REVERSIBLE COMPUTING: Computers 10^10 more energy efficient!

This will be one of the most important technologies ever implemented by humanity. What we are talking about is computers that will be 1/100,000,000,000 more energy efficient. In order to get this concept we need to go over a few other related concepts.

1. HOW SMART IS A ROCK?

To appreciate the feasibility of computing with almost no energy or heat, lets consider the computation that takes place in any ordinary rock. Although it may appear that nothing much is going on inside a rock, the approximately 10^25 (ten trillion trillion) atoms in a kilogram of matter are actualy extremely active. Despite its apparent solidarity, the atoms are all in motion, sharing electrons, changing particle spins, and generating rapidly moving electromagnetic fields. all of this activity represents computation, though not MEANINGFULLY organized. -The singularity is near

U of Oklahoma has been able to store 1,024 bits in the magnetic interactions of the protons of a single molecule containing 19 hydrogen atoms.
www.techspot.com...

In terms of computation, and just considering the electromagnetic interactions of a 1 kilogram rock, there are atleast 10^15 changes in state per bit per second, which represents about 10^42 (million trillion trillion trillion) calculations per second. YET THE ROCK REQUIRES NO ENERGY INPUT AND GENERATES NO APPRECIABLE HEAT -Singularity is near

Of course, despite all the activity at the atomic level, the rock is not performing any USEFUL or intelligent computation. If on the other hand, we can organize the particles in a more purposeful manner, we could have a cool(cold), zero-energy consuming computer with a memory of about (1,000 trillion trillion bits) and a processing capability of 10^42 operations per second.

If we were to add up the processing power of all human brains on the planet right now, we would have an estimated only 10^19 calculations per second.-Singularity is near

Today we use what is called IRREVERSIBLE COMPUTING, meaning

we are unable in principal to run software programs backwards. At each step, the input data is discarded-erased- and the results pass on to the next step. The act of erasing data generates heat, and therefor requires energy. According to the law of thermodynamics, that information bit is essentially released into the surrounding environment, thereby increasing its entropy.....
The fundamental concept is that if you keep all of the intermediate results and then run the algorithm BACKWARDS, upon completion of the calculation, you end up where you have started, have used NO energy, and generated NO heat. And along the way, you have still calculated your result.-Singularity is near

However, in order for us to receive our answer(output from PC), the process of copying and transmitting data is and always will be a IRREVERSIBLE process, meaning it will use energy. So we can do ALL of the computation without losing energy*, which is the majority of the work a PC does, and then by receiving the output, it requires only a fraction of the energy compared to its computation.

*

Because of essentially random thermal and quantum effects, logic operations have an inherent error rate. we can over come errors with error detection codes. however fixing an error is irreversible and requires energy. Generally error rates are low. If we have say 1 error per 10^10 operations, we have succeeded in reducing energy requirement by a factor of 10^10, though not eliminating energy dissipation altogether. -Singularity is near

Hamming code error detection: en.wikipedia.org/wiki/Hamming_code

Ed Fredkin: Reversible logic gates, cell-auto.com...

Ralph Merkle: Two Types of Mechanical Reversible Logic: www.zyvex.com...

Ray Kurzweil: The Singularity is near.

EDIT=======================================

Conventional models that have the distinction that the basic components are microscopically reversible. This means that the macroscopic operations of the computer is also reversible. This fact allows us to address the question “what is required for a computer to be maximally efficient? The answer is that if the computer is built out of microscopically reversible components then it can be perfectly efficient. How much energy does a perfectly efficient computer have to dissipate in order to compute something? The answer is that the computer does not need to dissipate any energy.

A more Conservative design for a massively parallel reversible computer was put forth by Eric Drexler, with his patented nanocimpter design

computation are performed by manipulating nano-scale rods, which are effectively spring loaded. after each calc, the rods containing intermediate values return to their original position, thereby implementing reverse computation. The device has 10^12 (trillion) processors and provides an overall rate of 10^21 calc per second, enough to simulate one hundred thousand human brains PER CUBIC CENTIMETER.

some more reading material on drexlers nano-computer
www.halcyon.com...




[edit on 12/2/2009 by VonDoomen]

[edit on 12/2/2009 by VonDoomen]

[edit on 12/2/2009 by VonDoomen]

Some more interesting information related to this matter.

