On the contrary; while I have heard the explanation that the commenter you replied to has said I have also heard a slightly different theory:
Our universe is the 3 dimensional event horizon of a 4th dimensional black hole. By extension we may find that black holes in our universe have similar funky 2 dimensional areas at their even horizons.
I am sure clickbait articles are part of it but there also seems to be several actual theories surrounding the idea of the nature of our universe relating to black holes.
I’m assuming you are thinking that time is the 4th dimension and we have time here so we are 4d?
Time may be the 4th dimension, but in our universe, time doesn’t actually behave like a proper dimension. For one thing, dimensions should be spatially perpendicular to each other and time is not. We also seem to only be able to move one way through time whereas we can move back and forth through the other 3 dimensions.
Dimensions get weird and complicated. For the intents and purposes of this conversation it’s correct to say that the universe were experiencing now is 3 dimensional.
3+1, not 4D (we cannot move freely in time). They’re referencing the holographic universe theory, or holographic principle. PBS Spacetime has a good episode on the holographic universe theory.
Moving through time is not equal to having free motion through time. It should frankly be embarassing to you for failing to understand that basic fact of reality…
Three spacial dimensions, which is normally what people mean when they say that, unless they specify otherwise. For example, we call them 3D game engines, not 4D. Yes, there’s also a time dimension that is special. It cannot be moved through freely.
Yes, but if you’re beyond the event horizon of a black hole time becomes basically* irrelevant. You could literally turn around, look back out towards the rest of he universe, and watch all of time play out in the blink of an eye.
You know that scene in Interstellar where they land on the planet for 5 minutes, but 20 years passes for everyone else due to the planet’s mass? It’s the same thing, but a billion-billion-billion times more severe.
No, time does not become irrelevant. It’s perfectly normal for things inside the black hole. Here’s the space time diagram for our universe on the right, and a black hole at the top-left. Time is the vertical axis, space is the horizontal. The speed of light is a 45° angle, and the solid lines are event horizons. The hourglass shapes are the cones of all your possible futures and pasts (aka, anywhere that isn’t faster than the speed of light from a position). Notice the space-time diagram looks exactly the same on the other side of the horizon. To get back through though you’d have to travel faster than that 45° angle, which is impossible.
Edit: I remembered there’s a PBS Space Time video that will help you understand this if you don’t. It goes a lot further than just this version of the diagram.
I’m aware of the Penrose diagram and also watch PBS SpaceTime :)
But I was referring more to the frame of reference of our universe vs that of being inside a blackhole (assuming you could magically avoid being ripped apart by gravity). To an observer inside a blackhole, “time” on the outside would blink by almost instantly. I wasn’t talking about moving through an infinite universe or near/into a black hole. Just stationary, floating just beyond the event horizon, looking out. Hence the asterisk on basically*.
I was leading them to what MotoAsh posted. But they beat me to it while I was typing.
Nah really it was probably some small thing the media got a hold of and just ran with. I think you’re spot on
Relevant xkcd
And a relevant smbc for good measure.
Your SMBC link doesn’t work for me, it just opens the index.
Try now.
Works now! Thanks, and very relevant.
Smbc is Saturday Morning Breakfast Cereal, but what does xkcd stand for?
It’s a random unique string, chosen to make the comic easily searchable.
Xaturday Korning Creakfast Dereal
Xerry kible cellow dip
Where’s PBF?
On the contrary; while I have heard the explanation that the commenter you replied to has said I have also heard a slightly different theory:
Our universe is the 3 dimensional event horizon of a 4th dimensional black hole. By extension we may find that black holes in our universe have similar funky 2 dimensional areas at their even horizons.
I am sure clickbait articles are part of it but there also seems to be several actual theories surrounding the idea of the nature of our universe relating to black holes.
Our universe is 4 d not 3 d
Nah, this universe is 3d.
I’m assuming you are thinking that time is the 4th dimension and we have time here so we are 4d?
Time may be the 4th dimension, but in our universe, time doesn’t actually behave like a proper dimension. For one thing, dimensions should be spatially perpendicular to each other and time is not. We also seem to only be able to move one way through time whereas we can move back and forth through the other 3 dimensions.
Dimensions get weird and complicated. For the intents and purposes of this conversation it’s correct to say that the universe were experiencing now is 3 dimensional.
That’s actually a crazy take that time isn’t a dimension. We’ll if someone say the sky is purple who am I to argue?
Like I said, time is likely a dimension. It just doesn’t behave like a proper dimension in our universe / reality.
Neither does light…
3+1, not 4D (we cannot move freely in time). They’re referencing the holographic universe theory, or holographic principle. PBS Spacetime has a good episode on the holographic universe theory.
YOU can’t move freely in time. Don’t speak for me.
Ok, I can’t either. But still…
I think I can move freely in time, just not voluntarily…
Sometimes I go through a whole day in like a minute, sometimes I blink and it’s Monday already.
Or maybe it’s working nights has that effect?
Freely means both directions, not just different speeds in one direction.
So, I can freely move through time if I consider alcohol as my time machine.
That’s more skipping forward in time, but then slowing down time when you come to the next day.
lol everything is relative.
You move through time every second…
Walk in the other direction then, let’s see how that goes.
That not how you do it. Watch a documentary called edge of all we know. Someone much smarter then you has that opinion.
Moving through time is not equal to having free motion through time. It should frankly be embarassing to you for failing to understand that basic fact of reality…
Sure you know more then the wheel chair guy gj
Three spacial dimensions, which is normally what people mean when they say that, unless they specify otherwise. For example, we call them 3D game engines, not 4D. Yes, there’s also a time dimension that is special. It cannot be moved through freely.
How not? Do you not save your progress? Do you not old up old files? Really think bud
Do you have any idea how little that narrows things down?
Yes, but if you’re beyond the event horizon of a black hole time becomes basically* irrelevant. You could literally turn around, look back out towards the rest of he universe, and watch all of time play out in the blink of an eye.
You know that scene in Interstellar where they land on the planet for 5 minutes, but 20 years passes for everyone else due to the planet’s mass? It’s the same thing, but a billion-billion-billion times more severe.
No, time does not become irrelevant. It’s perfectly normal for things inside the black hole. Here’s the space time diagram for our universe on the right, and a black hole at the top-left. Time is the vertical axis, space is the horizontal. The speed of light is a 45° angle, and the solid lines are event horizons. The hourglass shapes are the cones of all your possible futures and pasts (aka, anywhere that isn’t faster than the speed of light from a position). Notice the space-time diagram looks exactly the same on the other side of the horizon. To get back through though you’d have to travel faster than that 45° angle, which is impossible.
Edit: I remembered there’s a PBS Space Time video that will help you understand this if you don’t. It goes a lot further than just this version of the diagram.
I’m aware of the Penrose diagram and also watch PBS SpaceTime :)
But I was referring more to the frame of reference of our universe vs that of being inside a blackhole (assuming you could magically avoid being ripped apart by gravity). To an observer inside a blackhole, “time” on the outside would blink by almost instantly. I wasn’t talking about moving through an infinite universe or near/into a black hole. Just stationary, floating just beyond the event horizon, looking out. Hence the asterisk on basically*.
I was leading them to what MotoAsh posted. But they beat me to it while I was typing.