# Are there more than 4 dimensions?

ogb
Science 17 Jul '17 19:59
1. 17 Jul '17 19:59
How can scientists prove more than 4 dimensions?
2. 17 Jul '17 21:06
By experiment.

First they need a theory with more than four dimensions that makes predictions.
3. 18 Jul '17 00:28
you mean, like String theory
4. moonbus
Uber-Nerd
18 Jul '17 04:59
There are as many dimensions as needed. They cannot all be visualized, of course, because most of them have no sensory analogues.

https://en.m.wikipedia.org/wiki/Topological_data_analysis
5. 18 Jul '17 06:28
Originally posted by ogb
How can scientists prove more than 4 dimensions?
In physics and mathematics, one can and does use any number of dimensions depending on the problem at hand, including zero, one, any finite number, infinite and fractional.

You're probably referring to string theory. While I'm not an expert on the topic, as far as I understand many variations of string theory require more than 4 physical dimensions. You would show that these theories are correct by empirically verifying their predictions. In the case of string theory, this is extremely hard, which is why few people are working on the topic.
6. sonhouse
Fast and Curious
19 Jul '17 22:041 edit
Originally posted by @kazetnagorra
In physics and mathematics, one can and does use any number of dimensions depending on the problem at hand, including zero, one, any finite number, infinite and fractional.

You're probably referring to string theory. While I'm not an expert on the topic, as far as I understand many variations of string theory require more than 4 physical dimensions. ...[text shortened]... case of string theory, this is extremely hard, which is why few people are working on the topic.
Here is a book I read:

The Trouble with Physics, by Lee Smolin:

https://en.wikipedia.org/wiki/The_Trouble_with_Physics

This Wiki gives a 50 cent tour of the book. He hates string theory, bottom lineđź™‚

And another physicist chimes in: Peter Woit

https://en.wikipedia.org/wiki/Peter_Woit

Woit and Smolin both object to string theory on the grounds it has yet to make a single prediction that can be tested by any kind of technology in the foreseeable future.