There is a direct proportional relationship between the energy of an object and its potential to perform computation. the PE in a kilogram of matter is very large as we know from Einstein (E=MC^2). The potential of matter to computer is also governed by planks constant: 6.6X10^-34 joule-seconds. This is the smallest scale at which we can apply energy for computation. We obtain the THEORETICAL limit of an object to perform computation by:

dividing the total energy(avg energy of each atom x the # of particles) by plancks constant(6.6X10^-34 joule-seconds)

Since the amount of energy is so large, and plancks constant is so small, we get an extremely large number: about 5X10^50 CPS for 1 kilogram of matter....

If we relate this to the most CONSERVATIVE estimate of human brain capacity (10^19 CPS) it represents the equivalent of about 5 billion trillion human civilizations...

A 1 kilogram, perfectly efficient cold computer would be able to perform the equivalent of all human thought, over the last 10,000 years in 1/10,000 of a NANOsecond.

Just to give everyone an idea of the scale of computational power.

That is most definitely one of the most nonsensical ideas I've ever read. Compute BACKWARDS? What a joke? Lets see, all you have to do is start with the answer to the problem, then go back and figure out how you got the answer. Ummm... no. You can't start with the answer without FIRST doing the algorithm! Come on, this cannot be serious?

Originally posted by truthquest
That is most definitely one of the most nonsensical ideas I've ever read. Compute BACKWARDS? What a joke? Lets see, all you have to do is start with the answer to the problem, then go back and figure out how you got the answer. Ummm... no. You can't start with the answer without FIRST doing the algorithm! Come on, this cannot be serious?

What are you talking about? Did you even bother to read my post? REVERSIBLE means a process that once done, can be reversed.

and then run the algorithm BACKWARDS, upon completion of the calculation

============================================
The way this works is you run the computation(algorithm) forward to compute the answer. you then send the answer out(output, requires energy) and then you then run the algorithm in reverse(*returning the everything to its initial state*) before you ran the algorithm.
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The rock example is a perfect example of this except that we dont get output of info from a rock, thus why rocks dont generate any appreciable heat except due to random thermal/quantum effects (very low amount).

Reverse programming and reversible logic gates have already been proven to work and conserve energy. The only reason they havent been implemented on a vast scale yet is because the programming and software is very tricky and cost/time consuming to develop.

[edit on 12/2/2009 by VonDoomen]

Originally posted by VonDoomen

Originally posted by truthquest
That is most definitely one of the most nonsensical ideas I've ever read. Compute BACKWARDS? What a joke? Lets see, all you have to do is start with the answer to the problem, then go back and figure out how you got the answer. Ummm... no. You can't start with the answer without FIRST doing the algorithm! Come on, this cannot be serious?

What are you talking about? Did you even bother to read my post? REVERSIBLE means a process that once done, can be reversed.

and then run the algorithm BACKWARDS, upon completion of the calculation

============================================
The way this works is you run the computation(algorithm) forward to compute the answer. you then send the answer out(output, requires energy) and then you then run the algorithm in reverse(*returning the everything to its initial state*) before you ran the algorithm.
============================================
The rock example is a perfect example of this except that we dont get output of info from a rock, thus why rocks dont generate any appreciable heat except due to random thermal/quantum effects (very low amount).

Reverse programming and reversible logic gates have already been proven to work and conserve energy. The only reason they havent been implemented on a vast scale yet is because the programming and software is very tricky and cost/time consuming to develop.

[edit on 12/2/2009 by VonDoomen]

I still don't understand because computer hardware isn't constructed with algorithms but rather it is made of transistors. Therefore the idea that a processor could for example compute the value 5+5=10, then display it on the screen, then do it again in reverse to save energy seems like a crazy one.

I imagine the type of reversal being done must apply only to a small part of the hardware for a limited form of logic... not literally doing an entire software algorithm in reverse!

The explanations seem like dramatic over-simplifications... most notably the idea a rock can be re-arranged into something comparable to an intelligent being.

