From: jeffrey E. <jeevacation@gmail.com>
Sent: Sunday, August 14, 2016 12:00 PM
To: █████████
Subject: Re:

Thx perfect

On Sunday, 14 August 2016, ███████████ = < ██████████████████████████ <mailto:████████████████████████ > >= wrote:

Jeffrey, there are several sides=to this:

1. Computers that are technically different from our current digital comput=r architectures, but can do the same things, because they can mathematical=y be proven to be equivalent, and we can build a digital equivalent. Examp=es are computers with ternary logic, neural networks, factor graphs etc.

2. Probabilistic computers: instead of deterministic state transitions, the= change state with a certain probability. We can get them to approximate d=terminism with arbitrary precision by stacking the probabilistic gates. Ma=y cognitive scientists and Al researchers believe that brains are in that =ategory. (We can also reproduce their behavior on a digital computer by ad=ing random noise.)

3. Computers that are technically different from our current digital comput=rs, but are still mathematically equivalent, yet it may not be practical t= build a digital equivalent, because it would be too large or too slow. Ex=mples are DNA computers, chaotic computers etc. Digital physicists ( I believe that even the universe is in this category. thinks the brain is in this category (we need to build electronic simulations of spiking neurons).

4. Quantum computers: they still cannot do anything but manipulate informat=on, but they can (hopefully one day) do a few things efficiently, like fac=oring large numbers, so they are in principle more powerful than conventio=al computers. ██████ thinks the universe is in this category, and ████ thinks the brain is in this category.

5. Hypercomputers with true continuum dynamics. Such computers can solve th= 3 body problem with infinite precision in finite time etc. (Most of) trad=tional physics believed that the universe must be continuous, and even con=emporary physics usually has continuous time etc. Such computers can be ap=roximated to an arbitrary degree by digital computation, but not reproduce= exactly. Most computer scientists with an opinion on the matter think tha= such hypercomputers cannot exist.

6. Hypercomputers with true infinities, which can use an infinite number of=inputs to compute a result in finite time. For instance, in this view, all=of the universe (not just a finite amount of information in its lightspeed=cone) could affect a single point.

7. A-causal computers: For instance, a universe with time machines could se=d information that you compute today to help you in your past. Mathematica=ly, such computers can be described, but there is no indication that they =ould exist.

0. Reversible computers: A reversible computer cannot delete information, i=e. every state has exactly one preceding state. Reversible computers can b= easily implemented in a normal digital computer, but a reversible compute= that tries to implement a digital computer will accumulate entropy in the=form of garbage bits. I believe that our universe is a reversible computer=(our brain is obviously not).

The list is not exhaustive, but I think these are the most relevant categor=es of unconventional/alternative computation, from a theoretical perspecti=e. Additionally, there are notions of things that are "more than comp=tation" in any <u>of the senses</u> above. They involve referential semantic=, normative/social semantics and other dark magic. and man= other philosophers believe that our brains and the universe do "more=than computation", but they do not have good concepts to explain or f=rmalize their ideas. They probably cannot have such concepts, because they=would have to leave the domain of mathematics (i.e. formal languages) for =hem, so there is very little to talk about except for negative claims (&qu=t;computers cannot do X").

> On Aug 13, 2016, at 15:55, jeffrey E. <jeevaca=ion@gmail.com <javascript:;> > wrote:

>

http://uncomp.uwe.ac.uk/LCCOMP/Anunci=s/Entries/2015/8/31_UCNC_2015.html
<http://uncomp.uwe.ac.uk/LCCOMP/Anuncios/Entries/2015/8/31_U=NC_2015.html>

>

> On Sat, Aug 13, 2016 at 6:36 AM, <javascript:;» wrote:

> Looks interesting. Haven't seen it before. Sounds like somethi=g would know.

>

» On Aug 13, 2016, at 6:23 AM, jeffrey E. <j=evacation@gmail.com <javascript:=> wrote:

>>

» Natural/Unconventional Computing and Its Philosophical Significanc= - MDPI

>> MDPI > pdf

>>

>>

» Have you guys looked at this?

>>

>>

>>

>> please note

» The information contained in this communication is

» confidential, may be attorney-client privileged, may

» constitute inside information, and is intended only for

» the use of the addressee. It is the property of

>> JEE

» Unauthorized use, disclosure or copying of this

» communication or any part thereof is strictly prohibited

» and may be unlawful. If you have received this

» communication in error, please notify us immediately by

» return e-mail or by e-mail to jeevacation@gma=l.com <javascript:;> , and

» destroy this communication and all copies thereof,

» including all attachments. copyright -all rights reserved

>>

>

>

>

>

>-

> please note

> The information contained in this communication is

> confidential, may be attorney-client privileged, may

> constitute inside information, and is intended only for

> the use of the addressee. It is the property of

> JEE

> Unauthorized use, disclosure or copying of this

> communication or any part thereof is strictly prohibited

> and may be unlawful. If you have received this

> communication in error, please notify us immediately by

> return e-mail or by e-mail to jeevacation@gmail.c=m <javascript:;> , and

> destroy this communication and all copies thereof,

> including all attachments. copyright -all rights reserved

## =C2 please note

The information contained in this communic=tion is confidential, may be attorney-client privileged, may constit=te inside information, and is intended only for the use of the addresse=. It is the property of JEE Unauthorized use, disclosure or copying =f this communication or any part thereof is strictly prohibited and =ay be unlawful. If you have received this communication in error, pleas= notify us immediately by return e-mail or by e-mail to jeevacation@gmail.com, and<=r>destroy this communication and all copies thereof, including all atta=hments. copyright -all rights reserved