On 5/25/2022 1:05 PM, Dennis Bush wrote:
> On Wednesday, May 25, 2022 at 1:48:17 PM UTC-4, olcott wrote:
>> On 5/25/2022 12:45 PM, Mr Flibble wrote:
>>> On Wed, 25 May 2022 12:35:44 -0500
>>> olcott <No...@NoWhere.com> wrote:
>>>
>>>> On 5/25/2022 6:37 AM, Ben wrote:
>>>>> Andy Walker <a...@cuboid.co.uk> writes:
>>>>>
>>>>>> On 24/05/2022 23:59, Ben wrote:
>>>>>>> Jeff Barnett <j...@notatt.com> writes:
>>>>>> [...]
>>>>>>>> I think, that upon reflection, you will recall that isn't true.
>>>>>>>> I'm assuming that you are at least a moderate history of math
>>>>>>>> (etc.) buff and have read "Proofs and Refutations" by Imre
>>>>>>>> Lakatos. This book, as well as many others written by him or
>>>>>>>> others, go through the history of mathematics and show examples
>>>>>>>> where the whole community has bought a load of rope.
>>>>>>
>>>>>> Lakatos's work is interesting, but I wouldn't go overboard
>>>>>> about it. It's "philosophy of maths" more than "history" of
>>>>>> maths", and, AIUI, it's not so much a claim that any particular
>>>>>> theorem is "wrong", rather that as maths develops, its language
>>>>>> evolves and becomes refined. Of course there have been blunders,
>>>>>> which may have lain undetected for a long time, but more important
>>>>>> have been the "edge" cases, where what we mean by [eg] "function"
>>>>>> has developed esp as we moved from the intuition of the 18thC to
>>>>>> the rigour of the 19thC, so that theorems need to change to
>>>>>> reflect the new language.
>>>>>
>>>>> I found the original essays that form the core of the book online,
>>>>> and though I ave not finished reading, I think what Lakatos is
>>>>> saying is somewhat tangential to my point. His main focus is on
>>>>> the process of doing mathematics.
>>>>>
>>>>> Of course PO thinks (I should say now thinks because his claims
>>>>> shift over time) that he has "refined" the idea of halting.
>>>>>
>>>>>> Re history -- I recall that Warwick ran a history module
>>>>>> based entirely around the dead ends of geometry in the 19thC.
>>>>>> Stuff that is now utterly forgotten but for a few years was all
>>>>>> the rage. Had it not been so utterly forgotten, I'd be able to
>>>>>> quote some examples. But it serves as a reminder that maths is
>>>>>> not the "definitive" subject that is usually presented to students
>>>>>> [from primary school to research] -- "Here be maths as it is and
>>>>>> always has been ever since its discovery, and here be the unknown
>>>>>> bits where research is ongoing" -- but contains any number of
>>>>>> false starts and debates, many of which never resolve but just get
>>>>>> quietly dropped.
>>>>>
>>>>> I think that's true of many branches of human investigation, but
>>>>> since mathematics is the investigation of abstract "inventions", it
>>>>> is even more prone to going off on tangents that turn out to be
>>>>> fads. Then again, some fields come back to being centre stage.
>>>>> Number theory, once little more than an amusement, turned into a
>>>>> valuable area of research.
>>>>>> Re Lakatos -- his Wiki biography is interesting, and as
>>>>>> well as detailing his complicated private/political life says
>>>>>> quite a lot about "Proofs ...".
>>>>>>
>>>>>>> I don't know that book. I'll see if I can get hold of it. It
>>>>>>> sounds really interesting but, sadly, I no longer have access to
>>>>>>> world-class library :-(
>>>>>>
>>>>>> As Jeff says, copies are available. Bookfinder lists 296
>>>>>> copies for sale. But I find it hard to believe that you no longer
>>>>>> have access to any library with a copy [or able to get one for
>>>>>> you] -- it doesn't need to be world-class for that.
>>>>>
>>>>> I was just lamenting the loss as some places give retired academics
>>>>> library privileges and some don't! The local council library
>>>>> system is just about hanging on in most places in the UK so, yes, I
>>>>> can get any book through the inter-library loan scheme. It's just
>>>>> that waiting weeks is so last century.
>>>>>
>>>>>> Apart from that, you surely have some
>>>>>> friends/acquaintances with access to a university library?
>>>>>
>>>>> Strictly against the rules, so I would not want to put anyone in
>>>>> that position!
>>>>>
>>>>>> [...]
>>>>>>> And of course the halting theorem and Cantor's theorem are so
>>>>>>> simple they have been proved at a level of rigour that is quite
>>>>>>> unprecedented, and simply not possible for the vast majority of
>>>>>>> theorems.
>>>>>>
>>>>>> In the present context, that would be more interesting if
>>>>>> PO had pointed to some flaw, or potential flaw, in the theorem.
>>>>>
>>>>> For a long time that was exactly his claim, though as you say he
>>>>> never pointed out what he thought was the flaw.
>>>>>
>>>>
>>>> The flaw is that no one ever bothered to think through the effects of
>>>> a simulating halt decider.
>>>>
>>>> Instead of ever beginning this analysis simulation is simply rejected
>>>> out-of-hand on the basis that some simulations would never end.
>>>>
>>>> A simulating halt decider recognizes the infinitely nested simulation
>>>> behavior pattern of the conventional HP counter examples, thus
>>>> aborted its simulation before ever reaching the "impossible" part of
>>>> the "impossible" input.
>>>
>>> Those proofs DO NOT CONTAIN INFINITE RECURSION or an INFINITELY NESTED
>>> SIMULATION. You are MAKING THIS UP AND IT IS ERRONEOUS.
>>>
>> When we assume that the halt decider bases its halt status decision on
>> the behavior of its correctly simulated input
>
> By definition, the correctly simulated input is simulated by a UTM.

The correctly simulated N steps of the input to a halt decider would be
performed by a UTM. It must be augmented to be able to stop at any point
prior to reaching the final state of its input.

