OT "More is Different"

I was reading an article in the latest Physics today, and it lead me to this paper by P.W. Anderson.

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I found it interesting.

George H.

Reply to
George Herold
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Link doesn't work, even when bracketed (). What's with the /.../ ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Jim Thompson

maybe this?

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George H.

Reply to
George Herold

By analogy, some people design parts, and some people design complicated systems out of parts.

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John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    
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Reply to
John Larkin

Well OK, but that could still use the same basic 'skill set'.. Is there some "phase change" when you get a whole bunch of parts? Do you need to change the way you think about it?

I liked the money example at the end of the article*. Once you have a boat load of money does how you think about it change? Say you have enough so that you can't spend the interest faster than it grows.

George H.

*And NO I don't want to start a political, tax the rich, vs. cut taxes on the rich debate.
Reply to
George Herold

That works. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Jim Thompson

As a system gets more complex, the number of causality paths explodes as (n!)! or something radical like that. Some of those paths, just by accident, will then be diabolically evil. And then some of the diabolically evil paths will hide other diabolically evil paths.

Happens all the time. Like, this week.

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John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    
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Reply to
John Larkin

ed systems

(n!)!

ll then

ide

Hmm OK. But I assume Jim T. has the same type of issues in IC design. And I assume that you both use the same strategy that I do to deal with it. Th at is you break the big system into smaller parts. Get each of the small p ieces working. And then hope all the parts "play well together", or at le ast that the bad boys can be tamed easily. And it sorta looks the same for the next step up the ladder. If I'm buildi ng a big experiment, I'd buy pieces of electronics/ apparatus, put those to gether in small sub-units that are easy to test and debug. And then start adding the pieces together. I'm picturing the FEL where I worked years ago . A big complicated machine. Perhaps if it gets complicated enough you ge t to the point were there is no single person who can hold the whole "pictu re" of the machine in their head. Maybe Cern? How do they deal with it? I 'd guess it's just another layer of systems on top. I'm not seeing any pha se change. (But maybe I'm not clever enough.)

George H.

Reply to
George Herold

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The requested URL /~wktse/.../More_Is_Different_Phil_Anderson.pdf was not found on this server.

Reply to
Robert Baer

  • Yup! Can't help it.
Reply to
Robert Baer

..and then some of the diabolically evil paths will hide gold!

Reply to
Robert Baer

Not really. He uses a limited number of components, has good device models, simulates everything, and designs relatively simple stuff. It's simple by definition, since we build systems out of hundreds of discretes and analog and digital ICs.

We don't have good device models, and even if we did, simulating a complex mixed-signal system would take more time than checking it and building it.

We just design a product and release the docs to production, and they build us a couple rev A systems, production quality, and we test them. We don't build or test subsystems, excepting the occasional component breadboard.

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John Larkin         Highland Technology, Inc 

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Reply to
John Larkin

Yep. Like R's, C's, L's and every kind of transistor imaginable.... in other words the basic building blocks from which ALL things derive... as in ALL the parts you BUY.

Yes.

Simple? You mean like this...

A piece of which I asked you to explain... you couldn't.

And I do that with 10's of thousands of transistors.

Maybe, maybe not.

...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

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