Humans are smart..so why are babies so unsmart??

Hey Smart People, 

The first thing a baby giraffe experiences after being born is a 2 meter fall straight

down to the ground.

But within an hour, it’s standing, walking, and nursing on its own.

And a blue whale calf, after nearly a year growing inside mom, can swim to the surface

moments after being born.

Human babies on the other hand?

We’re born unable to move or eat on our own, we can’t communicate or fully sense

our world, and we leak Everywhere.

If humans are so smart, why are our babies so… un-smart?

Human babies begin life so undeveloped, that many people refer to a baby’s first few

months of life as the fourth trimester.

Compared to other animals, we lie on the “altricial” end of the spectrum.

Compare that with, say, a baby cow, a precocial animal, whose brain and body is developed

enough that they can stand and run just moments after being born.

Tiny humans require a ton of parental care before we’re ready to be on our own.

Our parents not only grow us for 9 months or so, they carry us, they feed us, they keep

us from dying, and teach us how to provide for ourselves for 15, 18 years… heck these

days even over 30 isn’t unheard of.

It’s actually totally normal.

That’s because, well, our brains come out half-cooked at best.

When we’re born our brain is around 30% the size of our adult brain.

That’s the smallest of all of our primate relatives.

Why does our smart species have such small-brained babies?

For a long time, scientists’ best answer to that question was the obstetric dilemma.

Basically, our brains come out as big as they physically can be.

The obstetric dilemma goes like this: if our brains were any bigger at birth, they wouldn’t

fit out the birth canal.

And if female pelvises were any wider, they would make walking and running less efficient…

which might not affect your life that much, but would’ve made it easier for our ancestors

to become dinner… which means no babies, which means no you or me.

So here, natural selection found a compromise: mom’s pelvis stays narrow enough to walk

and run, and babies are born earlier so their noggins don’t get stuck.

It’s a pretty logical idea.

But it doesn’t hold water.

Male and female bodies do have significant anatomical differences, but research has found

that wider or roomier pelvises don’t make walking and running, AKA “locomotion”

less efficient.

And, some women already have pelvic openings wide enough to fit bigger heads and brains.

Not every woman does, but if there was strong pressure from natural selection for roomier

pelvises, they’d have become more common.

So pelvis size isn’t why our babies come out half-baked.

The real answer might have more to do with metabolism.

The bigger a developing baby gets, the more it demands from mom.

I mean, women grow a completely new organ, the placenta, not to mention a complete humanbeing, inside their bodies, and that takes energy!

It might be that mom’s ability to provide enough energy for growing baby determines

when baby is born.

Humans and all other animals have what’s called a basal metabolic rate.

It’s how much energy we burn when we’re not doing anything else.

A Tour de France cyclist at peak human performance can hit maybe four or five times their basemetabolism.

But most of us normal humans?

We max out at around two times our basal rate.

We just can’t run our biological engines any higher for very long.

Like overclocking a CPU, there’s just a physical limit to how much extra energy we

can create.

For the last third of pregnancy, and even into nursing, a mother is at the limit, burning

twice as much energy as before baby.

Nine months happens to be right about the time a growing baby starts to demand more

energy than mom can provide, so it’s born.

It’s called the EGG hypothesis, or “Energetics of Gestation and Fetal Growth”.

But I like egg.

But even energy and metabolism might not be the full answer.

It could be that how helpless our babies are when they are born has had a big influence

on what happens after they are born.

How self-sufficient an animal’s young are at birth can be determined by a lot of things.

If they have to run from predators, if their parents are quickly on the move, or if their

egg had enough nutrients to hatch big.

But having helpless babies, and helping them get smarter, might’ve forced ancient human

parents to get smarter too.

It’s a pretty cool theory.

It works like this:

When we look at human ancestors, it’s clear that natural selection favored humans with

larger brains, because they tended to be smarter.

But human babies’ brains are already born as big as they can be because of the whole

energy thing, so the only way to make a bigger brain is for the brain to spend more time

growing after you’re born.

That requires longer parental care, which requires more intelligent parents, which over

time selects for parents with bigger brains.

It’s a feedback loop.

The more intelligent the parents, the better and longer they can care for a helpless baby,

and the bigger the baby’s brain can eventually grow.

Research tells us that modern human brains don’t finish developing until about age

25, which means I have been past my peak for a while, but it supports this idea that intelligent

parents caring for their children for longer have helped extend the amount of time our

brains get to grow before they’re done.

More intelligence probably made early human ancestors more social too, which made raising

helpless young even easier, which would start a whole other feedback loop making us more

and more social over time.

These aren’t the kinds of things that you’d notice in a generation or two.

They’d evolve across hundreds of generations.

There are definitely other reasons that our ancestors’ brains grew.

Making tools and hunting animals?

That helped a lot.

Harnessing fire and cooking food to get more calories and nutrients helped too.

But ask any parent: It is not easy to raise a helpless baby, especially for a decade or

two like humans do.

It takes our unique intelligence, and our unique social abilities to do it.

I mean, you give a human baby to a group of chimpanzees, it’s not gonna end well.

