I inherited a loose-leaf book of old Sci Am reprints from Michael Hardy
(whose dad was Prof of Zoology at Oxford), and one of them is the said
Penrose article, dated June 1959. They are basically a self-assembly
device with a hooking device which unhooks when there are enough devices
joined up. so it goes 1 + 1 + 1 + 1 -->> 1 + 11 + 1 -->> 111 + 1 -->>
1111 -->> 11 + 11. In other words pairs are stable, triads are
semistable and quadrads are unstable and divide into two pairs. If
anyone's interested I could scan my copy and put it up on our website
for downloading.
Julian
Dr R.J.Wootton wrote:
> Hi, Adrian,
>
> Have the self-replicating machines of the great Prof
> Penrose fallen out of folk memory, or are they much-quoted
> classics? They were made of plywood, and he supplied the
> necessary energy by shaking them in a tray. I remember him
> demonstrating them to delighted audiences when I was an
> undergraduate in the late 1950s. He was then Professor of
> Eugenics (!) at UCL, in the School of Biometry, Genetics
> and Eugenics headed by JBS Haldane. He did a Scientific
> American article on them, probably about 1960; I don't have
> the reference handy.
>
> Robin
>
>
> On Fri, 18 Mar 2005 10:08:55 +0000 Adrian Bowyer
> <[log in to unmask]> wrote:
>
>
>>Interest in our project to make a self-replicating machine is growing (see
>>http://www.bath.ac.uk/~ensab/replicator/). After discussions with Julian, I
>>have put an entry on that website to direct people who want to talk about the
>>project to our list. If traffic gets too heavy (I should be so lucky...), then
>>we might bud it off to another list, depending on how people feel.
>>
>>Best wishes
>>
>>Adrian
>>
>>http://staff.bath.ac.uk/ensab
>
>
> ----------------------
> Dr R.J.Wootton
> University Honorary Fellow (Insect Biomechanics) ics)
> University of Exeter
> School of Biosciences
> Hatherly Laboratories
> Prince of Wales Road
> Exeter EX4 4PS, UK
> 01392 275332 or 263753
> FX 01392 263700
>
> http://www.ex.ac.uk/biology/wootton
--
Julian FV Vincent [log in to unmask]
Professor of Biomimetics office 01225 386596
Centre for Biomimetics & Natural Technologies mobile 07941 933901
Dept of Mechanical Engineering fax 01225 386928
The University
BATH BA2 7AY
http://www.bath.ac.uk/Departments/Eng/biomimetics/
I hate quotations. Tell me what you know. (Ralph Waldo Emerson)
|