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Subject: Re: obvious example

Author: Robert Hyatt

Date: 06:42:58 10/03/01

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On October 03, 2001 at 09:12:59, Vincent Diepeveen wrote:

>On October 02, 2001 at 04:54:13, Bruce Moreland wrote:
>
>>On October 01, 2001 at 00:36:48, Robert Hyatt wrote:
>>
>>>On September 30, 2001 at 14:47:21, Bruce Moreland wrote:
>>>
>>>>On September 29, 2001 at 14:54:03, Robert Hyatt wrote:
>>>>
>>>>>On September 29, 2001 at 10:41:37, Miguel A. Ballicora wrote:
>>>>
>>>>>>Super-linear speedups are "probably" impossible but so far I did not see that
>>>>>>they are "provably" impossible. I would settle with "They are believed to be
>>>>>>impossible".
>>>>>>
>>>>>>Regards,
>>>>>>Miguel
>>>>>
>>>>>
>>>>>They simply _are_ impossible.  Unless you believe in perpetual
>>>>>motion, infinite compression, a fire that will burn forever, etc.
>>>>
>>>>Take a human who can move a 200-pound box, but only by scraping it along the
>>>>ground.  Compute the time it takes him to move 10 such boxes 100 yards.
>>>>
>>>>Assume that two humans can move a 200-pound box more easily.  Can they move a
>>>>200-pound box more than twice as fast as one human?  Would this violate laws
>>>>against perpetual motion?  Of course not.  It is perfectly valid to consider
>>>>working in parallel rather than working serially.  The mechanics of the task
>>>>might change, resulting in much increased efficiency -- they can lift the box
>>>>off the ground.
>>>
>>>
>>>I think that after you think about this example, you will see the flaw.
>>>Lifting the box off the ground takes _more_ effort.  So the two people are
>>>doing _more_ work in a given period of time than two people pushing two boxes
>>>at the same time.  The ancient Egyptions found that dragging was better than
>>>lifting.  :)
>>>
>>>
>>>
>>>>
>>>>Two workers cooperating to perform a task, do not *have* to go less than or
>>>>equal to the speed of two workers, each of whom does exactly half of a task that
>>>>can be fairly divided in two.
>>>>
>>>>There exists the opportunity for synergy.
>>>>
>>>>The argument that the above violates the prohibition against perpetual motion is
>>>>fallacious.
>>>>
>>>>bruce
>>>
>>>
>>>Not after you think about it.  If two people work and each of them moves 5
>>>blocks, then they do no more work than the 1 person did moving 10.  But they
>>>did it in twice the time.  If they _lift_ the block _and_ move it, they are
>>>doing _more_ work per unit of time.  They should have moved the blocks
>>>faster one at a time, but they were taking it easy...
>>>
>>> A computer can't do that.
>>
>>You can't possibly be arguing that there is nothing that N (N>1) people can't do
>>in less than 1/N the time that it takes one person.
>>
>>I was trying to find an obvious example.  If you don't like that one, I'm sure
>>there is another one.
>>
>>bruce
>
>Obvious example is killermoves. It improves branching factor too.


You can't improve branching factor beyond the normal serial search branching
factor.



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