why – Awesci – Science Everyday

Did a Teacher Ever Scold You for Yawning in Class?

By Anupum Pant

Background

I always found school interesting. I wasn’t one of those kids who felt bored and sleepy during the class. And yet, during the classes, I yawned often. I remember being sent out of the class a couple of times because I had yawned. This happened again, and again at college. However, lecturers never cared to send me out in college. And then there were no more classes.

Then, when I started working, at a meeting one day, a friend yawned in a board room where the head of the company was present. The head saw this happen. Being a fresher, the guy got scolded very badly by the head. I felt sad for him. I knew, he wasn’t really sleepy when he yawned; clearly he wasn’t bored too. There could have been a different reason for it. The head should have known this.

Yawning is universally considered as a sign of sleepiness or boredom. I however, am pretty sure that a yawn doesn’t necessarily comes when someone is bored or sleepy. I do have a theory to back my belief that I discuss below. Also, yawning has a lot to do with empathy too. But that is not what I’m discussing today. To educate yourself about the empathy side of it, you could watch the following video.

No one knows for sure why we yawn. In addition to that there might be several different reasons that could explain why we yawn. Like a couple of reasons that explain why we sleep (may be there are more). Most definitely, it isn’t a single reason.

A study shows that yawning could be the body’s way of cooling down the brain and it makes perfect sense to me!

The Study

Scientists from the Princeton University say that people yawn more during the winters. That is because during the winter the air outside is colder and the body knows that. So, it makes us yawn to take in the cold air to cool the brain by exchanging heat.

There’s also this other explanation which breaks down the process of yawning into two parts – 1. stretching of your jaw muscles and 2. air entering your mouth after you do that.

When you stretch the jaw muscles in the first step, blood flow increases in your face, brain and sinus area. Now the cool air enters and cools down the blood vessels in the nasal cavity and sinus area. These blood vessels in turn cool the blood and circulate cooler blood to your brain, to cool it down.

Teacher’s theory

Now, it’s a well-known human rhythm that bodies get heated up just before we fall asleep. As a result, we yawn more. So, teachers were not completely wrong. However, sleep is not the direct reason. The reason we yawn is because the brain gets heated up, and it may as well get heated up due to other reasons; not always due to sleepiness or tiredness. Plus the yawn tries to correct the heated-sleepy-brain by circulating cooler blood.

The body does this to cool down the over-heated brain – which obviously gets heated due to extra information processing – like a computer processor. Why would the brain heat up when I’m not actively processing information better. So, yawning doesn’t mean I’m bored, or I’m not actively listening to the teacher when they’re speaking. Teachers need to know this.

Even if yawning is a sign of boredom to some extent. A yawn actually helps you cool down and helps you to process information better. So, teachers should be happy when you yawn in their class. You are trying to be a better listener than people who aren’t yawning in the class!

Hit like if you learnt something interesting today.

Sun’s Green Flash

By Anupum Pant

More often while setting than rising, if the conditions are right, a part of the sun (on the top) can appear green. This happens for very short interval lasting for about 2-3 seconds and is considered a rare phenomenon. Since it is green and lasts for a very small interval, it is also called the green flash, emerald flash or green ray. If you have ever captured it or plan to do it in the future, do share your results with me through mail/twitter. [See the animation] [Real GIF]

What does it look like?

Sometimes the sun’s rim can appear green (in optically zoomed images). Otherwise, when the sun is set, for a brief moment, it appears as if a part of sun has separated from the main body and has turned green. It is usually seen as a horizontal line, like in the video below. But, a few lucky ones have captured complete green auras too.

Why does it happen?

The sun gives out a white light, which contains all the colors – Green is one among them. Normally, our eye isn’t able to resolve the separate colors and sees them as a mixture which is white. When the sun sets, our atmosphere acts like a prism and bends the colors. A few colors get bent more than others. For example, green bends more than red. As a result the two colors get separated enough to be resolved by our eye. But the right amount of bending happens only if the atmospheric conditions are right.

In extremely rare cases, blue or violet flashes have been reported. [image]

For a detailed explanation you can go through this – [Geometric Optics of Green Flashes]

At poles where the sun moves in a different manner, probably the green ray can last much longer. Admiral Richard Byrd has claimed to have seen this green flash for 35 minutes while on an expedition to Antarctica.

Ambergris – Whale Vomit Can Make You Rich

By Anupum Pant

It is yellow/gray, smells really bad and can make you rich [image]. Ambergris, or commonly known as whale vomit is a waxy, hard, flammable substance that sells for several thousand dollars a pound. Although it is known as whale vomit, it is usually excreted (not vomited) by the sperm whale. It is formed by the lumping of Bilary Secretions in a whale. They can’t be digested and are often excreted by whales. These lumps can float for years and might get washed to the beach or are found in whale abdomen.

A fresh lump would be black and slowly a lighter colored coating forms on it with age. Generally, lighter colored pieces have a sweeter smell because they have cured in the ocean for a longer time.

What makes it so costly?

Firstly, it is rare to find a lump of Ambergris. Secondly, as this substance ages, it leaves the stink and starts emitting a sweet, musky odor. Not all people like this smell. Other than its unique scent, the perfumes made of this substance last much longer than other scents that tend to evaporate. Both these reasons make it a substance in high demand.

Although the scent can be mimicked by using chemicals, there is nothing like using the real substance. Thus, whale vomit will always carry a premium price.

This year, Ken Wilman, while walking his dog on the beach, spotted a 6 lb lump of whale vomit that turned out to be worth £100,000.
Note to self: So, the next time you are going out for a walk on the beach, take your dog with you. And go on walks more often.

