History Definition and 555 Threads

What's the history of using extensions of file names (such as *.c, *.for, *.bmp etc) to indicate the general type of a file? My hazy memory of working on ancient mainframe computers is that a file name extensions were not mandatory for most software. For example, if you wanted to compile a...

I am trying to understand the picture below which is of a contractible and uncontractible loop in what I would call (proper name?) "rotation space", where "rotation space" is a solid ball of radius π with opposite points on the surface of the ball identified, each point of the ball representing...

I'm wondering how and in what time frame new technologies emerged and found application in the history of science. I could make several examples of those which suddenly and unexpectedly changed the world, but not the vice-versa. In particular, I'm wondering which didn't find an application or...

This Science magazine News article discusses a new scenario for early Earth history that is claimed to explain the Earth's surface metal distribution and that it could effect conditions affecting the origin of life. This was before the end of the heavy late bombardment (timeline diagram in...

Hi All, I would like to know who was the first scientist to use probability amplitudes in solving either math or physics problems. Best wishes, DaTario

When you look at a bird in a tree with binoculars, that is not the bird as it exists at the moment but the bird that was there before the light traveled to the scope, which for practical purposes is the bird. You can shoot the bird of before, and it will fall to the ground. However, when you...

Photo: Tomb of Ramses VI. Beautiful scrollable panoramas (360) on 360cities: Temple of Isis Tomb of Ramses III Temple of Horus Al Dier Monastery at Petra More panoramas: Mohamed Attef, panoramic photographer. Other panoramas: Ramses VI panorama (360) on facebook. A video showing the tomb of...

Four years ago, the youtube channel The Great War started producing weekly videos detailing the events of World War 1, as they happened, week by week, one-hundred years ago. Since then they've released hundreds of videos, including many about the weapons, equipment, tactics, and important...

I was thinking about the signals Mankind has sent out from Earth greeting other races out there. Is it reasonable to think that even if some being received the signals (data) they would have no idea about locating Earth because it would be in somewhere else in the Galaxy/Universe by then? So...

Could you guys put Philosophy, Sociology, History and Arts in the Homework sections? I would be very appreciated.

What's wrong with this article on Stonehenge history? http://fortune.com/2018/06/21/stonehenge-builders-used-pythagoras-theorem-centuries-before-birth-experts/

The choice of the North Pole being up on a map is arbitrary as far as I know. Is it that way because publishing cartographers came mostly from the northern hemisphere? Is there some reason related to navigation (like Polaris being over the north pole) that might motivate even a southern...

https://www.washingtonpost.com/news/capital-weather-gang/wp/2018/06/07/the-u-s-just-had-its-warmest-may-in-history-blowing-past-1934-dust-bowl-record/ This was interesting. I recall it being very humid too!

Greetings to such good forum! I cannot abandon the Science despite of all my attempts... :D So recently I have started discussion with one Scientifist, on the another forum. The topic of discussion was a role of Mass-Energy-Speed of light formula in development of Nuclear Weapon. I have stated...

This thread is a split-off of this post: https://www.physicsforums.com/threads/do-macro-objects-get-entangled.946927/page-2#post-5997089 So my issue is this: if, for convenience, we use a Copenhagen interpretation, and we measure an observable WF ##\alpha |A \rangle + \beta |B \rangle##, then...

How come atom was proven to exist just because the electron was discovered in 1874, atom was like a fad of truth on early 1800s right, where atom was pictured at that time like a small brick of ball and nothing else (no electrons, neutrons, protons, parts, etc) and on that year also, chemistry...

Hello! Hawking has written, that the physical mechanics and the time before the big bang singularity cannot be measured, as time in this big bang singularity has been bent indefinitly and therefore has just started with the big bang. Questions: 1. Does Hawking mean, there has not been any time...

I was surfing the net to get some ideas involving the Kerr electro-optic effect and noticed this Wikipedia external link. It's page two from Television History - The First 75 Years. It has some cool old articles and pictures like these (images can be made larger in your browser): Just...

mod: approved HexSim Life History Simulation Modeling Platform - free to download. Landscape ecology, anyone? After >10 years of development, the HexSim life history simulator is ready for use by students and researchers.HexSim is a free, versatile, multi-species, life history simulator ideal...

I am in search of one or more books that describe the progress in the field of physics (especially during the 18th 19th and 20th century) not only by mentioning the names of lead scientists and the abstract of their work but also have some deeper insights if possible (some math too) last but not...

says NASA, NOAA and an independent group Berkeley Earth. Science news article here with a nice gif of average temps going up since 1884.

A story which is frequently to be found on the Internet is the story recounted by the American mathematician Leonard Eugene Dickson to Hadamard: Dickson's mother Tracy (née Tracy ) and his sister spent an entire evening unsuccessfully trying to solve a geometry problem. During the night the...

I was just wondering if there was any proof that the medieval period had more conflicts like wars etc. but with less (peace) negotiation between parties than now? Thanks so much!

I was watching documentary "David Attenborough's Natural History Museum Alive" where he hides behind the exhibit of some small humanoid skeleton What the heck is this skeleton of? I tried searching it on google but could not find any info.

i failed to find the history of RA [right ascension] and why the vernal equinox was picked as the starting point on the web or in the forums here. does anyone know the origins of RA? picking a solstice or equinox is obvious but why the vernal? maybe because spring in the northern hemisphere...

