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128-bit storage: are you high?

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Re: 128-bit storage: are you high?

#21

Post by barrkel »

cperciva wrote: post #8
ten7 wrote: post #6

Nice article, great calculation. There's a much simpler argument for 128 bit storage though: the observable universe has at minimum 10^79 atoms in it. Even if you could use each and every one of those atoms as a bit to store data, you'd still have more than 50 ORDERS OF MAGNITUDE left in ZFS for the rest of the data. We're probably safe.

You realize that 2 ^128 is much less than 10 ^79, right?

A handy rule: log of 2 to base 10 is a bit more than 0.3, so divide the power of 2 by 3 (i.e. approximately multiply by 0.3), and you'll get an approximation of the power of 10. By this, 2^128 is in the region of 10^40, a lot less than 10^79.

(It's actually about 10^38.5.)

Re: 128-bit storage: are you high?

#22

Post by space-monkey »

pyre wrote: post #19

A (2004) at the end would be nice. > I've had people tell me every year, for years, that Moore's Law was > about to end. I've said the opposite, and have yet to lose the bet. > Limits on spot density are fundamentally arguments about 2D storage. > Once we move into 3D -- and this work is already underway -- we will > get many more orders of magnitude to play with. This comment was made in 2004. Where are our '3D' sto…

http://www.electroiq.com/index/Semiconductors/sst-blogs/chip...

I doubt he was thinking flash memory at the time, but 3D storage is already in use. One of the bigger limitations with this is heat, so we have people writing papers like:

http://scholar.google.com/scholar?q=Thermal+via+placement+in...

Re: 128-bit storage: are you high?

#23

Post by jerf »

mbreese wrote: post #15
gwern wrote: post #12

Earlier quoted context omitted.

Does Lloyd actually say that? IIRC, he simply reuses the Bekenstein bound: https://secure.wikimedia.org/wikipedia/en/wiki/Bekenstein_bo... Which is more than 1 bit per atom. (It does seem implausible for 1 bit per atom to be right. I mean, atoms themselves vary in hundreds of ways - # of protons, # of electrons, etc. Just using each element to represent a byte would seem to get you more than 1 bit per atom.)

But they also vary in size significantly, so it wouldn't be practical to store 8 different types of atoms. I think adjusting the spin state of one atom for one bit might be the limit.

This is a discussion of the theoretical limits. They may be substantially higher than the actual engineering limits we can attain with real configuration of real atoms. (Or relevant other building blocks as appropriate.)

However, the theoretical limits turn out not be entirely useless even if we can never attain them in practice; they offer some insight about the nature of the universe, and it may yet be some thoughts on how the universe can process information that cracks open the problem of what happens in black holes, rather than what you might think of as conventional physics. There's been a lot of interesting work done in that area; for instance, read http://en.wikipedia.org/wiki/Holographic_principle and observe how many times the word "information" comes up.

Re: 128-bit storage: are you high?

#24

Post by jodrellblank »

acabal wrote: post #3

The most interesting thing in this article is the reference to "Ultimate physical limits to computation." It's something I never thought about before and honestly it kind of blew my mind a little bit...

See also: http://en.wikipedia.org/wiki/Computronium

Re: 128-bit storage: are you high?

#25

Post by anon114 »

acabal wrote: post #3

The most interesting thing in this article is the reference to "Ultimate physical limits to computation." It's something I never thought about before and honestly it kind of blew my mind a little bit...

I'll just leave this here:

http://en.wikipedia.org/wiki/Matrioshka_brain

Re: 128-bit storage: are you high?

#26

Post by ten7 »

aw3c2 wrote: post #13
ten7 wrote: post #6

Nice article, great calculation. There's a much simpler argument for 128 bit storage though: the observable universe has at minimum 10^79 atoms in it. Even if you could use each and every one of those atoms as a bit to store data, you'd still have more than 50 ORDERS OF MAGNITUDE left in ZFS for the rest of the data. We're probably safe.

10^79 = 10000000000000000000000000000000000000000000000000000000000000000000000000000000 2^128= 340282366920938463463374607431768211456

Ahh shit, totally lame brained that.

Re: 128-bit storage: are you high?

#27

Post by ten7 »

ten7 wrote: post #6

Nice article, great calculation. There's a much simpler argument for 128 bit storage though: the observable universe has at minimum 10^79 atoms in it. Even if you could use each and every one of those atoms as a bit to store data, you'd still have more than 50 ORDERS OF MAGNITUDE left in ZFS for the rest of the data. We're probably safe.

Yea, I screwed up. What the hell was I thinking? Thanks for down voting: it's deserved.

Re: 128-bit storage: are you high?

#28

Post by Dylan16807 »

acabal wrote: post #3

The most interesting thing in this article is the reference to "Ultimate physical limits to computation." It's something I never thought about before and honestly it kind of blew my mind a little bit...

The problem is that it's a poor reference for storage. It's focused on maximum computation in a certain chunk of matter, which is a massive waste of energy. One of the comments on the blog talks about charging individual electrons at five orders of magnitude less energy, at the cost of much more mass. It might be possible to optimize this down to a lake-sized level of storage mass and boiling energy.

Re: 128-bit storage: are you high?

#29

Post by count »

rbanffy wrote: post #4
iwr wrote: post #2

One day, aliens will use our oceans as heat sinks for their great galactic computer. And even then, ZFS will serve them well.

We can use a ZFS storage system to make the moons of Saturn inhabitable. That's Sealand taken to a whole new level. The network latencies are terrible, however.

Charles Stross wrote a book loosely incorporating this concept (Accelerando, I think).

Re: 128-bit storage: are you high?

#30

Post by jessriedel »

sammcd wrote: post #16
acabal wrote: post #3

The most interesting thing in this article is the reference to "Ultimate physical limits to computation." It's something I never thought about before and honestly it kind of blew my mind a little bit...

A proffessor once told me never to believe the physical limits. He mentioned how a wavelength of light was the smallest we could etch silicon. He then mentioned that today (at the time of the class) we were etching with 1/20th the wavelength of light. He then said that he could not explain how the new 1/20th of of a wavelength drawing works because new physics had been learned, and it had not been in his physics book…

Your sentiment is healthy, but you should distinguish between "we don't know of a way to do X" and "X is impossible under the current laws of physics". The former is like etching sub-wavelength silicon. The latter is like moving faster than the speed of light.

> new physics had been learned, and it had not been in his physics book.

Again, there is a difference between learning new techniques and phenomena running on top of known physical law, and learning new fundamental laws. When engineers say "new physics", they refer to the former, but when physicists say "new physics", they refer to the latter. And there hasn't been any new physics, more or less, since the 60's.

The computational limits are thought to be encoded in the fundamental laws, in a way very analogous to the limiting speed c.

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