Hello, cybercitizens,

welcome to AVK classes now we know that most of our viewers are curious

about everything Some of us are very curious about astronomical

things and desire to know how the universe works

but whether you are a fan of astronomy or not you may be curious about this thing called

black hole so we have decided to make a mini-series covering

theories about black holes in our new section called the black hole theory

This is the first episode of the series so stay tuned to get even more smarter

and don’t forget to flex the brain muscles because we are going to get started,

the things we know about Black holes are that they are very heavy astronomical objects

they have a very high gravitational force so high that even light can’t escape its gravity

etc But we know that most of the object in universe

has mass and anything that has mass will try to pull less massive objects towards itself

because that’s how gravity works but the major difference between a black hole

and a normal object is not that it is black in colour but something related to its geometry

called Schwarzschild radius what is Schwarzschild radius you may ask

The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is

the radius of a sphere such that, if all the mass of an object were to be compressed

within that sphere, the escape velocity from the surface of the

sphere would equal to the speed of light. that means it becomes a black hole. so Black hole is not just a massive object

but it is also a denser So that means theoretically it is possible

to make black hole even in your lab all you need is this equation

this is the equation of Schwarzschild radius As you know Schwarzschild radius is the distance

from the centre of a black hole to a point below which nothing, not even light can escape

this is also called event horizon And how big it is only depends on the mass

of object since G and C square are constants So heavier the black hole bigger the Schwarzschild

radius now you can use the Schwarzschild radius equation

to find Schwarzschild radius of day to day objects

for example, you wish to convert an object having mass 100 kg to a black hole all you

need to plug in the values and you will get the Schwarzschild radius

this means you have to compress the object to such a very low radius to turn it into

a black hole that’s impossible you think. its not

when supergiant starts to die, their supernovae explosions are so powerful that they compress

the core of the stars past their Schwarzschild radius

turning them into black holes but now you might not be having supernovae

strength compression then you can instead make a black hole by adding more mass to your

object as we know mass is nothing but product of

the density and volume of the object in question the equation that you will be needing is here

here we will rearrange the equation so that we will find the radius with respect to mass

now the radius of the object with a given density is proportional to cube root of its

mass and as stated earlier Schwarzschild radius

of an object is proportional to its mass so on adding mass the Schwarzschild radius

of an object will increase much faster than its actual radius

now initially the Schwarzschild radius of an object is very small as compared to its

actual radius but if we keep on adding mass, at some mass

the objects actual radius will become Schwarzschild radius thus it becomes a black hole

For earth which has a density of rock, this tipping point occurs at radius of 140 million

kilometres basically the distance to the sun so you can turn any given object into a black

hole, well at least in theory, just by knowing its density and volume. So by calculations, For earth, you have to

add mass up to a radius of 140 million kilometres before it turns into a black hole

That’s it from the first episode of this mini-series, stay tuned for the next episode

if you liked it hit the thumbs up button to let us know,

please comment below, If you have any comments, suggestions and ideas for future episodes

Don’t forget to subscribe to AVK classes because we make videos every week

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below. Thank you for watching. Hope this video created a spark in your grey

cells and helped you to understand the intricacies We will meet again soon with another video

till then stay curious and keep learning. Thank you

Amazing fellas!

Just can't believe u guys aren't famous already!

Way of explanation 10/10

Everything fucking thing 10/10

Don't worry, you guys will surely be the stars of YouTube soon!! And ATB!

Tyvm it helped me understanding schwarzschild radius

Cool! How do you create such videos???

Saying that "they have a gravitational force so strong that even light cant escape" is wrong, light gets red-shifted to undetectable levels due to time dilation at the event horizon

Then,rs(schwarzschid radius) is proportional to r³?

need a clear explanation

Good explanation but that robot voice is horrible

Critical strike

Robot voice unfortunately pronounced schwarzschild incorrectly

Wtf is up with the robotic voice. Fucking gave me cancer

Thank you for explanation !

The "robotic voice" makes it difficult to stay focused on the explanation, sorry…

That's how mafia works

With the event horizon is it that light can't even cross the surface or is it that light can get a finite distance away from the surface but not far enough to reach the eyes of an observer a safe distance away?

I'm assuming that the schwarzschild radius formula 2GM/(c squared) holds because the extra gravity due to relativistic mass increase cancels the rapid increase in force required to get near the speed of light. Thus you can use the same formula whether the escape velocity is the speed of light or 30 miles per hour

can u please make a vedio on the detail and easy derivation of schwarzschild metric

You copied minute physics almost word for word. 👍

Schwarzschild radius

Robot voice killed it for me. Watchin something else instead. Bad call using that voice.

OMG. Please do smth with audio. Pop filter, or better micro.

Why the robot voice???