Hi. I am reading some history of physics and I have come to the radiation of the black body. After obtaining the correct spectral law, Planck stated that he was concerned not to be able to deduce it from basic physical laws. A friend said that Planck attempted to deduce from Maxwell's equations...

Hello I have a bunch of issues with the various interpretations of quantum physics. I'd like to dig into it but most textbooks on the topic just throw in your face a bunch of equations and tell you "that's the way it works" Intead, I'm looking for a detailed history of the experiments that led...

Hi there, my name is Isaac, and I am interested in metrology, math history, mathematical astronomy and their relationships found in the study of ancient texts ( Ephemeris, omen texts, procedural texts, etc ), mainly cuneiform and some pre-cuneiform I have no formal training in mathematics, am a...

Hello I would like to know more about the history of the discovery of the isotopes, what there was before, and the short term impact on the chemistry and nuclear physics. Is this topic discussed in any book/review? Thank you for your time. Regards, ORF

Hi, All! This is Gayathri, I am a Student Counselor and Blogger. I am Kerala. I like to read Books, write Blogs and listen to songs. I made my presence particularly to Ask my Doubts if any and Guide students with my Suggestions.

https://arstechnica.com/science/2017/06/cats-are-an-extreme-outlier-among-domestic-animals/

I am looking for a good book in English about the human history of food since ancient times. Perhaps at least 10000 years since. I would like to cover geological differences in the biological needs. (Like how Eskimos manage macronutrients from fish). The book should throw light on meal times...

Could someone please give me references on historical literature devoted to brachistochrone and catenary problems Thanks.

As I understand Aristotle believed that gravity was caused by certain objects trying to find the centre of the universe which was of course at the centre of the Earth. Newton gave us a better theory of gravity, but there were heliocentric philosophers before Newton. Not just Copernicus , Galileo...

Hello, lovely people. I was wondering if anyone knows what kind of battery Marty Cooper used for the very first cell (mobile) phone call in 1973? I know that by the 80s they were using Nickel-Cadmium batteries but I don't know about that first one. Thanks in advance, Kathy

I'm thinking about buying the following books: "the elegant universe", "welcome to the universe" and "a brief history of time". Do you aprove or should I buy some other books, and if so which books?

I would like to read a book, the chapter of a book or a website article (preferably comprehensive) on the history of the concept of a module and the development of the theory of modules in mathematics ... Can anyone help with some good references ... Peter

Does anyone know of a book or web page that gives a history of the concept of a module and the history of modules in algebra ... i have not not been able to find a book that covers the history of modules nor a website ... Help will be appreciated... Peter

Homework Statement Number 6: For this problem I'm changing the wave speed to 3.0 m/s instead of 1 m/s because that's what our teacher instructed us to do. Homework Equations None that I know of The Attempt at a Solution I'm having the hardest time making connections between the graphs and...

Hey, I was wondering if any of you smart people could help explain in a very simple way (if possible) how the first FM transmitter and receiver worked? I know, for example, that many current transmitters use a voltage variable conductor to change the frequency of the wave. Did Armstrong do...

Hi, I am researching the early history of electricity and I would love some help. So, in the very early 1900s (like 1906) there were several items created that were diodes (crystals, Fleming valve, electrolytic detector). As far as I understand, people would use these diodes to convert the AC...

Hi there, My name is Kathy and I am writing a book about the history of electrical discoveries. I am writing the book for adults who have limited (or no) science backgrounds with a lot of personal details (like Bose who liked to give electric kisses to attractive women, or Alexander Bell's...

I realized that I know nothing about the history of physics! Does anyone have any good recommendations on this topic? For example I'd like to have a clear timetable in my head about what was discovered at what time? by who? what were the methods/thoughts that went into it and what did the rest...

I'm interested in the knowledge that was available to aircraft engineers in the period 1900-1920. specifically the thermodynamics and mechanical engineering knowledge generally available, like in how much detail were the calculations on the performance, or the cooling of engines done, how...

I'm testing a part for fatigue, and I got a time series of Forces and Moments on three different parts of the body (A wind turbine hub). From the static structural fatigue analysis, I noticed that you need a von mises stress input - that's not a problem. My problem is, how do I place different...

I was reading an 1803 paper by Thomas Young (of double slit fame), "Experiments and Calculations relative to physical Optics". In it, he lists various dimensions of fringes of light and things. All without any error bars. It got me thinking, what's the history of error bars in scientific...

Archeology and evolution of QCD https://arxiv.org/abs/1610.07466 a ""few of the points which...illustrate well the QCD evolution (in time), both from a scientific and a sociological point of view.' I felt much of that energy expressed in that paper because as an undergrad and grad student, I...

This paper offers a Nobel laureate perspective on the history, status and future of GR in the astrophysical regime - https://arxiv.org/abs/1609.09781, General Relativity and Cosmology: Unsolved Questions and Future Directions.

Hello,everyone is there any book about a history of reactor physics ? Thank you for your help

That a quantum detector responds to classical light precisely according to Einstein's formulas for the photoeffect was already shown briefly in 1926 (the year the Schroedinger equation was born) by Wentzel, and was described in full detail in 1964 (when the development of the laser strongly...