Let Science Brief It

The Big Bounce Theory

2019-06-24T23:53:00.003+05:30

Every one of us knows that our universe was born after the Big Bang, but do you think that the fate of universe was a little bit different from our perception?

Maybe and maybe not.

So, my friends, let us try to explore the birth of our universe, which was probably the end of another universe.

Here, we will look at a completely different theory. THE BIG BOUNCE THEORY.

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WHAT'S THIS NEW BIG B?

This theory is based on Quantum mechanics. It states that the big bang, which was the beginning of our universe, was the end for another universe which existed before ours came into being.

You may ask that how is it possible! Another universe!

Yes, it is possible, but everyone needs an explanation, so let's understand it.

The big bounce theory simply says that our universe goes through expansion and contraction and so on.

Hold on! we will see the procedure later in this article.

Well, big bang says that the universe started from a singularity(a point in space with infinite density, zero volume and which is extremely hot), but big bounce says that singularities do not exist! You may like to read this article to know more about, why singularities cannot exist.

BIG BOUNCE VS BIG BANG.

BIG BANG

BIG BOUNCE

Big bang says that our universe was born from a singularity. All the mass was compresses to a single point with zero volume.

That point expanded decreasing the temperature and creating our universe.

But quantum mechanics says that when the universe was so small, it must have been ruled by micro particles, but quantum physics will not allow the particles to compress to an infinitely dense point(singularity).

But the particles are allowed to be compressed and have finite density and this place will be very hot.

This also means that there was a universe before ours which compressed into such a dense point and later created our universe.

THE CONTRACTION.

We understood the big bounce theory, but why will our universe or the one before ours contract?

For expansion the universe requires a special energy and when this energy will be exhausted, a new force will dominate which will cause the contraction and when it will have enough energy, it will start to expand again.

In these many ways can the universe end.

The energy we are talking about is heat which will be produced due to high density.

This theory is also very interesting as the big bang, but it raises many new questions.

If big bang was not the beginning then, how did this all start?

There are many other questions yet to be answered.

The unseen is yet to be answered.

The life cycle of a star.

2019-06-20T00:03:00.001+05:30

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Since childhood, we all love the song Twinkle Twinkle little stars. But how are these not so little stars are formed? If you want to know the answer then you are at the right place. If you are in a hurry, then you can go through the map below or you can read the full article for full details.

Image is subjected to copyright

LET'S BEGIN!

HOW IS A STAR BORN?

Stars are born just like any other mammal. OK! I am sorry.

So, what actually leads to the formation of stars? A one word answer is DUST. Since you all are my curious fellows, I will surely give my 100% to explain it in the easiest way possible.

A star is formed from an extremely dense cloud of dust and gas and these clouds are called nebula. The dust particles move very slowly and when this happens, the gravitational force starts to dominate.

The crab nebula

They come closer to each other and stick to each other. The temperature of the core becomes extremely high until it reaches several billion degrees Celsius which provide particles with excess of kinetic energy. Thus, they start to collide with each other vigorously.

BOOM! We have successfully created a BABY star.

The life of a star totally depends upon its size from its birth.

A NORMAL DAY FOR ANY STAR.

The vigorous collisions cause a phenomenon, in the core, namely nuclear fusion.

Primarily, hydrogen atoms take part in nuclear fusion to form Helium atoms. This phenomenon produces a tremendous amount of energy and this energy comes counters the collapse due to gravity furthermore.

After millions or billions of years, when the stars will run out of hydrogen, they will start to fuse helium to form other heavier elements. The fusion of heavier elements produce a huge amount of energy that now it starts to dominate the gravitational collapse.

Thus the star will start to increase in size and form into a red giant.

This is the beginning of the end of stars.

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Let us classify them as-

Normal stars

· Big stars

· Extremely big stars

Let us see, how different sizes of stars have different stories to tell about their end.

NORMAL STARS.

These stars have the longest life span among all the other stars. Let see what happens next in their story.

RED DWARFS

Basically, there are stars, the Red Dwarfs, which are smaller than the sun, near to the size of Jupiter. They simply burn for their whole life and when they run out of the energy source, they form the White dwarfs.

There are also brown dwarfs, they have a very little hydrogen to fuse and they die very soon.

