Every now and then we like to bring you a compilation of some of our older videos and the episodes in our "Great Minds" series are some of our favorites. There are too many brilliant scientists to share with you in just one compilation, so today we've decided to focus on five scientists who are undervalued during their lifetimes or who are nearly forgotten and often totally overlooked today.

First up, a scientist who is so ahead of his time that he was publicly ridiculed for understanding how the Earth fits together. He was right by the way.

Fact is, the whole of scientific history is full of people who were totally right and everybody thought they were wrong. Today, I want to tell you about one of those people. He changed the way that we look at the Earth.

Alfred Wegener was born in 1880 in Germany. He was one of those rare people that's just good at and interested in a lot of different things. He got his degree in astronomy but went into the relatively young field of meteorology, where he pioneered the use of balloons to track air currents and went on expeditions to Greenland to study polar weather, at which he was totally badass. He spent winters in a hut drilling ice cores, and he also made the longest crossing of Greenland's ice cap on foot. For the win.

But he was also interested in other stuff, including geophysics, which is why he got totally obsessed with this. He couldn't help but notice, like some schoolchildren will, that Africa and South America almost look like puzzle pieces. Sure, they're thousands of miles apart, but they really look like they fit together. Of course, other people picked up on this - like I said, you probably did around 4th grade.

But another one of Wegener's great qualities is that he wasn't afraid to ask the stupid-sounding questions, so he just started asking people, "Continents moving. Is that a thing? And if it was a thing, how would we know that it was a thing?"

And because he was a voraciously curious guy, he was looking for the answers to those questions in all kinds of places, and guess what? 

He found out that fossils of the same plant species had been found on both sides of the Atlantic, he discovered that the geology of the Appalachians was almost identical to that of the Scottish highlands, and he learned that distinctive rock strata found in South Africa were the same as in parts of Brazil, almost as if the continents, I don't know, drifted.

Finally, in 1914, while laid up in a military hospital bed during World War I, he pieced together his theory: that all of the land masses on Earth used to be part of a single continent called the Urkontinent, or the Origin of All Continents, and over time the masses moved, scattering fossils and rock patterns around the world. The next year, he published his research in a book, The Origin of Continents and Oceans, and the scientific community responded. [laugh track] Aw.

They totally freaked out on him. Geologists dismissed him as a glorified weatherman - they held entire conferences devoted to debunking his book. Even his father-in-law, who was the most prestigious meteorologist in Germany, told him he should have probably stuck to the balloon thing.

The conventional wisdom of the time was that continents used to be connected by land bridges that later collapsed or were covered by the oceans, and that's how they explained stuff like matching plant fossils.

Of course, Wegener didn't do himself a lot of favors by being actually pretty wrong about a lot of stuff. Like, he could not explain, he had no idea how the continents actually drifted. He thought they were just plowing through the Earth's crust like an icebreaker. He also suggested that the centrifugal force of the Earth's rotation was causing the continents to drift, which is just totally kinda crazy.

Yeah so, the damage had been done and everybody in Germany thought he was total crazy person. No one would hire him to teach anywhere; the only job he could get was as a meteorology professor in Austria.

And that is where he was in 1930, where he decided he wanted to go back to Greenland to set up some weather stations. And during a weeks-long excursion to bring supplies to one of these remote stations, Alfred Wegener disappeared in a blizzard. His body was found the following spring, and it is still there today, buried in the ice.

I know, right? Because he was right! I mean, not about everything, but about a lot of stuff! And at the time of his death, people were just starting to understand what the floor of the ocean actually looked like, and decades later that research showed that there were giant rifts and mountain ranges under the oceans, and those were the boundaries where continental plates were pulling away from each other or crashing against each other. It wasn't until the 1960s that plate tectonics became something widely accepted by the scientific community.

Though he wasn't vindicated during his lifetime, he is now respected as one of the greatest scientists of his era, and you can pay your respects to him through one of the many things in science that are now named after him, including the Alfred Wegener Institute for Polar and Marine Research or the Wegener Peninsula of Greenland, where he died, or craters on both the moon and Mars.

So, thanks, Herr Doctor Wegener.

Sometimes scientists aren't accussed of being wrong. Instead, their research is stolen while they are called emotional and basically just stupid. Unfortunately, that was the case for one of the scientists who discovered the shape of DNA - Rosalind Franklin. 

