I frequently hear people say that the universe is based off of a 4th-dimensional space-time continuum. As a result, it could hypothetically do things like loop on itself if you went in one direction long enough. However, people often point out that the 4th dimension is not time, but rather an independent spacial dimension. At the same time though, they might talk about how the 4th dimension actually is time in the space-time continuum, which makes no sense to me at all. Is the 4th dimension time in the space-time continuum, or something else?
In: 4
The easy ELI5 explanation is that a dimension is just a word for a number (or direction) that can’t mean anything else
On Earth you can talk about North vs South, which is just 1 dimension describing how far away from the equator
East vs West is a second dimension describing how far away from a certain line you are. Even though it’s a second dimension it’s still one number
Then you have altitude, the one number that describes how high you are (measured against sea level but that’s kind of arbitrary. Could be measured against anything as long as it’s consistent)
A 4th dimension is just another number that describes something that you can’t describe elsewhere.
In the case of time, the when is something you need without realizing it. If I’m going to meet up with you, I need a time to meet up with you otherwise I might be waiting at a place for a decade.
The fact I need a time (which is just some kind of number) is what makes it a dimension
Latest Answers