23 Dec 2018

Are we traveling in time?

Are we traveling in time?

Time travel

Whenever we think or hear about time travel, one thought must came in our mind that is about the theory of General relativity(given by Einstein) .That is, if we travel with the speed of light we could travel into time.
Appart from this all ,we are unaware to the incidents that is happening in our daily life that relates to the time travel.

Let's see such incidents.........

               Artificial satellites facing time travel everyday

Artificial satellites

As we know that, satellites that are installed in space orbits the earth with the speed of 14,000km/hr, and orbits the earth twice a day.  So the satellite clock (clock present in the satellite) are moving different than the clock present on the earth. And according to the general theory of relativity, as we moves faster time gets slower, by about 7 microseconds/day (millionths of a second) in the case of satellites.

Also, it revolves 20,000km above us. So, it experiences gravity that is 4 times weaker than on the earth. And according to general theory of relativity gravity curves space an time that results in tendency for orbiting clock to tick slightly  faster. That is about 45 microseconds/day.

As a result on calculating, the satellite clock advances faster than the clock present on earth, by about 38 microseconds/day.

Here many of questions came to the mind that, does this very little change in time can affect the working of satellites.

So yes, actually to determine the location of navigation satellite, the GPS receiver uses the time at which each signal from the satellite emitted. As determined by the on-board atomic clock and encoded into signal. To achieve a navigation accuracy of 15 meters, time throughout the GPS system must be known to be accuracy of 50 nanoseconds, which is equal to the time taken by the light to travel 15 meters.

But at 38 microseconds per day, this offset in the rate of satellite clock it is so large that, if left uncompensated, it would cause navigation errors that accumulate faster than 10 KMs per day.

Without the proper application of relativity, GPS would fail in its navigation functions without about 2 minutes.
So, think what happen when you plans a vacation trip and GPS system fails.
And think about Einstein and GPS tracer in cockpit, helping the pilots guide you to a safe landing.

   Astronaut as time travellers

Space stations

Now, try to relate the case of navigation satellite with the astronauts who are in the space stations or on a long rocket trip. Absolutely, they are not just only space travellers but also time travellers.
Actually this difference is not enough to notice but enough to measure. A 100 year to space travel is equal to one second forward in time.

So, if you also want to be a time traveller then you have to a space traveller.

          Scientific experiment on time travel

Time travel experiment

Now, we are aware about the time travel that is happening but, they are too small to be noticeable. Here in recent, experiments on time travel scientists got success.
These experiments was not on human or a rat, actually was on a particle. But, this is a great success in the history of time travel. These particle not only travel the time but also meet their ancient one.

A Washington State University physicists were able to slow down the movement of particles so much that “negative mass” was created, causing the particles to accelerate forward when they were pushed away. The physicists concluded that the particles went backward in time.

As well, physicists at the University of Queensland in Australia were able to make a single photon, or particle of light, go through a wormhole and interact with its older self on the other side.

There is also what’s called the delayed choice experiment. The delayed choice experiment illustrates how what happens in the present can change what happens(ed) in the past. It also shows how time can go backwards, how cause and effect can be reversed, and how the future caused the past.

22 Dec 2018

Does big bang really happens

Big Bang

Big bang

From the name we can guess that this is about something like explosion. This is not the usual explosion. According to scientific researches, Big Bang was an explosion which creates everything. Many people support Big Bang Theory and many opposes this. Let's know about this topic in detail.

                 What Big Bang Theory tells?

 According to this theory, before 13.8 billion years ago, everything is concentrated in a single point and the size of point is less then a atom and that point is known as point of singularity. At that time nothing exists and it means, no space, no time and nothing, only singularity exist. In a single point everything is concentrated, every energy that we can see today, wide space and everything.

Because of such a dense mass and energy that point is totally unstable and explosion takes place in it and that explosion is the thing what we called Big Bang today. That explosion creates universe. After fraction of a second after Big Bang( ten to the power - 34 sec after Big Bang) the cosmic inflation takes place and suddenly it ends ( when our universe was 10 to the power -32sec old). In such a small period of time, the size of our universe increases 10 to the power 26 times. This theory also says that the every single energy, space, time, masses, and everything comes in role because of Big Bang.

Hence, Big Bang is the most widely expectable theory in science. But still many people says that Big Bang is fake or just a hypothetical idea. Lets take a view on this.

                Against the Big Bang Theory 

Most of the scientists are accepting the big Bang Theory but many of them are standing against this theory. The peoples who are against Big Bang are raising some questions on this theory:

 1. Violating energy conservation principle:- according to Big Bang Theory the temperature, mass, Energy and density of the singularity is infinite. After Big Bang the space comes into play and everything and every fundamental unit becomes finite, so when we observe this here, the principle of conservation of energy is violating.

 2. This is impossible to whole universe is concentrated at single point: according to Big Bang, the temperature of singularity was infinite and as we know if any body is gaining temperature then it is gaining energy. If the temperature of a body is raising then the vibration of the particles inside body also increases and as we know the temperature of singularity was infinite so vibration of its particle also should be infinite, but there was no space so where those particles were vibrates? The vibration of so many particles is not possible in a point.

 3. How no space: according to Big Bang Theory, everything is concentrated in singularity and there was no space, no time and nothing. But the point of singularity also needs a space of a single point which was not present, so where was that singularity present.