In the end, like all interesting and complex human traits, our extreme intelligence and

our babies’ relative lack thereof can’t be explained by just one reason.

It’s a mix of many reasons.

Having a baby is not an easy thing to do.

But the very fact that humans are so good at having more humans, and caring for them

and each other as deeply and for as long as we do, is proof enough that we are a very

special species indeed.

Stay curious.

HOW WELL DO MASKS WORK

This is how COVID-19 is spread.

Through air currents, potentially carrying microscopic droplets full of coronavirus.

When we talk, Breathe, Or cough.

We can see this thanks to an imaging technique that lets us peer into the invisible world of airflow. And using this same technique, we can see if masks really do help to stop the spread of coronavirus.

  •If  you’ve been feeling confused about masks, what they do, what they don’t do, and whether or not you should wear one – I hope this video will help.

Matthew Staymates, a fluid dynamicist and mechanical engineer at the National Institute of Standards and Technology.

And while stuck at home he turned his garage into a lab. Using a technique called schlieren imaging he captured some incredible images of a world invisible to our eyes.

If you’ve ever seen wavering distortions above a hot road, that fluttery mirage happens

because different temperatures and densities of air bend light in different ways, like a fluid lens.

And when we talk, warm air streams out of our mouths meeting the sea of colder air around

us.

A schlieren setup lets us see these tiny differences.

A narrow source of light is bounced off a concave mirror towards a camera, with a thin

metal blade blocking some of the focused light.

As that light interacts with air in the space between, it’s bent in ever-so-slightly different

ways, creating shadows and bright spots in the final image.

Now, it’s important to remember that we can’t see viral particles in these images.

They are too small.But the viruses are carried on that breath just like a river carries fish.

In fact, an individual viral particle is smaller than the weave of most fabrics.

So why does this work?

Well, masks help in two interesting ways.

First, it’s important to understand that viruses don’t float around alone.

They fly out in droplets of moisture.

Most droplets are heavy enough that they fall within 2 meters or so, but any person or object

within that distance can get bathed in virus.

And without a mask, some of those droplets can evaporate into super tiny particles of

infection that can float on air currents far from your mouth or nose, and these microdroplets

are extremely hard for any mask to filter out.

But with a mask on, in the warm, humid space between your mouth and the mask, those larger

droplets don’t have time to evaporate, and they can be captured by common fabrics.

If it feels hot and humid in here, that means it’s working.

And the second way masks work, is that any droplets that do get through now have less

momentum.

The air currents disperse in eddies and swirls instead of flowing away in streams, which

means droplets won’t travel as far.

So, which mask is the best mask?

If it seems like recommendations change all the time, that’s because doctors and scientists

know more now than they did months ago.

And they will know more months from now, than they do today.

Which is exactly how science is supposed to work.

What we do know is whether you’re using a bandana, an N95 mask, or a cloth mask you

sewed at home, they all still have a lot of droplet-blocking power.

But that mask has to fit.

A mask that’s too tight, or has too many thick layers can actually force more air out

the sides.

A good test is to see if you can blow a candle out through your mask from about 1 foot away.

[blowing]

These schlieren images are clear evidence that masks are effective.

But the best science relies on multiple lines of evidence.

Here's an experiment that we did with a person talking through a sheet of laser light, illuminating all of the microdroplets released as we speak.

With a mask, those droplets are all caught.

And this microbiologist sneezed, sang, talked, and coughed over petri dishes.

A simple mask blocked nearly all of the germs, and even though this experiment detected bacteria and not viruses, they both leave our airway in the same respiratory droplets.

It should be pretty clear to you now why masks work, and the body of research that proves

that is getting stronger all the time.

But really, the most important question is, why should you wear a mask?

You know, it’s often said that masks aren’t to keep you from getting sick, but to keep

you from getting others sick.

Wearing a mask can dramatically reduce the chance of spreading COVID.

But that’s a strange thing to think about, because you might think “Well, I’m not

sick, I’ve got a strong immune system… so I don’t need to wear this.”

But we know that COVID-19 can go undetected, and almost half of infections may come from

people who don’t show symptoms.

That could be you.

Or it could be the person next to you.

And if it is, wouldn’t you want them wearing a mask?

They probably feel the same way about you.

Can masks harm your health, like lowering your body’s oxygen levels?

No, that’s a myth, and it’s been tested over and over again by healthcare workers

who work all day in masks.

And masks won't stop the pandemic on their own.

They’re best used in combination with other safety measures, like handwashing and physical distancing.

Stereotypically "macho" people have actually been shown to resist masks more.

I get it: Dudes, you don’t feel cool, even though lots of cool dudes wear masks.

Or maybe your nose itches, and your glasses fog up, your face is sweaty.

No fun.

I get it.

For most people wearing masks is new, and weird, and different.

But there are lots of things that used to be weird and different, until everyone just

started doing them.

I mean umbrellas used to be viewed as completely feminine accessories for rich people, and only to shade the sun.

Until one day some masculine men decided they were tired of getting rained on and suddenly enough people were using umbrellas that they became like the most boring, socially acceptable thing ever.

