Many a times I see people giving awkward(as they are to me) examples of bending space/time or travelling 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?