We define time by the rate at which physical processes (i.e. clocks) tick. With atoms for example we can define time by their energy transition rates such as in atomic clocks. But, what before atoms existed? Current cosmology theories make statements such as that '0.5 seconds after the Big Bang the universe was like this or like that' but how does time get 'measured' (i.e. defined) for such early epochs of the universe when no atomic processes existed yet? And a related question about 'Universal Time'. Such cosmological statements need to be expressed in an observer-independent frame of reference, that is 'in universal time'. Since special relativity tells us that the rate of passage of time is observer-dependent, how is universal time calculated so that we can make cosmological statements such as '3 minutes after the Big Bang...'? who's 3 minutes?