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Why is the word "usually" in quotes in the first sentence of the lead? If no one is opposed, I will amend this. Mr Ernie ( talk) 16:49, 11 February 2016 (UTC)
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Cheers.— cyberbot II Talk to my owner:Online 16:30, 2 March 2016 (UTC)
We should provide correct not misleading information to users.
I have corrected a slightly misleading description, but the editor of my latest correction is clearly interested in spreading misinformation.
Look at this sentence:
Mathematically it is a manifold consisting of "events" which are described by some type of coordinate system.
Manifold is not consisting of events because "n-dimensional manifold is a topological space M for which every point x ∈ M has a neighbourhood homeomorphic to Euclidean space Rn" Therefore manifold consists of points not events. Even if you put events in quotes, what quotes mean to anyone is anyone's guess. This is lacking precision required in encyclopedias.
The problem is a widespread negligence of equating events with their coordinates. The difference is not very subtle:
1. An event is a physical state change not some abstract set of coordinates. For one event there is an infinite set of coordinates from an infinite set of possible coordinate systems, while an event is unique in the whole universe history.
2. For the same set of coordinates there may be more then one event. Note Einstein's descriptions of two non distant events:
If at the point A of space there is a clock, an observer at A can determine the time values of events in the immediate proximity of A by finding the positions of the hands which are simultaneous with these events.
3. If an event is a state change, then this cannot be a part of an abstract space although an abstraction from an event can be associated with the point of space
4. While events may or not happen, the coordinates at which they may happen are unconditional.
5. Finally if logical arguments are not sufficient, here is the authority taking events:
It is neither the point in space, nor the instant in time, at which something happens that has physical reality, but only the event itself A.Einstein, The Meaning of Relativity, Princeton: Princeton University Press, 1988 page 30.
— Preceding unsigned comment added by AndrewWutke ( talk • contribs) 08:31, 7 August 2016 (UTC)
The Lorentz transformation dictates that the causal field (or causality field, or field of causality) is fundamental and spacetime isn't.
Why the non fundamental spacetime has an article and the fundamental causal field hasn't? I don't ask for lazy excuses. We must slowly create a new article. — Preceding unsigned comment added by 2A02:587:4110:E400:D8F0:821D:19CE:EA10 ( talk) 01:27, 12 October 2016 (UTC)
I've been on Wikipedia for quite some time, and this is just about the worst article I've seen. For starters, the lede paragraph isn't appropriate for a general-interest encyclopedia. It launches straight into speciality lingo like “ manifolds”, without anything so much as a simple explanatory parenthetical, like (a topological space) to make the lede more accessible to a general-interest readership.
Like so many of Wikipedia’s mathematical- and science-related articles, this one too appears to be suffering from a protracted period where authors were more anxious to demonstrate to other wikipedians just how smart-smart they are than to explain the subject matter using clear, non-pretentious prose that A) doesn't call attention to itself, B) uses plain-speak and explanatory parentheticals that doesn’t demand “click more links to learn the essential basics,” and C) has a lede and early sections that are appropriately accessible to a general interest readership.
Equally important are the graphics and illustrations, or lack therefore. One would reasonably expect that what graphics are in the article would actually help, but alas, no. Take the topmost graphic in the lede. The article is spacetime, yet the illustration primarily illustrates a tangential, secondary effect regarding how gravity distorts spacetime. Such a graphic needs to be placed later in the article, at the relevant subsection.
I'm not trying to dump on anyone; Wikipedia is an all-volunteer effort and no volunteer with good faith should be ripped for contributing. And I'm not sufficiently knowledgeable about the subject matter to help in a meaningful way… and even if I was, I’m too busy right now. I am encouraging that those who are active here need to take a step back and make a fresh assessment of what this page has grown into. Greg L ( talk) 00:42, 10 October 2016 (UTC)
Should this article be titled spacetime or space-time? Personally, I am happy with spacetime, but it seems that it isn't (yet) in the OED. I probably think it should be, but then it isn't my say. I am not voting to change it, but wondering what others think of the name. Gah4 ( talk) 03:05, 17 February 2017 (UTC)
Notice. An RFC ( poll, of sorts and discussion area) is ongoing on a relativity-related article here at Talk:Twin paradox. It is easier to discern a true consensus when more wikipedians thoughtfully weigh in.
@ Greg L: I find the hardest thing about animation is not the scripting/computer programming, although the effort there can be considerable. It's working out the storyboard: how much to show, when to show it, and how you show it.
Much of that is true of graphics in general. What colors do I want, how thick the lines, etc. There are a lot of compromises. For example, I may very much want to display grid lines, but their presence may make a graph too busy. My length contraction animation has undergone significant tweaking even after I uploaded a presentation that I thought was going to be a final version. My latest tweak to the animation was deciding that a small displacement of the "1" on the x axis was too distracting, so I've placed it where it is permanently bisected by the magenta curve. The result is slightly uglier, and the difference is mostly on a subliminal level, but not having a jump of the "1" means one less thing for the viewer to puzzle over.
Someone once said that you know that negotiations have gone well when both sides walk away from the negotiating table a bit unhappy. Well, I've got this right side of the brain and this left side of the brain that are unhappy with each other...
Stigmatella aurantiaca (
talk)
06:07, 9 April 2017 (UTC)
There are still a few things to do before I can consider myself as finished with the introduction. Most important is to explain the meaning of the term "observer" in special relativity. The Wiki article on the observer in special relativity has no graphics, nor do I see any suitable illustrations in Commons.
The next logical enhancement would be to provide an "Introduction (part 2)" to extend the spacetime description to weak gravitational fields. I don't really see how I can do this properly without having an intermediate section introducing the Lorentz transformation to show the relationship between my graphical descriptions and the math. I don't particularly like the existing Wiki articles on this subject. Too advanced for my target audience. Unfortunately, if I tackle this subject, I will be writing at too advanced a level for my target audience. No way I can win.
Stigmatella aurantiaca (
talk)
14:23, 10 April 2017 (UTC)