On 29 Oct 2012, at 17:03, John Clark wrote:

## Advertising

On Mon, Oct 29, 2012 Bruno Marchal <marc...@ulb.ac.be> wrote: >> We now know that computing or thinking is physical, > We don't know that. We know that as well as we know anything about physics.

`This is not valid. A priori we can be dreaming in some world based on`

`a different physics. Or, as with comp we might belong only to`

`sophisticated computations, which are entirely emulated already by`

`degree four diophantine polynomials.`

`And computation is a the start a purely mathematical, indeed`

`arithmetical, concept. All physical computations are defined by the`

`physical incarnation of the corresponding mathematical computation.`

> We deduce that in the Aristotelian's theories. I have no idea what if anything that means.

There are two main rational conception of reality.

`1) the Aristotelian one, in which the ultimate reality is a physical`

`world, and the erst emerges from it.`

`2) the Platonist one, in which the physical reality is the border, or`

`the shadow of a vaster invisible reality.`

`The idea that today science has solved the question of deciding`

`between those two conception is a crackpot idea of sunday type`

`philosophers.`

`The UDA illustrates this, by showing that if we take computationalism`

`seriously enough, the Platonist conception of reality is about`

`unavoidable, and that the physical reality is no more a primitive`

`notion, but a derivative of an ability owned by complex relation`

`between some numbers. This makes also comp testable, as the derivation`

`is constructive (albeit technically difficult).`

>> it takes energy to do it and it gives off heat;> Actually computation can be made reversibly, without dissipationof energy.With reversible computing you can make the amount of energy used fora calculation arbitrarily small and thus the heat emittedarbitrarily close to zero BUT, as I said before, only at the priceof slowing down the computation;

`I give a good energy at the start, and I can sped the non dissipating`

`process at the speed limited by light.`

we were talking about the theoretical feasibility of making aprediction and making a forecast of yesterday's weather is not ofmuch use.

No. We were talking on something else. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.