looking freckles should be checked out by a dermatologist. The best way to prevent skin cancer from developing is wearing clothing or sunscreen when exposed to the sun.

Source: health-cares.net

8.) Sunscreen

Sunscreen is something many people trust to keep them from getting sunburnt but how exactly does it keep the skin safe from harmful UV rays? The reason sunscreen works so well is because it uses multiple active ingredients that each do their part in protecting your skin. Most sunscreens use inorganic ingredients such as titanium oxide or zinc oxide to reflect UV radiation away from the body while organic ingredients such as octyl methoxycinnamate or oxybenzone convert the remaining UV rays into heat. The end results are creams with varying SPFs (Sun Protection Factors) that keep the body protected from UV radiation.

Source: everydaymysteries

9.) Songs Stuck in our Heads

Almost everyone has at one point or another had a song stuck in their head, and it can last hours until that annoying tune goes away. Whether it is a backstreet boys song, a simple beat, or “It’s a Small World,” the constant repetition can drive anyone crazy. So what exactly causes songs to get stuck in our heads? Scientists blame something they refer to as “earworms” which create a “cognitive itch” that makes the brain to fill in the gaps in a song’s rhythm. Songs trigger activity in the auditory cortex of the brain, and studies have found that the part of the auditory cortex that is active when you’re actually listening to a song is reactivated when you just imagine hearing the song. In other words, imagining a song will “scratch” the cognitive itch, but this just makes it worse. In any case, the song will eventually go away by itself but if you can’t wait that long you can try listening to other music or distracting yourself to get it out of your head.

Source: howstuffworks

10.) Hiccups

Hiccups are triggered by uncontrolled impulses of the phrenic nerve which lead the diaphragm to spasm. These contractions result in a quick intake of breath which is what we refer to as a hiccup. Hiccups can be caused many ways such as by eating or drinking too quickly, consuming spicy or cold food, drinking alcohol, or by quick breaths because of surprises, laughs, coughs, or sneezes. In some cases they occur for no real reason at all, which can be quite annoying. So how exactly does one cure the hiccups? I have heard of many remedies including drinking water upside down, holding your breath, eating peanut butter, distracting yourself one way or another, or getting someone to scare you. Some of these may seem ridiculous, but all of them either distract you or cause you to hold your breath which allows the diaphragm to relax and can help stop the spasms. If none of these remedies works, and the hiccups do not subside, it may be necessary to get medical attention. The longest case of hiccups ever recorded was with a man named Charles Osborne whose fit lasted 68 years. He hiccupped an estimated 430 million times and averaged from 20-40 hiccups a minute throughout his lifetime. Next time you find yourself complaining about hiccups, just be glad that they will be gone sooner than his were.