# How many dimentions are known, what is there or what exists?

1. Jun 18, 2015

### alteredmind

ok so I have a question, I really don't know in witch subject this belongs but its either physics or astronomy I am guessing. Are all the dimensions in scientific theories just that only? a theory or theories and nothing more like having more then 4 dimensions witch goes up to 11 dimensions in the universe? there is the first dimension, second dimension, 3rd dimension and the 4th dimension is time, correct? whats if that is all there is? doesn't that make things more simple instaid of all the mental complexity?

2. Jun 18, 2015

### Staff: Mentor

I'm sorry, I cannot understand what you're trying to ask here.

That is correct. The 4 dimensions correspond to the 4 numbers required to specify the location of an event or object in spacetime. Three numbers correspond to each spatial dimnension (think of them like the X, Y, and Z axes) and the 4th represents the position in time.

Theories with more than 4 dimensions might be much more complicated, but they have the potential to better explain our observations about the universe. No theory with more than 4 dimensions is currently considered 'correct'. All theories with more than 4 dimensions are purely theoretical/hypothetical at this time. It may turn out that we don't need more than 4 dimensions to explain the universe, or it may turn out that we do. Only time will tell.

3. Jun 18, 2015

### jerromyjon

The explanation which made the most sense to me was that each additional variable is another dimension. It isn't necessarily a dimension in space, like the 3+1 dimensions of space and time, but another dimension in the mathematics required to describe interactions.

4. Jun 18, 2015

### CWatters

Correct. We don't have proof that extra dimensions exist.

Some theories assume that the extra dimensions are curled up very small. Experiments have been done that attempt to put an upper size limit on the extra dimensions.