We found that there are two readings we believe is good to put in as one angle is to explain from maths equation and another one is suggestion why it cannot be visualized.

In summary, our finding till now is still very as below:-

1. In theory, science pointed to extra dimensions are available. (No matter how many)
2. In practicality, we cannot feel nor visualize.
3. Physical evidence is needed and is still under investigation.
4. Detail of each extra dimensions are still suggestion beside our existing 3 dimensions.

http://blogs.discovermagazine.com/cosmicvariance/2009/03/30/why-cant-we-visualize-more-than-three-dimensions/

http://physics.stackexchange.com/questions/10527/is-there-any-theoretical-proof-for-more-than-4-spacetime-dimensions