--
Copyright 2022 Pete Olcott

"Talent hits a target no one else can hit;
Genius hits a target no one else can see."
Arthur Schopenhauer

On Wednesday, May 25, 2022 at 2:25:03 PM UTC-4, olcott wrote:
> On 5/25/2022 1:05 PM, Dennis Bush wrote:
> > On Wednesday, May 25, 2022 at 1:48:17 PM UTC-4, olcott wrote:
> >> On 5/25/2022 12:45 PM, Mr Flibble wrote:
> >>> On Wed, 25 May 2022 12:35:44 -0500
> >>> olcott <No...@NoWhere.com> wrote:
> >>>
> >>>> On 5/25/2022 6:37 AM, Ben wrote:
> >>>>> Andy Walker <a...@cuboid.co.uk> writes:
> >>>>>
> >>>>>> On 24/05/2022 23:59, Ben wrote:
> >>>>>>> Jeff Barnett <j...@notatt.com> writes:
> >>>>>> [...]
> >>>>>>>> I think, that upon reflection, you will recall that isn't true.
> >>>>>>>> I'm assuming that you are at least a moderate history of math
> >>>>>>>> (etc.) buff and have read "Proofs and Refutations" by Imre
> >>>>>>>> Lakatos. This book, as well as many others written by him or
> >>>>>>>> others, go through the history of mathematics and show examples
> >>>>>>>> where the whole community has bought a load of rope.
> >>>>>>
> >>>>>> Lakatos's work is interesting, but I wouldn't go overboard
> >>>>>> about it. It's "philosophy of maths" more than "history" of
> >>>>>> maths", and, AIUI, it's not so much a claim that any particular
> >>>>>> theorem is "wrong", rather that as maths develops, its language
> >>>>>> evolves and becomes refined. Of course there have been blunders,
> >>>>>> which may have lain undetected for a long time, but more important
> >>>>>> have been the "edge" cases, where what we mean by [eg] "function"
> >>>>>> has developed esp as we moved from the intuition of the 18thC to
> >>>>>> the rigour of the 19thC, so that theorems need to change to
> >>>>>> reflect the new language.
> >>>>>
> >>>>> I found the original essays that form the core of the book online,
> >>>>> and though I ave not finished reading, I think what Lakatos is
> >>>>> saying is somewhat tangential to my point. His main focus is on
> >>>>> the process of doing mathematics.
> >>>>>
> >>>>> Of course PO thinks (I should say now thinks because his claims
> >>>>> shift over time) that he has "refined" the idea of halting.
> >>>>>
> >>>>>> Re history -- I recall that Warwick ran a history module
> >>>>>> based entirely around the dead ends of geometry in the 19thC.
> >>>>>> Stuff that is now utterly forgotten but for a few years was all
> >>>>>> the rage. Had it not been so utterly forgotten, I'd be able to
> >>>>>> quote some examples. But it serves as a reminder that maths is
> >>>>>> not the "definitive" subject that is usually presented to students
> >>>>>> [from primary school to research] -- "Here be maths as it is and
> >>>>>> always has been ever since its discovery, and here be the unknown
> >>>>>> bits where research is ongoing" -- but contains any number of
> >>>>>> false starts and debates, many of which never resolve but just get
> >>>>>> quietly dropped.
> >>>>>
> >>>>> I think that's true of many branches of human investigation, but
> >>>>> since mathematics is the investigation of abstract "inventions", it
> >>>>> is even more prone to going off on tangents that turn out to be
> >>>>> fads. Then again, some fields come back to being centre stage.
> >>>>> Number theory, once little more than an amusement, turned into a
> >>>>> valuable area of research.
> >>>>>> Re Lakatos -- his Wiki biography is interesting, and as
> >>>>>> well as detailing his complicated private/political life says
> >>>>>> quite a lot about "Proofs ...".
> >>>>>>
> >>>>>>> I don't know that book. I'll see if I can get hold of it. It
> >>>>>>> sounds really interesting but, sadly, I no longer have access to
> >>>>>>> world-class library :-(
> >>>>>>
> >>>>>> As Jeff says, copies are available. Bookfinder lists 296
> >>>>>> copies for sale. But I find it hard to believe that you no longer
> >>>>>> have access to any library with a copy [or able to get one for
> >>>>>> you] -- it doesn't need to be world-class for that.
> >>>>>
> >>>>> I was just lamenting the loss as some places give retired academics
> >>>>> library privileges and some don't! The local council library
> >>>>> system is just about hanging on in most places in the UK so, yes, I
> >>>>> can get any book through the inter-library loan scheme. It's just
> >>>>> that waiting weeks is so last century.
> >>>>>
> >>>>>> Apart from that, you surely have some
> >>>>>> friends/acquaintances with access to a university library?
> >>>>>
> >>>>> Strictly against the rules, so I would not want to put anyone in
> >>>>> that position!
> >>>>>
> >>>>>> [...]
> >>>>>>> And of course the halting theorem and Cantor's theorem are so
> >>>>>>> simple they have been proved at a level of rigour that is quite
> >>>>>>> unprecedented, and simply not possible for the vast majority of
> >>>>>>> theorems.
> >>>>>>
> >>>>>> In the present context, that would be more interesting if
> >>>>>> PO had pointed to some flaw, or potential flaw, in the theorem.
> >>>>>
> >>>>> For a long time that was exactly his claim, though as you say he
> >>>>> never pointed out what he thought was the flaw.
> >>>>>
> >>>>
> >>>> The flaw is that no one ever bothered to think through the effects of
> >>>> a simulating halt decider.
> >>>>
> >>>> Instead of ever beginning this analysis simulation is simply rejected
> >>>> out-of-hand on the basis that some simulations would never end.
> >>>>
> >>>> A simulating halt decider recognizes the infinitely nested simulation
> >>>> behavior pattern of the conventional HP counter examples, thus
> >>>> aborted its simulation before ever reaching the "impossible" part of
> >>>> the "impossible" input.
> >>>
> >>> Those proofs DO NOT CONTAIN INFINITE RECURSION or an INFINITELY NESTED
> >>> SIMULATION. You are MAKING THIS UP AND IT IS ERRONEOUS.
> >>>
> >> When we assume that the halt decider bases its halt status decision on
> >> the behavior of its correctly simulated input
> >
> > By definition, the correctly simulated input is simulated by a UTM.
> The correctly simulated N steps of the input to a halt decider would be
> performed by a UTM. It must be augmented to be able to stop at any point
> prior to reaching the final state of its input.