A red dwarf star

For now, you just understand that a White dwarf is a star’s corpse. They are extremely dense and are extremely hot. This is because; the heat is trapped inside them and has nowhere to go in the space. So, it will take many millions of years for them to cool down.

But what will happen to the stars like the Sun?!

YELLOW DWARFS

Well, even our Sun will one day form into a white dwarf, but it has another story to tell. Stars like our sun will form a red giant.

Just a reminder for you all; when the Sun becomes a Red giant it will engulf earth in itself. There is no need to thank me for making you aware of this.

A yellow dwarf

Now, as the Sun will grow bigger, its outer surface will go farther away from its core. Gradually, this star will start to lose its material to outer space, since its gravitational force will be negligible. Slowly these materials will leave the star's surface and they will form something called planetary nebula.

A planetary nebula

But, that star’s core will be left all alone. A white dwarf.

But what happens with the white dwarf?

When the heat trapped in it will completely extinguish, then they will form into a black dwarf. Please note that they are not the Black holes. These black dwarfs will evaporate if and only if protons decay.

A white dwarf

BIG STARS.

When these stars run out of hydrogen atoms, they fuse much heavier elements and their size grow extremely big.

Their energy source comes to an end when their core stars to fuse iron. At this time, the energy produced can no longer counter gravitational force. Therefore, it collapses under its own gravity and then explodes in a supernova. Its materials are now gone into the space, but even here we are left with the core, the neutron stars.

NEUTRON STARS

A neutron star

Neutron stars are incredibly dense objects. If you want to form a neutron star, then compress the mass of Mount Everest into a tiny sugar cube. They are so dense that the electrons and protons inside them fuse with neutrons and form a friction less fluid called Super fluid.

They feed on lighter bodies and eventually collapse to form a black hole.

Death of a black hole

EXTREMELY BIG STARS.

A black hole

They are extremely big stars. Their story is same as the big star, but here we do not meet any neutron star. Here we directly get a black hole after the supernova explosion.

Look around yourself, everything which you see is made up of the remnants of a star which died billions of years ago. Personally, I think that we should know more about them because they are trying to tell us something about our existence.

There is nothing like a true black hole| Dr. Abhas Kumar Mitra.

2019-06-19T23:27:00.000+05:30

Black holes are known to majority of people. Each individual gets really fascinated upon thinking about what lies inside this black giant. We know that we cannot see black holes since they reflect no light, but scientists have been trying to detect them by studying the behavior of the objects around them. On 10^th April, 2019, scientists revealed the first ever image of a black hole.

BLACK HOLE

But was it really a picture of a true black hole?

An Indian Astrophysicist, DR. Abhas Kumar Mitra, said that the objects which we assume to be black holes are actually Eternally Collapsing Objects (ECO). His theory was in limelight for a while, but it was soon dismissed, but not wholly.

Following him, several other scientists also tried to research more about ECO. Darryl Leiter and Stanley Robertson were one of them. They modified the name ECO to Magnetospheric Eternally Collapsing Objects (MECO).

So, let us start unleashing the secrets of ECO and how it is different from a theoretical black hole. Before that please visit the link below to get a quick glimpse over the life cycle of a star and if you are aware of it, then you are welcome to unleash the secrets!

The life cycle of a star

ETERNALLY COLLAPSING OBJECTS.

This is how an ECO must look like

An ECO is formed just like a black hole is formed, i.e. it is also formed after a supernova explosion of an extremely giant star.

They do not have the event horizon. They appear like a hot glowing body, just like the Sun, but its temperature is far greater than a star.

They have a very strong magnetic field of their own. They can be called quasi-black holes because they are not the true black holes but are on their way to become one.

WHY ARE THEY CALLED ECO?

The singularity of a black hole is formed in a finite time after the supernova explosion, but in ECO, after the explosion, formation of singularity takes infinite time.

REASON-

A supernova explosion

After the explosion, the star starts to collapse under its own weight and the core becomes very hot and dense due to contraction and therefore, the core starts to shine very brightly.

But even there is a limit, it's Eddington limit (The maximum luminosity of a star) , once a star reaches this limit, the contraction gets countered by an outward force. This outward push is nothing but the energy produced in the hot core.