Originally posted by VonDoomen
Today we use what is called IRREVERSIBLE COMPUTING, meaning

we are unable in principal to run software programs backwards. At each step, the input data is discarded-erased- and the results pass on to the next step. The act of erasing data generates heat, and therefor requires energy. According to the law of thermodynamics, that information bit is essentially released into the surrounding environment, thereby increasing its entropy.....
The fundamental concept is that if you keep all of the intermediate results and then run the algorithm BACKWARDS, upon completion of the calculation, you end up where you have started, have used NO energy, and generated NO heat. And along the way, you have still calculated your result.

You put that in quotes but I couldn't find that in the links you posted, did I miss it one of those links? I don't know if you're taking something out of context or not until I read the source but out of context it sounds like nonsense.

The link you posted doesn't sound like nonsense though, it's an interesting article about experimental storage methods being tested at the molecular level. We continue to see transistors getting smaller and smaller so based merely on that trend it seems inevitable that the molecular level computing will be a desired result of this trend, and if it's possible, I agree it should be very energy efficient based on the small size, but I don't see what this "reversible" stuff has to do with it.

I'd like to see the source for your quote there about irreversible computing.

[edit on 2-12-2009 by Arbitrageur]

Im sorry to truthquest. I just realized there was one portion I forgot to add into my first post, which would have (hopefully) made more sense.
Im gonna edit it in after this post. It should have gone in before eric drexlers nanocomputer.

=========================================
Conventional models that have the distinction that the basic components are microscopically reversible. This means that the macroscopic operations of the computer is also reversible. This fact allows us to address the question “what is required for a computer to be maximally efficient? The answer is that if the computer is built out of microscopically reversible components then it can be perfectly efficient. How much energy does a perfectly efficient computer have to dissipate in order to compute something? The answer is that the computer does not need to dissipate any energy.
=========================================

If a most efficient supercomputer works all day to compute a weather simulation problem what is the minimum amount of energy that must be dissipated according to the laws of physics? The answer is actualy very simple to calculate, since it is unrelated to the amount of computation. The answer is always equal to zero- Edward Fredkin, Physicist.

Originally posted by truthquest
The explanations seem like dramatic over-simplifications... most notably the idea a rock can be re-arranged into something comparable to an intelligent being.

No where DO I try to call a rock an intelligent being. No more than you would/could call a Computer an intelligent being. what I was trying to do is show, based on the most advanced stuff we know, the maximum capability of computation and storage we can legitimately theorize with 1 kilogram of matter.

Originally posted by VonDoomen
Im sorry to truthquest. I just realized there was one portion I forgot to add into my first post, which would have (hopefully) made more sense.
Im gonna edit it in after this post. It should have gone in before eric drexlers nanocomputer.

=========================================
Conventional models that have the distinction that the basic components are microscopically reversible. This means that the macroscopic operations of the computer is also reversible. This fact allows us to address the question “what is required for a computer to be maximally efficient? The answer is that if the computer is built out of microscopically reversible components then it can be perfectly efficient. How much energy does a perfectly efficient computer have to dissipate in order to compute something? The answer is that the computer does not need to dissipate any energy.
=========================================

If a most efficient supercomputer works all day to compute a weather simulation problem what is the minimum amount of energy that must be dissipated according to the laws of physics? The answer is actualy very simple to calculate, since it is unrelated to the amount of computation. The answer is always equal to zero- Edward Fredkin, Physicist.

Yes, that really makes a lot more sense now... enough for me to flag the topic for sure.

i agree. theoretically, this is a great idea, but if you think in terms of the programmers who would have to go about designing this, nearly impossible. What this implies is that the answer is already known. Brings new meaning to "working backwards"

To be honest as a developer I don't see how this could possibly work. We already have processes wrapped within "transactions" that allow the process to be reversed if an unexpected event occurs. In fact most serious database management systems & enterprise applications do this on a daily basis.

I can take a bit, set it to one, then set it back to zero, but that doesn't "undo" the energy used, it does the exact opposite. You use electricity to move the heads on the hard drive and magnetise the bit (setting it to 1), then you move the heads on the hard drive and demagnetise the bit (setting it to 0). Each time energy (electricity) is required to move the heads, so you're actually doubling the energy requirements.

This is one of the best threads i've seen in ages.

Anything is possible. You do the algorithm, and to reset the memory ie' the protons, photons, electrons and to stop the waste of energy and heat, you reverse the algorithm and it takes the memory back to its initial begining.

