←back to thread

Time is a dimension, but not like space

(bigthink.com)
171 points belter | 4 comments | 17 Oct 24 15:29 UTC | HN request time: 0s | source
Show context
nyc111 ◴[17 Oct 24 15:55 UTC] No.41870842[source]▶
I would really appreciate if people writing these types of articles first give rigorous and unique definitions of space and time.
replies(4): >>41871770 #>>41892831 #>>41892968 #>>41893041 #
blackbear_ ◴[17 Oct 24 17:36 UTC] No.41871770[source]▶
Something 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.

replies(4): >>41892048 #>>41892765 #>>41892770 #>>41892961 #
mise_en_place ◴[20 Oct 24 00:58 UTC] No.41892048[source]▶
Just represent it in a 4x4 multidimensional array that corresponds to the metric tensor.
replies(1): >>41892096 #
hn_throwaway_99 ◴[20 Oct 24 01:09 UTC] No.41892096[source]▶
Yes, that will really pull in the laymen...
replies(1): >>41892317 #
1. nvader ◴[20 Oct 24 01:58 UTC] No.41892317[source]▶
Reminds 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"

replies(2): >>41892360 #>>41892735 #
2. homebrewer ◴[20 Oct 24 02:07 UTC] No.41892360[source]▶
>>> 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

3. golly_ned ◴[20 Oct 24 03:55 UTC] No.41892735[source]▶
Reminds 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”
replies(1): >>41892928 #
4. esperent ◴[20 Oct 24 04:47 UTC] No.41892928[source]▶
This is great, can't believe I haven't heard it before.