Not declared by the 12yo, but pre-existing, it’s International Pallas Cat Day!

rocky montane, grasslands and scrublands. Though its range is reduced, today it makes its home in the Caucasus, Iranian Plateau, Hindu Kush, parts of the Himalayas, Tibetan Plateau, Altai-Sayan region and South Siberian Mountains.

#linocut #printmaking #PallasCat #manul #wildCat

As described this is a hand-printed lino block print of the shy and elusive, territorial and solitary Pallas’ cat, also know as the Manul (or Otocolobus manul). These short, round, wild cats have long dense grey-brown fun and is well camouflaged to its environment, rocky montane, grasslands and scrublands. The cat here is in a rocky mountainous background and printed in a gradient of grey to brown.

April 23 is International Pallas Cat Day. 🧪🐡 This is a hand-printed lino block print of the shy and elusive, territorial and solitary Pallas’ cat, also know as the Manul (or Otocolobus manul). These short, round, wild cats have long dense grey-brown fun and is well camouflaged to its environment, 🧵

Irregular reminder: Doomerism is functionally identical to Denialism

Cynicism & despair aren’t a tribute to rationality; they’re failure of imagination & resilience. Making things less bad is more important than achieving perfection. Any start is better than none.

Hope & Joy are essential activism

Happy Earth Day! 🐡🧪

drawing of a yeti crab, a cream yellow light crab covered in little hairs with extremely hairy leggies, on a black background.

drawing of a yeti crab, a cream yellow light crab covered in little hairs with extremely hairy leggies, on a white background.

Day 27 #Invertober2024 - Yeti crab (Kiwa hirsuta) 🦀

get your coat on, autumn chill is coming

#SciArt #invertebrates

Ooh, so good!

A Dürer-drawn celestial chart on a broadside with text and image parts. The image part looks like long lines travelling.

You see a Dürer-drawn celestial chart: an analog computer from the early sixteenth century. Have a seat, and enjoy this short paper instrument's 🧵 for #skystorians and more:

I will, thanks!

Yes, love those unexpected connections!

He learned about the Yeti crab from me and my linocut here

Yeti Crab

The 12yo has declared it Yeti Crab Awareness Day!

This surprising hirsute crustaceans (more squat lobster than crab) of the South Pacific reminded researchers of the Abominable Snowman or Yeti, with its long furry limbs. Its genus name Kiwa is from the Polynesian goddess of shellfish.

With Snyder he looked at gravitational attraction under these conditions & essentially predicted the existence of black holes!

minouette.etsy.com/listing/2436... #sciart #linocut #printmaking

(who then received the Nobel in 36).⁠
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On the astrophysical scale, he was interested neutron stars &White Dwarfs. The Tolman-Oppenheimer-Volkoff limit is the limit of mass of neutron stars beyond which nuclear forces are no longer able to withstand gravitational collapse.

isotope while ejecting a proton - now known as the Oppenheimer-Phillips process.⁠
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When Dirac showed that the electron should have a positively-charged counterpart, he understood that this could not be the proton. By 1930, he predicted the existence of the positron, discovered by Anderson in 1932

energy levels & we only have to worry about one type of motion at a time.⁠
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With Melba Phillips, he explained how deuterium could induce a type of nuclear reaction when the neutron half of an energetic deuteron fuses with a target nucleus, transmuting the target to a heavier

this means that the electrons are only allowed to be on a series of specific energy levels; these are the stepped horizontal lines. The diagram shows, as they postulated, that the difference (the vertical separation) between the 2 curves is much larger than the difference between the quantized

can be considered separately. The electrons are bound in an effective potential well called the Born-Oppenheimer surface; the wide copper-coloured U shaped curves. The lower curve is ground state & the upper curve is 1st excited state. Within each well energy levels are quantized;

within atoms. The Born-Oppenheimer or adiabatic approximation is based on the observation that electrons are 1000s times lighter than nuclei, so when bound to nuclei, in what we call a potential well, move much more rapidly than nuclei. In #quantum chem & molecular physics, this means the motions

Linocut portrait of Oppenheimer in a suit leaning on his hand, in purple ink on white paper. Above to the right is a spacetime diagram for a Blackhole in turquoise. Above to the left is a schematic for the adiabatic approximation in gold.

Born on this day: #physicist J. R. Oppenheimer (1904-1967). While best remembered for his role in the Manhattan Project, he was a giant of 20th century theoretical physics, nominated for a Nobel 3 times. ⁠🎢🧪🐡 #histsci
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In 1927 he & Max Born greatly simplified how we predict electrons behaviour 🧵

taken up by nerves from their targets & allowing them to survive, in ‘52.

minouette.etsy.com/listing/4319...

#womenInSTEM #sciart #histsci #histmed

at Washington U in St Louis post-war, where she worked for 30 years. She established fundamental role that cell death plays in formation of nervous systems, how target tissues communicate with nerve cells so only those that find targets survive & it ultimately led to her co-discovery of NGF,

in her microscope oblivious to her clandestine bedroom lab. She counted 1000s of chick embryo nerves for 2-19 days post-surgery, capturing development through time, rather than a snapshot. She saw the unexpected; nerve cells would die when deprived of a target.

Hamburger invited her to collaborate

& she had a heater for melting wax in which to embed embryos, to make paper-thin slices to observe with her microscope. She made a daring train trip to Milan to buy a microscope & had to satisfy police her caked-sized box wasn’t a panettone, illegal under rationing. Luckily they were uninterested

In ‘40, she reproduced & expanded on experiments of US-based scientist Hamburger on development of the nervous system & how nerve cells accurately connect muscles to the brain. He investigated what occurs if he removed the limb bud target of a nerve in a chick embryo. Her brother built an incubator

research which involved using fertilized eggs as a source of material. Soon, all of Europe felt unsafe & she opted to return to be close to her family but Turin became a target of nighttime aerial bombings. With her family’s support, she transformed her bedroom into a a secret research lab.

cancer inspired her to pursue medicine. Inspired by neurohistologist Levi to study nerves as an undergrad, she stayed on after med school in ‘36 as his assistant. Their research was cut short by Mussolini’s racist laws baring Jews from academic & professional jobs in ‘38.

In Belgium in ‘39 she did

In a gradient of magenta-red at the top to navy blue at the bottom, this is my linocut print of of neuroscientist Rita Levi-Montalcini in 1940, at a desk with compound binocular microscope, leaning on an incubator, holding an egg and looking at the viewer. Behind her is a large circular image of a photograph of nerve cells she took with this microscope

Happy birthday to Italian #neurobiologist Rita Levi-Montalcini (1909 – 2012) who won the 1986 Nobel Prize in Physiology or Medicine with for her co-discovery of nerve growth factor (NGF) 🧪🐡👩🏼‍🔬 #histsci

Youngest of 4 of a Turin Jewish family, she planned to be a writer but the death of a nanny to 🧵

I work from home and thought I could just have bare eyes at home and short distances and wear glasses if I leave the house, but it turns out it’s a problem even to go shopping if I can’t read labels, or if I drive and can’t read the dash because I have glasses on.

I think I have answered a slightly different question than you asked. But in case it’s useful…

I’m currently at glasses for distance & bare eyes to read, but it turns out you need both in quick succession at lot.

I don’t know if bifocals or progressives are better, but vote single pair of glasses