How did Eurasia separate and will it reconnect? Was it ever at all?

Answer 1

Separate from what?

I suppose that all of the Earth's land (in theory) was one big landmass at one time, but some scientists think that this happened millions of years ago.

If you buy into the "super-continent cycle" theory, the continents should all come back together millions of years from now.

----------------------edit--------------
Pangaea or Pangea (derived from Παγγαία, Greek meaning 'all earth') is the name given to the supercontinent that, according to the theory of plate tectonics, existed during the Paleozoic and Mesozoic eras about 250 million years ago, before each of the component continents were separated into their current configuration....

----------------edit2-----------
The supercontinent cycle describes the quasi-periodic aggregration and dispersal of Earth's continental crust. It is controversial whether Earth's budget of continental crust is increasing, decreasing, or remaining about constant, but it is agreed that this inventory is constantly being reconfigured. Continental collision makes fewer and larger continents while rifting makes more and smaller continents. The last supercontinent, Pangaea, formed about 300 million years ago. The previous supercontinent, Pannotia or Greater Gondwanaland, formed about 600 million years ago, and its dispersal formed the fragments that ultimately collided to form Pangaea. But beyond this the time span between supercontinents becomes more irregular...

Answer 2

Eurasia is not separate