What are the two principal thrusts in Physics?

Explanation

To answer the question regarding the two principal thrusts in Physics, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Principal Thrusts in Physics**:
- The principal thrusts in physics refer to the overarching goals or objectives that physicists aim to achieve in their research and understanding of the physical world.

2. **Identifying the Two Principal Thrusts**:
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