# Adding another time axis to space-time diagram

#### binbots

Can we add another time axis to Einsteins space time diagram? Since space and time are one thing they can be represented by one axis. The other axis can be a cosmological constant average axis. By adding this extra term can mass and energy be measured by a time scale relative to the expanding universe?

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#### PeterDonis

Mentor
Can we add another time axis to Einsteins space time diagram?
Not unless you come up with a theory that uses two time dimensions. There is no such theory currently known.

Since space and time are one thing they can be represented by one axis.
No, they can't. Space and time are still different dimensions of spacetime, and require different axes to represent them in a diagram.

The other axis can be a cosmological constant average axis.
What does this mean? It doesn't make any sense to me.

#### binbots

If there was no quantum fluctuations in the CMB then the expansion of the universe would have been smooth. This universe would have a average energy density after 13 billion years as well .
It doesn't require 2 time dimensions. I am only separating one time into two in order to find a different value of time.

#### PeterDonis

Mentor
If there was no quantum fluctuations in the CMB then the expansion of the universe would have been smooth. This universe would have a average energy density after 13 billion years as well .
This is true, but I don't see what it has to do with the topic of this thread. If you're just looking at the difference between the actual energy density in our actual universe, as a function of position, as compared to the average, this is fine, but what does it have to do with time?

It doesn't require 2 time dimensions. I am only separating one time into two in order to find a different value of time.
Still doesn't make sense to me. Do you have a reference for any of this? It looks to me like a personal theory, and PF does not allow discussion of personal theories. If, OTOH, you are asking about standard cosmological models, you'll need to specify which ones and what aspects of them you are asking about.

#### binbots

A smooth universe would occupy a larger space-time than ours at this moment. Therefore it would be further into the future than our own. We can use this as a back drop to set a marker of time ahead of use. The more energy or mass a object has the longer it will take to get the marker. Therefore the higher the mass the further back in time an object is.
I wouldn't call this a personnel theory. I was just hoping that people who know a lot about relativity and Minkowski diagrams could tell me If it made any sense.

#### Dale

Mentor
Then please provide a reference by PM and we can reopen the thread. As it is we are just trying to guess what you have in mind.

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