Undergrad String theory in 4 dimensions?

[TheHeraclitus]

TL;DR

Does Non-critical string theory really allow only 4 dimensions? Why it's not more popular?

Non-critical string theory, on Wikipedia it says:

Although this allows the construction of a string theory in 4 spacetime dimensions, such a theory usually does not describe a Lorentz invariant background.

Has it been experimentally disproven or are other reasons for its apparent obscurity?

 

[Demystifier]

Extra dimensions in string theory are a virtue rather than a nuisance. That's because theory in more dimensions is rich enough to accommodate a model as complex as 4-dimensional Standard Model, through various types of compactification or brane constructions. String theory in 4 dimensions, on the other hand, lacks such additional degrees of freedom so it lacks the needed richness. It could be a theory of something, but not a theory of everything.

 

[Kaluachchi]

What are the strings in string theory made of? This question puts one back into square one. The reason Einstein's theory of relativity does not work in sub atomic level. Like many theories it involves Calculus. Calculus always assumes infinity as something real when it is not. That is the basis of these theories. We do not need strings to define matter. It could be simple presence vs non presence. Just like 1 and 0. When matter is compressed to the maximum (What thought to be infinity before but there is a limit to infinity which defines this maximum.) then you can achieve the zero. The same zero present in black holes and outside the universe or before big bang.