And here are the actual digits, with the same color coding used in the previous post. #PiDay

Pretty wild that this chatbot-generated intro made it through every stage of the publication process.

Another in the long list of reasons to drop Elsevier.

https://www.sciencedirect.com/science/article/abs/pii/S2468023024002402

Happy π day! Here’s a color-coded representation of the first 10,000 digits.

Read it left-to-right, top-to-bottom. #PiDay

A thread about the announcement of Pluto's discovery, Percival Lowell’s insistence that Mars hosted a civilization, the relatively unknown woman whose calculations supported Lowell’s hunt for“Planet X,” and Clyde Tombaugh's ashes sailing off into the darkness of deep space.
https://mastodon.social/@mcnees/110016500960493362

@katzentratschen Oh wow! Those are marvelous! I'm trying to boost, but getting "server error" messages -- apologies if there's a series of boost / unboost.

Arg! I attached the wrong video! Just replaced it with the one where you can hear the bones.

Here are some photos. A little too dark for the phone camera, but on the other hand it looks sort of badass in profile like that.

This hawk just took a songbird in mid air, landed on a big branch outside our window, and ate the whole thing right there. It didn’t even flinch when I walked outside to get a closer look.

I was so close that you can hear the little bones crunching in the video.

Back in 1995, Macromedia made this little video in Director to commemorate the 50th anniversary of Bush's prescient article.
https://www.youtube.com/watch?v=c539cK58ees

Vannevar Bush, back in 1945, calling out you, specifically, for all the bad articles in your mess of open browser tabs.

That same month, July 1945, Vannevar Bush published "As We May Think" in The Atlantic.

It was a forward-looking essay that anticipated hypertext, the web, Wikipedia, and other information technologies in the form of a desk-like device he called a "memex."

https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/

The report argues that we must address national security, economic, and social issues with the sort of concentrated scientific effort Bush had overseen throughout the war.

It was a call for dedicated support of science to advance the public good.

You can read a copy here: https://www.nsf.gov/about/history/vbush1945.htm

In July of 1945 Vannevar Bush wrote to President Truman, responding to a request made by Roosevelt in 1944.

He submitted "Science the Endless Frontier," a report outlining a plan for Federal support for the sciences and the establishment of the National Science Foundation.

Bush would serve as chairman of the National Defense Research Committee and later, during WWII, director of OSRD.

In these roles he shepherded efforts ranging from the Manhattan Project to medical research to the development of radar.

He was also (informally at first, and later on in an official capacity) the first Presidential Science Advisor, serving under both Franklin Delano Roosevelt and Harry S Truman.

Bush and Hazen built their analog “differential analyzer” at MIT in the late 1920s.

It incorporated ideas from both Babbage and Kelvin (whose work was apparently not known to Bush) and could solve differential equations via integration.

In 1936, Bush hired a young electrical engineering graduate student to be his research assistant in charge of running the differential analyzer. His name was Claude Shannon.

https://www.sciencedirect.com/science/article/abs/pii/S0016003227900970?via%3Dihub

Vannevar Bush, an electrical engineer who built one of the first analog computers, was born #OTD in 1890.

He headed the Office of Scientific Research and Development during WWII, proposed what became the National Science Foundation, and devised an early hypertext system.

This was the last of Einstein's three "classical tests of general relativity" to be verified. The others were the anomalous precession of the orbit of Mercury, and the deflection of starlight by the gravitational field of the sun.

The paper is open access, so you should have no problem downloading it if you'd like to take a look.

Also, the American Physical Society has a lovely and very accessible discussion of the experiment here:

https://physics.aps.org/story/v16/st1

The Equivalence Principle says that photons with energy E should lose / gain energy as they move up / down in a gravitational field, like an object with mass m = E/c².

For the 14.4 keV gamma rays used by Pound and Rebka, this amounts to ΔE = mgh = Egh/c² = 3.5 x 10⁻¹¹ eV. The difference between ΔE on the way down and on the way up should be about 4.9 parts in 10¹⁵.

Pound and Rebka’s careful experiment yielded (5.13±0.51) parts in 10¹⁵ — a spectacular confirmation of Einstein’s prediction!

That is precisely what Pound and Rebka needed, as they sent photons up and down a 74 foot tower and tried to measure a tiny fractional decrease and increase, respectively, in their frequency.

Here is Robert Pound seated at the top of the tower, which stretched from the attic to the basement of Harvard's Jefferson laboratory. He is speaking on the phone to Glenn Rebka, stationed at the bottom.

Images: Harvard University News Office

Their beautiful 1959 experiment was made possible by Rudolph Mössbauer’s discovery of recoilless nuclear resonance fluorescence the previous year.

The “Mössbauer effect” provides an extremely sensitive mechanism for detecting energy shifts in photons.

Here's a thread about Mössbauer from last month. If you are using @ivory this will hopefully show up as quote post:

https://mastodon.social/@mcnees/111851445548777573