Hedy Lamarr, she invented the method of frequency hopping that allowed for allied torpedo's. Because she was an actress no one took her seriously and it wasn't adopted until the 1960's, today it makes cell phones and Bluetooth possible.

Charles Darwin (a lovely man, apparently), Carl Sagan, Richard Dawkins.

Dr. Bunsen Honeydew. ?

A few of my favorites: Carl Sagan (great scientist, educator, and communicator), Richard Feynman (brilliant, yet maintained a remarkably full, balanced life), Marie Curie (sacrificed her health for the sake of her important research), Nikola Tesla (a true visionary who understood the world in ways we're still grappling with).

So Many...
Hawkin is way up there. Darwin, Einstein, Turing, Curie, Tesla... the list keeps growing.
Brian Cox has been mentioned and I adore him. He's got this way of explaining complex concepts without dumming them down. I watch and rewatch his talks...
I would also include Brian Green for similar reasons. He's a pretty dynamic person and is a great conveyor of ideas.
Can't forget Roberta Bondar - Absolutely delightful and inspiring woman, (Astronaut/Neurologist/Photographer) whom I had the pleasure of meeting not long ago.

Hypatia, a female Greek philosopher
Gallelio who first looked at the heavens with a telescope.
Michael Faraday, who was born a pesant and became a world renoun scientist and invented the electric motor and generator.
Sir Issac Newton who invented calculus to understand how an apple falls.
Henrietta Swan Leavitt who discovered how Cepheid variable stars can be used to measure astronomical distances.
Cecilia Helena Payne-Gaposchkin who discovered how to measure the kinds of elements in stars and the amounts of them.
Einstein
Fritz Zwicky discovered dark matter in 1933.
Isaac Aisamov who wrote science texts and other books that span 10 of the 11 major categories in the card catalogue numbering system.
Hawking
Jared Diamond Guns, Germs, and Steel: The Fates of Human Societies.
And others.

British physicist Brian Cox became a household name in the U.K. in less than a decade, thanks to his accessible explanations of the universe in TV and radio shows, books and public appearances.Love his style nd his band

Stephen Hawking (1942– ): His books’ titles suggest the breadth and boldness of his ideas: The Universe in a Nutshell, The Theory of Everything. “My goal is simple,” he has said. “It is a complete understanding of the universe, why it is as it is and why it exists at all.” he was just genius

Richard Dawkins (1941– ): The biologist, a charismatic speaker, first gained public notoriety in 1976 with his book The Selfish Gene, one of his many works on evolution. Love reading his books reading The God Delusion

I could list over 100 but I'll just include the ones who I think affected my knowlege base the most. Tesla, Newton, Darwin, Einstein, Galilleo, Higgs, Curie,Turing, Planck, Bohr, Feynman, Hawking, Maxwell, Shrodinger, Heisenberg, Dawkins, and Guth.

Richard Feynman

I will always be hot for Tesla

They say science eradicated polio. The first polio vaccine was the inactivated polio vaccine. It was developed by Jonas Salk and came into use in 1955. The oral polio vaccine was developed by Albert Sabin and came into commercial use in 1961. Cases due to wild poliovirus have decreased by over 99% since 1988, from an estimated 350 000 cases then, to 22 reported cases in 2017. As a result of the global effort to eradicate the disease, more than 16 million people have been saved from paralysis.

Charles Darwin, Marie Curie, and Jared Diamond. I'm mostly a biosciences geek.

Neil degrasse Tyson, Stephen Hawking, Lawrence Krauss.

Bill Nye, Einstein, Tesla, Salk, Neil Degrasse Tyson, etc.

So many to list obviously among them the greats Sir Isaac Newton, Albert Einstein, Carl Sagan and the list goes on. I would have to say Bill Nye , Michio Kaku and Lawrence Krauss. But my two favorites are Michelle Thaller and Janna Levin.

Wilhelm Reich knew the score when it came to politics, sex, and the consequences of repressive human cultures. his later work DID get a bit wacky, but his scientific intuitions were proved to be often correct. the o n l y victim of US Government mandated book burning - 'freedom', etc..

Tesla
Dawkins
Diamond

Darwin has to be top of my list. How he shook the world !! and still is. That is what I call "science changes all".

Carl Sagan, Bill Nye, and Neil Tyson have made signicant contributions in the expression of rationality.

I ispired by marie curie and stephen hawkings.

dawkins is an asshole and terrible thought leadership for agnostics. and has no impact on the scientific community compared to his views on atheism.

einstein was brilliant as was hawking. hawking at least understood the importance of bringing people together with his works not alienating them which is exactly what dawkins does.

carl sagan was a humanist and in the same school as hawking.

Bill Nye the Science Guy!

Sam Harris, Elon Musk, Carl Sagan, Richard Dawkins, Jane Goodall, Alice Roberts, Neil DeGrasse Tyson, Bill Nye, etc...

Oppenheimer, for being smart enough to open pandoras box and smart enough to wish he hadn't. Plus going all hindu was neat.

So many choices. All our knowledge is built on the shoulders of giants (even if the original quote was a bit of bastardry).