I had to star LordGoofus.
Because like LordGoofus, I do not understand how reversing a process negates the energy consumed when common sense dictates that double the energy should be consumed.

And what is meant that with irreversible computing the data is discarded? Isn't the data all loaded into memory, how would a program work otherwise?

OK, now I am going to go back, stare at the wall and drool some more.
Duh,uhhhh

reply to post by LordGoofus


If you read the links I provided, you would see we are talking about a completely redesigned computer. We're not talking about magnetic disks.

Make sure you go back and read the part about the rock. The movement of its particles, among other things, can represent computation, though not meaningfully organized.
and yet, it uses no energy. That's because all of its atomic processes, at the tiniest level, are completely reversible.

Originally posted by LordGoofus
To be honest as a developer I don't see how this could possibly work. We already have processes wrapped within "transactions" that allow the process to be reversed if an unexpected event occurs. In fact most serious database management systems & enterprise applications do this on a daily basis.

I can take a bit, set it to one, then set it back to zero, but that doesn't "undo" the energy used, it does the exact opposite. You use electricity to move the heads on the hard drive and magnetise the bit (setting it to 1), then you move the heads on the hard drive and demagnetise the bit (setting it to 0). Each time energy (electricity) is required to move the heads, so you're actually doubling the energy requirements.

Database transactions do not work that way. They ensure that all commits are calculated and possible before proceeding. If a query fails, nothing within the transaction is committed. Technically nothing is actually reversed.

As for the second part. You are right that in current computing it is more energy intensive to change a bit's state back to 0. But if instead of wasting energy doing by doing this, we could pass energy directly between bits, be it a proton, an atom, a molecule or a static charge. Then we have a system that could become an enclosed power loop and extremely efficient.

reply to post by LordGoofus


This is from one of the books I've been reading.

Rolf Landauer showed in 1961 that reversible logical operations such as NOT (turning a bit into its opposite) could be performed without putting energy in or taking heat out, but that irreversible logical operations such as AND (generating bit C, which is a 1 if and only if both outputs A and B are 1) do require energy.
www.research.IBM.com/journal/rd/053/ibmrd0503c.pdf
Subscription require

In 1973 Charles Bennett showed that any computation could be performed using only reversible logical operations.
www.research.ibm.com/journal/rd/176/ibmrd1706g.pdf

-The singularity is near

While researching this topic more, i found a good article that gives a better written explanation that I supplied.

it can be found here-
www.wisegeek.com...

reply to post by VonDoomen


Would this be akin to building a castle out of Lego then disassembling the pieces for re-use rather than throwing away the castle only to build a ship from new pieces? It certainly sounds nice but just as it takes energy to construct a ship, it also takes energy to deconstruct it.

I guess these guys are smarter than me though and just because I don't get it sure as hell doesn't mean it can't be done. If it works, I'm sure we'll find out!

with the brightest minds the fault in man and the purity of manifestation of an object of matter will be the problem with implementing such and endeavor.in essence to create this means it has already been in manifestation; to act upon manifestation with the intent to reproduce these effects are folly.

reply to post by OZtracized


Hey thanks for the constructive criticism of the post!

For the people having a hard time figuring this out- read the very first paragraph!

To appreciate the feasibility of computing with almost no energy or heat, lets consider the computation that takes place in any ordinary rock. Although it may appear that nothing much is going on inside a rock, the approximately 10^25 (ten trillion trillion) atoms in a kilogram of matter are actualy extremely active. Despite its apparent solidarity, the atoms are all in motion, sharing electrons, changing particle spins, and generating rapidly moving electromagnetic fields. all of this activity represents computation, though not MEANINGFULLY organized.

Reality is continuously "computing" itself into existence. All of these different qualities of the atom(spin, charge, magnetic fields) are capable of storing information in a binary manner. The small components of reality utilize the lowest form of energy, and that is why they are able to seemingly change states endlessly. And remember, the changing of any state can be interpreted as computation. The trick to his is organizing every quality of every atom with meaningful binary information.

In terms of computation, and just considering the electromagnetic interactions of a 1 kilogram rock, there are atleast 10^15 changes in state per bit per second, which represents about 10^42 (million trillion trillion trillion) calculations per second. YET THE ROCK REQUIRES NO ENERGY INPUT AND GENERATES NO APPRECIABLE HEAT.