Gandhinagar Insti tute of Technology

Engineering Physics – 2110015“Topic: Black Hole”

Guided By: Prof. Sanket Thakor

Branch : Mechanical Engineering Div: L-3

Group of the StudentsStudents name and Enrollment No.

Harshil Zaveri (130120119251)

INTRODUCTION A black hole is a region of space from

which nothing, not even light can escape. It is the result of the deformation of space time caused by a very compact mass. Around a black hole there is an undetectable surface which marks the point of no return, called an event horizon.

It is called “black” because it absorbs all the light that hits it, reflecting nothing, just like a perfect black body in thermodynamics. It works similarly as a black body works in quantum mechanics.

Event horizon

HOW DO THE BLACK HOLE FORM? There are many theories to that question. Most common theory is where a colossal

star with a mass of more than 3 times the Sun’s reaches the end of its life, gets crushed under its own gravity, leaving behind a compact black hole.

When a gignatic star reaches the final stage of its life and is about to go supernova, it spends all the nuclear fuel by then. So it stops burning and heating up and cannot create the nuclear energy required to feed the star.

STRUCTURE OF BLACKHOLE The black hole is

surrounded by an event horizon which is the sphere from which light cannot escape

The distance between the black hole and its event horizon is the Schwarzschild radius (RSch= 2GM/c2)

The center of the black hole is a point of infinite density and zero volume, called a singularity

How Black hole look alike?

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1915: Einstein’s Theory of Gravity predicted the possibility of black holes, but no one believed they actually existed!

1967: Term “Black Hole” coined 1970’s: Convincing evidence that black holes are real

Today: NASA space telescopes have discovered evidence for black holes throughout the universe

Albert Einstein

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What did Einstein say about Gravity?Mass distorts space - “curving” it

Objects and light moving near the massive object are forced to take a curved path

around the object. Just like the Moon orbiting Earth.

Images courtesy of Professor Gabor Kunstatter, University of Winnipeg

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How much would you “weigh”?On Earth, let’s say you weigh 150

lbs.On the Moon, you’d weigh 25 lbs.

On Jupiter, you’d weigh 350 lbs.

On the Sun, you’d weigh 4,000 lbs.

Near a Black Hole, you’d weigh over

20 TRILLON POUNDS !!!

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Where do black holes come from?

Three classifications of black holes: Stellar-mass: 3 to 20 times the mass of our Sun

Supermassive: Black holes with millions to billions of times the mass of our Sun

Mid-mass: In between stellar-mass and supermassive

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Stellar-mass:Black holes are made when a giant star, many times the mass of our Sun, dies.Most of the star’s atmosphere is blown into space as a supernova explosion.The star’s spent core collapses under its own weight.If the remaining mass is more than the mass of 3 Suns, it will collapse into a black hole.

Where do black holes come from?

Credit: European Southern Observatory

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Supermassive:Extremely massive black holes have been found in the centers of many galaxies - including our own!

Where do black holes come from?

Credit: European Southern Observatory (ESO) - Very Large Telescope

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Mid-Mass:Scientists are finding these in the centers of large, dense star clusters.

Like this globular star cluster, called M15, in our Galaxy.

Where do black holes come from?

Image Credit: NASA and The Hubble Heritage Team (STScI/AURA)

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Falling into a Black Hole

Not to Scale

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Falling into a Black Hole

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Falling into a Black Hole

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Falling into a Black Hole

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M74 Photo Credit: NOAO/AURA/NSF

Great distances between the stars!

So how do we survive amid all these Black Holes?

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M74 Photo Credit: NOAO/AURA/NSF

Sun’s orbit >

Everything is orbiting fast enough!

So how do we survive amid all these Black Holes?

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Including one giant black hole at the very center.

There are 200 billion stars in our galaxy, the Milky Way

There are also millions of black holes

How have we survived?

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What would happen if the Sun was…

Not to Scale

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… changed into a Black Hole?

Not to Scale

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How do we know it’s there?

Hot material falling into the black hole.

“Weird” motions of

objects nearby

Jets of glowing gas

Credit: ESA, NASA, and Felix Mirabel

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How do we know it’s there?

Movie courtesy of R. Spencer, S. Garrington, D. McKay, T. Muxlow, P. Thomasson, C. de la Force, A. M. Stirling (University of Manchester, Jodrell Bank); G. Pooley (University of Cambridge); R. Fender (University of Amsterdam)

Jets of glowing gas

One month

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10 mind-blowing facts about Black hole

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Thank YOU