CREATE TABLE table_26148 ("Copper Age" TEXT, "Chalcolithic  ( 4500 BC - 3300 BC ) " TEXT, "Early Chalcolithic" TEXT, "4500 BC - 4000 BC" TEXT, "Ubaid period in Mesopotamia" TEXT)

When middle assyrian empire is the ubaid period in mesopotamia what is the copper age?
SELECT "Copper Age" FROM table_26148 WHERE "Ubaid period in Mesopotamia" = 'Middle Assyrian Empire'
SELECT "Copper Age" FROM "table_26148" WHERE "Ubaid period in Mesopotamia" = 'Middle Assyrian Empire'