
Physicist’s ideas of time - signa11
https://qz.com/1279371/this-physicists-ideas-of-time-will-blow-your-mind/
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haecceity
The example he gave is from special relativity where there's a distinction
between coordinate time and proper time.

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gus_massa
It's just a very bad explanation of general relativity.

General Relativity have some definition of time locally, that is more
complicated than the time in Special Relativity.

The problem in Special Relativity is that time is not the same for every
observer, because if you are moving the "time" you see is different than the
"time" I see. Anyway, you can convert your time to my time or vice versa using
some clear small math formulas.

In an abstract setting, it's essentially the same problem that right and left
have. Everyone has a different definition, but you can convert them. For time
the conversion looks more weird because in usual conditions you can
approximate that everyone has the same time and live happily, but it is only
an approximation.

In General Relativity the space-time is curved, so it is more difficult to do
the conversions. It's more difficult because the math is more difficult and
because you must stich the times from different parts, so there are real
problems to stich them. If you like bad analogies, it is the same problem that
make so difficult to make a good planispheres. Drawing the spherical surface
of the Earth in a plane cause problems.
[https://xkcd.com/977/](https://xkcd.com/977/)

In Special/General Relativity, the universe is made of "events", they are like
the "points" in a plane but instead of having two coordinates like (x, y) or
three like (x, y, z) they have four coordinates like (t, x, y, z). (For
technical reasons, you will be happier if you multiply the time by c and use
(ct, x, y, z).)

Each point in a plane exist on its own, but it is easier if you add some
differentiable structure and consider that the point (7.9999999999,
4.00000001) is "close" to the point (8.0, 4.0). In spacetime you can add a
similar structure to the events with four coordinates, but there are some
technical details because time is special. But it is not much more surprising
than defining the nearby points in a plane. In General Relativity the
curvature make everything more complicated, but not mind blowing.

I think the article mix the thermodynamic arrow of time to increase the
confusion, but if you want to understand the problem it's better to read
[https://en.wikipedia.org/wiki/Arrow_of_time](https://en.wikipedia.org/wiki/Arrow_of_time)

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basicplus2
Not very illuminating.. simply simply says time does not exist..

