I can provide some general information about how these individuals are often described.
Isaac Newton (1643-1727) is commonly depicted as having a serious and thoughtful countenance. He had a prominent nose and deep-set eyes. Although beauty is subjective, his appearance is generally not described as conventionally attractive.
Leonardo da Vinci (1452-1519) is often portrayed as having a striking and charismatic appearance. He is regarded as a Renaissance man, highly talented in various fields, including art, science, and engineering. While he may be considered attractive based on historical accounts, it's important to remember that personal preferences regarding physical attractiveness can vary.
Albert Einstein (1879-1955) was known more for his scientific brilliance than his physical appearance. He had a distinctive appearance with unruly hair, a bushy mustache, and a somewhat disheveled look. Einstein's image has become iconic and recognizable, but he may not be traditionally seen as handsome in a conventional sense.
It's worth noting that judgments of attractiveness are subjective and influenced by cultural and personal preferences. Therefore, opinions on the physical appearance of historical figures like Newton, da Vinci, and Einstein may vary.