What do we call the dimension measured with time?

In summary, the conversation discusses the concept of time as a dimension and its relationship with gravity. The three classical dimensions of length, breadth, and width are described as simply a means of measuring a physical property, while time is seen as a measuring tool that can be affected by physical means. The idea that time is a dimension is further explored in the context of black holes and special relativity, which show that both space and time can change depending on the observer's perspective. Ultimately, the conversation raises questions about the nature of time and its role in measuring dimensions.
  • #1
notsureanymore
I am told time is a dimension, indeed the 4th dimension

but then I am also told time is effected by other things such as gravity

These two seem to be at odds with each other.

the three classical dimensions are length breadth and width. yet no one I know of argues that gravity or any other force can effect them. they are indeed simply a means of measuring a physical property.

If the physical property of an item changes say the force of gravity causes a box to compress in the height dimension. its height is said to have changed. not the dimension we call height.

if the ruler is effected by gravity such that both the ruler and the box are compressed. no-one argues that the dimension of height has been warped.

So given the above it tells me that a dimension is unchangeable, it is a concept and has no physical attributes that can be effected.
The common belief today is that gravity effects time in such a way as the strength of the field is relative to the 'speed of time'.

This to me says that 'time' is a measuring tool, a ruler. and as a tool it is effected by normal physical means.

So if time is the tool we use to measure a 'dimension' what do we call that dimension?
 
Physics news on Phys.org
  • #2
You're mistaken. The fourth dimension accounts for space and time. The three physical dimensions, can be warped under great gravitational and acceleration scenarios. Take a black hole for example. That can warp space, and time.

However, to account to the last part of what you said... Time is a hard thing to explain. What is the past, future, present, and why things in the past can be "erased", and even if the "past" existed, are all things that take quite a bit of explaining and trying to understand. Braine Green does quite an adequete job explaining the whole situation, if you wish to take a look at The Fabric of the Cosmos.
 
  • #3
So in a black hole a 1 metre tall box crushed to 1 millimetre in height is still a 1 metre tall box?
 
  • #4
notsureanymore,

In special relativity, both space and time dimensions can change, depending upon who's looking. If a spaceship flies past you at high speed, you'll not only see the spaceship as if it were squashed (change in spatial dimension), shortened in the direction of motion, you'll also see the people inside it moving slowly (change in the temporal dimension).

- Warren
 
  • #5
notsureanymore said:
I am told time is a dimension, indeed the 4th dimension

but then I am also told time is effected by other things such as gravity

These two seem to be at odds with each other.

the three classical dimensions are length breadth and width. yet no one I know of argues that gravity or any other force can effect them. they are indeed simply a means of measuring a physical property.
No. General Relativity shows that gravity is a warp in spacetime. It also shows that there is less difference than we usually think between the three dimensions of space and the dimension of time: this is clear from the Lorentz transform. Take a look on Wikipedia. You will find that the Galilean transform (which you are used to thinking in terms of because of your life experience) changes space, but not time; however, the Lorentz transform (which we know to be more correct because of the failure of the Michelson-Morley experiment) changes both space and time, and in fact changes them into one another. Look at the equations and you will see what I mean. The interpretation of this is that spacetime is all one thing. So it is by no means surprising that if gravity warps space as GRT claims, then it warps time as well.
 
  • #6
Ok I have to ask this question then, Sorry if it seems inane

If I was to fly into a black hole. as I descended into the black hole would I be crushed or would it appear to the outside observer that I am crushed, but to me I would not notice the change at all?
 
  • #7
notsureanymore said:
Ok I have to ask this question then, Sorry if it seems inane

If I was to fly into a black hole. as I descended into the black hole would I be crushed or would it appear to the outside observer that I am crushed, but to me I would not notice the change at all?

You would be torn apart by tidal forces but it would appear to a distant observer that it took an infinitely long time to do so.
 
  • #8
notsureanymore said:
the three classical dimensions are length breadth and width.
So if time is the tool we use to measure a 'dimension' what do we call that dimension?
That would be "duration".
 
  • #9
Chroot had the answer space (3 dimensions) is relative. I have to stop thinking in layman ways.

time *and* SPACE does distort, not just time.
 

1. What is the dimension measured with time?

The dimension measured with time is called "time" or "temporal dimension." It is often represented by the variable "t" in equations.

2. How do we measure time?

Time is commonly measured using a clock, which tracks the passage of time through periodic movements, such as the rotation of the Earth or the oscillation of a pendulum. Other methods include using the decay of radioactive elements or the vibrations of a quartz crystal.

3. Is time a physical dimension?

Yes, time is considered a physical dimension because it is an essential component of our physical universe and is inseparable from space in the fabric of spacetime.

4. What is the unit of measurement for time?

The most commonly used unit of measurement for time is the second (s), which is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium 133 atom.

5. Can time be measured in other units?

Yes, time can be measured in various units depending on the context. For example, we can measure time in minutes, hours, days, years, or even in nanoseconds, microseconds, or milliseconds for more precise measurements. Other units used for time measurement include the rotation of a planet or the lifespan of a certain species.

Similar threads

  • Quantum Physics
Replies
3
Views
294
  • Beyond the Standard Models
Replies
2
Views
2K
Replies
12
Views
3K
  • Quantum Interpretations and Foundations
Replies
3
Views
1K
Replies
15
Views
1K
  • Other Physics Topics
Replies
20
Views
3K
Replies
2
Views
2K
  • Quantum Physics
5
Replies
143
Views
6K
  • Quantum Physics
2
Replies
48
Views
4K
Back
Top