# Understanding Time as a Dimension: A Detailed Explanation

• quant
Besides, entropy is a statisitcal term, and time is not a statistical event.Please, let's not complicate this discussion with irrelevant or incorrect statements.In summary, the concept of time as a dimension refers to its role in determining an object's position, size, and direction of movement. It is not just a measurement, but a dimension in its own right that is intertwined with the three spatial dimensions. The nature of time is still not fully understood, but it is believed to be related to concepts such as entropy and the expansion of the universe.

#### quant

Could someone give me a detailed explanation of *what* the Time dimention is? I don't mean for someone to start telling me about a clock, but rather to understand relativity you must understand Time as a dimension. I was wondering if anyone could help me out with that? Thanks!

Originally posted by quant
Could someone give me a detailed explanation of *what* the Time dimention is? I don't mean for someone to start telling me about a clock, but rather to understand relativity you must understand Time as a dimension. I was wondering if anyone could help me out with that? Thanks!

This thread should, perhaps, be in the Theoretical Physics Forum.

It is a good question that you ask. First off, a dimension is coordinate, which can be used to ascertain the position, size, and/or direction of movement, of an object. Position doesn't just refer to "where" something is, as many think. "Where" you are, refers to your position relative to the spatial dimensions. "When" you are, refers to your position on the time dimension. So, I can tell you the size of the Great Wall of China (for example), but unless it has also existed for a certain amount of time.

One common mistake is saying that the T dimension is just a measurement - of planets spinning, clocks ticking, atoms decaying, etc. Actually, time is a dimension of it's own, and does not measure, but is measured.

I hope I have been clear, and if you need clarification, or if I didn't adequately answer your question, just say so. But, I am in a hurry now, so I can't do my usual proof-reading, sorry.

Sorry about it being in the wrong topic.

Well, everything you just told me, i already knew. But, i guess i just need an image of it. Is there anything further anyone could add to explain it a bit more please?

Thanks.

Time in special relativity's spacetime is a zeroth (space being first, second, and third) dimension that juxtaposes spatial dimensions in a four-dimensional (conical) Pythagorean theorem:

x^2+y^2+z^2=(ct)^2 for "lightlike" surfaces,

x^2+y^2+z^2<(ct)^2 for "timelike" regions,

x^2+y^2+z^2>(ct)^2 for "spacelike" regions.

All light comes to observers through their contiguous lightlike surface. Inertial events that can affect them mechanically exist in relative timelike regions, and events out of direct communication exist in spacelike regions.

Physics also allows for time defined by entropy (the second law of thermodynamics), cosmology (the big bang), and radiation (quantum decay).

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Welcome to Physics Forums, quant!

Originally posted by quant
Could someone give me a detailed explanation of *what* the Time dimention is? I don't mean for someone to start telling me about a clock, but rather to understand relativity you must understand Time as a dimension.

To add to what the others said so well...

Time is part of the very fabric of the universe itself. It is an aspect of the universe that has a certain behavior that is directly tied to the other dimensions (3D space). A full understanding of its nature is not available at this time (just like a full understanding of space or gravity is not known). Whe can measure it and see its effects, but is it continuous/quantized? How does it work? Don't know.

See sig.

Originally posted by quant
Could someone give me a detailed explanation of *what* the Time dimention is? I don't mean for someone to start telling me about a clock, but rather to understand relativity you must understand Time as a dimension. I was wondering if anyone could help me out with that? Thanks!

quite simply, time is an increase of entropy (and what Mentat said is of great importance, esp. in relativity).

BTW, should relativity be capatilized or not?? I am very frustrated; I see it captilized one day, and the next, lower cased!

Huhhh? What has entropy got to do with it?

That how time's defined. It never occurred to me that there would be relationship..

Maybe, it has something to do with the expansion of the universe. For example, time-space are one in relativity. So naturally, as the universe's entropy increases, so does time.

Personally, I don't see the benefit in defining time via entropy. Sure, both are on a continuous one-way line, but I think they proceed at different rates.

## 1. What is time as a dimension?

Time as a dimension refers to the concept that time is a fundamental component of our universe, just like the three dimensions of space (length, width, and height). It is often described as the fourth dimension and is necessary for defining the position and movement of objects in space.

## 2. How is time different from the other dimensions?

Unlike the three dimensions of space, time is not static and can be perceived differently by different observers. This is due to the phenomenon of time dilation, which is the stretching or shrinking of time depending on the relative motion and gravity of an object. Time is also considered to be unidirectional, meaning it can only move forward and cannot be reversed.

## 3. Can time be traveled through like the other dimensions?

While time travel is a popular concept in science fiction, it is not currently possible according to our current understanding of physics. However, some theories, such as Einstein's theory of general relativity, suggest that time travel may be possible in certain circumstances, such as near black holes or through the use of wormholes.

## 4. How does time as a dimension affect our daily lives?

Time as a dimension plays a crucial role in our daily lives as it allows us to measure the duration of events and the intervals between them. It also influences our perception of reality, as our experiences and memories are tied to the passage of time. Additionally, our modern society is heavily reliant on precise timekeeping for various purposes, such as transportation, communication, and scheduling.

## 5. What are some ongoing research and developments related to time as a dimension?

Scientists and physicists are continuously studying and exploring the nature of time as a dimension and its relationship to other fundamental forces in the universe. Some current areas of research include the concept of time symmetry, the role of time in quantum mechanics, and the search for a unified theory that can reconcile the theories of relativity and quantum mechanics.