Everything has its wonders. Even darkness and silence . I learn whatever state I may be in ,therein to be content
Helen Keller
Introduction:
When we look at the night sky we see the beauty of nature in utmost glory and splendour .Looking at the night sky on a stary night give us peace we cherish and praise the nature.But to an intriguing mind,this seems to be a good opportunity to have a brief understanding of the cosmos expanded over 15 Billion light year . Uptill now what knew about the universe was sheer predicted material. The astronomers of the past looked at the sky and found the constellations.What was the benefit of it?Well,it helped the people of the past during their long and tiresome journeys so that they can reach their destinations following those constellations.As the frontiers of the human mind widened and took hold the telescope. He began to observe the universe more critically. Having the magnified image astronomers& physicists like Galileo and Newton began to study the motion of planets also the effect of the gravitational forces.This intellectual conflict began & remained for two to three centuries then Albert Einstein solved the quantum mystery as well as the cosmological problems .And we found out something new that was mathematically predicted to be a circle with a pitch black hole inside it.Einstein gave some interesting facts about this thing which came to be called Black hole . There has been a lot of research work done on the Black hole most notably by Stephen Hawking.Now,after telling you a brief history of black hole .Now let me give a layman definition of space -time.
Space-time :
Space constitute of three dimensions (x,y,z) time t is also a dimension and we know about it from matric level.Combining both of them give us space-time in which we basically the motion of heavenly cosmological bodies in space under some time frame.Which at ground level involves the Einstein’s General theory of relativity .
Now after brief information about space -time.Let us come to the main point what black hole really is:
Black Hole:
When huge stars reach the end of their life cycle .They began to collapse and give birth to black holes.Compared to stars black holes are not large instead they are denser and exhibit very strong gravitational effects.According to Einstein’s Theory even light can’t escape from inside it .
Einstein’s General theory of relativity predicts that compact mass occupying sufficiently small space can deform or bend the space time like a metal ball placed on a rubber sheet.
Now let me tell you some haunting facts of black hole.
The Point of NO Return: The point of no return most commonly known as Event Horizon.In layman words,it is more like the outer shell or surface before the start of the pitch black region.Any material object which reaches the event horizon can never make out of the black hole forever.Because beyond this point,time would be meaningless. And space time would be warped to an unimaginable extent .The physical laws of nature as we see them will longer hold beyond event horizon as the only force that is present there is Gravitational force.Which behaves in a very interesting way.
Does Black Holes really not let light escape?
Well,in a sense it may seem to be true but observing it very carefully will generate the answer that light does escape.Wait a moment,Gravitational force by black hole is so intense that it actually warps the space -time so that it looks like a wheel rotating light within in it .Thus,light does not escape from its grasp.
Singularity:
The centre of the black hole is known as the Singularity point.It is the only point in the universe where gravity is thought to approach infinity.With curvature approaching infinity .
Mathematically,
k(Kappa)=1/p
p= radius
For k = infinity , we have p= 0
As far as the density is concerned the density develops to infinity and everything gets crushed under this tremendous force .Matter get crushed under infinite gravity. The physical laws and that of space -time don’t seem to behave the way we thought of them to be behaving.
Does Time get distorted by Gravity of black hole?
Yes, Gravitational pull of the black hole does have a drastic effect on the space time continuum .Space does get distorted by gravitational effect just like gravitational pull of the moon raise tides on our earth.According to the special theory of relativity,time does get dilated when bodies move at very high speeds .Their motion get distributed in space time.In layman words,I can say that when we are at rest then at that particular instant we may feel we are not moving through space but our earth is also rotating thus at this instant we are moving through space as our clocks tick it explicitly tells us that we are passing through time at that instant . Thus when gravity warps space then time also get distorted . In a black hole , Gravity warps space time in such a way that it is in a continuous loop.
Gravitational time warps occur universally but are usually too feeble to be noticed. On Earth, for example, you would age one-billionth of a second less each year at sea level than you would atop Mount Everest [source: Harvard-Smithsonian]
In order to understand the basic concept of singularity one must have a thorough understanding of the density at the time of the Big Bang of the huge ball of mass which exploded and gave birth to our universe.
Formation of Black holes:
The Big Bang, most scientists believe, started from an earlier universe that was pulled together by gravity into a single point. After that, it exploded and made all the matter in the expanding universe. A black hole singularity is similar but there is a slight difference which can be neglected.Formation of black holes varies from star to star and this criterian is set by the mass of that particular sun. Imagine if our sun decreased to the size of the nucleus of an atom. It would be very dense. However, our sun does not have a high enough mass to become a black hole. It is well below the Chandrasekhar limit
(the Chandrasekhar limit is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about 1.4 M☉. White dwarfs resist gravitational collapse primarily through electron degeneracy pressure.) , which means it will shrink to a white dwarf, with radius of a few thousand miles. It can’t become a black hole, because it is too small.
Stages:
Stellar Nebula: It is actually the mixture of hot gases moreover gases in plasma state and lightest elements in the periodic table namely Hydrogen and Helium spread over million of miles then after almost 10 to 15 million years they give b rth to either Average star or Massive Star on the basis of intensity of reactions taking place in them.
Giants: By Giants I meant Red Giant stars from an average star or Red Super Giants from Massive Star . Red Super Giants shine much more brightly than a Massive Star ,same reason,intensity of reactions in the core over the course of time .
Supernova: Red super Giants after 3 to 4 million years give birth to Supernovas. These stars shine most brightly in the entire universe.Which can be seen over millions of miles.
- Neutron Stars & Black holes: The biggest size a star can achieve in its life time is of Supernova they are monstrous.At a certain point in their lifetime ,their gravity collapse them to such an extent that they only remain to a few thousand(in case of neutron stars) or hundred thousand kilometers(in case of black holes).Neutron stars have tremendous density but quite surprisingly they possess magnetic field strongest in the universe while being neutral . The recent researches have shown that the one teaspoon of mass of neutron star weighs one to ten tons varing from star to star. And the black holes the strongest Gravity in the universe. The researches on the black hole show that they have the ability to send things far far away in the universe some say that they open a dimension which leads to another universe. But they that got no evidence about it yet.
Were we ever be able to get a real picture of black holes:
This question was a mystery uptill now . April 10,2019 marks the scientific triumph of mankind that they ere to conguer the mount Everest of the Universe . One of the MIT Post doctoral Student Katie Bouman formulated the alogrithm that lead to give the real picture of the black hole. The inquisitive approach of man bore him fruit.That picture of the Black hole resembles the one used in the one of the Hollywood’s Best movies “Interstellar” the pictures are compared as follows:
The Einstein’s General Theory of relativity survives yet another test that the shape predicted by Einstein matched the original one quite interestingly
Shape of Real Black Hole:
The image depicts an orange-toned lopsided ring circling the dark shadow of a black hole that gobbles up matter 55 million light-years away at the center of a galaxy known as Virgo A (Messier 87). The blurry look confirms that einstein equations works perfectly even at the boundary of giant abyss.
How Black Holes were predicted by Einstein?
Einstein’s theory of relativity first predicted that when a massive star died, it left behind a hugely dense core. If this core was over three times as massive as the sun, his equations showed that the force of gravity produced a hole that is pitch black i the center because no light escapes it, according to NASA.
Carl Sagan .
“Somewhere, something incredible is waiting to be known.” …
communication 