There are so many concepts in science, especially Physics, that make absolutely no sense to me unless I begin to study the underlying history of the concepts. So please correct me when I'm wrong because I'm sure I am sometimes. The first concept I think about is Voltage. I was extremely familiar...
My wife read a bit of this book and lost interest :cry:. The condition is excellent, hardly used, and it looks new, with no creased pages. I'm willing to give this away to someone in North America who hasn't read this all-time classic yet.
I noticed that the three seed articles about space-time quantisation are aligned in 1994.
https://inspirehep.net/literature/371960 Garay
https://inspirehep.net/literature/386329 Doplicher et al
https://inspirehep.net/literature/379391 Rovelly-Smolin
I wonder, does anybody remember why this...
Maybe 1860s - 1870s tintype. Post processed heavily to reveal the image.
What do you think they are building?
I'm not student or engineer. I'm an archivist. (non-professional) I get lots of old photos and films that need some deciphering, so hope this group can help out.
I recently visited the Imperial War Museum London for the first time in almost a quarter of a century and was not only captivated but humbled.
The building that houses the museum and its artefacts is an astounding beauty. Within are wonders from eras spanning from the First World War through to...
I heard about a chart today which I knew I immediately had to check.
It's called the Histomap (by Rand McNally) and cleverly shows the evolution of the powers of empires, nations and states throughout 4'000 years.
Here is an article about it, including the "histomap":
“The Histomap: 4000...
Am on the 'net' quite often and for extended periods of time perusing scientific sites and historical ones as well. Have BSCE degree from California State University, military experience,and other professional history.
I haven't watched the whole series yet, but I caught part of Episode 5.
Tony Robinson Down Under 3 Episode Marathon! Ep 1-3 | Time Travels
Tony Robinson Down Under 3 Episode Marathon! Ep 4-6
This may sound weird but after having watched "Forged in Fire" a bunch of times on History channel (Europe) I've developed a desire to try out blacksmithing, and I'm not normally what you would call a "hands-on" kinda guy. I'm not even sure I could swing a hammer long enough to make a dent in a...
I am interested in many subjects; history, physics, biology, art... well, just about everything. Why? Because the only truly useless knowledge is the knowledge you don't have. My interest in the sciences mainly derives from three sources: 1) my Dad's ongoing interest, as a layman, in sub-atomic...
Let us try to promote some physics history in this sub. What are some anecdotes in the history of physics that you want to share? Be it a true story or a popular myth.
I'll start:
I recently tried to check if the story of Schrödinger's equation was true: Schrödinger going out for the...
I think a specific forum for history of physics and mathematics here would be fun. It could also help some users understand the origin or the motivation of whatever topic they are studying.
There is a forum for for art, music, history and others, but it seems focused on discussing many things...
I read that chalkboard is invented only in the 19 century, so how teacher before that explained pupils math and grammar with just oral instruction?
It seems impossible that people need 1000 years to figure out that teaching with board is much more effective.
Something must be wrong with this...
If one studies American history and industrial development of the late 1800s and early 1900s, one will probably encounter stories of the railroad barons. One may have heard of Jay Gould (and son George Jay Gould), James Fisk, Cornelius Vanderbilt, E.H. Harriman, J.J. Hill, and the Van Swerigen...
This was an advanced system at the time (1973), my first programming job. Multiple HP 2100 mini-computers (1 is HP 2116), each computer mult-tasking, a database server for 160 users at the time I left the company. Underneath each mini-computers is a 10 MB hard drive used to queue messages...
British Isles - a piece of visual history (1/2)
TL;DR (too long; didn't read): Old photos of historical sites on the British Isles.
Since there seems to be quite a few PF members interested in history, I thought I'd share a couple of old photos of mine of historical sites in the United Kingdom...
Hi, I've recently developed an interest for the history of the development of cosmology and find it very interesting. The key events I have been reading up on are:
1915 - Einstein's theory of General Relativity was published.
1923 - Hubble discovered a Cepheid variable in the Andromeda...
Back in the 19th century British explorers came across Eskimos who were so isolated that they'd forgotten that any other humans existed. Nevertheless they had a little bit of iron that they used to put an edge on their knives. They had no trade so where did they get it?
Fortunately their...
Hello :
I apologise for my last post about the titanic , I didn't think it will be considered conspiracy theory , although I see it as a good science post
Best regards
Hagop
The recent spate of train derailments has put the spotlight on derailments and railroad safety in general.
Railroads are generally a safe means of transporting cargo, including hazardous chemicals, and in fact railroads are safer than a decade or two ago. Yet, one catastrophic accident...
