# Do multiple dimensions exist? [duplicate]

I came up with this line somewhere:

To properly experience $$n$$ dimensions the retina of the organism should be at least of $$n-1$$ dimensions.

And human eye has $$2$$ dimensional retina, so we can experience at most 3 dimensions properly.

Now my question is:

1. Do more than 3 dimensions exist?

2. What is the proof that 'there exist only 3' or 'more dimensions do exist'?

• Unrelated to dimensions, but multiple instances of "do" in your title do exist. – Marc van Leeuwen Nov 27 '15 at 9:18
• I doubt this assertion. Our 2-dimensional retina can by no means observe the third dimension, as is demonstrated with lots of optical illusions. We only have a 2-dimensional projection to work with which can be the result of an infinite number of 3-dimensional arrangements. With two eyes/retinas the situation is different but one could argue that the resulting overall optical system is actually 3-dimensional. – Peter - Reinstate Monica Nov 27 '15 at 10:54
• On the contrary I would contend that in order to fully observe 3-dimensional objects including their insides one needs an 4-dimensional retina, or at least one with 3 dimensions of which one is orthogonal to the dimensions of the object. We as 3-D beings can fully grok a surface, but another surface in the same plane as the observed one could not. Same with 3 dimensions. In order to look inside a body you need another dimension. – Peter - Reinstate Monica Nov 27 '15 at 10:58
• It's interesting to note that jumpings spiders have several retina layers, so the are three-dimensional. – jinawee Nov 27 '15 at 12:49