Our ability to wonder why is the basis for our success as a species.
And our resolve to find out is the reason for it.
The way we do it is called the scientific process:
This is what separates the material from the myth, and not just for life’s big ideas. Sometimes it’s esteem-enhancing to be able to answer the little questions that pop up from time to time. So, let’s be thankful for those who just had to know and took the time to confirm their research.
Here are one dozen everyday phenomena that we can conclusively say we know why they happen:
1. Why do we sweat when we’re nervous?
Your body deals with a potential threat by going into fight-or-flight mode.
This involves the part of your brain that controls basic functions — the hypothalamus — telling your adrenal gland to release a load of hormones. One of these is epinephrine, also known as adrenaline, and it’s what gets your sweat glands going.
The idea is you’ll need to keep cool while you’re confronting the threat, even if it’s just giving a presentation.
2. Why do we blush?
This is another symptom of the fight-or-flight response.
When you’re embarrassed, your body releases adrenaline. Your blood vessels then dilate in order to get more oxygen to your muscles by letting more blood through your veins. This has the unfortunate side-effect of making your face look redder.
Incidentally, it’s an involuntary reaction, so there’s absolutely nothing you can do about it.
3. Why is the sky blue?
Sunlight looks white, but it’s actually made up of all the colors in the rainbow.
When it hits Earth’s atmosphere, it’s scattered by particles in the air. Different colors of light have different wavelengths, and blue is the shortest, so it gets scattered most.
Conversely, sunsets featuring brilliant shades of red occur because that’s the color of the longest wavelengths. They’re on an observer’s horizon, meaning the light’s wavelengths must travel through more of Earth’s atmosphere. The short ones have already been diffused by the journey — meaning blue skies exist to an observer beyond the horizon — and only the long ones remain.
4. Why do we yawn?
You probably know that yawning is contagious. Seeing someone else yawn, or even just reading this sentence, might trigger you to yawn yourself.
However, a yawn is more than a social stimulant. It actually serves to cool down our brains. The deep intake of breath forces a downward flow of spinal fluid and blood from the brain. Air breathed into the mouth cools these fluids.
5. Why do humans not have tails anymore?
Simply put, we don’t need tails anymore.
They were useful for balance when we used to walk along tree branches, but when we started swinging from them and, eventually, walking upright, we didn’t need a counterbalance anymore.
An extra limb we don’t need is just using up energy, so once we no longer had a use for them, our tails disappeared via natural selection over the next few millions of years.
All we have left now is the coccyx at the base of our spine, also known as the tail bone.
6. Why do we get hiccups?
Hiccups happen when your diaphragm contracts.
It’s a reflex, so you have no control over it, as you’ve probably discovered the hard way. Your diaphragm sits under your rib cage and helps control your breathing.
There are many of causes of hiccups, but one of the most common is an irritation of either your esophagus or your stomach.
7. Why do we get dark circles under our eyes when we’re tired?
The dark bluish tint is caused by blood flowing through the veins just underneath your skin.
When you’re tired, your body produces more cortisol, and the volume of blood in your body increases. This increase is more visible under your eyes because of the thinner skin there.
8. Why do we cry when we’re sad?
Tears show others that you need support.
Humans are the only species we know of that produce emotional tears and still cry in adulthood.
We cry instead of emitting sounds when we’re distressed because of our evolutionary history. Making a sound signifying a moment of weakness would attract predators.
9. Why do we get bored?
We’ve all learned that one the hard way, too.
Boredom comes about when we have difficulty paying attention to information, either internal (like feelings) or external (like what’s going on around us). We do recognize this, but we try to blame it on the environment instead.
10. Why do we laugh?
We use laughter as a mating ritual and as a way to bond.
It might have originated as a way to show relief after danger had passed and show trust in the people surrounding you.
But laughter is also used to exercise control over a group. Dominant individuals — like bosses in an office — are more likely to orchestrate laughter than their subordinates.
11. Can you get sunburned through glass?
Glass stops 97% of those UV rays that cause sunburn and skin cancer, and almost 40% of the less harmful type
But that’s not 100%
So with long enough exposure, you can still get burned.
12. Why do we sleep?
We’ve long known that we need sleep to function properly, but exactly why we sleep and what happens while we’re sleeping has long been a mystery.
While we sleep, our brains basically spring-clean themselves, using cerebral spinal fluid to flush out “molecular detritus” and harmful proteins that can lead to dementia if they build up.
This defragmentation process is most likely one reason we all experience crazy dreams from time to time.