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  • It's AumSum Time

  • Can you guess the title of my next video?

  • Hurry up.

  • Write your guess in the comments section below.

  • How do stars form?

  • Stars are like huge balls of fire that emit a tremendous amount of heat and light.

  • Stars don't form in a few seconds, minutes or hours.

  • Star formation process is so slow that it can take millions of years.

  • A star begins its life inside vast molecular clouds of dust and gas.

  • These molecular clouds are also known as nebulae or dark nebulae.

  • They mostly contain hydrogen and helium molecules along with some other particles.

  • Now, let us hold on for a second and try to answer a question.

  • In Latin, nebula means: Dust.

  • Gas.

  • Snow.

  • Mist.

  • And your time has begun.

  • Start guessing.

  • C'mon, C'mon, C'mon.

  • Get that brain working and write your answer in the comments section.

  • The correct answer is option number 4, that is, mist.

  • Let's get back to our video.

  • Normally, these molecular clouds are cold and stable.

  • However, a nearby supernova explosion or galactic collision may send a shockwave or tremendous amount of energy through a molecular cloud.

  • Now, in the molecular cloud.

  • This energy causes a gravitational disturbance due to which it begins to collapse on itself under its own gravity,

  • Causing hydrogen and helium to clump together.

  • Thus, increasing the mass in the center of the cloud.

  • This increase in mass, increases the gravitational pull.

  • Thus attracting even more molecules and particles from the surrounding.

  • As more and more molecules and particles collapse or fall into the center of the cloud, the center begins to heat up.

  • This heated center or heated core is known as a protostar.

  • Now, before going further, I'll ask you a question.

  • What are shooting stars?

  • Dead stars.

  • Meteors.

  • Migratory stars.

  • Rogue stars.

  • C'mon guys.

  • Clock is ticking.

  • Start typing your answers.

  • The right answer is option number 2, that is, meteors.

  • Now, let's continue with our video.

  • A protostar continues to pull more molecules and gets hotter and hotter until the temperature.

  • Pressure reach to such an extent that hydrogen nuclei begin to fuse with one another producing helium.

  • Releasing heat, light and radiation.

  • This process called nuclear fusion.

  • When this happens.

  • The inward force of gravity is exactly balanced by the outward force created by heat and radiation.

  • These inward and outward forces maintain balance and thus, a star is born.

  • Topic: Electric Charge.

  • How does a plastic comb attract paper?

  • What?

  • You don't believe me?

  • Ok.

  • Let us try.

  • Take a plastic comb and bring it close to some pieces of paper.

  • Hey, Wait.

  • Don't laugh.

  • We need to do something first.

  • Rub the comb on your dry hair and then bring the comb close to the pieces of paper.

  • See, I was correct.

  • The pieces of paper got attracted to the plastic comb.

  • Do you think it is magic?

  • No, the reason behind this is electric charge.

  • Electric charge is the quantity of electricity held in an object.

  • There are 2 types of electric charges, positive and negative.

  • However, there are some objects where the positive and negative charges are equal to one another.

  • In such cases, we say that the object is electrically neutral.

  • So, was the plastic comb initially electrically neutral or electrically charged?

  • Initially, the plastic comb was electrically neutral.

  • That means it had equal number of positive and negative charges.

  • Hence, it did not have the ability to exert a force and attract the pieces of paper.

  • So, after rubbing the plastic comb on our dry hair, why was it able to attract the pieces of paper?

  • I will tell you why.

  • When we rubbed the plastic comb on our dry hair, it gained an electric charge.

  • Once it got electrically charged, it got the ability to exert a force on the pieces of paper and attract them.

  • This charge is called as static electricity.

  • However, do you think, like a plastic comb, a metallic comb will also attract the pieces of paper?

  • No, you are wrong.

  • A metallic comb will not attract the pieces of paper like the plastic comb.

  • Wondering why is that so?

  • It is because plastic is not a good conductor of electricity.

  • It does not allow the electric charges to flow through it onto the earth.

  • As a result, the charges build in the plastic comb.

  • Making it electrically charged and enabling it to attract the pieces of paper.

  • However, metal is a good conductor of electricity.

  • It does not let the charges build in it.

  • It allows the electric charges to flow through it onto the earth.

  • Thus, not allowing the metallic comb to get electrically charged.

  • As a result, the metallic comb does not attract the pieces of paper.

It's AumSum Time

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星星是如何形成的?| 星星是如何形成的? (How do Stars form? | #aumsum)

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    AumSum 發佈於 2021 年 01 月 14 日
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