Is e Normal?
mathpages.com
mathpages.com
EDIT: It is easily possible for simply normal numbers, i.e. if you only consider single digit frequencies but not frequencies of digit pairs, triples and so on. 0.(0123456789) is simply normal in base 10 because every digit occurs with frequency one tenth but it is not normal in base 10 because only ten out of one hundred digit pairs occur. But it is also not simply normal in base 10¹⁰ because it then consists only of the single digit representing 0123456789 repeated indefinitely.
Brought up here as well: https://news.ycombinator.com/item?id=10966819
[1]http://crd-legacy.lbl.gov/~dhbailey/dhbtalks/dhb-nonnormalit...
Wikipedia does this, adding the extra term "simply normal" for the case where we are talking about relative to a single base:
We say that x is simply normal in base b if
the sequence S(x,b) is simply normal, and
that x is normal in base b if the sequence
S(x,b) is normal. The number x is called a
normal number (or sometimes an absolutely
normal number) if it is normal in base b
for every integer b greater than 1.
For the purposes of explanation, especially to non-technical audiences, I think the approach taken is fully justified. <span style="font-family:Symbol">p</span>The author probably did see a "pi", but should have been using an embedded font, or even better, the unicode "GREEK SMALL LETTER PI", π.
[1]: http://www.fileformat.info/info/unicode/char/03c0/fontsuppor...
<span style='font-family:Symbol'>p</span>
Apparently the Symbol typeface has π as p: https://en.wikipedia.org/wiki/Symbol_(typeface)#Encoding. I guess that ones who has the correct font installed will see the expected character.> Postscript: In November 2013 I received an email from Dan Corson informing me that, using digits of e computed by a program called “y-cruncher”, he had checked the number of CPSs up to 100 million digits, and found that it does finally approach the expected value, although even by this point it has not quite ever reached the expected value
It's generally expected that non-integer square roots are normal, and yet they always have repeating CFs.
All that combines to mean that I would be surprised if e turns out not to be normal.
Seems like a case for the high-bandwidth high-latency hard-drive-by-mail method.
Yes, and obviously so. Take a (base 10) normal irrational and divide it by 10^1000000000000. The first trillion or so digits of the result will be 0, but the result is still irrational (because duh) and (base 10) normal because the frequencies of the digits have to converge in the infinite limit and giving one digit a large finite head start won't change its overall proportion in the limit. QED.
Note that for a base 10 normal irrational by the definition of "convergence" in this case means || (number of digits of value a) / (number of digits of value b) ||_\infty < ε (sup norm over all a, b from 0 to 9, a ≠ b) for some ε > 0 such that for some fixed n (the number of digits in the decimal expansion, halted), we have that whenever N > n this inequality holds.
In the case where there are a fixed number m of leading "a"s (whatever digit a is), we have ||(m + dig_a)/(dig_b)||_\infty = ||m/dig_b + dig_a/dig_b||_\infty -- we only need this to be less than SOME fixed ε (not necessarily the same ε as above) for every N > n for some n we choose.
By assumption ||dig_a / dig_b||_\infty < ε whenever n > N. Choose n' > n such that dig_b satisfies m/dig_b < ε
(Note: this is possible as dig_b increases as n' grows: since m is constant and if dig_b were to be constant for n > N' then ||dig_a/dig_b||_\infty would be larger than ε for some n).
Then we have ||m/dig_b||_\infty < ε and ||dig_a/dig_b||_\infty < ε so ||m/dig_b + dig_a/dig_b||_\infty < 2ε.
Thus it converges -- satisfying the same definition as above chooseing n = n' and ε = 2ε.
If bits were copyrighted, you could just transform them into different bits. Change a single bit and then it's no longer copyrighted. Or xor them all. Or only every other bit. Or xor the whole thing with a different file, like a one time pad.
You could also change the content itself. Say it's a video. Shift all the pixels to the right. Or tint it slightly red. Or play it on a monitor and record it with a camera, then invert the resulting video.
There are an infinite number of possible transforms that result an infinite number of possible bits. What matters is information, not bits. They are not the same thing! Information is the bits, and the method you use to transform them together.
Often it's proposed that you can compress a file by storing the index where it occurs in pi. The problem is the index where your file starts will be bigger than the actual file! So you no longer need the file, but you still need this other set of bits that represents the index. The bits have changed, but the information has not.
If you don't have the index, then the whole procedure is entirely useless. Yes, pi theoretically contains season 5 of breaking bad - and an infinite number of variations and derivative works of it. But you will never ever find it unless you already know where to look.
And no computer could possibly calculate pi to that many digits in millions of years, so the whole thing is impractical anyway.
I know the parent comment was a joke, but the idea is serious. I've seen a lot of people have really weird ideas about copyright and illegal numbers.
Anyway those examples are trade secrets and other legal issues, they weren't copyrighted.