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128-bit storage: are you high?

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Re: 128-bit storage: are you high?

#11

Post by foco1234 »

dschobel wrote: post #7
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...

Agreed. Unfortunately the Nature article is behind a paywall but the original paper is available on arxiv: http://arxiv.org/abs/quant-ph/9908043

I've read the intro. of the paper, but I'm not a physicist, so this question might seem dumb, but here goes:

The paper describes the "ultimate laptop" as being a computer that can use one atom to store 1 bit of information. Why is an atom the smallest unit of matter a computer can store a bit in?

Re: 128-bit storage: are you high?

#12

Post by gwern »

foco1234 wrote: post #11
dschobel wrote: post #7

Earlier quoted context omitted.

Agreed. Unfortunately the Nature article is behind a paywall but the original paper is available on arxiv: http://arxiv.org/abs/quant-ph/9908043

I've read the intro. of the paper, but I'm not a physicist, so this question might seem dumb, but here goes: The paper describes the "ultimate laptop" as being a computer that can use one atom to store 1 bit of information. Why is an atom the smallest unit of matter a computer can store a bit in?

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.)

Re: 128-bit storage: are you high?

#13

Post by aw3c2 »

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

Re: 128-bit storage: are you high?

#14

Post by _b8r0 »

thushan wrote: post #10
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.

Doesn't Douglas Adams touch on that? Wasn't Earth a big computer in the Hitchhiker's Guide to the Galacy? From a wikipedia entry... "[The computer] Deep Thought does not know the ultimate question to Life, the Universe and Everything, but offers to design an even more powerful computer, Earth, to calculate it. After ten million years of calculation, the Earth is destroyed by Vogons five minutes before the computation…

Deep Thought used ZFS. The ZFS pool for the calculations was 98% full when the Vogons came.

Re: 128-bit storage: are you high?

#15

Post by mbreese »

gwern wrote: post #12
foco1234 wrote: post #11

Earlier quoted context omitted.

I've read the intro. of the paper, but I'm not a physicist, so this question might seem dumb, but here goes: The paper describes the "ultimate laptop" as being a computer that can use one atom to store 1 bit of information. Why is an atom the smallest unit of matter a computer can store a bit in?

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.

Re: 128-bit storage: are you high?

#16

Post by sammcd »

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.

Re: 128-bit storage: are you high?

#17

Post by andrewf »

MaxMorlock wrote: post #9

The 128-bit storage of ZFS reminds me a bit of TeX. As far as I can remember reading the TeX book, Don Knuth also wanted to play it safe. Internally, everything relies on integers (no floating point operations), and the smallest internal unit of measurement is less than the wavelength of light (don't remember the color ;-) ).

At least one game programmer is recommending sticking with integers for distances. " 64 bits of precision gets you to the furthest distance of Pluto from the Sun (7.4 billion km) with sub-micrometer precision. "

http://home.comcast.net/~tom_forsyth/blog.wiki.html#%5B%5BA%...

Re: 128-bit storage: are you high?

#18

Post by fexl »

MaxMorlock wrote: post #9

The 128-bit storage of ZFS reminds me a bit of TeX. As far as I can remember reading the TeX book, Don Knuth also wanted to play it safe. Internally, everything relies on integers (no floating point operations), and the smallest internal unit of measurement is less than the wavelength of light (don't remember the color ;-) ).

I too played it safe and avoided floating point operations in the loom.cc code:

https://loom.cc/?function=grid_tutorial&help=1

All asset quantities are signed 128 bit integers under the hood. However, when the wallet interface displays a quantity, it uses a scale factor to place the decimal point. An asset type denominated in a fiat currency like USD or EUR typically uses a scale of 2. An asset type denominated in a commodity currency like GAU (grams of gold) typically uses a scale of 7, allowing a number like 31.1034768, which is the precise number of grams in a troy ounce. If you want to see it in kilograms, you can use scale 10.

Re: 128-bit storage: are you high?

#19

Post by pyre »

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' storage devices?

Re: 128-bit storage: are you high?

#20

Post by wcoenen »

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…

Well, for practical purposes the wavelength of light doesn't really have a lower limit. If the wavelength of visible light isn't small enough, you use ultraviolet.

If you need smaller wavelengths still, you could use gamma lasers - though so far these are only possible in theory. There is some speculation that positron annihilation could be used to drive such a laser.

edit: looks I was wrong - while ultraviolet lasers exist, the currently available ones still don't have a small enough wavelength for say a 45 nm process. Other tricks like multiple patterning and immersion are used.

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