4 ms·
I would really appreciate if people writing these types of articles first give rigorous and unique definitions of space and time.
by nyc111 2y ago
I would really appreciate if people writing these types of articles first give rigorous and unique definitions of space and time.
- blackbear_ 2y agoSomething like (from Wikipedia): > In the presence of gravity spacetime is described by a curved 4-dimensional manifold for which the tangent space to any point is a 4-dimensional Minkowski space. Perhaps? A good way to lose 99% of the readers before the end of the first sentence.
- mise_en_place 2y agoJust represent it in a 4x4 multidimensional array that corresponds to the metric tensor.
- hn_throwaway_99 2y agoYes, that will really pull in the laymen...
- nvader 2y agoReminds me of the mathematician who was asked how he mentally visualizes a 4 dimensional space. "I simply imagine an n-dimensional space, and then set n to 4"
- homebrewer 2y ago>>> After Hilbert was told that a student in his class had dropped mathematics in order to become a poet, he is reported to have said "Good--he did not have enough imagination to become a mathematician" https://scienceworld.wolfram.com/biography/Hilbert.html https://scienceworld.wolfram.com/biography/Hilbert.html
- golly_ned 2y agoReminds me of Geoffrey Hinton who, when asked how to imagine a 14-dimensional space, said: “imagine a 3-dimensional space, and say ‘fourteen’ very loudly”
- esperent 2y agoThis is great, can't believe I haven't heard it before.
- deleted 2y ago[deleted]
- zbobet2012 2y agoI'm a huge fan of providing laymen explanations. And at some point if you _actually_ want to understand you have to stop using those and pickup and understand the math. http://therisingsea.org/post/mast30026/ http://therisingsea.org/post/mast30026/ Has a good introduction to space, and the notion of a manifold, and what a Minkowski space is.
- verzali 2y agoOk, but almost nobody is going to read an article that requires you to work through 21 lectures, 9 tutorials, and 3 assignments first. It'd be great if they did, and it'd be nice to give the link for interested people, but otherwise it is just making the subject inaccessible to almost everyone.
- slashdave 2y agoThat's in the article on Minkowski space. It's actually a good summary, with a hyperlink to manifold. Here's the introduction to the "spacetime" page: > In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing and understanding relativistic effects, such as how different observers perceive where and when events occur.
- whatshisface 2y agoTime: a separation between individual events that can be crossed by cause and effect. Space: a separation between individual events that cannot be crossed by cause and effect. "Individual event" is meant in the familiar sense, like a "bang" from a gun, or your birthday party.
- HappMacDonald 2y agoThat's a solid burn, suggesting that nobody else came to their party
- ziofill 2y agoMy favourite explanation (which IIRC is in a book by Brian Greene) is that you can think that everything always moves at the speed of light in a 4D spacetime. That way, if you stand still, you're moving only along time, and as you tilt your velocity vector more and more toward the space dimensions you have to travel more slowly along the time dimension. At the limit you are moving at the speed of light along some space axis and technically your time is "frozen".
- at_a_remove 2y agoOr as I tell people, kidding on the square, we're trapped in a time machine hurtling us into the future at the rate of one minute every sixty seconds! It is important you say that last bit in a panicked, breathless voice. My God, that means every three hundred sixty-five days or so, we'll have gone forward a year!
- deleted 2y ago[deleted]
- colordrops 2y agoBut then it gets weird and the time axis changes scale relative to other elements in space.
- ndsipa_pomu 2y agoFor an observer, maybe
- colordrops 2y agoThere is no absolute frame.
- Ringz 2y agoThee is no „Stillstand“, you can’t stand still relative to anything in the universe.
- DiscourseFan 2y agoAs per Kant: Time: inner sense, intuition of continuity, unity Space: outer sense, intuition of objects Its a bit more complex but that’s a basic summary from the guy who came up with the “space and time” thing. Read the “Transcendental Aesthetic” in the Critique of Pure Reason for more.