It's true, look it up.

Most people didn’t use condoms in sexual relationships until the risks of HIV and other

infections pushed people to change their behavior, and now it’s not only normal, it’s a way to say I respect you, and I want to protect both of us.

This is also a sign you want to protect others and have them protect you.

And the sooner that this becomes part of everyone’s normal, everyday life, the sooner we can all

get back to normal, everyday life.

In every pandemic in history, it’s the actions and choices of individual people that have

made the difference.

A mask can stop a virus, but it also sends a message: We’re all in this together.

And that’s something we all need to hear right now and every day.

Stay curious.

5 weired involuntary behaviours exposed!!

We’d like to think that we walk through our lives completely conscious, free to choose

whatever we like, totally completely in control.

Not even close.

Our bodies leave a lot to autopilot, which is a good thing, because imagine having to

regulate your heartbeat and your breathing and your digestive system and your body temperature,

all while not peeing your pants or falling down. That would be hard.

Many of those involuntary actions are mysterious, annoying, just plain weird.

Here are five of the human body’s strangest out of control behaviors.

Start typing “why does my” into Google and the top result is an eye-opener.

TWITCHING

Involuntary twitching of the muscles around the eye has a number of causes including dry

eyes, caffeine, bright lights, and just like during a tough workout, from simple fatigue.

It’s usually totally harmless and eventually goes away on its own and is a good hint that

you’ve probably been looking at that screen enough for one day.

Looking at bright light can cause more than an eye twitch.

SNEEZING

 In Aristotle’s "Book of Problems"

he asks “Why is it that one sneezes more after one has looked atbthe sun” proving that people have been asking a lot of the same questions for a long time and that no one told Aristotle that you’re not supposed to stare at the sun.

Like, ever. Don’t do it.

The so-called photic sneeze reflex, AKA the Autosomal Cholinergic Helio-Ophthalmic Outburst, abbreviated "ACHOO"… yes, seriously…

 is experienced by about 1 in 4 people, leading

scientists to believe it is genetically heritable.

While the exact cause hasn’t been pinpointed, many scientists think it’s due crosstalk

between the optic nerve and nerve that feeds the tickling sensation in your nose.                 

The visual cortex of sun-sneezing people is also prone to overstimulation, which might send the sneeze sensing parts of their brain haywire.

HYPNAGONIC MYOCLONUS

•Have you ever been just about to go to sleep, walking through the gates to Dreamland, only

to have the floor pulled out from under you and you’re suddenly falling and then you

wake up!

This frustrating sleep starts have another cool medical name, hypnagogic myoclonus.

When we drift off, the areas of our brain that control motor function are inactivated

in favor of those that control our sleep cycles, which is why you can dream about riding your

bike without actually moving your feet.

As the sleepy part of your brain fight with the awake and moving parts of your brain,

the battle can spontaneously tip back in favor of the motor control side and suddenly you’re

like… WHOA, I'm awake.

Sleep starts aren’t the only myocloni that we experience.

HICCUPS

Hiccups are an uncontrollable contraction of the diaphragm muscle that we use to draw

air into our lungs.

About a quarter second after that muscle contracts, the vocal cords snap shut, creating the characteristic

[hic].

Scientists still aren’t sure what causes em, but possible explanations include hiccups

being an evolutionary remnant from a few hundred million years ago when our ancestors still had to pump water over their gills.

Or, since hiccups mainly happen in mammals, that they started as a way for nursing infants

to clear air from their stomachs.

If you want to get rid of hiccups, it seems that increasing the amount of CO2 in your

blood can do the job, which is common remedies include drinking water, holding our breath,or breathing into a paper bag.

YAWNING

•Yawning, another long, slow, involuntary form of breathing, is common throughout the animal

kingdom and even happens in the womb.

We know it’s associated with sleep and boredom, but that doesn’t explain why it happens, and like most human behaviors, if you stop and think about yawning long enough, it starts to become a really, really weird thing to do.

Hippocrates believed that yawns released noxious fumes that had built up in the body, but modern medicine has shown us that usually happens on the other end of the body.

We also know that about 50% of people who observe a yawn will yawn in response, so it’s

thought to be a social cue to synchronize biological clocks.

One theory says yawns might even cool the brain slightly to make us more alert as we

get bored or sleepy.

Even watching someone talk for extended periods of time can induce yawning, so next time you’re getting bored in class, tell your teacher it’s Mother Nature’s fault.

PEE SHIVERS

Finally, I’ll leave you with one bonus behavior: post-micturition convulsion syndrome, or the

pee shivers.

This is another behavior for which scientists haven’t quite shaken out all the details,

but some believe its simply because we’re exposing sensitive areas of our body to the

cold while we expel some internal warmth.

They might also arise from a bit of conflict between our autonomous nervous system that’s usually quietly keeping all that pee inside and the part of our conscious mind that’s

in charge of the plumbing at that moment.

These weird, wild, and often twitchy behaviors may defy nice, neat explanations, and yes,

sometimes they are very annoying, but in the great movie that is life, they’re a nice

reminder of all the amazing things going on behind the scenes.

Stay curious.