Reasons for 1D Time vs 2D Time: Metrics Explained

  • Context: Graduate 
  • Thread starter Thread starter Dmitry67
  • Start date Start date
Click For Summary
SUMMARY

The discussion centers on the implications of having one-dimensional (1D) time versus two-dimensional (2D) time in theoretical physics. Key points include the stability of 3D space compared to the instability of 4D systems, and the potential for closed timelike curves in a universe with two timelike dimensions, which could lead to violations of causality. The conversation highlights the mathematical relationship between time dimensions and the behavior of light, specifically noting that in a 2D time framework, lightspeed could become instantaneous in certain directions.

PREREQUISITES
  • Understanding of theoretical physics concepts, particularly spacetime dimensions
  • Familiarity with Maxwell's equations and their implications in physics
  • Knowledge of causality and its significance in the context of time
  • Basic grasp of mathematical definitions related to spacetime metrics
NEXT STEPS
  • Research the implications of closed timelike curves in theoretical physics
  • Explore the stability of higher-dimensional spaces in physics
  • Study the mathematical foundations of spacetime metrics and their applications
  • Investigate the consequences of multiple time dimensions on causality
USEFUL FOR

The discussion is beneficial for theoretical physicists, mathematicians, and students interested in advanced concepts of spacetime and causality, particularly those exploring the implications of dimensionality in physics.

Dmitry67
Messages
2,564
Reaction score
1
Metrics, +++- vs +++--

There are reasons why our space is 3D. In 2D all systems are bound, in 4D they are unstable.

What 'reasons' are for having 1D time vs 2D time? I don't want to go deep into the AP stuff; just may some constraints one might know like 'Maxwell equation won't be consistent' etc.
 
Physics news on Phys.org


With 2 timelike dimensions you could have closed timelike curves even in flat spacetime. I don't think we would have causality in such a universe.
 


hm, interesting, you're right.
Yes, if there are 2 "times", t and u, then null path can be defined as
s^2 = t^2 where u=0 for example,
which makes lightspeed 'instantaneous' in some directions of time.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 95 ·
4
Replies
95
Views
8K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 12 ·
Replies
12
Views
5K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 81 ·
3
Replies
81
Views
15K