Copying a bit requires deleting the old value. So Landauer's limit applies.
Reversible computing is free but really isn't useful for AGI. The brain is not a quantum computer. Training a neural network performs irreversible state changes. On Sun, Feb 3, 2019, 4:22 PM TimTyler <[email protected] wrote: > On 2019-02-03 10:19:AM, Matt Mahoney wrote: > > > The problem is power consumption. Mechanical adding machines are older > > than vacuum tubes and would have very low power consumption if we > > could shrink them to molecular size. > > > > Copying bits in DNA, RNA, and protein costs less than a millionth as > > much energy as copying bits in RAM. The human body transcribes 10^19 > > bits of amino acids per second at a cost of 10^-17 J each. (We consume > > 30 g of protein per day and use 100 watts). The theoretical (Landauer) > > limit is kT ln 2 = 3 x 10^-20 J per bit copy at room temperature. > > > The Landauer limit applies to *deleting* bits not *copying* them. > There's no corresponding > > thermodynamic limit to copying - or any other process essential to > computation - as illustrated > > by computation-universal reversible cellular automata - and reversible > cellular automata capable > > of supporting self reproduction. No bits have to be deleted in order to > compute things. That is > > part of the interest in reversible computation. > > -- > __________ > |im |yler http://timtyler.org/ > ------------------------------------------ Artificial General Intelligence List: AGI Permalink: https://agi.topicbox.com/groups/agi/Ta6fce6a7b640886a-Mda3383c37abd3b2dfe86930c Delivery options: https://agi.topicbox.com/groups/agi/subscription
