Monday, 27 June 2016

Travelling to a parallel universe via Wormhole

                         Parallel Universes via Wormholes


Ever thought about how big is our universe?

Best estimates of astronomers indicate 100 billion galaxies; Andromeda galaxy is closest one to ours and is 2.5 million light years away.
One light year is how much light can travel in vacuum within 365.25 days (1 Julian year)
Which is,   distance =speed x time
                   Distance = (3x108(m/s)) x (365.25x24x60x60(s))
                 Distance =946728x107kms or 9.467e+12kms =1 light year
You can imagine how gigantic our universe is!

Scientists have a theory that we are living in a multiverse, as per this theory ours is not the only universe, rather many universes exist parallel to each other and these are called parallel universes. They are anticipated to be similar but not same (with very few changes).
We agreed on our universe being enormous (taken into infinity), added to it are infinite parallel universes. Too Hard to picture!

Wormhole: it is a hypothetical concept (no proves found yet) and is like a tunnel through the space time or like a short-cut. 


White hole: It releases matter outward unlike black hole that sucks it in. Black hole ends at a singularity and white hole is born from singularity.

Entering a wormhole can be familiar to black hole (black hole + white hole could make up worm hole) and exiting it leads to 2 set of predictions

A)  Exiting in the same universe you entered but at a completely different space-time as shown in down imagine. So if there is a wormhole between our galaxy and Andromeda galaxy, and it is stable enough for interdimensional travel. I will be able to reach Andromeda galaxy within few minutes or hours(definitely less than 2.5 million light years) And therefore I even travel in time, that is travel to future (my friends on earth and I will experience time dilation due to me passing through wormhole  which is warping of space-time) 


B)  Exiting into a parallel universe as shown in first image. As in case of Alice in wonderland.
Our universe started off with a ‘Big Bang’ and is expected to end in a ‘Big freeze’. Few scientists hope that this can be avoided by hopping into a parallel universe.

The bridge of wormhole connecting two places is called Einstein-Rosen Bridge. Einstein believed that any communication through the bridge would be impossible, but recent studies show it hard but perhaps probable.
Amount of matter-energy needed to create wormhole is immensely large and it would still be highly unstable and disappear in wink of an eye, making it impossible to use it as an interdimensional travel.


So if you are bored of this universe, you may be lucky enough to travel through universes for some adventure in a future, if you live long enough by that i mean few centuries and when these theories turn into laws.

Monday, 20 June 2016

Black hole an interesting ambiguity !!

                                                              BLACK HOLES

Biggest one of many mysteries of Universe, can’t be seen can only be detected by changes in the surrounding space-time fabric. As the name suggests they are black and can be similar to hole formed in the space-time fabric. 



Ever wondered why they are black?

Objects can be seen only if they reflect light; well in case of a black hole its gravitational pull is very intense that even particles moving at 3x108m/s or light cannot escape. Escape velocity of earth is 11.2km/sec. Black hole occurs where there is immense mass in small volume, we know from Einstein’s theory of relativity that more the mass , more the warping of space-time, and more the gravity.              

To give an idea of mass contained in a black hole, shrinking the earth to size of golf ball without removing any of its mass gives us a small black hole.

HOW ARE THEY FORMED?

 Dying stars whose mass is 20 times mass of sun or more form black holes. Stars shine due to enormous amount of heat liberated in nuclear fusion process. Stars are formed from condensed gases (mostly hydrogen nucleus ), these gases are stay put due to gravity which is also powerful  enough to crush the star. But these hydrogen nuclei gets fused together to form helium and thereby releasing large amounts of energy (E=MC2), this process is called nuclear fusion and this energy released tends to explode the star. As a result, gravity and nuclear fusion in star’s core are at a war, till the core of star runs out fuel and gravity Wins. Fate of the star hence forth is decided by its mass, in case of black holes we focus on super massive stars, gravity crushes the star aiming to form a singularity (infinite mass at one point).

Black holes are primarily of singularity within and an event horizon. Event horizon is also called “The point of no return”, because once you enter beyond this event horizon black hole sucks you to singularity and is impossible to escape its tug. 



WHAT IS IT LIKE TO FALL INSIDE A BLACK HOLE?

Time slows down inside a black hole, and at singularity time stops, laws of physics as we know, breaks down. Assume an unfortunate astronomer falls into a black hole, he will not realize it until he passes event horizon. Now, he undergoes a process called spaghettification(being stretched like a spaghetti) that is, gravitational pull at his head and feet is not same, it would stretch him and tear him apart. To his friends in spaceship orbiting the black hole, it appears as the astronaut slowed down and stopped at the event horizon, his time stops here.

Just for the sake of fun, we assume he overcame this spaghettification process and manages to reach center of black hole alive. Here starts our science fiction(interstellar, star trek, star wars), unproved theories(hypothesis), it could be a gateway to another universe, you could visualize present, past and future at once, time travel could be possible and much more.



DID U KNOW: There is a massive black hole at the center of our own Milky Way galaxy; as a matter of fact every galaxy has a black hole at its center. They are capable of destroying entire galaxies 

Monday, 13 June 2016

General Relativity simplified

GENERAL RELATIVITY

This theory spins around gravity; it is like an extension to special relativity by counting gravity too. Einstein developed it fundamentally based on equivalence principle

EQUIVALENCE PRINCIPLE:

Imagine being locked up in a closed container like an elevator with opaque walls and you are given a tennis ball. As you bounce the ball it touches floor of elevator with acceleration of 9.8m/s (earth’s gravity) as anticipated.

