Answered on : 2024-01-24
1. **Definition**: Philosophiæ Naturalis Principia Mathematica, often called Principia, is a book by Isaac Newton explaining his laws of motion and the principles of natural philosophy[0].
2. **Significance**:
- **Scientific Milestone**: Regarded as a turning point in science, it's considered one of the most important scientific works ever published[0].
- **Foundation of Physics**: Newton's laws in Principia form the foundation of physics, contributing to contemporary physics, engineering, and technical practices[3].
3. **Relevance Today**: Newton's laws, outlined in Principia, remain relevant and are applied extensively in various scientific and engineering fields[3].