There are no "air miles" between England and Scotland because both are constituent countries of the United Kingdom. Domestic flights (e.g., London Heathrow → Edinburgh or Glasgow) operate entirely within UK sovereign airspace.
Typical domestic flight distances:
These are domestic sectors—no passport, no customs, no international air miles accrual (unless your frequent-flyer program counts domestic segments).
For overland travel: train (4.5–5.5h London–Edinburgh) or drive (~400 miles, 7–8h) are popular alternatives.