“O God, I could be bounded in a nutshell, and count myself a king of infinite space” (Hamlet by William Shakespeare).
“What is now proved was once only imagined.” (William Blake)
“You never know what is enough unless you know what is more than enough.”
The Planck length is equal to 1.6 x 10-35
Planck time (5.39 × 10-44 s): the time it takes for a photon at the speed of light to travel one Planck length in a vacuum.
Our description of the early stages of the observable Universe is about what happened 5.39 × 10-44 s after the Big Bang.
Currently laws of physics do not make sense when applied in scales smaller than the Planck time and the Planck length (unless someone were to unify gravity and quantum theory).
In proportion the Planck length is smaller than an electron, as a hair is smaller than a galaxy.
General relativity expands Newton’s original theory of gravity, since Newton’s gravity theory works fine for bodies at rest or bodies moving at rates much smaller relative to the speed of light. Einstein also added the distorsion that gravity can have on space and time.
-13.8 billion years ago: We have all been told at a certain point in our lives that the origin of our Universe somehow has to do with a massive explosions known as the ‘Big Bang’. It will become clearer why rarely in history a worse choice of words could have been used to illustrate a concept (indeed the ‘Big Bang’ was a term coined by a critic of the theory and as such it was meant as to be derogatory).
In reality the ‘Big Bang’ refers to the sudden expansion of the Universe from an extremely dense and hot point. This point is known as the singularity.
We know nothing of why such point existed in the first place. However we have deduced its existence because we know that the universe is expanding (due to the redshifts of the stars), hence if we could go backwards we would imagine that the Universe would have to have started expanding from somewhere.
Lemaitre originally called what we know refer to as the ‘Big Bang’ the ‘Primitive atom’. In the book “l’hypothese de l’atome primitif’ he narrates that the evolution of the universe was a kin to a “display of fireworks that has just ended”. Hence all we can now is to observe the smoke, the wisps and the ashes of the original explosion.
The rather spontaneous question now would be “but what came before the Big Bang?”. The writer here will not impose any religious or philosophical implication to the reader, but will keep the discussion within the realm of the scientific paradigm (that is a process of experimentation). Since no valid experiments about what came before the Big Bang, the question is like a dead one in science. And as such, to put it very concisely, the answer is that nobody knows. Even supposing one were to find out that ‘z’ came before the big Bang, the new question would be what came before ‘z’? And if someone were to find that ‘y’ caused ‘z’, then we would ask what came before ‘y’ and so forth. This leads to a typical situation known in logic as the ‘Infinite regress’- that is an unfortunate condition where no valid arguments can be made because each argument would require to be validate by infinely many arguments before.
Sadly, such are the daunting paradoxes that arise when our precarious minds try to venture within the deepest mysteries of our universe.
Cosmological principle: the Universe is homogenous and isotropic. Homogenous means that (considering large scales) the Universe’s average density of matter in all its places is about the same. Isotropic means that the Universe’s observers looking at the universe at different directions will not see any differences in the structure of the Universe. This implies that the Universe has no center and that there is no specific point where the Big Bang occurred because space expanded towards all directions.
Holyle used the baloon analogy in 1960.
If we were to think of an explosion then the explosion would be an explosion of space, rather than an explosion in space.
In Greek mythology Haepheaestus created robots to do work for him.
Pygmalion falls in love with his own sculpture (Galatea).