The Bizzare world of Quantum mechanics

Lying just beneath everyday reality, is a breath taking world, where much of what we perceive about the Universe is wrong. In the world smaller than the size of atom, the laws of physics as we know them, completely break down. If we, humans had been living in that world, we'd have been able to do the things which may sound completely insane. For example, you being in the school and sleeping in your home at the same time, Travelling from one place to another without covering the distance between them, Walk through the walls, or make your twin brother do what you want without any kind of communication between you two, even if he is millions of light years away from you. Sounds absurd right? really isn't in the world of atoms, electron and photons.

Our perception of reality has completely changed over the past seventy five years, because we've discovered new revolutionary set of laws; the laws of quantum mechanics. These laws govern every atom in every piece of matter in stars and galaxies, rocks and oceans, and in you & me. Therefore, the nature of reality lies deep down to the smallest scale; the scale of quantum particles, where these strange and crazy laws rule.

Something unknown is doing we don't know what—that is what our theory amounts to.[Expressing the quantum theory description of an electron has no familiar conception of a real form.]

— Sir Arthur Stanley Eddington

There is a sense in quantum mechanics that particles don't like to be in one place at a time. They can be in many places at the same time. And according to quantum physicists, these particles continue to be at more than one places and do more than one things until you observe them, the act of observation forces them to choose one place to be in and do one thing  out of all the places where they could've been and all what they could've been doing. This all goes back to the double slit experiment, when there was no observing the photons they formed the pattern of waves, actually behaving like waves, interfering, cancelling each others effects and all that stuff. But when no one was observing the process, they behaved as particles; forming the pattern of particles on the screen behind the double slit metal plates.  

Photons behaving as particles when being observed and as waves when not being observed

Plus, the M theory predicts 11 dimensions, 10 of them in space and one dimension of time. As we live in 3 dimensional world, we are not able to observe or even imagine these dimensions but that's the way it is. Some of these dimensions are smaller than the size of photons. And the nature of reality in each point of  space is determined by the behavior of the strings in these hidden dimensions.

Perhaps the most puzzling, the most bizarre, the most absurd, and the most craziest thing which quantum physics predicts is entanglement. Two particles when come closer to each other, they become entangled. If one particle spins in clockwise direction, the other entangled particle must spin in anti-clockwise direction. And when the spin of any of those two particles is changed, the other one automatically changes its spin in the direction opposite  to that of the entangled particle. Sounds perfectly alright. But now comes the crazy part; if you separate those particles they still remain entangled, even when  one particle is millions of light years away from the other. How could this be? How can two things remain connected without any kind of  communication or connection between them. Einstein called it 'spooky action at a distance'.

Two entangled particles

So why do we believe in all this? that's because these laws of quantum mechanics describe everything and every experiment made in  the history of science perfectly, and not a single exception or disagreement has been found yet. Although people may found this stuff hard to believe. There was one person In the 1930s who found these things very hard to believe; Einstein . Because Einstein believed in certainty, not probability. 'particles being in more than one places at one time until someone looks towards them' wasn't Einstein's cup of tea. As he said: "I'd like to think that the moon is still there even when I'm not looking at it"

Einstein believed that there was something missing in the laws of quantum mechanics. Some kind of missing piece which will describe everything completely with certainty, and not just with probabilities. There was a whole kind of rivalry between Einstein and quantum physicists like Bohr, Heisenberg and de Broglie etc.

Einstein claimed that God doesn't play Dice with the Universe, and Bohr Answered him : "Stop telling God what to do."