[read more]

A Bat’s Inverted Sleep Position

by Anupum Pant

I have written about sloths in the past. In that post, we appreciated the way their bodies are engineered to stay inverted for most of their lives. It turns out, a bat’s body is designed (rather evolved) in a similar way, which enables them to relax and sleep upside down. In this post, I would like to discuss – why did they evolve this way and how do they do it?

If you are interested to know more about bats, you will definitely like this post from the archives. [Bats can See]

How can bats manage to sleep like this?

Humans sleep in a horizontal position, cows sleep with their eyes open, horses sleep in a standing position, and of course, bats sleep in an inverted position. What makes an animal sleep in the position they do, is basically their anatomy – the way their bodies are designed. While sleeping upside down might seem as an anomalous behavior to us, it is a normal position for the bat’s body. Like we don’t exert energy when we are lying down, bats’ bodies don’t consume extra energy for hanging down like that.

Firstly, a bat’s claw is like a hook. A better way to understand why this helps is, to look at a converse behavior – the way a human hand works. We use up energy to contract tens of muscles and make up a hook with our fingers; this is not a normal state of our hand. Also, our relaxed hands are open where we don’t exert any energy and we sleep with our hands in that position. A bat’s claws are designed in a completely inverse fashion; they are hooked in the normal position. They don’t take up energy to make them into hooks, they are like that. And they sleep like that – which enables them to hang without using energy.
So, unlike our hands, a bats’ closed fist is their relaxed position. They have to contract tendons and use energy to open them up. This anomalous talon design allows them to hang in a relaxed position.

Secondly, unlike every other bird, a bat can’t take off from an upright position, or from the ground. They have to be inverted to start flying. This is because they have relatively weaker wings which can’t make them fly from a stationary position. Think of an X-51A Waverider, which has to be carried on a B-52 plane and dropped down to start a flight. They drop down for a very small amount of time and beat their wings vigorously to start a flight. Since, they have to wake up inverted to go flying and catch a meal, they go to sleep like that.

Why did they evolve this way?

They’ve evolved this way to simply stay away from the predators:

By hiding up in a place where not many predators would look – under a bridge, roof of the cave and dark tree canopies. Also, at places like these, they don’t have to compete with other birds for a place.
And by escaping quickly in case of an attack by attaining instant flight [see above].

The Purpose of Sleep – Theories

by Anupum Pant

Did you know?

You can live longer without food than you can live without sleep.
On an average, a person sleeps for 1/3rd of his life. That means if you are 30 years old, you’ve slept for 10 years already.
The world record for the longest span remaining awake is 11 days. The record was set by 17-year-old Randy Gardner in 1964 when he was awake for 264 hours and 12 minutes. (Don’t try this)
If it takes you less than five minutes to fall asleep then very likely you are sleep deprived. It should take about 10 minutes normally.
You can lose up to 2 grams every minute while sleeping. That comes to about a lost Kilogram at night.

What is Sleep?

Everybody sleeps. On an average, everyday, a bat sleeps for 15 hours while just 3 hours are enough for a Horse to feel rested [How much do animals sleep – chart]. Dolphins can sleep with half of their brains active and even the smallest of worms need sleep. But, till date, scientists haven’t been able to reach a consensus on why we actually do it?

Sleep can be understood as a life sustaining activity. It can be compared to another of our important activity – eating. These strongest of the human urges – eating and sleeping – serve a nearly common purpose – quell the urges; just as eating relieves hunger, sleeping relives sleepiness.

While it is true that we may have not been able to spot the primary purpose of sleep, years of research hasn’t gone wasted. With time, we have learnt a lot more about sleep than we used to know 50 years back. There have been hundreds of practical and impractical theories on why we sleep. I’ve mentioned a few of the realistic ones here.

Purpose of Sleep – Theories

Inactivity Theory:

According to this old theory, sleep evolved out of the need to be safe. It suggests that inactivity at night is an adaptation that serves as a survival mechanism. It functions as an activity which would keep an animal safe during the time it is most vulnerable e.g. Humans are vulnerable at night because they don’t see well in dark.

This theory is easily countered using the argument: Being conscious and still, is much better way to stay safe than lying unconscious and still.

Energy Conversation Theory:

It suggests, the main function of sleep is to reduce the demand and consumption rate of energy at times when searching for food isn’t an efficient option. Some believe, that this theory is a part of the inactivity theory. But, unlike the inactivity theory, this theory has been bolstered by various experiments which prove that the consumption of energy is reduced when an organism sleeps.

Restorative theory:

It explains sleep as an opportunity for a body to rejuvenate in terms of muscles, tissues, proteins, cells and growth hormones. Also, during sleep, the body clears an accumulated molecule called adenosine from the system, and makes us feel alert when we wake.

A recent study also seems to support the restorative theory in a fresh manner. It says, brain accumulates toxins [like beta amyloid] while it is awake. The concentration of such toxins keeps increasing during waking state. The study observed an increased activity of spinal fluid being pumped into the brain in rodents (hasn’t been studied on humans yet). This spinal fluid functions as a medium to pump out toxins from the brain. This theory could be a breakthrough in the study of causes and prevention of Alzheimer’s as it is known that toxins like beta amyloid cause the disease in humans [How beta amyloid causes Alzheimer’s].

Brain Plasticity Theory:

According to this, sleep plays a critical role in brain development. Infants (age when the brain develops the most), for example, sleep for about 13 – 14 hours every day. On the other hand, the poor ability to learn and perform tasks due to the lack of sleep explains the role of sleep in adults. Since, It has been proven that brain is highly active during sleep, this theory remains the most plausible one in being able to state one of the functions of sleep.