Radio waves, like light waves and all other forms of electromagnetic radiation, normally travel in straight lines.
Obviously this does not happen all the time, because long - distance communication depends on radio waves traveling beyond the horizon.
How radio waves propagate in other than straight-line paths is a complicated subject, but one that need not be a mystery.
We provide basic understanding of the principles of electromagnetic radiation, the structure of the Earth's atmosphere and solar-terrestrial interactions necessary for a working knowledge of radio propagation.
More detailed discussions and the underlying mathematics of radio propagation physics can be made available in a classroom format.
The Sun, being the largest engine in our solar system, has a great effect on propagation as its "exhaust" interacts with our Earth's magnetic field.
A rudimentary knowledge of sunspots, solar flares and mass ejections will help your take advantage of these effects to understand this plight. A good basic understanding of this can be had from our presentations.