But this does not mean that the contraction has stopped, this only means that the contraction has become a very gradual process. Thus this core collapses under its weight forever. Therefore its name is Eternally Collapsing Objects.

They are also called Extremely hot and Relativistic Radiation supported stars. This is because the energy coming out of their core as radiations slows down the process of contraction. This process of contraction and emission of radiation is continuous.

THE CONCEPT BEHIND ECO.

WHY CANT A STAR COLLAPSE TO FORM SINGULARITY?

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According to general relativity, time dilation occurs around the objects with gravity near to infinity. But it also says that space time is not constant, but it is relative.

If a star is ready to form a singularity, its gravitational force will become infinity and thus this will cause time dilation. But one cannot be sure if this theory of formation of singularity is correct or not from their frame of reference.

Even many renowned scientists agreed with the fact that a star cannot collapse to form a single point because there is a certain limit, that limit is the Schwarzschild radius. According to them, although mathematics can go inside that radius, but the space inside that radius is not a physical region, it belongs to a different universe. An ECO has a radius which is just a little more than its Schwarzschild radius.

Schwarzschild radius of a black hole

But still, the concept of a true black hole was widely accepted by everyone because of two reasons, but yet no one bothered to look at the flaws of these two proofs of existence of a black hole.

The two proofs with there are explained in detail in the following –

1. Proof- Two American physicists showed with the help of dust that a star, after the explosion, went through a collapse under a finite time and formed a singularity and an invisible event horizon.

Dust cloud, located about 6,000 light-years away in the constellation Sagittarius

Flaw- They represented it through dust and this state of matter has no pressure of its own.

2. Proof-An esteemed mathematical physicist, while doing his research about the gravitational collapse of a star, assumed that if a star starts to collapse, there will be formation of an invisible one way trap door. This assumption was very similar to the event horizon. Due to this assumption, he was able to present a mathematical proof of the formation of singularity.

Flaw- He was not able to explain that why that trap door was formed.

You would ask that how can any object collapse into itself forever? I mean, we cannot even think to do that! Well, for us it will be nearly impossible because we do not warp space-time at that extent.

Let me explain it to you. If the gravitational force increases of any object, it will sink more into space-time. If you still did not understand it, then look at the image below.

Space time warpped around earth. This curvature of space time is only the gravity.

Thus an ECO has the ability to sink more and more into the space time as its gravitational force increases.

If you have not yet understood the difference between these two objects, then let us understand the following points.

DIFFERENCES.

1. ECOs are quasi black holes, i.e. they are not the true black holes.

2. Since ECOs are radiation supported stars, they have a physical surface made up of hot plasma, but black holes do not have any physical surface.

3. Unlike black holes, ECOs do not have an event horizon.

4. 1 out of every 1 million photons, can escape the surface of an ECO, since its gravity is not infinity, but to a distant observer, an ECO would appear to be black, but nothing can escape a black hole.

5. Unlike Black holes, the laws of physics do not break down in ECOs.

6. ECOs have a very strong magnetic fields, but a black hole can either have a very weak magnetic field (rotating black holes)or no field at all (static black holes).

I know that a question is continuously wandering in your head, “Is there any evidence of presence of an ECO/MECO?”

EVIDENCES OF AN ECO.

1.In 2006, a quasar (The most luminous objects in the universe) was observed which was approximately 9 billion light years away from earth. Actually, whenever an object is about to enter a black hole, it starts to revolve around it at a very high speed. This causes production of heat and thus this causes a luminous glow. We even know that an ECO has also a very strong magnetic field. Since, the observed quasar had a very strong magnetic field of its own; it provided a strong evidence for ECO.

An artistic impression as how a quasar looks

2.The detection of gravitational waves provide an evidence of black holes, but these waves are also accompanied by unknown noise signals and we very well know that even sound waves need a surface to get reflected and the space near a black hole is vacuum. But an ECO has a physical surface. This is also an evidence of ECO.

n this artist’s conception, a binary black hole produces gravitational waves that travel outwards and carry energy away from the system.