 4. How no time: according to Big Bang Theory, time also didn't exist and we all ready know that the particles are vibrating in singularity it means particles are in motion and Motion needs time.

              In favour of big Bang Theory

 1. The proof of big Bang is present everywhere in the form of cosmic microwave background in this universe.

 2. Today we know that our universe is expanding with a great speed, so if we look back in time then at one time we will find that everything is concentrated in a small point which has a infinite temperature.

We can't understand big Bang Theory with these points but we need a better theory to understand this.

                     Eternal inflation theory

Big bang

Inflation theory was first proposed by Alan guth. Inflation is the time when the size our universe increases 10 to the power 26 times. This is a small unit of time. Today we have 15 different kinds of inflation theory and one of most acceptable of them in eternal inflation theory.Today we know that, if we say any space is empty/vacuum then it is false. Actually vacuum is also a physical object which have it's own energy density and pressure. The reason of inflation is gravitational repulsion which creates because of a unstable entity named as false vacuum.

Let's understand false and true vacuum. Everything in this universe has its own energy level, higher energy level means greater amount of energy in that particular system and lower energy level means less energy in that particular system. Everything in this universe follows the concept of stability which means everything in this universe tries to remain at lowest energy level.  In quantum mechanics we learn that the property of universe is originated from quantum field. It means, from quantum field, any particle gets a information and that information decides that how they are going to interact with other particles. The quantum fields tries to remains in lower energy field which is called vacuum state.

In some circumstances, they enters in meta stable state which is a period of a unstable state which remains for a long term. From this state they can't reached to vacuum state so the can't loose energy therefore false quantum fields like hikes field carry a large amount of energy inside itself and those type of field is known as false vacuum. False vacuum is unstable and because of extreme density their gravitational force becomes repulsive rather than attractive.

The gravitational force in false vacuum is a powerful force because of  such a huge density and that force forces space near around itself to expand. That expansion is not linear but it is exponential. False vacuum is unstable so it loose energy randomly and decay in random patches.Because of decay these patches were in lower energy state than before so the rate of inflation in these patches decreases. These low vacuum energy regions form microscopic energy bubbles which starts expanding and their size increases from plank size to bigger than the size of our observable universe.

The interior of these bubbles are new local big bang and in every bubbles like these a new universe created which expands with time and these bubbles are called multiverse. From inside it looks like as the universe as we see today but from outside it seems like a black hole.  Inflation Theory not only talk about universe but it talks about multiverse which is expanding with a great speed ( more than the speed of light). If still there is any questions in our Mind then we need to find the exact position of electron to answer that.

Is everything going to its end?

Is everything going to its end?

Collision of planet

Everyone, once in his life tries to think how big is universe, where we are living, how everything is going to end and most importantly who/what is creator. So let's try to get answer of these questions which make us crazy about this universe. In this article we will learn possibility ( we can't predict anything exactly until we get our theory of everything) of ending of everything.

                      End of life from earth

End of life

Let's move our time dial to 50000 years forward.
Now because of global warming, earth's temperature has been raised, life on earth is a tough and challenging task for humans (here we are assuming that we didn't get any other planet where we can shift our civilization). Dusty storms and smoky clouds are normal now. Half of human population has been end because of different types of cancer (from chemical smoke and from direct uv rays).

Let's move our time dial to 5000000 years forward. Temperature on earth is getting normal now and earth is looking more greenly then 5000000 year before it looks like. The reason behind this is end of human civilization from earth, as we know humans are only transporter and life only need producer and decomposer. I can see a beautiful and greenly planet now, at a time which is almost destroyed by humans and I can say this now " this planet don't need humans".

End  of our solar system

End of solar system

Here we jump 5000000000 years in future. Our Sun change itself from star to a red dwarf and ingest some planets like Mercury, Venus, earth and Mars. In between these, milky way galaxy is collide and intermix with another galaxy named Andromeda. if humans were still there than they can see a beautiful scene at night because of increase in number of stars and gas cloud. This is what called beauty of nature.

Hawking’s radiation

Hawking’s radiation

Hawkins radiation

For understanding the concept of hawking’s radiation we should must have some general information about black holes, because this topic is totally related to black holes. Do you ever tries to think, if black holes are really black than how we are able to see them. Let's find out answer of these questions.

                            Black holes

Black holes

You must know some general information about Black holes like, they are body of heavy mass, time slow downs near a black hole and many more. Let's know some more about Black holes in detail.
Scientist named this object, monster of universe and that suits on its nature.
Yes, they are the body of very- very high mass and most important thing is that such a huge amount of mass is concentrated at a point which is called singularity. Because of such a huge amount of mass, time Slows down near a black hole.

              Birth of monster of universe

Star life to supernova

 Black holes are the dead body of a star of heavy mass which is nearly equal to 20solar mass. When the process of nuclear fusion stops in a star then it lost its stability. This happens as, hydrogen fused into helium, helium fused into lithium, lithium into beryllium, beryllium into boron, boron into carbon, carbon into nitrogen and nitrogen into ( iron further can't fused). When this process is done in a star then that star lost its fuel and a explosion held in that star.
That explosion is called supernova. Here gravity comes into play and star gets contract towards its own core and converted into a single point which is singularity. Because of such a high mass in a single point, that singularity make a bigger curve in space time than any other body. Hence this curve and singularity collectively called a black hole.