TLDR on Cosmology

Ashwin Narayanan
2 min readMar 2, 2021

Got 10 minutes and curious how our universe got to where it is and who calls the shots (laws of nature)? read on

So how did it all begin?

  • The most common cosmological explanation is that our universe started from a singularity which is a fancy term for “extremely tiny thing ever”.
  • Then, there was a random disturbance in this extremely tiny thing (quantum fluctuation) which led to a big bang.
  • The big bang blew up the extremely tiny thing and created everything including space-time (which is the substrate in a way), matter including galaxies, stars, and eventually biology.
  • We don’t know what happened before the big bang or if that question even makes sense. Because we don’t know if ‘time’ is a local concept or more fundamental to the universe.
  • But for now, we can summarize that 14 billion years ago, our universe started with almost nothing, then something created a spark and the universe expanded and complexity exploded to give rise to physics, chemistry, biology, life, cognition, and curiosity.

Great, what about the laws of nature?

  • Where did the rules by which the universe operates come from? In short, Laws of Nature can be thought of as a set of mathematical axioms combined with the initial set of conditions our universe had.
  • E.g, the Pythagorean theorem is derived from the axioms of Euclidean geometry and will be invalid in a non-euclidean geometry (if space is curved).
  • Hence the axioms of our universe are a subset of a ‘set of all axioms’ and the initial conditions during the early stage of the big bang decided what subset of those axioms held true.
  • Had the initial conditions inside the singularity been different, a different set of axioms would have held true and we would have a different physics, different chemistry, and different biology.

Oh btw, we still don’t know what the majority of the universe is made of. physicists call them dark matter and dark energy.

I know you’re wondering, where does this majestic ‘set of all axioms’ live- don’t know. Ask a philosopher (Plato had some lead on this)

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