Notices tagged with otd

If you are a nerd of a certain age and want to fail your save vs feeling very old, the Dungeons & Dragons animated series debuted #OTD 41 years ago.

Physicist Carl Anderson was born #OTD in 1905.

Anderson developed an improved cloud chamber that he used to identify the positron – the antiparticle of the electron first theorized by Dirac.

Nowadays we use these particles for positron emission tomography (PET), android brains, and ghost busting.

Physicist Ernest Rutherford was born in Brightwater, New Zealand #OTD 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

Astronomer Milton Humason was born #OTD in 1891.

He dropped out of the *eighth grade* and had little formal education, but a knack for difficult observations helped him collect much of the data used to establish what we now call Hubble’s Law.

Image: Emilio Segrè Archives

This #OTD thread contains my favorite newspaper headline of all time.
https://mastodon.social/@mcnees/110882817597054183

Astronomer Helen Sawyer Hogg was born #OTD in 1905. She was an authority on variable stars and globular clusters, and a pioneer of communicating science to the public.

Image: University of Toronto, Department of Astronomy and Astrophysics

Chemist Stephanie Kwolek was born #OTD in 1923.

She invented Kevlar, used in high-strength / low-weight applications like body armor and airplane parts. She also invented the Nylon Rope Trick demo!

Images: DuPont/Stephanie Kwolek

Humans first set foot on the Moon #OTD in 1969.

Aerodynamics engineer and mathematician Irmgard Flügge-Lotz was born #OTD in 1903.

She advanced the understanding of aerodynamic pressure on wings and turbine blades, pioneered the theory of discontinuous control systems, and was the first woman named full professor of engineering at Stanford.

Medical physicist and radiologist Edith Quimby was born #OTD in 1891.

One of the founders of nuclear medicine, she developed diagnostic applications for X-rays and radioisotopes. Her research on the penetrating power of radiation established safe levels for its use in treatments.

#OTD in 1609, Galileo Galilei aimed his telescope at the Moon.

While not being the first person to observe the Moon through a telescope (English mathematician Thomas Harriot had done it four months before but only saw a "strange spottednesse"), Galileo was the first to deduce the cause of the uneven waning as light occlusion from lunar mountains and craters. In his study, he also made topographical charts, estimating the heights of the mountains. via @wikipedia

#science #astronomy

Friends, here is a fun little physics story about satellites and relativity. It’s a day late for an #OTD, but please indulge me.

The Navigation Technology Satellite 2 (NTS-2) was launched into orbit on June 23, 1977, an early step in establishing the GPS NAVSTAR network. It was the first satellite to carry a Cesium atomic clock into orbit! 🧵

Image: Institute of Navigation

Sally Ride became the first US woman in space #OTD in 1983.

She was one of three mission specialists aboard the Space Shuttle Challenger for STS-7. At age 32 she was also the youngest US astronaut.

Image: NASA

A day late for an #OTD boost, but it’s always fun to look through a thread of Ralph McQuarrie concept art!
https://mastodon.social/@mcnees/110537520573170629

Mathematician Bernhard Riemann gave his famous lecture "On the Hypotheses Which Lie at the Foundations of Geometry" #OTD in 1854.

Riemann expanded on ideas introduced by his mentor Gauss and introduced what we now call Riemannian geometry.

Image: Familienarchiv Thomas Schilling

Astronomer Frank Drake was born #OTD in 1930.

Can we productively talk about how many alien civilizations throughout the Milky Way might be actively broadcasting or receiving messages? How would we estimate that?

N ≈ R×fp×ne×fl×fi×fc×L

R = ⭐️ formation rate
fp = fraction of ⭐️ with 🌎
ne = 🌎 per ⭐️ on avg that could support life
fl = fraction with life
fi = fraction of life becoming intelligent
fc = fraction that 📡 into 🌌
L = how long they broadcast

Speaking of, the Hubble Space Telescope sent its first image back to Earth #OTD in 1990.

Folks knew right away that something was wrong with the optics, but the problem was eventually corrected.

Ground Image: E. Persson (Las Campanas Observatory, Chile)/Observatories of the Carnegie Institution of Washington
Hubble Image: NASA, ESA, and STScI
https://mastodon.social/@mcnees/110378772317401238

Albert Einstein completed his dissertation “A New Determination of Molecular Dimensions” #OTD in 1905.

When he submitted it to the University of Zürich on July 20, his committee complained that it was a little short. It was only 21 pages long!

https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/139872/eth-30378-01.pdf

An #OTD thread from last year, about the scientific contributions of Julius Oppenheimer.

A lot of "common knowledge" about black holes – infinite redshift, the slow progress of an infalling observer from the point of view of a distant spectator – can be traced back to an influential paper Oppenheimer wrote in 1939.
https://mastodon.social/@mcnees/110245056828062741

#OnThisDay, 20 Apr 1902, Marie and Pierre Curie refine radium chlorine. The discovery leads to Marie being the first woman to win the Nobel Prize for Physics in 1903.

The Academy originally planned to award only Pierre and Henri Becquerel. Pierre insisted that Marie should also be included.

#WomenInHistory #OTD #History #WomenInSTEM #NobelWomen