Answer: Could there be extra time dimensions?

Transcript

Read and summarize the transcript of this video on Glasp Reader (beta).

Summary

In this video, the speaker discusses the concept of extra dimensions of time in the context of string theory. While there are 11 dimensions in string theory, including the four dimensions we are familiar with, the possibility of additional time dimensions is explored. The speaker explains that time is fundamentally different from space and that introducing multiple time dimensions leads to various problems and contradictions, such as causality paradoxes. The speaker acknowledges that attempts to incorporate extra time dimensions have been made, but so far, they have not been successful. The possibility of a framework where both space and time are emergent concepts is also mentioned. Ultimately, it is uncertain whether there could be more dimensions of time, as no sensible description of physical reality without a unique time has been conceived yet.

Questions & Answers

Q: What is the concept of extra dimensions in string theory?

In string theory, there are a total of 11 dimensions, which includes the four dimensions of space and time that we are familiar with. The idea of extra dimensions suggests that there are additional spatial dimensions beyond what we can perceive.

Q: Is it possible for some of the extra dimensions to be time-like?

Yes, it is theoretically possible for some of the extra dimensions in string theory to be time-like. This raises the question of whether there could be additional time dimensions apart from the one we currently experience.

Q: Has anyone explored the possibility of extra time dimensions before string theory?

Yes, the concept of extra dimensions dates back to the 1920s with the work of Kaluza and Klein. However, it was Andre Sakharov who wrote an interesting paper before the advent of string theory, exploring the possibility of extra time dimensions.

Q: How does time differ from space in terms of dimensions?

Time is fundamentally different from space. While in ordinary space, we can move in circular paths and return to the same point, time only has one dimension and movement is unidirectional. Introducing additional time dimensions would allow for circular movement in time, which leads to various problems and paradoxes.

Q: What are some of the problems associated with having multiple time dimensions?

Introducing multiple time dimensions leads to inconsistencies and contradictions, particularly regarding causality. The possibility of going back in time and altering events creates causality paradoxes, such as the ability to kill one's own grandmother and thus negating one's existence. Thus, all attempts to incorporate extra time dimensions have resulted in breakdowns of causality.

Q: Have there been any successful attempts to incorporate extra time coordinates?

So far, no successful attempts have been made to incorporate extra time coordinates within a consistent framework. People have tried to either explain away the existence of extra time dimensions or show that they are unobservable, but this hasn't resolved the contradictions. The problem of multiple time dimensions remains unsolved.

Q: Is it possible that a framework with both space and time as emergent concepts could have more dimensions of time?

It is conceivable that in a framework where both space and time emerge as concepts, the number of dimensions of time could also be emergent. This would mean that the concept of time, including the number of dimensions, is not fundamental but arises from a deeper understanding of the nature of reality. However, no such framework has been developed yet.

Q: Is there a sensible way to describe physical reality without a unique time?

As of now, no sensible way of describing physical reality without a unique time has been conceived. Time is a fundamental aspect of our theoretical framework, and its uniqueness plays a crucial role in maintaining causal relationships and avoiding paradoxes. While it is interesting to speculate about the existence of multiple time dimensions, there is currently no solid basis for such a concept.

Takeaways

The concept of extra time dimensions in the context of string theory raises intriguing questions about the nature of time. However, including multiple time dimensions leads to inconsistencies, paradoxes, and breakdowns of causality. Although attempts have been made to resolve these issues, no successful framework incorporating extra time dimensions has been developed. It is uncertain whether a sensible description of physical reality without a unique time is possible. The possibility of both space and time being emergent concepts remains open but requires further exploration.