extra dimensions

In  everyday life, we experience three spatial dimensions, and a fourth dimension of time. How could there be more? Einstein’s general theory of relativity tells us that space can expand, contract, and bend. Now if one dimension were to contract to a size smaller than an atom, it would be hidden from our view. If we could look on a small enough scale, that hidden dimension might become visible again. 

CERN research center in Geneva, Switzerland 

Well, it turns out that we do not really know yet how many dimensions our world has.One way of revealing extra dimensions would be through the production of “microscopic black holes” in a super accelerator eg CERN.
https://www.youtube.com/watch?v=E9SMwSrJElI