Most of these people were never called scientists
The word did not exist until 1833. At a meeting of the British Association, the philosopher William Whewell proposed it — built from science the way artist is built from art — because the people in the room needed a name for what they did and nobody liked the alternatives. It was mocked for decades as an ugly Americanism.
Before that they were natural philosophers, or simply men and women who happened to study things — often while employed as something else entirely, since almost nobody was paid to do research. GALILEO, NEWTON, BOYLE, HALLEY and GALEN all lived and died without the label. FARADAY was working when it was coined and reportedly disliked it. The job is a good deal older than the word, which is usually true of jobs.
Marie Curie's notebooks are still dangerous
CURIE handled radium daily for decades, carried tubes of it in her pockets and kept a glowing sample by her bed because she liked the look of it. Nobody knew. The illness that killed her in 1934 is now generally attributed to that exposure.
Her laboratory notebooks are held at the Bibliothèque nationale in Paris in lead-lined boxes, and anybody who wants to read them signs a waiver first. Radium-226 has a half-life of around 1,600 years, so the pages will still be radioactive well into the fourth millennium. She remains the only person to have won Nobel Prizes in two different sciences.
The name that is not in this grid
WATSON and CRICK are here for working out the structure of DNA in 1953. The photograph that showed them it was a double helix — Photo 51 — was taken by Rosalind Franklin, and they were shown it by a colleague without her knowledge or permission.
She died of ovarian cancer at 37, four years before the Nobel Prize was awarded, and the rules do not allow posthumous awards, so the question of whether she would have shared it has no clean answer. What is clear is that the discovery is usually told as two names when it needed at least three. It is a good habit, with any list of famous people, to ask who is missing from it.
Being wrong is most of the job
NEWTON spent more of his life on alchemy and biblical chronology than on physics, and was quietly certain he would be remembered for the latter. GALILEO was right that the Earth goes round the Sun and wrong about what causes tides, which he insisted was the Earth's motion sloshing the oceans. KEPLER arrived at his laws of planetary motion while trying to prove a theory about nested geometric solids that turned out to be nonsense.
This is not a failure of the people in this grid; it is how the thing works. A scientist publishes something checkable, other people check it, and most of it gets corrected. DARWIN, MENDEL, PASTEUR, EINSTEIN, BOHR, PLANCK, MAXWELL, FEYNMAN, HAWKING, COPERNICUS, HUBBLE, PAVLOV, TESLA and SAGAN are all in here for the parts that survived the checking.