General video · Level B2 - Part 1

Rare Facts About Sleep

We spend a third of our lives doing it, yet we still don't completely understand this bizarre ritual we carry out each night.

Level: B2 · 162 sentences

Transcript

We spend a third of our lives doing it,
yet we still don't completely understand this bizarre ritual we carry out each night.
You lie down, your body goes unconscious,
you see the weirdest pictures in your head,
and then wake up, only to repeat the whole process the next day.
Sleep is funny, and here's the proof:
Like I said, you spend a third of your life off in dreamland,
that's about 25 years if you were doing the math.
We also spend about seven years of our lifetime trying to fall asleep.
Everybody thinks you need eight hours of shut-eye each night,
but your sleep hour requirement changes throughout your life.
Children need 10 to 12 hours,
teens need 8 to 11,
adults 7 to 8 hours,
and seniors are fine with six to seven hours.
Now, good sleep is necessary for effective work and productivity,
but good doesn't necessarily mean long.
Some famous historical figures slept very little,
from two to four hours,
and this didn't prevent them from doing great things:
Da Vinci, Franklin, Tesla, Churchill.
And that's not all.
There's a sleep mutation that allows a person to sleep just 2 to 6 hours
and not experience any side effects.
Now, if you have a dog or cat,
then you might have noticed that they make funny sounds while they're sleeping.
Yes, they do dream,
and experts aren't quite sure why or what they see.
My dog Riley even barks in his sleep.
Temperature is a critical part of sleep and possibly dreams.
If your room is too cold or hot, it can trigger nightmares,
like you're in a cramped space or a fire.
Some great discoveries were found thanks to dreams.
For example, Mendeleev created the periodic table after he dreamed about it.
This happens because our brain processes and analyzes all the events we experience throughout the day.
Many experts believe this is why we dream in the first place.
By the way, I love hearing dream stories.
What's one dream you remember the most,
or maybe have on a regular basis?
Let me know down in the comments.
And onto that weird sudden twitch your body might do as you're falling asleep,
this happens because the brain sends impulses to the muscles.
It's called a hypnic jerk.
But why does the brain do it?
Nobody knows for sure.
Our brain shuts off all our muscles when we sleep.
This is so that you don't run away in real life as you're dreaming about running away from some pursuer.
But the brain doesn't shut off the eye muscles,
which is why your eyes can move,
and they do during the deepest part of sleep,
a stage called REM or rapid eye movement.
But what if your brain wakes up, and your body muscles are still disabled?
This condition is called sleep paralysis.
Many people have experienced it at least once in their life,
and those same people say it's far from pleasant.
Sleep and reality are mixed in this state,
and individuals can see hallucinations.
Babies dream in the womb,
but there are no visual images in these dreams,
only tactile and auditory sensations.
Our spine relaxes and stretches when we sleep,
meaning you can be a wee bit taller in the morning than in the evening.
People sleep under blankets not only for warmth,
though that does help.
It's also psychological.
We relax better thanks to the blanket's touch, even if it's heavy.
That slightest bit of pressure on our bodies soothes the nervous system,
much like a hug.
We also feel more protected when we sleep under the covers.
A body out in the open makes a person feel uncomfortable and vulnerable,
especially when you're about to let your guard down and go to sleep.
And, well, the blanket thing is just a custom,
even if you don't feel like you need it,
it feels weird to sleep without it.
Japan and South Korea get the least sleep on Earth,
less than six hours.
New Zealand gets the most, a whopping eight hours,
one of the few places getting the recommended amount.
College students might not believe me,
but pulling all-nighters cramming for an exam won't help your grade.
If you're gonna do that,
do it a couple of days before the big test day.
The night before, get good sleep.
It helps you retain learned information.
Nobody knows for sure what causes déjà vu.
One of the theories is associated with sleep.
Even though it translates from French as "already seen,"
you likely dream something but forgot about it by the morning.
Then, in reality, you see those events that are a bit like the forgotten dream.
Have you ever had déjà vu?
A lot of animals, like horses and zebras, sleep while standing.
Their body has evolved to pull this off
so they can run away from danger at any moment.
Some birds, the albatross as an example, can sleep while flying.
There's a whole laundry list of animals
dolphins, manatees, penguins, and crocodiles, to name a few,
that sleep with one eye open.
It's possible because half of their brains are working and watching the situation around,
while the other half sleeps.
Some people not only snore during sleep
but can also grind, gnash, or clench their teeth.
This is called bruxism.
Like a lot of things connected to the world of sleep,
nobody knows the exact causes of this phenomenon.
Sleep is as vital to humans as food and water are.
A healthy person will live longer without food than without sleep.
It seems obvious that we need to sleep
so that all our body's bits can refresh themselves,
but no one has fully figured out all the effects sleep has on the body
only that we need it, and we don't do well at all without it.
One thing's for sure: our body accumulates energy during sleep.
If you don't sleep for a long time,
then the body looks for this energy in food.
Not surprisingly, lack of sleep often leads to weight gain.
Sleepwalking is another mystery we haven't figured out yet,
but there are plenty of misconceptions surrounding it.
You might imagine a sleepwalker with their arms extended out in front of them like a zombie,
but that's just not the case.
You often can't even recognize if a person is sleepwalking.
And waking a sleepwalker won't give them a heart attack,
but it probably will give them a shock,
and they might try to fight you.
It's much better to gently guide a sleepwalker back to bed without waking them,
if you can.
Many people claim that they don't dream at all,
but they likely just forget the dreams they do have.
If you want to remember your dreams,
then put a notebook or a voice recorder next to the bed.
As soon as you wake up, immediately get to writing or recording.
The first 90 seconds after waking up are ideal.
It might take some practice,
but you will start remembering more and more of your bizarre brain movies.
If you do remember your dreams,
how many do you think you have a night?
One big long epic movie?
Nope.
It's more like four to six of them each night,
and your dreams get longer throughout the night.
It's the final one you're probably recalling.
Before there were alarm clocks,
people had all kinds of ways to wake up.
Some got up with the sun at the crack of dawn,
others depended on their rooster to wake them,
and in more populated areas,
it was thanks to the ringing of the city tower.
There was also a special profession called a "knocker-upper."
This probably not-very-popular fella
would walk among houses in the morning
and knock on bedroom windows to wake people up for work.
Lullabies - how do they work on babies so well?
Well, imagine you're a baby again.
You've had a busy day discovering new things in this world,
all kinds of smells, sounds, materials.
The day you found your toes? It was a particularly busy one.
It's hard to fall asleep at the end of the day
when your brain is struggling to analyze such a massive storm of new information.
But when you hear a lullaby,
your brain can concentrate on one thing
that soothing, hypnotic voice.
Your head clears, you feel at peace,
and sleep soon follows.
On that note, I'm getting kind of sleepy myself.