We spend one-third of our life doing it, and most of us don’t get enough of it. We’re talking, of course, about sleep. And although it remains a necessity to human beings, sleeping also remains a mystery. In fact, scientists still can’t say why human beings sleep at all, or why almost every other creature on Earth also sleeps each day. What is known is that a lack of sleep, or sleep deprivation, can have devastating affects on people of all ages, from newborn babies to aging seniors. And if you dig into the science of sleep, you will find a lot of unusual things can impact a good night’s rest. With all that in mind, here are some surprising facts about sleep that you probably never considered.
10. The Number “2” Is Involved In When We Feel Most Tired
According to The National Sleep Foundation, people feel most tired at two different times of the day: 2 AM and 2 PM. This, apparently, is when people young and old experience a natural dip in their alertness and attentiveness, which definitely explains the tiredness many of us feel after lunch and in the early afternoon. Still, why those particular times, and why the 12-hour correlation? Well, actually, scientists don’t have a definitive answer for that. However, repeated studies on sleep and sleep deprivation have discovered, reliably, that people are their most drowsy at both those specific times. Some scientists and sociologists have tried to chalk this phenomenon up to biology and evolution, but there is no clear answer for the impact the number “2” has on human exhaustion.
9. A Full Moon Can Keep You Awake
There’s a lot of “hocus-pocus” related to the moon, some of it true and some of it pure fiction. From allegedly turning people into werewolves, to the very real effect it has on tides, the moon exerts a powerful force on the Earth. But did you know that a full moon has also been shown to keep people awake, and can negatively impact sleep patterns? It’s true. A study conducted at the University of Basel in Switzerland looked at how soundly people slept during different phases of the moon. It was found that, on average, it took people five minutes longer to fall asleep during a full moon, and their sleep cycle was shortened by about 20 minutes when a full moon hung in the night sky. And no. it was not because moonlight was shining in people’s windows. That factor was actually taken into considerations, through several controls were built into the study, including closed curtains. In fact, the study participants didn’t even know there was a full moon the night they had a shortened and restless sleep. Weird.
8. We Don’t Smell Anything When Asleep
It has been shown that people still hear things when they are asleep, which is why a loud noise tends to wake us up. However, people do not smell things once asleep, which becomes more dangerous when you consider that the smell of smoke is a telltale sign of a fire. A study conducted at Brown University found that participants who were exposed to different types of smells during their sleep cycle had no response to scents ranging from peppermint to smoke from a house fire. Even when fitted with a chin strap that forced the study participants to breathe through their nose, and when exposed to the strongest and most noxious of fumes, the sleeping subjects still did not react. In comparison, the same study found that even light sounds were enough to pull people out of the deepest phase of a sleep cycle. We can only assume that this is why smoke detectors have very loud alarms.
7. Sleep Texting Is Real
Sleepwalking is a real and well-documented phenomenon, where people get up in the middle of the night and go for a walk while they are still technically asleep, possibly to the kitchen, bathroom or even down the street. However, in recent years, researchers have documented a new development among people known as “sleep texting.” Billed as a natural evolution in sleepwalking, sleep texting and even sleep e-mailing is happening with greater frequency among teenagers and adults. According to professors at New York University, the act of texting and of answering an alert on our smart phones has become such a habit for most of us, that it is now crossing over to when we are unconscious and asleep. Messages sent when sleep texting vary between incoherent gibberish and texts that are perfectly spelled and readable. Some people, when asleep, even send inappropriate romantic texts to people who are on their mind, which would no doubt be embarrassing once you wake up and discover what you’ve done.
6. Humans Are (Probably) The Only Species That Dreams
The subject of whether animals and other creatures dream when asleep, as humans do, has occupied many scientists. In fact, revered science fiction author Philip K. Dick even named one of his most famous novels “Do Androids Dream of Electric Sheep?” (which was the basis for the movie Blade Runner). However, despite countless studies and trials, there is no concrete evidence that other animals or creatures dream as people do when sound asleep. While studies show that other animals do enter deep “REM” sleep, there is no hard proof that other animals dream (although some studies have suggested it’s possible). And, scientists cannot explain why human beings dream. While sleep enables the body to rest, there is no scientific reason for us to dream, and what purpose dreams actually serve remains a mystery.
