History Definition and 555 Threads

536 AD - Worst Year in History (by Kings & Generals) https://en.wikipedia.org/wiki/536 Glacier cores reveal Icelandic volcano that plunged Europe into darkness https://www.science.org/news/2018/11/why-536-was-worst-year-be-alive The Worst Year Ever to Be Alive in History...

I need some gentle bedtime reading... where can I find some stories about various notable physicists who grew up or were based in the uk?

I've read a lot about Gato / Balao / Tensch class submarines, the ones America used in WWII, and I can't seem to sort out the specific consequences of a dead battery. A lot of you are diesel experts, so maybe someone here knows? Historical accounts are vague. Dead batteries are certainly a big...

1.One can now see why all bodies fall at same rate: A body of twice the weight will have twice the force of gravity pulling it down, but it will also have twice the mass. According to Newton’s second law these two effects will exactly cancel each other, so the acceleration will be same in all...

How close to "antenna" was the metal barbell thing which was part of Heinrich Hertz' apparatus? Did he know in theory how to build a radio but just didn't have the right components to do it? I know someone around that time referred to the problem of radio in terms of needing proper sustained...

What is the origin and/or history of the usage of the term "percent grade" for 100 times slope in, especially but not exclusively, civil engineering? The combinations of search terms I've tried so far only bring back the definition, examples of how to use quantities in this format, and other...

What are good candidates for the most indecisive battles in history? There are plenty of lists online for the most decisive battles, bloodiest battles, largest battles etc. There ought to be a list of the most indecisive!

I'm reading through Stephen Hawking's 'A Brief History of Time' and came across this sentence in the second chapter: " If the law were that the gravitational attraction of a star went down faster or increased more rapidly with distance, the orbits of the planets would not be elliptical, they...

Railroad history is one of my hobbies and somewhat of a passion. Like some people have favorite sports teams, I have favorite railroads, all of which are fallen-flags, i.e., they no longer exist. Conrail grew out of the ashes of the largest bankruptcy at the time involving the Penn Central...

I am reading the text 'Innovations in Maxwell's Electromagnetic Theory'. on page 44 there is a discussion on Ampere's circuital law . The passage is below. I don't understand the final statement. "In general represent a kind of relationship that obtains between certain pairs of phenomena , of...

What does Feynman's sum over histories mean to the interpretation of our world? Does it mean that we (or a particle) do not have a definite history, but only the most probable one?

What is the best books about the history of solid state physics? I only found this: Out of the Crystal Maze: Chapters from the History of Solid State Physics by Lillian Hoddeson Are there any other books? Thanks for your suggestions

Summary:: Given the Mayan date (8,10,193) determine the Mayan date that is 0,2,3,5,10 days later. The Mayans used a complicated date system. The question asks: Given the Mayan date (8,10,193) determine the Mayan date that is 0,2,3,5,10 days later. The system the Mayans used had two...

I know that arc length is L=rx where x is the central angle in radians. But, that doesn't help me here, because I don't know the central angle, and because I need to use Leonardo's table of chords. I don't understand how the table works.

I have just finished reading the book 'Three Roads to Quantum Gravity' by Lee Smolin. My question interestingly is associated with my geology background. Lee Smolin notes Fay Dowker concludes that if Consistent Histories is true then we cannot deduce the existence of dinosaurs 100 million...

Today the inexact differential is usually denoted with δ, but in a text by a Russian author I found a dyet (D-with stroke, crossed-D) instead: In response to my question to the author about this deviation from normal usage, he stated that this was a suggestion from von Neumann. (Which of course...

Archery in the United States underwent a radical evolution in the space of about 15 years between 1955 and 1970. It essentially evolved from the primitive sport that it always was into the modern sport it is today. I was there and I saw it. I don’t think it’s really been written about and there...

In 1982 I was given a ZX Spectrum by a Timex employee. It was one of only three English units that had been converted to NTSC from PAL. They worked for Timex but had their own company on the side to write software for the Timex computer and for the spectrum They hired me to do the title screen...

Riccardo Giacconi (1931-2018) was an italian astrophysicist who was awarded with the Nobel prize in physics back in 2002 for his important contributions to astrophysics. Since he was an astrophysicist he must have heard about the multiverse hypothesis, but I have not found a single paper or...

I have only found so far on the web forums about physics and math. I have questions about philosophy and history that I would like to ask. Does anyone know of good webforums where I can do that? (Since that's forbidden on here :wink:)

Archimedes Riemann integral is one of the most elegant achievements in mathematics, I have a great admiration for it. Mr. Patrick Fitzpatrick commented on it as Archimedes first devised and implemented the strategy to compute the area of nonpolygonal geometric objects by constructing outer...

The term "Steam plant" can refer to a place that distributes steam for heating buildings - as opposed to a plant that generates electricity. I have the impression that there are few, if any, such steam plants in operation in the USA. When was their heyday? Were there accidents from broken...

As we all learned a long time ago, the trajectories of individual air molecules can't be predicted, but the behavior of macroscopic air masses can be predicted--if imperfectly, as with weather forecasts. Similarly, the behavior of human individuals isn't always predictable. The less well...

What distinguishes discussions of the what-ifs of history from forum-prohibited discussions of personal theories and speculations? My thoughts: 1. Academic historians do discuss the what-ifs of history. 2. Speculations about things that might have happened can clarify the significance of...

