Science is an imaginary world?

Why it doesn't matter if it is impossible take a photo of an atom, but know that they exist? How can we make such claim? Aren't we entering the imaginary world?

Paul Dirac said on that matter the following:

[…] the main object of physical science is not the provision of pictures, but is the formulation of laws governing phenomena and the application of these laws to the discovery of new phenomena. If a picture exists, so much the better; but whether a picture exists or not is a matter of only secondary importance. In the case of atomic phenomena no picture can be expected to exist in the usual sense of the word 'picture', by which is meant a model functioning essentially on classical lines. One may, however, extend the meaning of the word 'picture' to include any way of looking at the fundamental laws which makes their self-consistency obvious. With this extension, one may gradually acquire a picture of atomic phenomena by becoming familiar with the laws of the quantum theory.

There is nothing depressing out there. On the contrary, the Universe would be a boring place if could we visulaize/imagine everything in i