5. We Need Less Sleep As We Grow Older
A newborn baby typically sleeps about 17 hours a day during the first month of its life. Teenagers need about 10 hours of sleep a night. Middle aged adults, meanwhile, should get eight hours of uninterrupted sleep per night. Finally, senior citizens over the age of 65 only need five or six hours of sleep each night. While you would assume that seniors would need more, not less, sleep, it seems that the reverse is true. Why is this? Nobody knows. But for whatever reason, as people grow older, they sleep less, even when they are old and frail senior citizens. It turns out, while people’s physical energy levels decrease with age, the need for sleep also decreases and people are able to function better on less sleep as they enter their twilight years. Some scientists theorize that as seniors expend less energy during the daytime, they need less sleep at night, but the exact reason for this trend is unclear.
4. Sleep Deprivation Kills People Faster Than Food Deprivation
A lot of people assume that sleep deprivation cannot kill a person, but they are completely wrong. In reality, people can actually go about 10 days without sleep before they die. That seems like a lot of time, but that is faster than dying from food deprivation. People who go without food die in 14 to 21 days, or two or three weeks depending on their levels of hydration. But without sleep, people’s bodies shut down and their minds stop working in far less time, even if the sleep deprived person has continued eating and drinking normally. Humans tend to hallucinate after only two days without sleep, and four or five days without sleep can permanently damage the immune system. Clearly, sleep is very important to people, and in fact, it has been shown to be more important than eating and drinking. Who knew?
3. Giraffes Sleep Less Than Any Other Animal
On planet Earth, giraffes have the distinction of sleeping less than any other animal. The average giraffe sleeps less than two hours a day, and they tend to sleep in five minute intervals throughout a 24-hour period. By contrast, koalas, which are native to Australia, are the animals that sleep the most, averaging 22 hours of sleep per day. That means that koalas are only awake for two hours during a 24-hour day, or about as long as a giraffe sleeps! Why do giraffes sleep so little and koalas sleep so much? It’s a mystery. Why certain species need more or less sleep cannot be explained. Some researchers try to explain it with biology and diet, but there is no clear answer, especially since many animals eat the same diet of vegetation and have completely different sleep patterns from one another. What is interesting is that the sleep patterns of animals tend to be consistent, by which we mean that almost all giraffes sleep less than two hours a day regardless of their location and age, and all koalas tend to sleep 22 hours per day wherever they happen to live.
2. Sleep Paralysis and Hypnic Jerks
Strange and interesting things can happen to us as we first fall asleep, or when we try to wake up. For example, many people experience a sudden jolt, jump, or twitch when falling asleep. This is known as a “hypnic jerk” and it is usually preceded by the feeling of falling. Many people also experience the feeling of paralysis when trying to wake-up from sleep, where they are aware that they are asleep and want to wake up, but find that they cannot move. During this paralysis, some people also report that they cannot breathe as well. This phenomenon is known as “sleep paralysis.” Many theories abound as to what causes hypnic jerks and sleep paralysis, but nobody knows for sure, although some people theorize that hypnic jerks are the result of the brain and muscles relaxing too quickly at the point of unconsciousness. As for sleep paralysis, that has long been blamed on spirits, aliens and witchcraft, likely due to the fact that people who report sleep paralysis also tend to report feeling that they are not alone in their bedroom at the time. Creepy.
1. Blind People See Accurate Images In Their Dreams
Many blind people report that they see accurate and detailed images in their dreams. In fact, blind people are often able to vividly describe the images they see in their dreams. This would make sense for people who once had sight and were blinded in the course of their life from an accident or disease. But what’s really interesting is that even people who have been blind from birth see images in their dreams, and can describe them in accurate detail. While many people blind from birth also describe dreaming of emotions, sensations and smells, they can recount with great accuracy images, pictures and structures from their dreams, such as descriptions of houses by people who have never seen a house, or remembering fields full of flowers by those who have only smelled a flower and never seen one. This is a bizarre phenomenon that has no explanation in science, but certainly proves the power of dreams.