The first part says the gravitational force between objects is proportional to the product of their masses.
Galileo, and later Huygens, had established an important fact: Earth’s gravity causes objects to accelerate at the same rate, independent of their mass.
Newton’s 2nd law of motion, stated earlier in the Principia, equates an object’s acceleration to the force it experiences divided by its mass: a = F/m. Here, mass quantifies inertia, an object's tendency to resist changes in its motion.
The wonderful Waterman Butterfly World Map that @fabian and I created a few years ago from scratch is now available for download!
As I wrote back in 2019: »I always wanted to design my own maps. But it seemed difficult and trivial at the same time. […] Then I discovered the Waterman Butterfly projection. And I was in love.«
If you want to find out more about our design process and the technical challenges (or if you just want to download the map) read on:
Newton's insight gave a precise explanation of hundreds of years of astronomical observations. Despite being superseded by general relativity, it is sufficiently accurate that we used it to land people on the moon.
What does it mean, and how did he arrive at it?
One of the main results contained in the Principia is Newton's "Law of Universal Gravitation."
Newton describes gravitation as producing a force between two objects "according to the quantity of solid matter which they contain and propagates on all sides to immense distances, decreasing always as the inverse square of the distances."
Some of this had been explored by earlier scientists, but this is the first time all the pieces come together in a consistent and quantitative explanation.
You can thumb through one of Isaac Newton's personal copies of the Principia, courtesy of the Cambridge Digital Library.
Donated by the 5th Earl of Portsmouth in 1872, it contains many of Newton's own notes, annotations, and corrections.
Sir Isaac Newton's "Philosophiæ Naturalis Principia Mathematica" was published #OTD in 1687. Often referred to as just “the Principia,” it presents Newton’s laws of motion and his universal law of gravitation.
336 years old and we still teach its main results!
One of the difficulties that a cohort of new users to #mastodon will face is that there is no #algorithm controlling the content they consume. It makes the job of populating timelines, a personal effort. #socialmedia #fediverse
CARTOGRAPHY IN THE EUROPEAN ENLIGHTENMENT = volume 4 of The History of Cartography series is now, as of today, FREELY AVAILABLE !!!!!
Goto https://press.uchicago.edu/books/HOC/index.html and click the link for volume 4.
WOW WOW WOW
The prettiest of all the volumes, if I say so myself. All thse mss in full color!
The start of a new Renaissance Mathematicus series
https://thonyc.wordpress.com/2023/07/05/from-τὰ-φυσικά-ta-physika-to-physics-i/
Rabin, S. J. (2014). Early Modern Jesuit Science. A Historiographical Essay, Journal of Jesuit Studies, 1(1), 88-104. doi: https://doi.org/10.1163/22141332-00101006 #openaccess #oa #history #earlymodern #histodon #histodons #science #histsci #catholic #church #maths #math #mathematics #astronomy #physics #cartography #telescope @histodon @histodons @science
#image attribution: art designer at PLoS, modified by Wikipedia users Nina, Beao, and JakobVoss, CC0, via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_transparent.svg
Antunes, C., & Negrón, R. (2022). The Dutch Republic and the Spanish Slave Trade, 1580-1690. TSEG - The Low Countries Journal of Social and Economic History, 19(2), 17–44. https://doi.org/10.52024/tseg.12315 #history #histodon #histodons #europe #spain #dutch #earlymodern #17thcentury #C17th #research #article #social #economic @histodon @histodons
#OTD in 1687, Sir Isaac Newton published his magnum opus, the Principia — one of the most important works in the history of science.
It was in the Principia, or the Philosophiæ Naturalis Principia Mathematica, that Newton first set out in mathematical terms the principles of force, time and motion, and revolutionized methods of scientific investigation. via @iaeaorg
Principia mathematica (3 vols) by Alfred North Whitehead & Bertrand Russell is being proofed by @DProofreaders.
The oldest humans identified as riders (so far). #bioanthropology #horse #archaeology #openaccess
The authors report five Yamnaya individuals well-dated to 3021 to 2501 calibrated BCE from kurgans in Romania, Bulgaria, and Hungary, displaying changes in bone morphology and distinct pathologies associated with horseback riding.
"Ninth Dedekind number discovered: Scientists from the Universities of Paderborn and Leuven solve long-known problem in mathematics" https://www.eurekalert.org/news-releases/993662 #Maths #Math #Mathematics #Science @science
Google Says It'll Scrape Everything You Post Online for AI
https://gizmodo.com/google-says-itll-scrape-everything-you-post-online-for-1850601486
Haihua Bai and others, The Genome of a Mongolian Individual Reveals the Genetic Imprints of Mongolians on Modern Human Populations, Genome Biology and Evolution, Volume 6, Issue 12, December 2014, Pages 3122–3136, https://doi.org/10.1093/gbe/evu242 #openaccess #oa #science #biology #genetics #genome #evolution #research #article #mongolia @science
#image attribution: art designer at PLoS, modified by Wikipedia users Nina, Beao, and JakobVoss, CC0, via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_transparent.svg
Reading between the Gridlines
https://blogs.loc.gov/maps/2023/06/reading-between-the-gridlines/
A cartographer is using maps to fight climate change. She creates interactive visualizations that show the impacts of rising sea levels, extreme weather, and carbon emissions on different regions. Her maps aim to raise awareness, inspire action, and inform decision-making. #maps #climatechange #visualization https://www.technologyreview.com/2023/06/22/1074262/cartographer-fights-climate-change/?utm_source=flipboard&utm_content=HariTulsidas%2Fmagazine%2FArchetypes
Another #Mastotip for this megathread of tips for people new to #Mastodon from #Twitter. I was just introduced to Followgraph, which lets you plug your profile in and graph out who your follow's are following, so you can possibly find more interesting accounts to follow! https://followgraph.vercel.app
H/T: @jfkimmes
#OTD 4 July 1753 Jean-Pierre Blanchard was born. He became a pioneer in ballooning, becoming the first to cross the English Channel in a balloon on 7 January 1785.
Not a bot; a rather corpulent male approaching fifty years of age; married; father; a very very slow reader; barely reaching up to the level of mediocrity; an ignoramus who reads occasionally.
Toots are humanities, sciences, books and maps related. Toots or follows or boosts or mentions ≠ endorsements of any particular notion or notions. Expect many typing errors.
Addendum: for those wondering, I do not physically resemble a fountain pen.