Now your elevator has a fuel tank or you were actually in a rocket, which is accelerating at 9.8m/s (32 feet/sec). When ball is bounced at the moment, what would happen? Would it be same as before?      
Yes to you it would just appear to hit the bottom as before because your body is also accelerating with 9.8m/s. But for an outside observer, it would be the floor accelerating at 9.8m/s towards the ball.

You are shielded inside and you cannot tell if its gravitational frame’s work or accelerating frame’s work that causes ball to touch the floor. In other more scientific and confusing words: laws of physics are same in accelerating (non-inertial) and gravitational frame (inertial) of references, this is called equivalence principle.

Combination of equivalence principle with its analogue in pure mathematics leads to formation of Einstein’s theory of gravitation. (This alone deserves another blog post)

GENERAL RELATIVITY: back to main topic
Einstein’s mathematics consists of 4 dimensions (3 spatial dimensions and 1 time dimension) also called space-time relations. He said “space itself is curved”.

Imagine a rock placed on a spread blanket, there is a depression caused by placing the rock, now a marble shot into blanket will follow an elliptical path around the rock. In analogy, blanket is the space-time fabric, this distortion is formed by matter is called warping of space-time (curving of space time). Imagine is a reference to warping

Proving this:
Light always chooses the least time taking path (hence it’s always straight line), when passing objects as sun (heavy objects that cause warping) light beams bend and the shortest distance it chose being a curved line, articulate us that space-time fabric itself is curved. This phenomena of bending of light is called gravitational lensing


Due to gravitational lensing of sun, light from distant stars is bent and we receive multiple apparent images of them. This was proved during 1919 eclipse; measures of distances of stars were taken at night (absence of sun) and during eclipse (so that sun’s light wouldn’t overwhelm star’s light). Observations obtained were close to Einstein’s theory predicted values. Einstein’s theory overcame, many limitations in newton’s predictions, though it had its own set of difficulties in mathematics domain.

E=MC2

Heard about it too often! But what does it signify?
As Energy is supplied to a particle, it increases its velocity thereby increasing its kinetic energy and mass. This extra mass emanates from energy supplied, it’s also another perspective into saying speed of light is not achievable; as the particle reach speeds close to speed of light, energy supplied is converted to mass gained by the particle.

E=MC2 implies

MATTER is condensed form of ENERGY, a storage unit of energy. 
Insignificant amount of matter can generate loads of energy as mass is multiplied by speed of light squared (which is a huge number).


In conclusion: As matter-energy is more ─> curvature of space-time fabric increases hence more the gravitational tug.                    
 Einstein’s relativity theories led to foundation of principles behind motion of black holes, stars, big bang etc.

Wednesday, 8 June 2016

Special relativity simplified to its best

                    SPECIAL RELATIVITY

Special relativity postulated by the genius Albert Einstein                                                                                         
Relative velocity

To understand this spooky topic in a simplified and easier way lets clear out topic of relative velocity

Assume We both are on a flight (why train always?) just sitting there and having ice cream, so our both velocities are same and are zero with respect to each other (can also be said as relative to each other). Same case, now when our velocities are considered with respect to the ground(frame of reference is ground)we are in motion with a particular velocity( relative to the ground) and a different velocity when frame of reference is another plane flying across ours cause the velocity of that plane is subtracted from ours . so basically relative velocity pronounces  that speed with which we are moving varies with respect to our frame of reference (hence comes word relative) and also that space is not absolute.

Frame of reference:to the above Paragraph, it is from where one is calculating plane’s velocity

Back to main topic: SPECIAL RELATIVITY

Bottom line of this theory says Speed of light is constant for every observer. Okay I have been listening to this from really long time, what’s spooky about this?

Let me expand and confuse you a little more before clearing it out
For a space ship ‘A’ moving with speed of 2x108m/s  and another space ship ‘B’ moving with speed of 1x108m/s the speeds of light beam travelling parallel to them must be
For A  (3-2)x108=1x108m/s
For B (3-1)x108=2x108m/s  in accordance with relative velocity
But in reality it’s found out to be 3x108m/s for both……does it seem absurd now? Now this appears to defy the concept of relative velocity.
In conclusion speed of light is always constant compared to anyone moving at any speeds, does it now make sense as to why you can’t beat this speed? Because when a particle moves closer to speed of light, light still passes that particle at 3x108m/s.

Okay, all this is cool, but how can it be same?C'mon Something has got to change!
Yes, time compensates it.
TIME DILATION comes to play here.

TIME DILATION:

This basically says that racing of time depends on velocity, the faster you move slower your time runs. As you move with speeds closer to speed of light your time slows down, congrats you will age slowly than your peers. You will have more time in your hand. Same principle is used with various examples, most common one being a pulse bouncing off between 2 surfaces. Similar thing happens with length and this phenomenon is called length contraction.
If you hate Justin Bieber, you might be lucky enough to travel across space at speeds closer to speed of light and come back after a few minutes, few minutes is according to you, but for us on earth it would’ve been years-this is also the main principle of twin paradox(All these paradoxes will be put on soon)

In conclusion:

Special relativity is about speed of light being absolute and constant, doesn’t matter speed of observer, because pacing of time is altered.

Note: Difference between Special relativity and General relativity is that special relativity does not take gravitation into consideration unlike General relativity
And precise value of speed of light is 299792458 m/s