On Apr 28, 2010, at 20:49, Michael Ash wrote:

> Actually, while there are finite decimal numbers with no finite binary
> representation, the reverse is not true. Every binary number can be
> represented by a finite number of decimal digits. I believe this is
> because 2 is a factor of 10. To prove it to yourself, just take
> successive negative powers of two and notice how you never get a
> repeating decimal. The fractional part of a binary float is just a sum
> of various negative powers of two, and if the individual components
> are finite, the result must be as well.
I'm pretty sure that what I said was 100% accurate this morning, but that the 
fundamental mathematical laws of the universe have changed since then and now 
I'm wrong. You're right.

>> Plus, you'd have to expect that encoding doubles would require, in the worst 
>> case, at least 309 significant digits, which is a much longer string than I 
>> want in my archive.
> 
> I think you've flipped your math around somewhere here.

Yup, I noticed earlier I'd gone overboard with this, and got myself mixed up 
with the maximum exponent.

Good thing I published a disclaimer earlier, or otherwise I've have to feel 
embarrassed now.

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