3. In theory, a true black hole has no mass. (It must be noted that here ‘no mass’ does not mean an absence of matter. In general relativity it simply means the total sum of the energies around that body and negative self-gravitational energy of that body, i.e. the self-gravitational energy of a star so strong that it can counter the other energies around it.)

But, in observation, black holes with finite masses were only detected.

WHY IS THIS THEROY STILL NOT ACCEPTED?

Many scientists support this theory given by Dr. Abhas Mitra, but still it is not accepted because majority of scientists believe that it is not an alternative to black holes.

I mean to say that, even an ECO is on its way to attain the state of singularity, although the process is eternal. Hence, the conclusion will be the same.

Black holes are really interesting, but the theory of ECO/MECO is not less interesting. I hope that very soon in the future, this theory will again come into limelight and will be under a serious consideration.

Death of a Black hole.

2019-06-14T13:00:00.001+05:30

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Before you come to any conclusion, just take a note that you cannot destroy a black hole. But probably that black giant is waiting for you somewhere out in the universe, so be equipped to fight them.

On a serious note, is it really possible for a black hole to evaporate or even get destroyed? Why is it

even necessary?

Black holes are very famous for their ever-lasting friendship, as they do not let anyone leave them once they cross its event horizon. Black holes are very friendly. Once in, you can never get out of their circle (EVENT HORIZON).

But sadly, none of us would want to get near them until we have a space suit which can oppose their gravity easily.

WHY ARE YOU SO RUTHLESS?

After billions of years from now, our universe will face a black era; era of the black holes, and none of us wants to be surrounded by these black giants.

That is the reason why it is necessary for these black giants to evaporate or probably get destroyed.

I don’t think that any creature on this earth would like to get surrounded by these black giants.

Black holes can be compared to us. We like to eat every time which results in an increase in our size. Similarly black holes do the same, they eat and increase in size, but they can too, like us, eat less and lose more in order to decrease in size. If they are really that similar to us, then do they have a temperature like us?

BLACK HOLES| TEMPERATURE.

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Every time a black hole feeds itself, it grows larger leaving us with a very little hope of its destruction. How can a body, which has a tendency to suck I everything (literally, only the things which cross the event horizon. So do not freak out!) , can have a temperature of its own?!

I mean, we do not know what is inside the black hole, then how can one possibly determine its temperature?

Anything which has a temperature emits radiation. Even at lower temperature, the radiations are emitted. But, black holes are very famous for their world class sucking ability. Then how can a black hole emit radiation?

Hawking Radiation is the answer to this question.

HAWKING RADIATION.

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I will give you a very short introduction to these radiations.

We have been told that Space is an empty space, but is it really empty?

The answer is NO. There occurs formation of virtual particles which consist of particle and antiparticle. As soon as they are formed, these two particles form a pair and annihilate each other. This happens every time.

But the negatively charged particle is a little less powerful than the positive one, which makes it weaker in front of gravity.

Suppose this pair appears just at the event horizon.

Being weak, the antiparticle will be sucked in by the black hole. But what about the other particle?

Yes, it escaped! And thus the particle which escaped is the radiation. Please note that this radiation is not emitted from the black hole, but from the edge of its event horizon.

And thus, we can say a black hole has a temperature of its own.

THE GRAND FINALE.

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Coming back to the topic, can this radiation destroy the black hole?

A simple and short answer, YES!

But if you would ask for a brief answer, I would still say yes, but with a climax.

This process might take billions of years. The emissions from the black holes will be a very slow process.

The antiparticle, which has negative energy, will slowly decrease the mass of black hole. Thus it becomes smaller and smaller with time.

Scientists are yet not conformed as what will happen when these entities will become very small. Their predictions say that there will be an explosion. A VERY DESTRUCTIVE EXPLOSION.

Black holes are very amazing entities, very attractive, very fascinating, but please do not fall for them. Likewise, do not fall for attractive things, maybe you won’t return forever!

In these many ways can our universe end!

2019-06-11T20:55:00.000+05:30

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Suppose you're enjoying your life in an isolated island with all the comfort and everything ends abruptly!

You have no where to go in the universe!

No place left in the universe!

And no universe to live in!

This seems quite illogical, right? How can a universe this big can come to an end out of nowhere?

But that isn't the major question! You should ask yourself, "If this is even possible then how will it even happen? "

What can possibly lead to the end of a universe so big?!