And if the UTM simulation reaches a final state then a simulating halt decider must also simulate that same input to a final state, otherwise it is wrong by definition

On 5/25/2022 1:31 PM, Dennis Bush wrote:
> On Wednesday, May 25, 2022 at 2:25:03 PM UTC-4, olcott wrote:
>> On 5/25/2022 1:05 PM, Dennis Bush wrote:
>>> On Wednesday, May 25, 2022 at 1:48:17 PM UTC-4, olcott wrote:
>>>> On 5/25/2022 12:45 PM, Mr Flibble wrote:
>>>>> On Wed, 25 May 2022 12:35:44 -0500
>>>>> olcott <No...@NoWhere.com> wrote:
>>>>>
>>>>>> On 5/25/2022 6:37 AM, Ben wrote:
>>>>>>> Andy Walker <a...@cuboid.co.uk> writes:
>>>>>>>
>>>>>>>> On 24/05/2022 23:59, Ben wrote:
>>>>>>>>> Jeff Barnett <j...@notatt.com> writes:
>>>>>>>> [...]
>>>>>>>>>> I think, that upon reflection, you will recall that isn't true.
>>>>>>>>>> I'm assuming that you are at least a moderate history of math
>>>>>>>>>> (etc.) buff and have read "Proofs and Refutations" by Imre
>>>>>>>>>> Lakatos. This book, as well as many others written by him or
>>>>>>>>>> others, go through the history of mathematics and show examples
>>>>>>>>>> where the whole community has bought a load of rope.
>>>>>>>>
>>>>>>>> Lakatos's work is interesting, but I wouldn't go overboard
>>>>>>>> about it. It's "philosophy of maths" more than "history" of
>>>>>>>> maths", and, AIUI, it's not so much a claim that any particular
>>>>>>>> theorem is "wrong", rather that as maths develops, its language
>>>>>>>> evolves and becomes refined. Of course there have been blunders,
>>>>>>>> which may have lain undetected for a long time, but more important
>>>>>>>> have been the "edge" cases, where what we mean by [eg] "function"
>>>>>>>> has developed esp as we moved from the intuition of the 18thC to
>>>>>>>> the rigour of the 19thC, so that theorems need to change to
>>>>>>>> reflect the new language.
>>>>>>>
>>>>>>> I found the original essays that form the core of the book online,
>>>>>>> and though I ave not finished reading, I think what Lakatos is
>>>>>>> saying is somewhat tangential to my point. His main focus is on
>>>>>>> the process of doing mathematics.
>>>>>>>
>>>>>>> Of course PO thinks (I should say now thinks because his claims
>>>>>>> shift over time) that he has "refined" the idea of halting.
>>>>>>>
>>>>>>>> Re history -- I recall that Warwick ran a history module
>>>>>>>> based entirely around the dead ends of geometry in the 19thC.
>>>>>>>> Stuff that is now utterly forgotten but for a few years was all
>>>>>>>> the rage. Had it not been so utterly forgotten, I'd be able to
>>>>>>>> quote some examples. But it serves as a reminder that maths is
>>>>>>>> not the "definitive" subject that is usually presented to students
>>>>>>>> [from primary school to research] -- "Here be maths as it is and
>>>>>>>> always has been ever since its discovery, and here be the unknown
>>>>>>>> bits where research is ongoing" -- but contains any number of
>>>>>>>> false starts and debates, many of which never resolve but just get
>>>>>>>> quietly dropped.
>>>>>>>
>>>>>>> I think that's true of many branches of human investigation, but
>>>>>>> since mathematics is the investigation of abstract "inventions", it
>>>>>>> is even more prone to going off on tangents that turn out to be
>>>>>>> fads. Then again, some fields come back to being centre stage.
>>>>>>> Number theory, once little more than an amusement, turned into a
>>>>>>> valuable area of research.
>>>>>>>> Re Lakatos -- his Wiki biography is interesting, and as
>>>>>>>> well as detailing his complicated private/political life says
>>>>>>>> quite a lot about "Proofs ...".
>>>>>>>>
>>>>>>>>> I don't know that book. I'll see if I can get hold of it. It
>>>>>>>>> sounds really interesting but, sadly, I no longer have access to
>>>>>>>>> world-class library :-(
>>>>>>>>
>>>>>>>> As Jeff says, copies are available. Bookfinder lists 296
>>>>>>>> copies for sale. But I find it hard to believe that you no longer
>>>>>>>> have access to any library with a copy [or able to get one for
>>>>>>>> you] -- it doesn't need to be world-class for that.
>>>>>>>
>>>>>>> I was just lamenting the loss as some places give retired academics
>>>>>>> library privileges and some don't! The local council library
>>>>>>> system is just about hanging on in most places in the UK so, yes, I
>>>>>>> can get any book through the inter-library loan scheme. It's just
>>>>>>> that waiting weeks is so last century.
>>>>>>>
>>>>>>>> Apart from that, you surely have some
>>>>>>>> friends/acquaintances with access to a university library?
>>>>>>>
>>>>>>> Strictly against the rules, so I would not want to put anyone in
>>>>>>> that position!
>>>>>>>
>>>>>>>> [...]
>>>>>>>>> And of course the halting theorem and Cantor's theorem are so
>>>>>>>>> simple they have been proved at a level of rigour that is quite
>>>>>>>>> unprecedented, and simply not possible for the vast majority of
>>>>>>>>> theorems.
>>>>>>>>
>>>>>>>> In the present context, that would be more interesting if
>>>>>>>> PO had pointed to some flaw, or potential flaw, in the theorem.
>>>>>>>
>>>>>>> For a long time that was exactly his claim, though as you say he
>>>>>>> never pointed out what he thought was the flaw.
>>>>>>>
>>>>>>
>>>>>> The flaw is that no one ever bothered to think through the effects of
>>>>>> a simulating halt decider.
>>>>>>
>>>>>> Instead of ever beginning this analysis simulation is simply rejected
>>>>>> out-of-hand on the basis that some simulations would never end.
>>>>>>
>>>>>> A simulating halt decider recognizes the infinitely nested simulation
>>>>>> behavior pattern of the conventional HP counter examples, thus
>>>>>> aborted its simulation before ever reaching the "impossible" part of
>>>>>> the "impossible" input.
>>>>>
>>>>> Those proofs DO NOT CONTAIN INFINITE RECURSION or an INFINITELY NESTED
>>>>> SIMULATION. You are MAKING THIS UP AND IT IS ERRONEOUS.
>>>>>
>>>> When we assume that the halt decider bases its halt status decision on
>>>> the behavior of its correctly simulated input
>>>
>>> By definition, the correctly simulated input is simulated by a UTM.
>> The correctly simulated N steps of the input to a halt decider would be
>> performed by a UTM. It must be augmented to be able to stop at any point
>> prior to reaching the final state of its input.
>
> And if the UTM simulation reaches a final state then a simulating halt decider must also simulate that same input to a final state, otherwise it is wrong by definition

You did not say that accurately. If the UTM simulation of the input
reaches the final state of the input then a simulating halt decider
would have this same behavior.

