When determining what goes into the background information of an educated person, it would be useful to distinguish between general knowledge and specialized knowledge.
We expect a physicist to know that in the quark theory, the only elementary particles are quarks and leptons, but it is hardly necessary for a lawyer, doctor, or sociologist to have this information, and hence we would treat it as specialized knowledge.
As a sample of the leading ideas in the physical sciences in modern times, consider the following: The earth is a spherical object that spins around its axis and revolves around the sun.
Neither the earth nor the sun is at the centre of the universe.
The universe came to exist in a big bang several billions of years ago, and it has been expanding ever since. All matter is composed of molecules which are formed out of atoms.
Atoms are composed of smaller particles some of which have positive and negative electric charges, whirling about in empty space.
The concept of the functional asymmetry of the left and right brains was not part of human knowledge in the seventeenth century, but today it is part of not only the knowledge of the specialist, but also the lay educated person.
A few centuries ago, specialists and non-specialists alike believed that the sun revolves around the earth.
The requirement articulated above may give the misleading impression that the information that an educated person should have is what is important for practical matters.
Given that ideas about the expanding universe and the evolution of the species are not relevant for practical decisions in life, is it necessary for an educated person to be familiar with them?