More i think about it, the less it makes sense. Lets take worm holes. If your universe is 2d, you have to bend it trough a higher dimension for a wormhole to work. In 3d, youd have to bend our universe in- time? How does that make sense? Id think that 4d is more of a “bridge”, a middle between alternative realities. a room with doors to other places to make it imaginable. Time is a dimension to travel trough, but its not a higher nor lower dimension, it happens in all dimensions at once, and even in our 3d reality, we still travel trough time, just fowards. It just doesnt make sense for time to be the 4th dimension. Am i wrong here?
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Yes, obviously you are. If you count time as a dimension you get tangible results doing math that give you observable, measurable outcomes. And that’s really where the discussion ends.
Yes. In relativity (both special and general), we learn that time is a dimension similar to the three spatial directions that under certain conditions (e.g., motion at relativistic speeds) can “rotate” into the other dimensions. That is, you just like how you could define points on a 2-d grid (like say street map of Manhattan) in terms of avenues/streets, you could also define them in terms of dimensions of (north-south) and (east-west) (because the street grid of Manhattan are about 29deg off true North). Similarly, when you travel at relativistic speeds, you will start to observe things like length contraction and time dilation as time coordinates will be shifted into spatial coordinates.
Time isn’t put in as an extra physical dimension to embed wormholes or anything. If you see the diagram of a curved 2-d sheet with a wormhole linking through, you should be very clear that there’s no time dimension being explicitly shown.
We arrange to meet, we establish the x,y,z coordinates in space and we assign a time value for when we will be there, simples.
length, width, height and time, 4 dimensions.
First off wormholes probably aren’t real, though we can’t exactly say for certain. Even still, the math that describes wormholes does not require higher dimensions to function.
We live in a 4-dimensional spacetime. All the dimensions are co-equal dimensions.
Everything travels at the speed of light all the time. If you are at rest in the spatial dimensions, then you are travelling at 1 second per second in time. If you move in the spatial dimensions then the magnitude of your velocity vector in the time dimension is shorter, so you move through time at less than one second per second as observed by someone outside your moving frame of reference. You, of course, remain stationary in spatial dimensions as the universe moves around you.
None of this works unless time is a dimension exactly like space.
Because this is deeply counterintuitive, the only way I have found to explain it to people to the extent they really understand it is to do the actual math of general relativity.
I recommend Sean Carrol’s lecture notes and book.
Think of it as duration
Time isn’t the “4th dimension” – it is one of the 4 dimensions. There isn’t anything that specifies an “order” to them. Don’t think about it in terms of wormholes – think about it in terms of how you can specify your location in the universe. To fully describe where you were, you need 3 spatial coordinates and a time. 4 dimensions.
even in your 2D world, if you want two objects to meet, they have to agree at what time to meet. that is the third dimension of that world