--
Copyright 2022 Pete Olcott

"Talent hits a target no one else can hit;
Genius hits a target no one else can see."
Arthur Schopenhauer

On Wednesday, May 25, 2022 at 2:37:39 PM UTC-4, olcott wrote:
> On 5/25/2022 1:31 PM, Dennis Bush wrote:
> > On Wednesday, May 25, 2022 at 2:25:03 PM UTC-4, olcott wrote:
> >> On 5/25/2022 1:05 PM, Dennis Bush wrote:
> >>> On Wednesday, May 25, 2022 at 1:48:17 PM UTC-4, olcott wrote:
> >>>> On 5/25/2022 12:45 PM, Mr Flibble wrote:
> >>>>> On Wed, 25 May 2022 12:35:44 -0500
> >>>>> olcott <No...@NoWhere.com> wrote:
> >>>>>
> >>>>>> On 5/25/2022 6:37 AM, Ben wrote:
> >>>>>>> Andy Walker <a...@cuboid.co.uk> writes:
> >>>>>>>
> >>>>>>>> On 24/05/2022 23:59, Ben wrote:
> >>>>>>>>> Jeff Barnett <j...@notatt.com> writes:
> >>>>>>>> [...]
> >>>>>>>>>> I think, that upon reflection, you will recall that isn't true.
> >>>>>>>>>> I'm assuming that you are at least a moderate history of math
> >>>>>>>>>> (etc.) buff and have read "Proofs and Refutations" by Imre
> >>>>>>>>>> Lakatos. This book, as well as many others written by him or
> >>>>>>>>>> others, go through the history of mathematics and show examples
> >>>>>>>>>> where the whole community has bought a load of rope.
> >>>>>>>>
> >>>>>>>> Lakatos's work is interesting, but I wouldn't go overboard
> >>>>>>>> about it. It's "philosophy of maths" more than "history" of
> >>>>>>>> maths", and, AIUI, it's not so much a claim that any particular
> >>>>>>>> theorem is "wrong", rather that as maths develops, its language
> >>>>>>>> evolves and becomes refined. Of course there have been blunders,
> >>>>>>>> which may have lain undetected for a long time, but more important
> >>>>>>>> have been the "edge" cases, where what we mean by [eg] "function"
> >>>>>>>> has developed esp as we moved from the intuition of the 18thC to
> >>>>>>>> the rigour of the 19thC, so that theorems need to change to
> >>>>>>>> reflect the new language.
> >>>>>>>
> >>>>>>> I found the original essays that form the core of the book online,
> >>>>>>> and though I ave not finished reading, I think what Lakatos is
> >>>>>>> saying is somewhat tangential to my point. His main focus is on
> >>>>>>> the process of doing mathematics.
> >>>>>>>
> >>>>>>> Of course PO thinks (I should say now thinks because his claims
> >>>>>>> shift over time) that he has "refined" the idea of halting.
> >>>>>>>
> >>>>>>>> Re history -- I recall that Warwick ran a history module
> >>>>>>>> based entirely around the dead ends of geometry in the 19thC.
> >>>>>>>> Stuff that is now utterly forgotten but for a few years was all
> >>>>>>>> the rage. Had it not been so utterly forgotten, I'd be able to
> >>>>>>>> quote some examples. But it serves as a reminder that maths is
> >>>>>>>> not the "definitive" subject that is usually presented to students
> >>>>>>>> [from primary school to research] -- "Here be maths as it is and
> >>>>>>>> always has been ever since its discovery, and here be the unknown
> >>>>>>>> bits where research is ongoing" -- but contains any number of
> >>>>>>>> false starts and debates, many of which never resolve but just get
> >>>>>>>> quietly dropped.
> >>>>>>>
> >>>>>>> I think that's true of many branches of human investigation, but
> >>>>>>> since mathematics is the investigation of abstract "inventions", it
> >>>>>>> is even more prone to going off on tangents that turn out to be
> >>>>>>> fads. Then again, some fields come back to being centre stage.
> >>>>>>> Number theory, once little more than an amusement, turned into a
> >>>>>>> valuable area of research.
> >>>>>>>> Re Lakatos -- his Wiki biography is interesting, and as
> >>>>>>>> well as detailing his complicated private/political life says
> >>>>>>>> quite a lot about "Proofs ...".
> >>>>>>>>
> >>>>>>>>> I don't know that book. I'll see if I can get hold of it. It
> >>>>>>>>> sounds really interesting but, sadly, I no longer have access to
> >>>>>>>>> world-class library :-(
> >>>>>>>>
> >>>>>>>> As Jeff says, copies are available. Bookfinder lists 296
> >>>>>>>> copies for sale. But I find it hard to believe that you no longer
> >>>>>>>> have access to any library with a copy [or able to get one for
> >>>>>>>> you] -- it doesn't need to be world-class for that.
> >>>>>>>
> >>>>>>> I was just lamenting the loss as some places give retired academics
> >>>>>>> library privileges and some don't! The local council library
> >>>>>>> system is just about hanging on in most places in the UK so, yes, I
> >>>>>>> can get any book through the inter-library loan scheme. It's just
> >>>>>>> that waiting weeks is so last century.
> >>>>>>>
> >>>>>>>> Apart from that, you surely have some
> >>>>>>>> friends/acquaintances with access to a university library?
> >>>>>>>
> >>>>>>> Strictly against the rules, so I would not want to put anyone in
> >>>>>>> that position!
> >>>>>>>
> >>>>>>>> [...]
> >>>>>>>>> And of course the halting theorem and Cantor's theorem are so
> >>>>>>>>> simple they have been proved at a level of rigour that is quite
> >>>>>>>>> unprecedented, and simply not possible for the vast majority of
> >>>>>>>>> theorems.
> >>>>>>>>
> >>>>>>>> In the present context, that would be more interesting if
> >>>>>>>> PO had pointed to some flaw, or potential flaw, in the theorem.
> >>>>>>>
> >>>>>>> For a long time that was exactly his claim, though as you say he
> >>>>>>> never pointed out what he thought was the flaw.
> >>>>>>>
> >>>>>>
> >>>>>> The flaw is that no one ever bothered to think through the effects of
> >>>>>> a simulating halt decider.
> >>>>>>
> >>>>>> Instead of ever beginning this analysis simulation is simply rejected
> >>>>>> out-of-hand on the basis that some simulations would never end.
> >>>>>>
> >>>>>> A simulating halt decider recognizes the infinitely nested simulation
> >>>>>> behavior pattern of the conventional HP counter examples, thus
> >>>>>> aborted its simulation before ever reaching the "impossible" part of
> >>>>>> the "impossible" input.
> >>>>>
> >>>>> Those proofs DO NOT CONTAIN INFINITE RECURSION or an INFINITELY NESTED
> >>>>> SIMULATION. You are MAKING THIS UP AND IT IS ERRONEOUS.
> >>>>>
> >>>> When we assume that the halt decider bases its halt status decision on
> >>>> the behavior of its correctly simulated input
> >>>
> >>> By definition, the correctly simulated input is simulated by a UTM.
> >> The correctly simulated N steps of the input to a halt decider would be
> >> performed by a UTM. It must be augmented to be able to stop at any point
> >> prior to reaching the final state of its input.
> >
> > And if the UTM simulation reaches a final state then a simulating halt decider must also simulate that same input to a final state, otherwise it is wrong by definition
> You did not say that accurately. If the UTM simulation of the input
> reaches the final state of the input then a simulating halt decider
> would have this same behavior.