From where I stand, human evolution from primates is more evidence-based and storied than our understanding of bats. Do we have an evolutionary understanding of bats? Or are their origins still more myth than science?
Suppose, for a certain a repo, I create a branch protection rule for the main branch with the following:
Require pull request before merging. This means that each feature or bugfix must be on separate branches, which will be later merged with main.
Maintain linear history of the main branch...
I didn't remember the Lavoisier died at the guillotine.
The world's roundest object helps solve the longest running problem in measurement -- how to define the kilogram. I knew about the Pt the Pt-Ir standard. I didn't realize that the mass of various 'standards' changed in time...
I just happened to hear this one night last week. It is a history of the US from the perspective of two historians from the early 20th century.
https://librivox.org/history-of-the-united-states-vol-i-by-charles-and-mary-beard/
https://librivox.org/group/495
I was listening to this around the...
If you enjoy both physics/science and history like me, you may enjoy this video from the Royal Institution. It's about groundbreaking experiments (no theoretical physics); X-rays, particles etc.
I'm only 45 minutes in so I haven't seen the entire video yet, but I wanted to share it...
When I went to college, more than 30 years ago, as far as I can remember, nobody was talking about the use of Occam's razor in science. Reading the works of past scientists, I rarely see them invoking principles of parsimony, let alone cite Occam's razor. Yes, Newton, Einstein, and few others...
Kathy Joseph makes wonderful videos (and now a book) about the history of electricity. Her research is very thorough.
I just watched the video below, and found it instructive. Especially interesting is how Nikola Tesla and Westinghouse in the USA got the fame and credit for three phase power...
Generally, we try to apply scientific knowledge in some manner to benefit humanity. Often the application requires some standards or precautions so that the applications will have maximum benefit and minimal risk. One such application was that of ionizing radiation. X-rays were discovered in...
I gave a short Maxwell's equation history lesson and included a quick explanation of the connection to Maxwell's predecessors. Just wanted to see if I hit those points right. I don't think I made any physics mistakes, but this was a little more conceptual with some calculus flavor as the student...
The article talks about how car manufacturers waged a psychological battle to win ownership of the streets from pedestrians by convincing them to blame themselves for getting hit by a car.
Voltage SI unit = Volts
Current SI unit = Ampere
Resistance SI unit = Ohm
Ohm's law : V=IR
Did Georg Ohm (German), Ampere (French) & Volta (Italian) collaborated when Ohm came out with this electricity equation with units for voltage, current & resistance as per their surnames?
Credit goes to...
I just finished watching a documentary "The Spartans" which I found pretty interesting. Funny bunch they were, casually oiling themselves up and combing each others hair before facing almost certain death at the hands of the Persians at Thermopylae. I am looking for suggestions of documentaries...
I am looking for a history of metallurgy. I have found two books that look interesting
Smil: Still the Iron Age
https://www.amazon.com/dp/0128042338/?tag=pfamazon01-20
Smith: A History of Metallography
https://www.amazon.com/dp/0262691205/?tag=pfamazon01-20
Does anyone have any other suggestions?
One of my friends sent a link to this illustration which I found very, very fascinating:
(Image by Matt Baker, UsefulChart.com, image source: link)
If I decipher the chart correctly, e.g. the letter "O" developed from an image of an eye.
According to the wiki page about "O" an eye indeed...
does anyone have a good reference on the history of calculating the standard gravity parameters of solar system bodies? My guess is a rough estimate of Jupiter's SGP can be gained from observing the motion of its moons, in which case the first estimates could have been made soon after Newtonian...
I found this interesting article: The 60-Year-Old Scientific Screwup That Helped Covid Kill
It discusses why the initial COVID recommendations were focused on 2 meters distance, hand washing but not much else, and how indoor transmission over larger distances was overlooked initially (largely...
Does anyone know when it was first realized that a heliocentric model of the cosmos should show the phases of Venus in the way Galileo saw them in the 17th century.?Was it known in the time of Aristarchus or did people only realize this was a consequence of helicoentrism later on, perhaps only...
Extraordinary Roman mosaic and villa discovered beneath farmer's field in Rutland, UK
https://phys.org/news/2021-11-extraordinary-roman-mosaic-villa-beneath.html
The same institution that discovered the remains of King Richard III under a parking lot.
Anyone who watches "Time Team" can...
Hello,I am trying to teach myself mathematics by starting with Euclid and going up to today. My only background is college algebra and high school algebra and geometry. I am 44 years old.
I've read Euclid and Apollonius. I understood everything except he Appendix in the Conics book (Green Lion...