I’m of the opinion that exchanging information is the only thing that separates us from the beasts. Books are the most amazing thing ever if you stop and take a look at them. Can you imagine passing round tablets or papyrus?
However, the internet has kind of surpassed books now. You have access to essentially the totality of human knowledge in an instant. That’s… amazing.
For science – the microscope! The whole field of science changed after the invention of the microscope because for the first time, scientists could look at things they thought were invisible – like bacteria and cells. Modern medicine wouldn’t have been possible without the microscope, and without modern medicine, most of us wouldn’t be here!