Does Bending Space/Time Have Credibility?

[aleemudasir]

Many a times I see people giving awkward(as they are to me) examples of bending space/time or traveling through different dimensions of space e.g. I once saw a person demonstrating bending of space/time by bending a sheet of paper(like U) and then joining the ends while marking one end with 2013 and the other end with 1000 BC with a pin, and then explaining that like these ends are now joined, similarly the space/time can be joined and we can travel from 2013 to 1000 BC if we bend the space. This was done by a person who is a pass out of one of India's top science college IIT-Bombay. Likewise, once I saw someone on TV on Discovery channel mixing two glasses of liquids of different colors while trying to make us understand about some space connectivity(this one really bounced over my head! :( ).
I just want to know whether such examples hold any credibility, are worth discussing, are acceptable among the scientific community or not?

 

[ghwellsjr]

Worthless junk, as far as I'm concerned.

 

[tom.stoer]

In most cases these examples can be understood as simplified representation of some aspects of an underlying physical principle. But in most cases they misrepresent other aspects!

So be careful, b/c if you start asking questions like "look, if I use this model and do xyz" then in most cases xyz belongs to the aspects not represented correctly and you are not asking questions regarding the physical principle anymore, but about the misrepresentation. The question is therefore not applicable. Any "explanation" using such representations should always come with a caveat.

 

[Naty1]

Almost all such examples have limitations, but may remain useful for initial and limited
understanding.

Regarding time travel, which you posted, consider reading about 'wormholes'.

For an example of a model and a good explanation of its uses and limitations, check this out:

THE BALLOON ANALOGY

http://www.phinds.com/balloonanalogy/

Obviously, some explanations and models are better than others.