X-Message-Number: 25523 Date: Wed, 12 Jan 2005 07:42:43 -0500 From: Thomas Donaldson <> Subject: CryoNet #25513 - #25522 Well, let's see here: For Peter Merel: I mentioned in my last message that I would give a reference. It is Rodney A Brooks, ROBOT. Brooks has been a leader in the approach to building animate robots for some time, and in my previous message I summarized (I hope clearly) just how he did it. If I remember rightly something that happened years ago, when I was actually involved with parallel computing, it turned out that a research group as Stanford had been able to construct a robot able to move along a road very slowly and painfully, occasionally running into the gutter or a branch of a tree --- and while they were making their robot, which busily computed every step, Brooks had build several creatures able to scamper about in similar settings. For Mathew Sullivan: As I said, you may be interested in my editorial in the coming PERIASTRON. As for the durability of our brains, I will defy you to design a brain using whatever materials which will not be subject to destruction by some means. A suitable helmet and pressure suit would protect me from the setup you describe (clothes, too, can be tools. Spacesuits and diving suits are examples). The fundamental problem which we try to solve when we engineer anything is to find a design which will perform as well as possible under the PARTICULAR conditions under which we want to use it --- and we learn very soon that no design will do well in all possible circumstances. Given that if you're going to redesign your body so that it can suffer large impacts and remain whole, you're dressing it in a helmet and pressure suit, but making those clothes a part of it rather than removable. Now do you really want to go everywhere in your pressure suit? For Jeff Soreff: Computer neural nets are at best only faint copies of a brain and how it works. And here I go again: the latest PERIASTRON actually has a discussion of how real brains work, with its primary source a series of recent articles in NATURE 431(2004) 759-803. EVEN OUR SYNAPSES CANNOT BE CONSIDERED SIMPLE CONNECTIONS BETWEEN NEURONS. Even a true neural net (instead of one imitated in a single computer) consists of multiple processors (one for each node) --- which makes our brains very highly parallel. The most interesting and distinctive thing about the approach taken by the neuroscientists who wrote these articles was their attempt to work out just what algorithms the different parts of our brain (including single isolated synapses) performed. If you're a computer person you will have to get used to the biological language; however even by now we have some algorithmic understanding of how our visual centers really work. No, I personally doubt very much that the kind of complex neural nets which make our brains have failed or will fail at common sense reasoning. But to attempt to imitate a highly parallel (at least 10^11 processors) with a single processor no matter how fast, or to fail to take account of the simple fact that our brain connections constantly change, strikes me as a strategy which is bound to fail. And finally to anyone here who subscribes to PERIASTRON: As usual, there were the usual number of typos. The cover sheet had the biggest one (I try to reuse my cover sheets). It discussed subscriptions as if the rate for a single issue was $3.00 US, and announced that it would soon increase to $4.00 an issue. Sorry, but that's already happened. A year (6 issues) used to be $18. It has now risen to $24.00 US. This was caused by changes in the exchange rate of the US dollar. My apologies if you think it's still $3.00 when you get your issue. And apologies to all those who expected an earlier PERIASTRON. Due to various personal and nonpersonal interruptions I found it impossible to get out a separate September issue before November rose above the horizon, so this PERIASTRON is really a double issue. It has a longer editorial than usual, 2 articles, and more Science Reports than usual. It also has 2, rather than just 1, short articles: one about a species of carp able to remain active for 5 days without oxygen, the other about nanoscale self-assembly. But still, it is coming quite late. It's now time for me to think about the NEXT PERIASTRON. And yes, the side you'll see when you get your issue tells you of the new Updates to the GUIDE. After all, I don't just publish PERIASTRON. Best wishes and long long life for everyone, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=25523