5. INTRODUCTION
What is black hole?Black Holes a region of space having a gravitational field so intense
that no matter neither radiation light or anything else cannot escape
from there.
Why it is called black hole?
Because even light cannot escape, we can't see the black holes.
They are invisible. We see the black holes with the Telescope and the
special tools.
6. GENERAL INFORMATION
How much would you “weigh”?
On Earth, let’s say you weigh 150
lbs(69kg).
On the Moon, you’d weigh 25 lbs(12kg).
On Jupiter, you’d weigh 350 lbs (160kg).
On the Sun, you’d weigh 4,000
lbs(1800kg)Near a Black Hole,
you’d weigh over
20 TRILLON POUNDS (9071847400000kg)!!!
7. TYPES OF BLACK HOLES
Black Holes
Stellar Black
Holes
Intermediate-
Mass Black
Holes
Super
Massive Black
Holes
8. Stellar black holes
Its mass can be up to more than the mass of the sun.
Intermediate mass Black hole
Super massive black holes
They has the mass up to times more than
the mass of sun.
They have the masses equal to mass of sun and they
are foung in the center of galaxies.
20 times
thousands
10^4 to 10^10
9. The idea of a body so massive that even light could not escape was first put forward by
geologist John Michell in 1783.
In 1915 Albert Einstein developed the theory of general relativity.
Robert Oppenheimer and Hartland Snyder predict that massive stars can collapse into black
holes (1939)
Karl Schwarzschild did find black holes as a solution to Einstein’s equations by using
Newton’s theory. (1916)
The modern theory of black bole is proposed by Stephen Hawking.
10. FORMATION OF BLACK HOLE
• First the Star is born in a nebula
• The new star now goes through its main cycle burning fuel and creating
heat as it should
• When it is near finish burning its fuel it expands due to rising pressure
within it and becomes a Red Giant
• After this expansion gravity does its thing and makes it contract, creating a
White Dwarf.
• This White Dwarf further collapses itself making it supernova. Making a
Black Hole
DO ALL STARS BECOME BLACK
HOLES?
11. It all depends on the
amount of mass
stars contain
Mass < 1
sun
Becomes
a Nebula
Mass ≈ 3
suns
Becomes
a Neutron
star
Mass > 8 suns
Becomes
a Black Hole
12. STRUCTURE OF BLACK HOLE
Although black come in a variety of masses and sizes BUT their
structures are all alike
The center of the Black Hole is most often
referred to as the “singularity”
Singularity has almost infinite density and creates enormous
gravitational force. And black hole’s entire mass is
concentrated in an almost infinite small and dense point
called a singularity.
13. This point is surrounded by the event horizon. And a
rotating black hole is surrounded by the ergo sphere, a
region in which the black hole drags space itself. The
radius of the black hole is called “Schwarzschild
radius”.
R=2GM/c2
15. MERGING STAGES OF BLACK HOLE
2: Merger Stage
3: Ringdown stage
1: Inspiral
16.
17. IS THE BLACK HOLE’S ARE DANGEROUS?
Black hole are so massive that nothing, not even light, can
escape its path. So that means that even stars and asteroids
or much less any thing in its path would get sucked up and
crushed into absolutely nothing. So yes there are
dangerous.
18.
19.
20. How Scientist Find It?
A black hole can not be seen because strong gravity
pulls all of the light into the middle of the black hole
Why light can not escape a Black hole?
21. We know on earth that if anything is to escape the earth,
it should be projected at a speed of 11.8 km/sec. This
means that the escape velocity earth is 11.8 km/sec.
But
In the case of black hole the scenario is entirely different.
Due to its huge gravitational pull the escape velocity from
a black hole is even greater than the SPEED OF LIGHT
which means greater than 3*10^8 m/sec. Hence we can
conclude that even light cannot escape from it & thus a
black hole appears BLACK.
22. But the scientists can see how the strong gravity affects the
stars and gas around the black hole. Scientists can study stars
to find out if they are flying around, or orbiting, a black hole.
When a black hole and a star are close together, high-energy
light is made. This kind of light can not be seen with human
eyes. Scientists use satellites and telescopes in space to see
the high-energy light.
Black holes emit radiation and x-rays
We have telescopes that can find radiation and x-rays
After reception of these emissions we calculate where it is and how
large it is.
24. HOW MANY BLACK HOLE ARE KNOWN TO
MAN THAT ARE IN THE UNIVERSE
• There are so many types of black hole are in the universe they are
impossible to count it.
• The milky way galaxy contain about 100 billion stars. Roughly out of that
1000 stars that firm is massive enough to become a black hole. The
nearest one is some 1,600 light year from earth.
• The most massive black hole was discovered by hubble space telescope at
10th january 2008. Its mass is equivalent to small galaxy.
25. STEPHEN WILLIAM HAWKING gave the theory
“Top down Cosmology” Which say that the universe had 0 unique initial state
Stephan Hawking proposed that microscopic Black hole formed in huge explosion
that gave birth to the universe.
“Black hole are not really black off all: they glow like a hot
body, and smaller they are the more they glow”. Hawking
famous theory says that the temperature of black hole varies
inversely to its mass.
26. On the basis of charge and motion
there are 4 types of black hole
Schwardzchild Black Hole
Don’t Rotate and have no charge
Reissner – Nordstorm Black Hole
Don’t Rotate but have Charge
Ker black hole
Rotate but have no charge
Kerr – Newman Black hole
Rotate and have no charge
27. Black Holes are celestial structures which has a very
high mass and due to it has a high gravitational field
for itself.
From black holes even light can’t escape.
A star after its death may or may not become a black
hole depending upon the mass.
The accepted facts about black holes may change
over time.
Our sun can’t transform to a black hole.
All Black Holes Evaporate over time due to Hawking
Radiation
Conclusion