On 5/25/2022 1:40 PM, Dennis Bush wrote:
> On Wednesday, May 25, 2022 at 2:37:39 PM UTC-4, olcott wrote:
>> On 5/25/2022 1:31 PM, Dennis Bush wrote:
>>> On Wednesday, May 25, 2022 at 2:25:03 PM UTC-4, olcott wrote:
>>>> On 5/25/2022 1:05 PM, Dennis Bush wrote:
>>>>> On Wednesday, May 25, 2022 at 1:48:17 PM UTC-4, olcott wrote:
>>>>>> On 5/25/2022 12:45 PM, Mr Flibble wrote:
>>>>>>> On Wed, 25 May 2022 12:35:44 -0500
>>>>>>> olcott <No...@NoWhere.com> wrote:
>>>>>>>
>>>>>>>> On 5/25/2022 6:37 AM, Ben wrote:
>>>>>>>>> Andy Walker <a...@cuboid.co.uk> writes:
>>>>>>>>>
>>>>>>>>>> On 24/05/2022 23:59, Ben wrote:
>>>>>>>>>>> Jeff Barnett <j...@notatt.com> writes:
>>>>>>>>>> [...]
>>>>>>>>>>>> I think, that upon reflection, you will recall that isn't true.
>>>>>>>>>>>> I'm assuming that you are at least a moderate history of math
>>>>>>>>>>>> (etc.) buff and have read "Proofs and Refutations" by Imre
>>>>>>>>>>>> Lakatos. This book, as well as many others written by him or
>>>>>>>>>>>> others, go through the history of mathematics and show examples
>>>>>>>>>>>> where the whole community has bought a load of rope.
>>>>>>>>>>
>>>>>>>>>> Lakatos's work is interesting, but I wouldn't go overboard
>>>>>>>>>> about it. It's "philosophy of maths" more than "history" of
>>>>>>>>>> maths", and, AIUI, it's not so much a claim that any particular
>>>>>>>>>> theorem is "wrong", rather that as maths develops, its language
>>>>>>>>>> evolves and becomes refined. Of course there have been blunders,
>>>>>>>>>> which may have lain undetected for a long time, but more important
>>>>>>>>>> have been the "edge" cases, where what we mean by [eg] "function"
>>>>>>>>>> has developed esp as we moved from the intuition of the 18thC to
>>>>>>>>>> the rigour of the 19thC, so that theorems need to change to
>>>>>>>>>> reflect the new language.
>>>>>>>>>
>>>>>>>>> I found the original essays that form the core of the book online,
>>>>>>>>> and though I ave not finished reading, I think what Lakatos is
>>>>>>>>> saying is somewhat tangential to my point. His main focus is on
>>>>>>>>> the process of doing mathematics.
>>>>>>>>>
>>>>>>>>> Of course PO thinks (I should say now thinks because his claims
>>>>>>>>> shift over time) that he has "refined" the idea of halting.
>>>>>>>>>
>>>>>>>>>> Re history -- I recall that Warwick ran a history module
>>>>>>>>>> based entirely around the dead ends of geometry in the 19thC.
>>>>>>>>>> Stuff that is now utterly forgotten but for a few years was all
>>>>>>>>>> the rage. Had it not been so utterly forgotten, I'd be able to
>>>>>>>>>> quote some examples. But it serves as a reminder that maths is
>>>>>>>>>> not the "definitive" subject that is usually presented to students
>>>>>>>>>> [from primary school to research] -- "Here be maths as it is and
>>>>>>>>>> always has been ever since its discovery, and here be the unknown
>>>>>>>>>> bits where research is ongoing" -- but contains any number of
>>>>>>>>>> false starts and debates, many of which never resolve but just get
>>>>>>>>>> quietly dropped.
>>>>>>>>>
>>>>>>>>> I think that's true of many branches of human investigation, but
>>>>>>>>> since mathematics is the investigation of abstract "inventions", it
>>>>>>>>> is even more prone to going off on tangents that turn out to be
>>>>>>>>> fads. Then again, some fields come back to being centre stage.
>>>>>>>>> Number theory, once little more than an amusement, turned into a
>>>>>>>>> valuable area of research.
>>>>>>>>>> Re Lakatos -- his Wiki biography is interesting, and as
>>>>>>>>>> well as detailing his complicated private/political life says
>>>>>>>>>> quite a lot about "Proofs ...".
>>>>>>>>>>
>>>>>>>>>>> I don't know that book. I'll see if I can get hold of it. It
>>>>>>>>>>> sounds really interesting but, sadly, I no longer have access to
>>>>>>>>>>> world-class library :-(
>>>>>>>>>>
>>>>>>>>>> As Jeff says, copies are available. Bookfinder lists 296
>>>>>>>>>> copies for sale. But I find it hard to believe that you no longer
>>>>>>>>>> have access to any library with a copy [or able to get one for
>>>>>>>>>> you] -- it doesn't need to be world-class for that.
>>>>>>>>>
>>>>>>>>> I was just lamenting the loss as some places give retired academics
>>>>>>>>> library privileges and some don't! The local council library
>>>>>>>>> system is just about hanging on in most places in the UK so, yes, I
>>>>>>>>> can get any book through the inter-library loan scheme. It's just
>>>>>>>>> that waiting weeks is so last century.
>>>>>>>>>
>>>>>>>>>> Apart from that, you surely have some
>>>>>>>>>> friends/acquaintances with access to a university library?
>>>>>>>>>
>>>>>>>>> Strictly against the rules, so I would not want to put anyone in
>>>>>>>>> that position!
>>>>>>>>>
>>>>>>>>>> [...]
>>>>>>>>>>> And of course the halting theorem and Cantor's theorem are so
>>>>>>>>>>> simple they have been proved at a level of rigour that is quite
>>>>>>>>>>> unprecedented, and simply not possible for the vast majority of
>>>>>>>>>>> theorems.
>>>>>>>>>>
>>>>>>>>>> In the present context, that would be more interesting if
>>>>>>>>>> PO had pointed to some flaw, or potential flaw, in the theorem.
>>>>>>>>>
>>>>>>>>> For a long time that was exactly his claim, though as you say he
>>>>>>>>> never pointed out what he thought was the flaw.
>>>>>>>>>
>>>>>>>>
>>>>>>>> The flaw is that no one ever bothered to think through the effects of
>>>>>>>> a simulating halt decider.
>>>>>>>>
>>>>>>>> Instead of ever beginning this analysis simulation is simply rejected
>>>>>>>> out-of-hand on the basis that some simulations would never end.
>>>>>>>>
>>>>>>>> A simulating halt decider recognizes the infinitely nested simulation
>>>>>>>> behavior pattern of the conventional HP counter examples, thus
>>>>>>>> aborted its simulation before ever reaching the "impossible" part of
>>>>>>>> the "impossible" input.
>>>>>>>
>>>>>>> Those proofs DO NOT CONTAIN INFINITE RECURSION or an INFINITELY NESTED
>>>>>>> SIMULATION. You are MAKING THIS UP AND IT IS ERRONEOUS.
>>>>>>>
>>>>>> When we assume that the halt decider bases its halt status decision on
>>>>>> the behavior of its correctly simulated input
>>>>>
>>>>> By definition, the correctly simulated input is simulated by a UTM.
>>>> The correctly simulated N steps of the input to a halt decider would be
>>>> performed by a UTM. It must be augmented to be able to stop at any point
>>>> prior to reaching the final state of its input.
>>>
>>> And if the UTM simulation reaches a final state then a simulating halt decider must also simulate that same input to a final state, otherwise it is wrong by definition
>> You did not say that accurately. If the UTM simulation of the input
>> reaches the final state of the input then a simulating halt decider
>> would have this same behavior.
>
> If it was correct it would have the same behavior. But if H(P,P)==0, then UTM(P,P) will halt, so H(P,P)==0 is wrong by definition.