When there are scientific discoveries, everybody wins, but also sometimes there are a few losers. But few scientists have lost out more famously than the woman who helped discover the structure of DNA, Rosalind Franklin. For that discovery, almost everybody knew the names of the men who got most of the credit, James Watson and Francis Crick, and what people did know about Franklin's contributions they knew mostly from Watson's 1968 book The Double Helix.

In it, Watson describes Franklin as "belligerent, emotional, and unable to interpret her own data". Forget for the moment the unpleasantness of insulting a woman who had been dead for ten years at the time of the publication of Watson's book, or that he repeatedly refers to her as "Rosie", a name she never used. The fact is, had she been alive in 1962 when Watson, Crick, and Maurice Wilkins were awarded the Nobel Prize for their discovery, many believe that Franklin would have, or at least, should have, shared the stage with them.

Born in 1920 in London to wealthy parents who stressed the value of education, Franklin studied physics and chemistry at Cambridge University. She earner her PhD with a thesis on the porosity of coal, before moving to France in 1946. There, she became an expert in x-ray crystallography, a skill that would prove invaluable when she returned to England in 1951 for a job at King's College.

Her arrival there coincided with a race among scientists at labs on two continents to be the first to deduce the structure of DNA. Franklin and Wilkins worked at the same lab, leading separate research groups, but their work inevitably overlapped as they worked the DNA puzzle. Many scientists then believed DNA had a helical structure like a corkscrew, but it hadn't been confirmed, and there was disagreement over whether it was a single or double or triple helix.

Using x-ray diffraction techniques on crystallized fibers of DNA that involved exposures lasting hundreds of hours, Franklin was able to separate patterns that had baffled other researchers. In early 1952, one particular pattern that she would label as "Photograph 51" clearly showed two black stripes, the first real evidence of a helix with multiple chains.

The now-famous x-ray portrait not only confirmed the double helical shape but also hinted at its manner of replication. Franklin continued her analysis, unaware that at nearby Cavendish Laboratory in Cambridge, Watson and Crick were working on their own models but still unable to confirm the helical structure. Though Franklin had yet to publish her images, Watson got a peek thanks to Wilkins, who shared the photograph with his rival in early 1953 without the knowledge or permission of Franklin.

Watson wrote of the photo, "The instant that I saw the picture, my mouth fell open and my pulse began to race." Less than two months later, using their own data, Watson and Crick announced to the world that they had discovered the structure of the double helix. Franklin's analysis and images would be published in the same 1953 issue of Nature, in which Watson and Crick announced their findings, but by that point it was a postscript.

Franklin left King's College in 1953 to continue her work at Birkbeck College in London. While traveling in the US on business in 1956, she discovered a lump on her abdomen that turned out to be ovarian cancer. She died less than two years later, at the age of 37.

Tragically, her pioneering work with x-rays may have lead to her early death. Like many scientists of her time, she rarely took precautions to protect herself from radiation over hundreds of hours spent taking images. No matter what anyone said or wrote about her, the world deserved more than 37 years of Rosalind Franklin. 

He may not be a classic household name, but this next scientist made what Albert Einstein considered one of the greatest discoveries of the 20th-century.  Alright, quick, who are the three greatest and most influential physicists who ever lived?  Isaac Newton, Albert Einstein, and...it's okay if you couldn't think of a third one.  Not a lot of people could, but most physicists would probably agree that a lot of modern physics owes more to a man named James Clerk Maxwell than to anyone else who ever lived.  

Maxwell was born in 1831 in Edinburgh, Scotland to a wealthy Scottish family.  He published his first academic paper, a new method of mechanically plotting mathematical curvies using a piece of twine, at the age of 14.  So yeah, he was an early bloomer.  By age 25, he was appointed chair of Natural Philosophy at University of Aberdeen, 'Natural Philosophy' being what they called physics back then, meaning that he wasn't just a professor, he was the head of the entire department at 25.  Within the next couple of years, he made a discovery that you probably learned about in grade school. 

He showed that Saturn's rings were made of snow particles swirling around the planet together.  Before this, nobody had any idea what the rings of Saturn were made of.  Scientists thought they might have been solid, but if they were, then the rings should have been banging into each other or even into the planet, and if they were a liquid, why wouldn't they break apart?  Well, using math, Maxwell showed that the only way that the rings of Saturn could remain relatively stable was if they were made of lots and lots of tiny particles, each one acting as an independent satellite orbiting the planet.  All the tiny satellites in the same ring had to be moving in the same direction and at the same speed or else they would crash into each other and the whole system would fly apart.  