There is at least one article online disputing the historical veracity of the popular book "D-Day Through German Eyes" https://www.dailymail.co.uk/news/article-7017619/Amazons-D-Day-bestseller-HOAX-Historians-claim-German-Eyes-book-fabrication.html (Of course, the Daily Mail might perpetuate...

I recently came across some good histories of GE and ALCO locomotives. ALCO was the second of the two preeminent steam locomotive manufacturers, the other being Baldwin. Diesel-electric locomotives were replacing steam locomotives, although steam continued through the 1950s, especially on...

I was wondering if it would be possible to see the history of space if one was to stand at the edge of the universe as it expanded faster than the speed of light. If the universe was to be expanding faster than the speed of light right now, and I was able to somehow go there and keep up with it...

https://www.google.ca/amp/s/phys.org/news/2020-02-astronomers-biggest-explosion-history-universe.amp

I will basically focus on 18th and 19th century, I got to know from the biographies of Max Planck and few other that there were no organized syllabus in Universities for studying. Students had to take classes that they could understand and it was less like a lecture and more like a private...

Since this is on the history of philosophy linked to set theory, rather than set theory itself, I presume I can't put it into the Set Theory rubrik. First, for those who are unfamiliar with the Reflection Principles of Set Theory (or more properly model theory),there are several versions, but...

Check it out: https://www.amazon.com/dp/B07PYMLZWJ/?tag=pfamazon01-20 Its available free if you have Kindle Unlimited. Many books do not get right that Einstein knew QM very well indeed and greatly admired Dirac, of whom he said: 'Dirac, to whom, in my opinion, we owe the most perfect...

Nobel laureate Hans Bethe was a friend of mathematician-physicist John von Neumann, and he once said: "I have sometimes wondered whether a brain like von Neumann's does not indicate a species superior to that of man" and "[von Neumann's] brain indicated a new species, an evolution beyond man"...

https://www.foxnews.com/entertainment/neil-peart-rush-drummer-dead I first saw anything Rush in an 8th grade Jazz Band practice in 1989 (I played trumpet), when my instructor put on a video of a solo similar to this and I was just blown away. I'd never seen anything else like it and still...

I recently watched a YouTube video on the history of the telephone. It was fairly generic, stuff I knew, but he spent some time on the carbon microphone, which made me curious about the real details of the development of carbon microphones. I easily found lots of info with a search. But that...

I have lately been reading, with interest, the history leading up to Einstein's work as well as some of the debate that ensued after his theories were published. In particular, I was reading some of the ideas Ritz proposed and the disproof of his theories by de Sitter. A question occurred to me...

Summary:: What are the most important physics publications in history according to you? thanks in advance :)

Does the CMBR contain the imprint of the entire expansion history of the universe or only of the last scattering ?

Thought following might be of interest - application of Ptolemy's Theorem from "De Revolutionibus Orbium Coelestium: Liber Primus".

I couldn't match this question with another topic, so I made a new topic. Suppose we have past H and present P at a certain moment. In present P a measurement is made. For matter of speaking we adopt MWI, so we have the two measurement outcomes A and B diverging in two realities A and B in...

I do not know exactly where to ask this. I do not even know if I can. I chose the General Discussion forum since it seems to me the best place to ask this within this site. Having said this, Did John von Neumann ever go to Oslo or any other part of Norway? It is known that he traveled at least...

Aristotle further believed that objects fall at a speed that is proportional to their weight. In other words, if you took a wooden object and a metal object of the same size and dropped them both, the heavier metal object would fall at a proportionally faster speed. link I mean these guys were...

Thought this might be of interest to some. Thomas Gilcrease Institute of American History and Art Explore 28,694 items from Gilcrease Museum's collection, totaling more than 350,000 art, archive, anthropology and library materials that span 13,500 years of North American history and art...

Now home water filter is ubiquitous using almost every family. I am wondering who designed such systems (and become its standard form used today) ? I think after second world war the New York water is pretty dirty hence the development of such filter. But I am not sure whether it is correct or not.

In the USA, the usual solution to keeping water lines from freezing is to bury them. In cold climates this implies digging deep trenches. (On another forum, a person from Minnesota said water lines are typically buried 7 ft deep.) In the days before modern excavating equipment, were...

I've been very interested in history a long time, read many books and watched many documentaries during the years. I've recently started to watch documentaries on parts of history I did not know very well (the Napoleonic era), and I thought it would be a nice idea to have a thread where those...

Hi all. I'll get to the point. I've been interested in electricity since I was in college. Concepts such as current and resistance seemed easy to grasp for me but voltage remains a little bit obscure. It's thanks to this forum (specially forum members Jim Hardy r.i.p and SophieCentaur, sorry if...

what does it mean when you say the stars all fall in on each other?And what does the line uniform distribution of stars outside this region mean?and what does this line mean- again fall in?what does fall in mean? would really appreciate some help in understanding the meaning in simpler words...

Intense, dramatic, fantastic and at the same time terrible. A must see for history buffs, I'd say. WW2 - D-Day. Invasion of Normandy [Real Footage in Colour]

I'm familiar with the history of the concept of the square-cube law going back to Galileo, Watt, etc. However, I don't know the origin and history of the language we use to talk about it today. When was the specific term "square-cube law" coined? When did that name become commonly...

I found these timelines on the Computer History Museum which are quite interesting to checkout: https://www.computerhistory.org/timeline/ai-robotics/ For me, it brought back memories of machines long past. They even mentioned the construction of my robot persona for the Forbidden Planet...