general relativity
Overall: Einstein was one of the most creative and intelligent figures in human history. During his lifetime he pioneered four fields of physics: special relativity, general relativity, cosmology, and unified field theory. He was one of the main founders of quantum theory and made significant contributions to molecular motion theory and quantum statistics theory.
Spatial conjecture and unified field theory
Einstein was the greatest scientist and thinker of the 20th century. His ideas on science and philosophy (philosophy of science, philosophy of society, philosophy of life) are insightful and extraordinary. Einstein's contributions to modern physics are unmatched, and he has been diligent in his scientific career, exploring the universal and constant laws of physics. His theory covers all the fundamental problems of nature, from the universe to subatomic particles. He revised the traditional concepts of time and space, energy, and matter. His theory of relativity not only impacted the classical theoretical system of physics since Newton, but also changed the traditional concept of space and time. Einstein ushered in a new era of modern science and technology and is recognized as the greatest physicist after Galileo and Newton.
Tagore
Tagore: Einstein is often referred to as a lonely man. The realm of mathematical imagination helps to free the spirit from the multitude of mundane objects, and in that sense I think he is indeed a lonely man. His philosophy can be called a transcendental materialism, which reaches the forefront of metaphysics, where entanglement with the world of the self can be completely severed. For me, science and art are manifestations of our nature, and they are of ultimate value above our biological needs.
Yang Zhenning: Of the three major contributions to physics in the 20th century, two and a half were made by Einstein.
Hawking: Over the past 100 years, the world has undergone unprecedented changes, not because of politics or economics, but because of science and technology – science and technology that come directly from advanced basic science research. No other scientist can represent the advancement of this science more than Einstein.
Einstein's old age
Li Xingmin: Einstein is another peak that stands in front of us. His thoughts are like a symbiotic mine with a very complete range and extreme taste, which contains rich spiritual treasures. Although many people of insight have carried out valuable exploration and excavation, as long as they change to a new perspective to explore, or dig deeper in the same place, there will often be unexpected discoveries and gains. You know, the wealth of Einstein's ideas seems to be inexhaustible.
Fang Zaiqing: Einstein was a great scientist who was well known to almost everyone but did not know very well; as a scientist, Einstein was undoubtedly the most influential person in the 20th century.
Isaacson: He was both human and detached, talented and a little confused. With an absent-minded and cynical sense of humor, Einstein wandered everywhere and made his home. He acted honest about flaws and faults, and sometimes (but not always) did indeed be as naïve as he seemed. He is concerned with the fate of mankind as a whole, but also with specific people. His preoccupation with cosmic truths and world issues makes him seem less concerned about what's at hand. No one should give up individual freedom for the sake of the state.