cellular differentiation

In  science of embryology, it can not explain precisely how a single cell type differentiates to many types of specialised cells,i.e liver cells, brain cells so what really happen is not clear until now
how a single cell explodes-- like the big bang theory told us about the creation of universe--
to many differentiated forms of cells to create -like stars and planets-differentiated ,specialised organs
and they do not stop at the stage but the organs still grow and differentiate more and cells make that action and stop the other as long as there is time to do that, and the question rise here
what kind of planned or random energy makes that development ,it is not only hidden in this small structure which is the cell but it is an energy framework the at which the cell got in touch within and behave like this or that in this energy framework according to the state of energy at that site of the framework . so the cell  divide in various direction according to this framework .and then time is also crucial ,so when a cell in certain site came in contact with a certain area in that energy framework at a certain time ,a  certain gene will be triggered to do something different inside the cell which make the cell differentiate to a certain type and not the other.
so it is something there outside the cell to drive the cell to do so or not the other 
thank you. plz, dear scientists investigate that 
thank you