Jeff Barnett <jbb@notatt.com> writes:

> We retired to a place where we knew nobody but had a university with a
> CS department. I made an appointment with the chair and had lunch one
> day. I did not want to teach but wanted some connection with the
> department. I was granted a status called "visiting colleague" that
> gave me library and campus store privileges as well as put me on
> various lists such as the seminar and department talks invitees'
> list. Now a I days can attend them via ZOOM.

Interesting arrangement. I don't think that's at all common in the UK.
I think it's sometimes done for people who retire famous, or who hold a
personal chair (would that be "full professor" in the US?), but I was
just a tenured lecturer ("associate professor" in the US?) and not
famous!

> As far as I know, most universities in the US have similar
> arrangements though the name of the "positions" vary. I just assumed
> that you would have similar access or there would be a position such
> as "Emeritus" with your prior employer or even other institutions.

I have a very tenuous connection to the nearest university in that,
decades ago, I wrote a course module for them, but even so I'd feel very
odd popping in for a chat with the head of department.

Anyway, much more interested in dog behaviour and training these days.
Much rather hook up with people at the IMDT or CIDBT or some such.

--
Ben.

On 5/25/2022 1:37 PM, Ben wrote:
> Jeff Barnett <jbb@notatt.com> writes:
>
>> We retired to a place where we knew nobody but had a university with a
>> CS department. I made an appointment with the chair and had lunch one
>> day. I did not want to teach but wanted some connection with the
>> department. I was granted a status called "visiting colleague" that
>> gave me library and campus store privileges as well as put me on
>> various lists such as the seminar and department talks invitees'
>> list. Now a I days can attend them via ZOOM.
>
> Interesting arrangement. I don't think that's at all common in the UK.
> I think it's sometimes done for people who retire famous, or who hold a
> personal chair (would that be "full professor" in the US?), but I was
> just a tenured lecturer ("associate professor" in the US?) and not
> famous!

Not all "fulls" hold named and endowed chairs. However, the top two
professorial ranks are tenured, The normal arrangement at one time was
that you had to reach a tenured rank in 7 years or move on - did not
want non-tenured (or not so good) to became de facto forever employees.
I don't know if the current picture is like that or not.

However and more to the point, I find it hard to imagine that a
University in this country would not grant stack privileges to a retired
academic whether their affiliation was there or another school. I also
don't think such access would be denied to a researcher who spent most
of their career in industry or think tanks.

As to doing lunch with department head, I'll make a few remarks: When I
was younger and the world was friendlier I became used to an environment
where you could pick up the phone and call anyone in the field that you
thought it was important to talked to. Importance included things like
"what did you mean in this paragraph?" or "do you have any grad students
chasing x?", etc. We used to go to Boston from the West Coast every few
months on red eye flights that arrived between midnight and 3AM (1960s).
We would rent a car and go to Tech Square at MIT, walk in, and take an
elevator to the top floor, then go in to the computer labs to start
sessions with whoever was around. There were no locks on the doors, no
security, just a bunch of kids playing with computers. So the idea, even
today, of calling a department head seems unremarkable.

In any event, there was a twist in this story. The head at that time was
a woman that I had met many years ago. I was at an university institute
and she was a grad student at that time who spent a summer there so we
had crossed paths. At lunch, I happened to remember a startling
personnel revelation from that summer. Some of the students there for
the summer were making a lot of noise in the halls and having a
generally good time with their projects. They were talking, trading
notes and laughing. I thought to myself: "They are kids and it's good to
see them be so enthusiastic and enjoying their work!" It was then, for
the first time, I realized I was no longer a kid and I was doing the
tolerating rather being tolerated.

>> As far as I know, most universities in the US have similar
>> arrangements though the name of the "positions" vary. I just assumed
>> that you would have similar access or there would be a position such
>> as "Emeritus" with your prior employer or even other institutions.
>
> I have a very tenuous connection to the nearest university in that,
> decades ago, I wrote a course module for them, but even so I'd feel very
> odd popping in for a chat with the head of department.

Does the head have a secretary or some kind of administrative staff? If
so call them and ask what arrangements are available. You might directly
check with the library and see if they can offer access to retirees or
colleagues living in the area.

> Anyway, much more interested in dog behaviour and training these days.
> Much rather hook up with people at the IMDT or CIDBT or some such.
We are mainly cat people but completely understand the attraction to
animals per se. Sometimes when I read these threads I wonder why we
bother with humans at all: and some even think we are made in the image
of god! What an insult to a god or gods if there is such entities. It's
the same hubris that makes folks believe that can understand the results
of the greatest minds of recorded history by quickly scanning the
opening paragraph of the abstract!
--
Jeff Barnett

On 2022-05-25 14:57, Jeff Barnett wrote:

> However and more to the point, I find it hard to imagine that a
> University in this country would not grant stack privileges to a retired
> academic whether their affiliation was there or another school. I also
> don't think such access would be denied to a researcher who spent most
> of their career in industry or think tanks.

