I would really appreciate if people writing these types of articles first give rigorous and unique definitions of space and time.
replies(4):
> 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.
http://therisingsea.org/post/mast30026/
Has a good introduction to space, and the notion of a manifold, and what a Minkowski space is.
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.
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.
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.
My God, that means every three hundred sixty-five days or so, we'll have gone forward a year!
Although that sounds theoretically impossible, I would remind you that somehow the opposite seems to be possible (a particle with zero mass that moves through time at a rate of zero seconds per second), despite that not making a lot of sense to a layperson.
Footnote: Talking about time in seconds makes very little sense here because our notion of time is so heavily linked to how light moves through space, but hopefully my point is clear. Maybe someone has a better unit we could use to measure time independently of space?
But back to observable reality: let’s say you fall into a dark place where the time stands still and that means you are not moving, from an outside observer you are still moving relative to the space outside your black hole. Let’s say the observer fall on his way to your black hole into another black hole and experience the same phenomenon like you, from a third observers perspective everyone is moving.
> I would also say that there can’t be two or more infinite masses at the same time
...for the same reason that there can both be infinitely many fractional parts between 1 and 2 and at the same time, infinitely many between 2 and 3.
You raise the question on 'observable' reality, which is interesting. I would say that the example is a bit flawed (you can't 'observe' things that happen inside an event horizon'). Indeed, from an outside observer's perspective, what actually happens is that you arrive at the event horizon and 'freeze' in time and movement. Eventually, you red shift into invisibility.
I previously considered this to be a strange artifact of light, but perhaps the correct understanding is that you actually start moving at '1 second per second' through time, and stop moving through space completely?
It feels like this is the sort of thing people much cleverer than me would already be able to answer, so perhaps I'm way out of my depth here :)
Mathematically true but wouldn’t a infinite mass have infinite gravity? That means every other mass (infinite or not) would fall into that mass at the speed of light - even if they are far far away. If they are in the same space of course.
An infinite mass would mean that there is no „flat space“ left and everything is on the slippery slope to the center of that infinite mass.
That’s what I mean with my badly worded „ I would also say that there can’t be two or more infinite masses at the same time, or they would move (at the speed of c (?) But that would have additional implications on mass and time) to the point between them.“