1. Albert Einstein: Known for the theory of relativity, which revolutionized our understanding of space, time, and gravity.
2. Isaac Newton: Formulated the laws of motion and universal gravitation, laying the foundation for classical mechanics.
3. Marie Curie: Pioneered research on radioactivity and discovered the elements polonium and radium. She was the first woman to win a Nobel Prize.
4. Charles Darwin: Developed the theory of evolution by natural selection, fundamentally changing how we view the development and diversity of life.
5. Galileo Galilei: Conducted pioneering observations of celestial bodies, which supported the Copernican theory and laid the groundwork for modern astronomy.
6. Michael Faraday: Made important discoveries in electromagnetism, including electromagnetic induction, which laid the foundation for many electrical technologies.
7. Nikola Tesla: Serbian-American inventor, engineer, and electrical researcher who contributed significantly to the design of the modern alternating current (AC) electrical system.
These are just a few examples, and there are countless other scientists who have made groundbreaking discoveries and advanced human knowledge. The selection of "7 Giant Scientists" would likely vary based on individual criteria and areas of interest within the scientific community.