When I lived in the USA, I taught at a small liberal arts college just
outside of Boston. While it was a good college, the library wasn't
terribly great where my research interests were concerned. However, it
was trivially easy for me to get borrowing privileges at MIT and Harvard
which had more extensive holdings just by virtue of being on faculty
somewhere (a large fee was required for Harvard, but fortunately the
college was willing to foot the bill for that).

There was, however, a marked difference between the two libraries. While
the MIT libraries all have signs at the entrance indicating that they
are only for use of MIT faculty and students, anyone could really make
use of them since there was never any ID checks unless you were checking
out materials. Anyone could read materials in the library regardless of
who they were. Harvard, on the other hand, wouldn't even let people into
the building unless they could prove they had library privileges. In
fact, they checked your ID *twice*: once to get into the building, and
then again to get into anywhere other than the lobby.

Based on my experience, most American university libraries are more like
the MIT one than the Harvard one. However, a conversation which I
recently had with someone who did their PhD at UC London suggests that
British libraries tend to be much more "Harvard-like" than "MIT-like".
Once she had graduated, she found it very difficult to get library
access while living in England.

Where I am now (Canada), the university library only grants borrowing
privileges to faculty and students, but the library is explicitly open
to the general public if anyone wants to make use of materials within
the library.

André

--
To email remove 'invalid' & replace 'gm' with well known Google mail
service.

On 5/25/2022 4:15 PM, André G. Isaak wrote:
> On 2022-05-25 14:57, Jeff Barnett wrote:
>
>> However and more to the point, I find it hard to imagine that a
>> University in this country would not grant stack privileges to a
>> retired academic whether their affiliation was there or another
>> school. I also don't think such access would be denied to a researcher
>> who spent most of their career in industry or think tanks.
>
> When I lived in the USA, I taught at a small liberal arts college just
> outside of Boston. While it was a good college, the library wasn't
> terribly great where my research interests were concerned. However, it
> was trivially easy for me to get borrowing privileges at MIT and Harvard
> which had more extensive holdings just by virtue of being on faculty
> somewhere (a large fee was required for Harvard, but fortunately the
> college was willing to foot the bill for that).
>
> There was, however, a marked difference between the two libraries. While
> the MIT libraries all have signs at the entrance indicating that they
> are only for use of MIT faculty and students, anyone could really make
> use of them since there was never any ID checks unless you were checking
> out materials. Anyone could read materials in the library regardless of
> who they were. Harvard, on the other hand, wouldn't even let people into
> the building unless they could prove they had library privileges. In
> fact, they checked your ID *twice*: once to get into the building, and
> then again to get into anywhere other than the lobby.
>
> Based on my experience, most American university libraries are more like
> the MIT one than the Harvard one. However, a conversation which I
> recently had with someone who did their PhD at UC London suggests that
> British libraries tend to be much more "Harvard-like" than "MIT-like".
> Once she had graduated, she found it very difficult to get library
> access while living in England.
>
> Where I am now (Canada), the university library only grants borrowing
> privileges to faculty and students, but the library is explicitly open
> to the general public if anyone wants to make use of materials within
> the library.
I guess I wouldn't be surprised if many US places were more restrictive
in the way you describe. The world I grew up in seems to be rapidly
disappearing and I don't like that. The instinct, at least within the
academic and research communities, was toward trusting unknown
individuals and exercising the choice to see what they had to say. It
seems today that more doors are locked, phones associated with the
university exist but are not answered or checked, and publicly known
email addresses are not monitored.
Something just pop back to memory: I had an acquaintance who was a
mathematician at UCLA. We were mainly social friends but occasionally
talked shop. For awhile he was acting Chair of the department, a
position he did not want. I asked him how they handled calls from the
public: you know the kind of questions: "Why isn't pi just 3 so we can
do quick calculations?" or "How can anybody be so stupid to believe
something you can't prove?". He said since his university was part of
The California state school system, the department felt obligated to
serve the public. So the math faculty took turns fielding such calls.
The department secretaries knew who's turn it was and so directed the
telephone calls! I think they might have kept a log of the nuttier
questions they got asked. I have no idea whether this "service" is still
available to the public.
--
Jeff Barnett

On Tuesday, 24 May 2022 at 03:05:09 UTC+8, olcott wrote:
> On 5/23/2022 1:52 PM, Mr Flibble wrote:
> > A simple multiple choice question for Olcott:
> >
> > All things being equal which is more likely:
> >
> > (a) Olcott is correct and everybody else is incorrect
> > (b) Olcott is incorrect and everybody else is correct
> >
> > ?
> >
> > /Flibble
> >
> Believability has the word [lie] embedded directly within itself.
> Instead of the fake measure of credibility one must employ actual
> validation.
>
> Actual validation conclusively proves that H(P,P)==0
> is correct. This means that everyone that disagrees is either
> insufficiently technically competent or a liar.
>
> Halting problem undecidability and infinitely nested simulation (V5)
>
> https://www.researchgate.net/publication/359984584_Halting_problem_undecidability_and_infinitely_nested_simulation_V5
>
> --
> Copyright 2022 Pete Olcott
>
> "Talent hits a target no one else can hit;
> Genius hits a target no one else can see."
> Arthur Schopenhauer

GUR says a correct halting decider is impossible.
Thanks to your tireless efforts for these years, my GUR is getting more and more
solid to have anti-proof demonstrated impossible (or only possible by idiot).

