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The mathematician Marjorie Lee Browne, whose work focused on linear algebra and the properties of classical groups, was born in 1914. She was one of the first African-American women to earn a PhD in mathematics from a US university.

Epidemiology pioneer John Snow, who doubted the prevailing miasma theory for the spread of a cholera outbreak in London, traced infections and spoke to locals to pinpoint a public water pump as the source. He removed its handle in 1854, helping put an end to the outbreak.

You can see the famous “ghost map” (which was made later) of the outbreak here:
It's a foundational document of data visualization, zeroing in on the pump as the culprit.

Physicist James Van Allen was born in 1914. His 1958 satellite experiments (Explorer 1 and 3, Pioneer 3) revealed donut shaped "radiation belts" where charged particles captured from the solar wind are trapped by Earth’s magnetic field.

He was an early advocate for scientific experiments on satellites and rockets: first with captured V-2 rockets after the war, then rocket-assisted balloons dubbed “rockoons“, and finally satellites launched by the US space program.

Images: AAS, NASA

Congratulations to Prof Dame Jocelyn Bell Burnell on receiving the Breakthrough Prize in Physics for her 1967 discovered of pulsars.

And congratulations to the founders and judges of the Breakthrough Prize for doing what the Nobel Committee wouldn’t.

She’s donating the prize money to support women, under-represented minorities, and refugee students who want to pursue a career in physics.

The astrophysicist Dr. Jaqueline Hewitt, known for her pioneering work on gravitational lensing, was born in 1958. In 1987 she led the team of observers at the Very Large Array that discovered the first Einstein ring.
Image: Hewitt et al, Nature 333, 537 (1988)

John Dalton made an entry into his logbook in 1803 that introduced a set of symbols to represent elements. His system, which was the first to use symbols, was replaced about a decade later by the modern notation introduced by Berzelius.

Something like this is likely to happen on timescales not too different from ecological disasters like climate change, so add it to your list of things to worry about!

As global disasters go, it will be one of the prettier ones. The aurora will be dazzling and bright enough for you to read a book by; birds will think day is here. But telecoms will be down for a while, and there’s a pretty good chance your power grid will collapse.
Image: NAS

At some point it will happen again, and it won’t miss. But the infrastructure we rely on now is much more susceptible than it was in 1889. The National Academy of Sciences says the economic impact of a modern-day 'Carrington Event' could top $2 trillion.

A “Carrington-class” solar storm occurred in 2012, but the coronal mass ejection from that one just missed the Earth.

Carrington & Hodgson made the first solar flare observations in 1859, just before a colossal geomagnetic storm. They made their observations independently and published simultaneously in MNRAS.

The solar storm that followed was one of the most intense on record. Auroras were reported all over the world and there were mass telegraph outages. Currents induced in the telegraph lines were strong enough to melt contacts, shock operators, and set kinds of paper on fire.

The physicist Ernest Rutherford was born in Brightwater, New Zealand in 1871. He discovered the nucleus, proton, and α and β particles; explained nuclear decay; and was the first person to successfully transmute one element into another.

Image: George Grantham Bain Collection, LOC

Physicists appreciated Faraday's skill as an experimentalist. But he was largely self-taught, and there were gaps in his education. Faraday didn't have the mathematical tools to formalize his more abstract ideas, so his contemporaries were skeptical of the concept of "lines of force."

Then Maxwell came along and said "Uh, I think he was on to something?" In the preface to "A treatise on electricity and magnetism" ( Maxwell wrote:

Faraday explained induction in terms of what he called "lines of force."

This was an idea that was ahead of its time. He thought of lines of force as truly fundamental. All matter and interactions, he believed, could be realized as knots and wiggles in this medium.

Faraday expected that gravity and electromagnetism, understood as disturbances in his lines of force, would propagate with (probably the same) finite velocity. So in a sense, Faraday anticipated the modern idea of fields.

Faraday's ring-coil apparatus is on display at the Royal Institution's Faraday museum. They also have his notebooks. Here is the page from August 29, 1831, where he describes the construction of his apparatus.
Ref: The Royal Institution, RI MS F_2_C

Michael Faraday first demonstrated the phenomenon of electromagnetic induction in 1831. He wound insulated wire coils around two sides of an iron ring, then observed a brief current in one as he connected the other to a battery.
Images: The Royal Institution, Paul Wilkinson

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