====== Spacetime atoms ======

The concept of (seemingly) smooth Einsteinian spacetime (three physical dimensions inextricably bound together with time as the fourth) has not yet been unified with the theoretical and observable 'granularity' of quantum physics.

As a means of integrating these two seemingly incompatible paradigms, the idea of Spacetime Atoms (i.e. discrete particles of spacetime) was introduced in the early 2000s.

>__We  do  not  have  a  successful  theory  of  spacetime  that coherently incorporates the quantum nature of the physical world, so we do not  yet  know  the  nature  of  the  deep  structure  of  spacetime. __  Some  of  the observational  facts  on  which  the  new  theory  will  be  built  may,  therefore, now be only roughly communicable and our sense-experience of the passage of time may be an example of such a fact.  In the last decades, however, progress on one approach to finding a theory of quantum spacetime – or quantum gravity as it is usually called – affords us  a  forward  look  at  how  the  passage  of  time  may  eventually  find  a  place in science."\\ \\ See:[[https://arxiv.org/pdf/1405.3492.pdf|'The birth of spacetime atoms as the passage of time' ]] (2014) by [[http://www.imperial.ac.uk/people/f.dowker|Professor Fay Dowker]], Blackett Laboratory, Imperial College, UK.

Note that the spacetime atom theory, along with //causal set theory// (see paper above) supports a cosmological effect analogous to so-called [[content:physics:cosmology:dark_energy|dark energy]], and also asserts that it had a //negative// value at the 'beginning' of the universe - thus accounting for the (measured) acceleration of the expansion of the universe.

//Further info:// A [[http://www.bbc.co.uk/programmes/b08pdzxj|BBC radio (podcast) interview with professor Dowker]], 2107.

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Also see: [[content:physics:cosmology:times_arrow|Arrow of Time]]