Acids are perhaps the first chemicals that humans recognize. They readily react to most materials, and the result of those reactions would appear magical. Although at first they became the essential tools of alchemists, they provide much of the answers in explaining the world in less mystical terms.

This article will deliver the story of how this transition occurred. 

In our last article on philosophy, we discussed the Scientific Method, that is, how we know the thing we know. In this article we ask a different question: 'why'. Science moves forward for a reason; at times out of necessity to solve a real-world problem, at others just for the joy of discovery. But a deeper answer comes in the form of a philosophical question of being.

Plato, the ancient Greek philosopher, attempts to illustrate this in his famous allegory: the Cave

Contrary to what you may believe after reading Part 4, classical physics never went obsolete. It simply could not be used answer certain questions that had emerged out of late 19th century discoveries. See it like mathematics, you can't possible solve a multi-variable differential problem with only simple arithmetics, you need calculus for that.

And similar to calculus, modern physics became more esoteric and mathematically abstract. But we'll try our best to simplify it.

In mathematics, it was always assumed that everything is based on our rational understanding of logic and common sense. Unlike physics, which can get extremely esoteric, mathematics limits itself how abstract our understanding of logic can get.

But once in a while there are those who cross over that limit, into fields that borders on pseudoscience such as numerology. Gerge Cantor was such a person.

One of the oldest engineering problems of humanity is how to get to the other side of a river, gorge or any particular gap-based obstacle. Needless to say one of the oldest professions out there is therefore the humble engineer, a job with probably the most overlooked impact to our lives.

This article wouldn't explain everything involved in bridge-building, but it explains enough to that the next time you came across a civil engineer you might get an idea of how he or she thinks in terms of problem solving.