If I let him get going he would talk all day about physical principles.
This is a basic view of the physical principles involved.
What is the one basic physical principle that makes a photocopier work?
Yet all seek to use basic physical principles to increase safety.
In any event, there are certainly places where faith, not physical principles, is the ruler.
They have found some of the proposed weapons may not even be based on sound physical principles.
In the 1940s, models were first derived from basic physical principles.
While we cannot build one today, it violates no physical principles.
In sailing, the physical principles involved are the same as for aircraft.
The required drive forces for the mirror movement can be provided by various physical principles.