Can you guess the title of my next video?

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Write your guess in the comments section below.

What is a black hole?

Usually, when a star is alive.

The inward force of gravity is exactly balanced at each point by the outward force created by hot gases and radiation.

These inward and outward forces maintain balance and hold the star together.

However, when the star runs out of fuel, there are no hot gases and radiation.

Hence, there is no outward force to balance the inward pull of gravity and thus, the star begins to die.

The star's core begins to collapse under its own gravity.

This collapse causes the outer layers to blow apart in a huge explosion called a supernova.

Now, it is estimated that if a star has at least 20 times more mass than our sun.

Then the star collapses to form a black hole.

The surface or boundary of a black hole is called event horizon.

Nothing can escape from within the event horizon of a black hole, not even light.

Hence, the black hole appears black.

Topic: Human Eyes.

What are eye boogers?

They are similar to burgers.

No.

Eye boogers generally contain oil, dust, germs, etc.

They are formed from the tear film on our eyes.

Does the film have any action scenes?

Oh no.

The tear film mainly consists of three layers.

Mucin layer, aqueous layer and lipid or oily layer.

Together, these layers moisturize our eyes.

They also trap dust and germs which are removed while blinking.

When we blink, the eyelid closes.

If there is any dust or germ, it gets discarded along with some tear film through the tear duct into the nasal cavity.

But while sleeping, since we don't blink.

The tear film, dust and germs get collected in the inner corners of our eyes and start to dry out.

Forming eye boogers.

How does placebo effect work?

I don't know dude.

Alright.

I'll explain.

Placebo in Latin means 'I shall please' and this is what placebos do.

Placebos are inactive sugar pills, injections, etc. that look like real medications or treatments.

In most cases, they relieve pain and make us feel better, even though they are not actual medicines.

This effect of placebos on our body is called the placebo effect.

Now, one of the reasons why placebos are effective is that when we take them.

Our mind perceives placebos as real medications.

Hence, our brain reacts to the placebo in a manner which is similar to when we take real medications.

Thus, our brain releases natural painkillers like endorphins that help relieve pain.

In addition to this, it also decreases the production of stress hormones, thus making us feel better.

Why does airplane food taste bad?

I don't know.

Wait.

I'll explain.

Our ability to perceive taste is affected by a few factors such as humidity, air pressure, etc.

In an airplane, the humidity is less as compared to that on the ground.

This makes the air in the airplane quite dry.

Also, to maintain the air pressure inside and outside the airplane, the air pressure inside it is decreased.

Decreased air pressure and dry air, dries our nose and mouth.

Dry nose cannot properly smell odors.

Yes.

I'm not abe to smell the burger.

Now, smell of food helps us to understand the flavor and ingredients of the food.

Thus, the food which we cannot smell properly appears unappealing.

Also, dry mouth reduces the sensitivity of our taste buds.

As a result, we cannot perceive the taste of food properly.

Topic: Respiration.

Why should we not overwater potted plants?

It's because the water will overflow and make the floor dirty.

No.

Leaves of a plant take in oxygen from the air present in the atmosphere.

While, the roots, being buried in the soil, take in oxygen from the air present in tiny spaces of the soil.

When we overwater a potted plant, the air in the tiny spaces gets replaced by water.

So, do the roots know how to swim in water?

Please listen.

As air gets replaced by water, the roots do not get sufficient oxygen to breathe and they begin to rot.

This may adversely affect the growth of the plant.

Thus, we should always try to supply adequate water to the potted plants and not overwater them.