The 17th century was a pretty interesting time to be alive. They didn't have all this newfangled technology. They didn't have everything all mapped out. They were discovering and figuring things out all the time. This poem (like a lot of Donne's poems) draws on the popular scientific beliefs and discoveries, some of which were brand new, and some of which were holdovers from medieval times.
- Line 17: The "Indias of spice and mine" refer to India (in Asia) and the newly established West Indies. New and exotic products were being brought in daily on ships from these strange worlds, which made the world more accessible to folks like Donne, but also opened up new doors of discovery, making the world seem ever larger.
- Line 30: The bed becomes like the earth and the boundaries of the room form the sun's new and limited sphere in the poet's imagination.