# E-folding explaination needed

1. Feb 27, 2013

### Mordred

I've tried several searches on the term e-foldings, However I've been unable to find any decent write ups on the terminology or calculations. Surprisingly even Wiki doesn't have much on the subject.

2. Feb 27, 2013

### Staff: Mentor

Well, let's look at two articles from wiki.

First: http://en.wikipedia.org/wiki/E_folding
Second: http://en.wikipedia.org/wiki/E_(mathematical_constant)
If I'm reading this correctly, it appears that e-folding is simply the amount of time it takes for space to expand by approximately 2.71828 times its original size. Does that help at all?

3. Feb 27, 2013

### Mordred

Ah yeah it does the second link provided the details I needed. I couldn't figure out how they derived the 2.71828 value thanks so much

4. Feb 27, 2013

### marcus

Quite right! And loge 10 = 2.3
So 60 e-folds is the same as 26 "ten-folds"

Distances increasing by a factor of e60 is the same as their increasing
by a factor of 1026