There are many ways in which our universe may come to an end, leaving us no place to escape to, until we open the gates to the multi-verse.

For a long time scientists have been studying these phenomenons. We know that the gravitational force keep everything together in this universe. On the other hand, our universe is expanding.

Between these two forces, which will dominate the universe? Which of them will decide the universe's fate? Let us see the possible ways which may decide the fate of our universe..

The Big Freeze

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In this scenario, the universe keeps on expanding forever and this will result in decreasing of temperature. Every body in the universe will bid each other adieu, and they no longer will have any contact with each other.

That means you no longer can communicate with your friend, say John, who lives in your neighboring galaxy.

Jokes apart, this will result in isolation of every body and the stars will no longer have any access to raw materials which act as their fuel. This will result in light going out and this will be inevitable.

The universe will continue to expand and it will continue to get colder and colder and colder. At one point, when the temperature will reach at absolute temperature, literally everything will stop! There will not be any energy.

At this state, universe will reach maximum level of entropy.

The Big Rip

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Our universe has been expanding due to dark energy which is a mysterious entity. We do not know anything about it till date. It has been known to increase the rate of expansion of the universe.

According to this theory, the universe will expand at an tremendous rate until a state comes when the matter, including sub-atomic particles, will stretch themselves and could not hold themselves. They will get ripped out. That is the reason this theory being called The Big Rip.

The probability of this event taking place, totally depends upon critical density.
(Critical density- A value at which the universe will stop. No expansion, no contraction.) .

Scientists believe that if this will ever happen in the future, it will happen after 22 billion years, when Earth would have been swallowed by a Red giant Sun and if somehow it survived(IT WILL NOT), we will have thirty minutes after the big rip starts.

The Big Slurp

The higgs field

Suppose a bubble forms somewhere in the universe and inside it there is a complete different physics (probably of another universe) , there exists everything which we do not about.

Your question might be, how will this happen? Was there a kid who blew out that bubble? Ha Ha.. Well, I know that you are not so lame.

In reality, this might have happened, the only reason we might have not seen it yet is because of the expansion of the universe. The more the bubble gets bigger and tries to reach us, the more it gets away.

''Hey! How will this happen?!" Yeah, I am coming to that.

So, according to Quantum field theory, our universe is made of stable layers. There are many layers and one of them is the Higgs field. The field provides mass to elementary particles.

We know that every object in this universe tends to posses least energy as to be stable. But there is someone out there who pretends to be stable but is not really stable. They are Higgs boson. They are the excitements in the Higgs field or you can say that they are the elementary particles of that field.

Since they are meta-stable, they have a lot of potential energy and if they lose it, a huge amount of energy will be released. Although that energy is very little for our reality, but in quantum level it will be a huge amount of energy. But what possibly can push a Higgs Boson from its meta-stable state?

That is QUANTUM TUNELING.

If this bubble will be formed or if it has been formed, it will start to advance at a speed of light. But you need not worry. You won't live that long for it to reach you, so do not worry!

The Big Crunch

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This theory has its base on The Big Bang Theory. In this scenario, the universe will not expand forever. This can happen if the universe has enough density of matter, which can oppose the expansion of universe by just enough gravitational force.

Once the expansion stops, the universe will set to shrink again and continue shrinking until it forms something of very huge density, like singularity.

Now, according to this theory, the universe is in a shape which is closed, say a sphere.

These events are just like as if our universe breathes in and then breathes out!

When it breathes in, The big crunch happens.

When it breathes out, The Big bang happens.

That is why, scientists believe that these events might have happened in the past.

And this gives birth to the BIG BOUNCE THEORY!

Forget Big Bang, we might have had the big bounce!

So, in a nutshell, these four ways are very likely to happen but in a very far future.

So, currently we do not have to worry about them. The space is full of amazing things which gives all of us goosebumps.

Do share your your views.

Space-time oscillation

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The oscillation of Space-time is called Gravitational waves. They are the disturbances in the space time. It's one of the major predictions of General Relativity.

Before general relativity, space was rigid, it neither expanded nor contracted.

The equations of general relativity shows that space expands and contract in time and it provided a better image of gravity.

