The Magnetic Field One of Nature's Great Mystries

If there is a current flowing in a wire then there will exist a magnetic field around it. Looks like the magnetic field and current are companions! What is this mystery?

The Speed of Light What is The Definition?

As it stands now the speed of light is defined in terms of miles per second, or measurement of length over measurement of time.
The problem there is no definition of length and time in the abstract sense.

Gravity one of Nature's Great Mysteries

Gravity! What nature wants to do? Why it does exist? Does nature want to do something?