The quantum world that is the world of
infinitesimally small…the world of electrons and Photons, is pretty different
from what we observe in daily life. The reality at quantum dimensions is so
weird and understanding that great physicists of the status of Einstein, Niels
Bohr, Richard Feynman have failed to understand it fully. Niels Bohr quipped,
“If anybody says he can think about quantum physics without getting giddy, that
only shows that he has not understood the first thing about it”. The problem
with the world at quantum level is that the quantum particles seems to have no
regard for the rules of classical
mechanics framed by Newton and others that seems to so well describe our
observable universe.
For example
1.At quantum levels you can create reality
by simply looking at it.
2.A quantum particle
can occupy more than one place or take more than one path at the same time. This simultaneous
coexistence of all possibilities is known as coherent superposition or quantum
coherence.
3.Quantum entanglement: As shown by Non locality experiment that if we send twin
photons that were joined earlier to different sectors of space, any action
performed upon one instantaneously affects the other as if they remained
forever bound in spite of their spatial separation.
In Quantum world a quantum particle actually
exists as a wave function with the probability of finding it extending till the
end of universe but with a high probability of finding it at one particular
space. This description of quantum particle actually arises from the famous uncertainty principle of Heisenberg
who stated that it is impossible to measure the position and velocity of a
quantum particle accurately beyond a certain fixed level of accuracy defined by
his equation. This impossibility is not due to the fault of measuring
instruments but is inherent characteristics of quantum world. That the position
of quantum particle is defined in terms of probability led Einstein to utter: “God Does Not
Play Dice”. However as soon as a quantum particle is observed by a
conscious agent they collapse from their wavy nature to reality at a particular
position.
For example let us consider that you are an
electron seated in a chair. But in quantum world you are actually a wave spread
over the entire universe with high probability of finding in your chair. You
will remain in that state until and unless a conscious agent looks upon and
collapses you into reality seated in the chair. This may sound like the staff
of science fiction but the postulates and predictions of quantum mechanics have
been proved through numerous experiments like EPR and Young’s Double Slit Experiment.
THE EPR EXPERIMENT
Now the question is what is consciousness (click on the link to know more about consciousness)? Scientists
are too in debate over this question and we will deal with it in our next
article.
Let us return again to uncertainty principle of Heisenberg.
The uncertainty principle can also be stated in terms of energy and time. It
states that if time is stretched enough and we look at very very tiny interval
of time while trying to find out about the energy of a certain small volume of
space we would be so uncertain about its energy content that a particle may pop
out of existence out of nothingness provided it vanishes as soon as it appeared.
To show you how this could happen let me tell you a small story.
Around 1928 Physics was suffering from
another big problem. The two most important theorems of physics did not agree
with each other. On the one hand you had Einstein’s special theory of
relativity that described the description of particles moving at a speed close
to the speed of light encapsulated in the beautiful equation E=MC2 and on
the other hand Planks discovery of quantum and the revolution that followed
describing the bizarre rules of very very small. Problems arose when trying to
describe the behavior of particles that were small enough for quantum rules to
be applies and moving fast enough for Einstein’s special theory of relativity
to be applied, (especially the behavior of electron). If this theory could not
be married it meant that one of them had to be wrong.
At this critical moment Paul Dirac; a
brilliant scientist came up with a very elegant description of election that
helped to marry the Einstein’s special theory of relativity with plank’s
quantum mechanics.
This elegant equation is known as the Dirac
equation. In his description of electron Dirac was forced to use a set of four
equations represented by the symbol γ.
While the first to equations were quite
familiar and referred to the behavior of electron as observed in the
laboratory. The next two pair were suggesting to a type of electron never
before observed. In some way just like the electron yet very very different. It
came to be known as the anti-electron. Dirac realized that if the things and
anti-things ever meet each other they would instantly annihilate converting all
their mass into energy.
Now here was the answer to the riddle of
empty space. Heisenberg had suggested that matter could pop into existence from
empty space for very very small amount of time. Dirac provided the mechanism
how this could happen. So
actually whenever a matter particle pops into existence from empty space so
does its anti particle and then they quickly fall back upon each other and
annihilate.
Strange as it may seem just like a compulsive
credit card addict, pairs of particles and antiparticles constantly borrow
energy from space to pop into existence before annihilating again and returning
back the energy. Thus what may seem as vacuum is constantly seething with this
activity which is known as quantum
fluctuations. But as soon there is sufficient energy made available by
any source, stable particles are able to emerge and have a ‘real’ existence in
the world.
Now you might be wondering why am I
discussing so much about nothingness and quantum world?! Well for the curious
mind here is the answer…Wherever you see in the observable universe including
sun, moon; stars, you and I all have come out of this vacuum. So to understand
and get the big picture you have to understand the small…. Om tat sat
It was in 1916 that Einstein published his
general theory of Relativity. It was a defining moment not only for physics or
science but for mankind as a whole. It would forever change the way we look at
the universe. Before Einstein came out with his theory of relativity space was
considered static. But Einstein’s space is dynamic. It curves and bends due to
the presence of mass in it. It appears almost like a living entity which reacts
to its surrounding. Einstein’s
general theory of relativity thus stated that the planets which moves in
orbital paths around the sun or the way in which every other heavenly body
moves is not due to the action of the force of gravity but are actually moving
in the simplest of paths that is formed due to curving of space.
When
Einstein’s equations of general theory of relativity were applied to the space
a more startling and bewildering discovery was made. It was found out that the space
was actually expanding. The idea was so adverse to common sense logic that
Einstein became convinced that there must be something wrong in his equations.
So Einstein went again to his drawing board to reintroduce a cosmological
constant in his equations to stabilize the expanding universe that his
equations predicted. But Einstein was going to fix something that wasn’t
broken. The fact that universe was expanding was shown by Edwin Hubble.
(Hubble knew that for a light source moving towards the observer the
waves emitted by it would get compressed and so the light would appear to be
blue in color. On the other hand for a light source that is moving away from
the observer the waves would get stretched and the light would appear reddish
in color. With this knowledge in mind and armed with the hooker telescope
Hubble saw that most of the galaxies were red shifted and the further the
galaxies were the faster were they moving apart.)
Einstein paid a visit to Hubble and saw this
with his own eyes.
Einstein later admitted that changing the
equations would have been his greatest scientific blunder. Hubble and Einstein
jointly came to the conclusion that if the universe was expanding now then at
some time in the past the universe must have had a beginning. If the future was taking the galaxies far
away, then it stood to reason that in the past they must have been closer
together. So close ultimately that the matter’s compression might result in
what Einstein’s equations
predicted to be a point of singularity. (Upanishad’s rishis also said the same thing thousands of
years ago and the termed the singular point ‘Dahar’)
The fact of physics pointed to clues that
eventually made the case for a cosmic explosion as the event that kicked off
the expansion of universe. Georges Lemaître, a Belgian priest conceived the
idea, and British astronomer Fred Hoyle, in jest coined the term “Big Bang” to describe
the explosion.
It is however important to note that it was
an explosion of the space itself and not an explosion in any existing space. In
the expanding universe today, it is the space between galaxies that is
expanding. There was no
space before; it appeared along with the Bang.
My
discussion on Big Bang and reality continues in my next article...But before
that let me discuss about the weird nature of quantum world because this
infinite universe was shaped by this weird quantum world at its infancy...Om
tat sat