Space-time is curved and this curvature depends upon the shape of matter. Thus we may expect ripples just like in water.

If you were floating in space and watching a ring of marbles floating freely in front of you, and a gravitational wave passed through the center of the ring, you would see this type of oscillation-

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The Alcubierre Warp Drive | Is time traveling possible?

2019-06-07T13:55:00.002+05:30

Is it possible for you to go back and undo all your mistakes?
Is it possible for you to meet your ancestors?
Is it possible for any of us to travel in time?

The possibilities send shivers down my spine knowing that I can travel back in time and watch my favorite cartoon shows!

You and I know very well that there are many other ways of time traveling, but they are theories and are yet to be proved.

Alcubierre Warp Drive is a device which allows one to travel in space and time and this is inspired by People's favorite film series, Star Wars!

FICTION TO REALITY| IS IT POSSIBLE?

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Many of us have dreamed of of our favorite fiction becoming a reality, but will this fiction be reality?
Before discovering more about this question, let us understand the principle on which this spaceship works.

The Warp Drive was first proposed by Mexican Scientist Miguel Alcubierre.

This spaceship warps the space-time around itself thus enables traveling in time. This is very favorable because one cannot think of traveling faster than the speed of light.

The question you may ask that how can it warp space-time around itself?

We can now understand it by saying that this spaceship remains inside a bubble which is surrounded by the rings of negative energy. This phenomenon shrinks the space-time at the front of it and stretch the space-time behind it and this would enable to travel at speed more than the speed of light!

Inside the bubble, the speed would remain ideal i.e less than the speed of light and thus general relativity would remain intact.

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Now, after the brief introduction, let us again raise the question, IS THIS EVEN POSSIBLE?

The answer can be a YES and a NO.

REASON FOR A NO.

Why is there always a NO?!

This spaceship requires energy in huge abundance so as to create the negative energy.

The only problem is, the warp drive would require a minimum amount of energy about equal to the mass-energy of the planet Jupiter.

Secondly, there are not any known methods to create a warp bubble in a region of space which would meet the desired requirements. Also, if somehow we come to know how the bubble is made, yet we will face problem in leaving it once we get inside it.

REASON FOR A YES.

How can we overcome the problem?

The recent researches claim that the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA, launched in 1977, when the ring of exotic/negative matter

will be made of a shape of a doughnut.

Furthermore, if the intensity of the space-time can be oscillated, the energy requirements would also reduce very much.

Space time oscillations

While scientists are approaching the solutions of different problems, this only opens the gate to other problems. Science is full of LOOPHOLES!

HUMBLE EXPERIMENT.

Scientists have begun experimenting with a tiny version of this warp device in the laboratories.

They set up what they call the White-Juday Warp Field Interferometer at the Johnson Space Center and it detects micro version of space-time warps.

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This project is called a "HUMBLE EXPERIMENT", as it represents a promising first step.

If humanity is really serious about traveling into space, then this idea of warp drive should paid very crucial attention.

There are many questions and problems between humanity and the nearest star. Numerous researches are conducted so as to find an answer.

Alcubierre Warp Drive is also a kind of project which would enable humanity travel at a speed 10 times more than the speed of light.

Although these experiments are yet bounded to the book of theories, they hold a very important answer to our questions.

What do you think about this project. Will humanity be able to travel in space and time?

Please share your views.

Let Science Brief It

The Big Bounce Theory

WHAT'S THIS NEW BIG B?

BIG BOUNCE VS BIG BANG.

THE CONTRACTION.

The life cycle of a star.

There is nothing like a true black hole| Dr. Abhas Kumar Mitra.

Death of a Black hole.

In these many ways can our universe end!

The Big Freeze SOURCE \

The Big Rip

The Big Slurp

The Big Crunch

This theory has its base on The Big Bang Theory. In this scenario, the universe will not expand forever. This can happen if the universe has enough density of matter, which can oppose the expansion of universe by just enough gravitational force.

Space-time oscillation

The Alcubierre Warp Drive | Is time traveling possible?

FICTION TO REALITY| IS IT POSSIBLE?

REASON FOR A NO.

REASON FOR A YES.

HUMBLE EXPERIMENT.

The Big Freeze

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