Maxwell also predicted that the rings would spread apart gradually until they disappeared because of the effects of Saturn's gravity and that is happening, but until then, we have rings.  More than 100 years later, the Voyager probes would fly by Saturn and send back some pictures proving that he was totally right.

In 1816, Maxwell was laid off when his college merged with another college and the other chair of Natural Philosophy got his job.  Can you imagine being the guy who made James Clerk Maxwell redundant?  That would be like if two karaoke teams merged together and Ariana Grande got bumped for me.  After that, he took a professorship with King's College in London, where he made what scientists like Albert Einstein, Richard Fineman, and Max Plank considered the greatest discovery of the 20th century.

He published a set of equations now known as Maxwell's Equations and proved that light, electricity, and magnetism all came from the same force, what we now call the electromagnetic force.  This is still the greatest leap forward anyone has ever made in creating a grand unified theory of physics.  These days, we know that electricity is what you get when electrons move from one place to another, and magnetism is what you get when electrons spin in the same direction.  We also know that light is what you get when electrons move from a higher to a lower energy state.  When they do that, they release a photon.  All of these are examples of electromagnetic force in action.  Basically, it's how electrons shape the world around us, but when Maxwell published his equations, electrons wouldn't be discovered for another 30 years.

He figured out that all of these things were connected by observing how magnets could affect currents and currents could affect magnets.  He theorized that they were all doing that with electromagnetic waves, which spread out through space from their point of origin, potentially forever.  He measured how fast these waves were moving and found that they traveled at the speed of light, and since nothing is as fast as light, that meant electromagnetic waves and light must actually be different forms of the same thing.  

The idea that energy could travel through space in waves blew away the old Newtonian idea of physics, where gravity was the only thing that could affect objects at a distance and it paved the way for the development of quantum mechanics plus like everything Einstein ever did, especially once we started figuring out that sub-atomic particles were a thing.  

Without Maxwell's understanding of electromagnetism, there also wouldn't be any radio, television, or microwave ovens.  Maxwell of course made a lot of other discoveries, too.  For one thing, he was the founder of the kinetic theory of gases.  This theory led to the new field of statistical physics, which introduced probability to the science of very small things and was the precursor to quantum mechanics, and he produced the first color photographs in the world after he realized that the human eye only perceives three colors: red, blue, and green.  He created red, blue, and green filtered images and layered them together to make a colored photo of a tartan ribbon.  This trichromatic process was the forerunner to all modern color photography.  

Maxwell died of abdominal cancer in 1879 at the age of 48, but he'd already transformed the field of physics forever.  So who knows, if he'd lived another 20 or 30 years, maybe we'd have floating cities and flying cars by now.

In her time, Henrietta Swan Leavitt couldn't get hired to do the astronomy work she'd studied in school because she was a woman, so she volunteered at the Harvard College Observatory instead, and still managed to contribute discoveries that revolutionized astronomy.  

How far away is the Andromeda Galaxy?  What's the diameter of the Milky Way?  How do we even know that the universe is expanding?  These are questions that give me a headache, but we can answer them because we can measure the distance to stars.  Astronomers do it all the time in a bunch of different ways, but we first learned how to do it only 100 years ago from a great mind who's as unrecognized now as she was in her own time, Henrietta Swan Leavitt.

She was born in Massachusetts in 1868 and would attend what would later be known as Radcliffe College where she studied and excelled at astronomy, but after graduating in 1893, she couldn't turn her skill into a paying career so she gave it away for free.

She volunteered at Harvard College Observatory working in an office full of women who were known as computers, cataloguers who sorted, analyzed, and classified hundreds of thousands of photographs of the sky taken all over the world.  It was tedious work, but for many women astronomers, it was the only work available.  Women couldn't direct their own research at the time and they weren't even allowed to operate Harvard's telescopes.  In fact, women were only allowed to serve as computers because the observatory couldn't find male scientists willing to do the work.

So Harvard's "computer office" became a hothouse of some of America's greatest, if least known, astronomical minds.  One of Leavitt's colleagues, for instance, was Annie Jump Cannon, who devised the spectral class system we still use to classify stars today.  Leavitt, however, focused on stars in a cluster called the small Magellanic cloud.  She was tasked with cataloguing a class of stars known as cepheid variables, stars that go through cycles of varying brightness over regular periods of time.  

