May 25 – Let’s Work

Today’s factismal: Marie Curie was awarded her PhD 113 years ago today; she would win her first Nobel prize within the year.

To many scientists, the happiest day of their lives is the day when they finally receive their PhD. Short for “Doctor of Philosophy”, the degree shows that the person has made at least one original contribution to their field. In the case of Marie Curie, that is a bit of an understatement; Marie Curie had been making contributions to the fields of chemistry for more than a decade before getting her PhD in 1903. And, unlike the typical graduate student, Marie Curie’s contributions were important enough that, along with her two collaborators, she was awarded the Nobel prize for Chemistry in 1903.

Marie Curie, discovering yet another element

Marie Curie, discovering yet another element

As is the case with most PhD students, Marie Curie’s PhD actually begins with something that her advisor thought was odd but didn’t have enough time to investigate himself. Marie’s advisor was Henri Becquerel who was investigating X-rays. At the time, all that anyone knew was that uranium could produce an image on a photographic plate even when the plate was covered in paper to prevent all light from getting through. Most scientists thought it was a form of phosphorescence; that is, that the uranium somehow transformed visible light into a different type of light. But Becquerel had discovered that uranium didn’t need visible light to produce the “X-rays” that made the image. So he tossed the problem to Marie Curie and let her work on it.

The photograph Becquerel "took" using uranium

The photograph Becquerel “took” using uranium

The first thing that she did was invent a name for the process by which uranium produced X-rays; she called it radioactivity for “radiation activity”. Using sensitive instruments, she was able to show that the amount of radioactivity depended only on the amount of uranium. Based on that, she hypothesized that the uranium atoms themselves must be breaking down. At the time, that was an incredible idea as atoms had been thought of as indivisible for more than 2,000 years. Nevertheless, Marie Curie was soon shown to be right and was awarded the 1903 Nobel Prize in Physics, along with Henri Becquerel and Pierre Curie.

Marie at work with her husband. That lab coat she is wearing was her wedding gown.

Marie at work with her husband. That lab coat she is wearing was her wedding gown.

She then began trying to isolate the part of the uranium that created the radioactivity. Working with her husband and her advisor, Marie Curie discovered radium (named for the radioactivity it generated)  and polonium (named for Marie Curie’s beloved Poland) Indeed, it was the radioactivity of polonium and radium that allowed Marie Curie to isolate them from uranium. The new elements were so radioactive that they have made her laboratory notebooks too dangerous to handle even now. Because she had been the driving force behind the discoveries, the 1911 Nobel Prize in Chemistry was given to Marie Curie alone.

A page from Marie Curie's notebooks

A page from Marie Curie’s notebooks

Unfortunately, Marie, Pierre, and Henri were awarded another prize as well – radiation poisoning. Because they didn’t understand the dangers associated with radioactivity, all three of them ended up with severe radiation burns; it is likely that their exposure to radioactive elements contributed to the deaths of Becquerel and Marie.

Their discovery of radioactivity led to a new theory of the universe, one which is being tested right now in “atom smashers” across the globe. If you would like to help physicists with their research by donating unused time on your home computer, then why not join LHC@home?

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