On 5/25/22 1:35 PM, olcott wrote:
> On 5/25/2022 6:37 AM, Ben wrote:
>> Andy Walker <anw@cuboid.co.uk> writes:
>>
>>> On 24/05/2022 23:59, Ben wrote:
>>>> Jeff Barnett <jbb@notatt.com> writes:
>>> [...]
>>>>> I think, that upon reflection, you will recall that isn't true. I'm
>>>>> assuming that you are at least a moderate history of math (etc.) buff
>>>>> and have read "Proofs and Refutations" by Imre Lakatos. This book, as
>>>>> well as many others written by him or others, go through the history
>>>>> of mathematics and show examples where the whole community has bought
>>>>> a load of rope.
>>>
>>>     Lakatos's work is interesting, but I wouldn't go overboard about
>>> it.  It's "philosophy of maths" more than "history" of maths", and,
>>> AIUI,
>>> it's not so much a claim that any particular theorem is "wrong", rather
>>> that as maths develops, its language evolves and becomes refined.  Of
>>> course there have been blunders, which may have lain undetected for a
>>> long time, but more important have been the "edge" cases, where what we
>>> mean by [eg] "function" has developed esp as we moved from the intuition
>>> of the 18thC to the rigour of the 19thC, so that theorems need to change
>>> to reflect the new language.
>>
>> I found the original essays that form the core of the book online, and
>> though I ave not finished reading, I think what Lakatos is saying is
>> somewhat tangential to my point.  His main focus is on the process of
>> doing mathematics.
>>
>> Of course PO thinks (I should say now thinks because his claims shift
>> over time) that he has "refined" the idea of halting.
>>
>>>     Re history -- I recall that Warwick ran a history module based
>>> entirely around the dead ends of geometry in the 19thC.  Stuff that is
>>> now utterly forgotten but for a few years was all the rage.  Had it not
>>> been so utterly forgotten, I'd be able to quote some examples.  But it
>>> serves as a reminder that maths is not the "definitive" subject that is
>>> usually presented to students [from primary school to research] --
>>> "Here be maths as it is and always has been ever since its discovery,
>>> and here be the unknown bits where research is ongoing" -- but contains
>>> any number of false starts and debates, many of which never resolve but
>>> just get quietly dropped.
>>
>> I think that's true of many branches of human investigation, but since
>> mathematics is the investigation of abstract "inventions", it is even
>> more prone to going off on tangents that turn out to be fads. Then
>> again, some fields come back to being centre stage.  Number theory, once
>> little more than an amusement, turned into a valuable area of research.
>>
>>>     Re Lakatos -- his Wiki biography is interesting, and as well as
>>> detailing his complicated private/political life says quite a lot about
>>> "Proofs ...".
>>>
>>>> I don't know that book.  I'll see if I can get hold of it.  It sounds
>>>> really interesting but, sadly, I no longer have access to world-class
>>>> library :-(
>>>
>>>     As Jeff says, copies are available.  Bookfinder lists 296 copies
>>> for sale.  But I find it hard to believe that you no longer have access
>>> to any library with a copy [or able to get one for you] -- it doesn't
>>> need to be world-class for that.
>>
>> I was just lamenting the loss as some places give retired academics
>> library privileges and some don't!  The local council library system is
>> just about hanging on in most places in the UK so, yes, I can get any
>> book through the inter-library loan scheme.  It's just that waiting
>> weeks is so last century.
>>
>>> Apart from that, you surely have some
>>> friends/acquaintances with access to a university library?
>>
>> Strictly against the rules, so I would not want to put anyone in that
>> position!
>>
>>> [...]
>>>> And of course the halting theorem and Cantor's theorem are so simple
>>>> they have been proved at a level of rigour that is quite unprecedented,
>>>> and simply not possible for the vast majority of theorems.
>>>
>>>     In the present context, that would be more interesting if PO had
>>> pointed to some flaw, or potential flaw, in the theorem.
>>
>> For a long time that was exactly his claim, though as you say he never
>> pointed out what he thought was the flaw.
>>
>
> The flaw is that no one ever bothered to think through the effects of a
> simulating halt decider.
>
> Instead of ever beginning this analysis simulation is simply rejected
> out-of-hand on the basis that some simulations would never end.
>
> A simulating halt decider recognizes the infinitely nested simulation
> behavior pattern of the conventional HP counter examples, thus aborted
> its simulation before ever reaching the "impossible" part of the
> "impossible" input.
>
> Since I have said this many hundreds of times you are quite dishonest to
> say that I never said this before.
>
>

No, YOUR flaw is beginning with an ASSUMPTION that a Simulating Halt
Decider can actually exist and be correct.

You are PRESUMING that it can be correct, and from that try to prove
that it is. This is a classical logical fallicy.

You don't understand what you are talking about to realize you are
making that sort of mistake, but it is clearly there from the way you
describe things. A big part is you just don't understand what
Computation actually is and what can be assumed to be a computation.

For instance, knowing if you can prove something is not necissarily
computable. In particular, you statement that H will halt when it can
prove that its input is non-halting, isn't computable, and assuming that
is can is basically assuming a Halt Decider exists.

So yes, and argument that includes as an assumed premise that a Halt
Decider can exist, can easily prove that Halt Deciders exist, it is just
that such an argument is UNSOUND.

On 26/05/2022 00:42, Jeff Barnett wrote:
>>> However and more to the point, I find it hard to imagine that a
>>> University in this country would not grant stack privileges to a
>>> retired academic whether their affiliation was there or another
>>> school.

My [former] university had [and probably still has] a self-imposed
duty to make [unspecified] provision for retired staff. I think it was
understood to include office space, IT provision, e-mail access, library
[sorry, "resource centre"] access, and perhaps other privileges. I've
never used any of that; but some of my former colleagues [who I still
meet regularly on a social basis] do. FWIW, in the topics of my main
interests, books, and even journals, are of little value; there is more
up-to-date and instantly accessible material on the web, and for older
stuff I still have several hundred books on my own shelves [partly 'cos
colleagues mostly disposed of their collections on retirement, whereas I
can't bring myself to part with any book].

[André:]
>> [...] However, a conversation
>> which I recently had with someone who did their PhD at UC London
>> suggests that British libraries tend to be much more "Harvard-like"
>> than "MIT-like". Once she had graduated, she found it very
>> difficult to get library access while living in England.

(a) I suspect this varies a lot between universities, (b) and
over time [tightening up in the light of security issues, etc]; and
(c) that it matters whether you are a former student or staff. There
is also the consideration that there are still public libraries which
will get "anything" for you via inter-library loans and the like.

[...]
> I guess I wouldn't be surprised if many US places were more
> restrictive in the way you describe. The world I grew up in seems to
> be rapidly disappearing and I don't like that. The instinct, at least
> within the academic and research communities, was toward trusting
> unknown individuals and exercising the choice to see what they had to
> say. It seems today that more doors are locked, phones associated
> with the university exist but are not answered or checked, and
> publicly known email addresses are not monitored.

Indeed. The atmosphere of academic freedom when I started [1960s]
was quite different from that when I finished [2007] and has deteriorated
since, to the extent that I wouldn't want to be a university lecturer just
starting on a career now. In fact, I have no idea what I would want to be
now [apart from retired!].

> [...] I asked him how they handled calls from the
> public: you know the kind of questions: "Why isn't pi just 3 so we
> can do quick calculations?" or "How can anybody be so stupid to
> believe something you can't prove?". He said since his university was
> part of The California state school system, the department felt
> obligated to serve the public. So the math faculty took turns
> fielding such calls. [...]

Perhaps the UK has a different class of nutter; but we got very
few crank calls [and our secretaries handled them by diverting to the
nearest member of staff]. We got many more in my time as an astronomer
[mostly to do with astrology, alignments or relativity], and they usually
went to the PhD students in some sort of rotation, though they sometimes
went to the tea/coffee room for general amusement.

--
Andy Walker, Nottingham.
Andy's music pages: www.cuboid.me.uk/andy/Music
Composer of the day: www.cuboid.me.uk/andy/Music/Composers/Schubert