Through her computing, Leavitt identified 2400 new cepheids, doubling the number known to science, but more importantly, in 1912, she made a discovery that would revolutionize astronomy.  She found that the largest cepheid stars in the cloud also had the longest periods of peak luminosity.  The bigger they were, the longer they were at their brightest.  The correlation was so precise that Leavitt could measure a star's size and immediately calculate its true luminosity.  Now, this was a huge deal, because until then, there was no way of knowing whether a dim looking star was dim because it was just far away or because it was actually dim, but since the stars she studied were all about the same distance from Earth, she had discovered a kind of yardstick.  You could pick a variable star anywhere in the sky, figure out its true luminosity using Leavitt's techniques, and use that to calculate its distance.  

This changed astronomy forever.  Before Leavitt, astronomers could only measure stars about 100 light years away.  Thanks to her discovery, what is now known as Leavitt's Law was used to measure cepheid stars millions of light years away.  

It helped settle the debate about whether other galaxies existed beyond our own and it was ultimately used by Edwin Hubble to determine that the universe was expanding.  Of course, Leavitt couldn't do any of this stuff herself, because she wasn't allowed to touch the menfolks' telescopes, but Hubble later said that Leavitt deserved the Nobel Prize for her work, and he wasn't alone.  In 1923, Swedish physicists asked the Harvard Observatory for Leavitt's research to nominate her for the Nobel Prize in Physics, but unfortunately, Leavitt had died of cancer three years earlier at the age of 53, and though women can get Noble Prizes now, dead people cannot.  That's just one of their rules.

So thank you to Henrietta Leavitt and all the other "human computers" who didn't get space telescopes named after them for helping us understand how big and how awesome the universe is.

Let's end this collection of overlooked scientists on a high note.  Way before computers even existed, Ada Lovelace was arguably the first computer programmer, and while she wasn't always recognized in her lifetime, her mentor, the father of the computer, thought the world of her.  

Her father was one of Britain's greatest poets but her mother, hoping to steer her away from those "dangerous poetic tendencies" made sure she received tutoring in math and music, and it worked.  Today, Ada Lovelace is considered by many to be the first author of a computer program, despite living a century before the invention of the modern computer.

As long ago as the 1840s, Lovelace envisioned machines that could manipulate symbols instead of just numbers, and while there are some who would debate her title as the world's first programmer, there's no denying her influence as a gifted mathematician who was also way, way, way, way, way, way ahead of her time.  Her father was the poet Lord Byron and while he wasn't around for much of his daughter's life, he too encouraged her to pursue a career in science.  In 1833, young Ada was introduced to Charles Babbage, a mathematics professor at Cambridge University who today is commonly recognized as the father of the computer.

Ada was 17.  Babbage was 42, but intellectually, they were peers.  Ada soon met and married William King, the count of Lovelace, and took on all the stuff what went with being a nobleman wife and mother, but she continued to correspond with Babbage for the next two decades.  Babbage's most notable invention was the analytical engine, a brass and iron steam powered machine he first envisioned in 1837.  It included a central processing unit called the mill, and expandable memory, which he called the store. 

Controlled by punched cards which could be used to input data, the engine could be programmed to carry out different mathematical operations.  In 1843, Babbage asked Ada Lovelace to translate a description of his engine written by an Italian mathematician.  Over the next nine months, Lovelace did just that, but also appended her own set of notes, which ended up being three times longer than the actual translation.  They included some of Babbage's own calculations, at least some of which she found errors in and corrected, but to demonstrate the machine's possible applications, she also described how it could be used to calculate an arcane brain teasing sequence of figures known as Bernoulli numbers.  She proved it by diagramming the computations that the analytical engine would make, which, believe it or not, looked like this.  Essentially, she had written a computer algorithm.  She also speculated that the device might be used beyond numbers and could be used to manipulate anything within a fixed set of rules.  She said it could be used for both practical and scientific purposes and it might one day compose elaborate pieces of music of any complexity or extent, basically all the stuff that we use computers for today.

While the analytical engine was never built, Lovelace's translation was published and well-received, earning her fans in Britain's scientific community, like pioneering electrochemist Michael Faraday.  In 1852, at the age of 36, Lovelace died of cancer.  It wasn't until 101 years later that her work was republished, just as people were starting to actually build the computers that she envisioned and it became clear how prescient she was.  

Lovelace liked to call herself "an analyst and metaphysician", but Babbage called her "the enchantress of numbers".  

We owe a great many debts to these five scientists and we cannot thank them enough and I want to thank you as well for watching this compilation of great minds.  If you have a compilation idea for us to do in the future, please let us know in the comments and if you want more SciShow, there's another one every day here at youtube.com/scishow.