Top boffin Freeman Dyson on climate change, interstellar travel, fusion, and more

Bill592
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Topic 198268

http://www.theregister.co.uk/2015/10/11/freeman_dyson_interview/?mt=1444629442111

Lots of interesting comments in this article !

The one that surprised me is that it is possible to get to 1\2 the speed of light by 'Riding' a laser beam ...

Bill

Mike Hewson
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Top boffin Freeman Dyson on climate change, interstellar travel,

Freeman is one of those old-school scientist types who still believes in reference to reality as the measure of a theory. A 'living fossil' that rigor was once prevalent/dominant in most disciplines. As a contemporary of Richard Feynman - he did an enormous amount to reconcile the apparently divergent formulations of quantum electrodynamics - he has much to say about the divide between theory and observation, and which is pre-eminent. I love this one :

Quote:
The division between string theory and the rest of physics is now wider than the split between string theory and mathematics.


I recall speaking a few years ago with a recent university graduate in animal biology, who had come up to the mountains around my home to study a certain tree dweller. I thought that was interesting and so I asked what the aim of the study was. She said they were going to demonstrate that some habit ( mating or food ) was relevant to that species. I said ( paraphrase ):

"You mean you are going to test whether that idea is true?"

"No, I'm going to collect the data to demonstrate the habit is occurring."

"But what if it isn't ?"

"Professor Bob has designed the study, so all I have to do is carry it out. He's my thesis supervisor."

... and that was that. OK. Hard for her to disagree there given the asymmetry of her role. But the deeper problem is that she will likely ( overtly or implicitly ) come to believe that prejudgment of results is correct methodology. Why ? Because that is what you get rewarded for. If you don't get what you expected then you have done it wrong ..... with the corollary that you keep fiddling, by whatever means, until the 'right' outcome emerges !

... thus 'science' wanders off towards output related to the sociology of human groups. IHMO that explains quite a lot, there being many 'string theory' analogies out there ... especially using what I call The Area51 Method : absence of evidence becomes proof*.

Cheers, Mike.

* Why do UFO's exist ? Because the USAF denies it ! :-)

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
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I am keen to use this

I am keen to use this opportunity to refer to this speech by Richard Feynman in 1974. He had picked up on the beginnings of the slippage that has led to many piled-high intellectual rubbish heaps of what used to be genuine scientific inquiry. So those that picked up the Cargo Cult have taught and are now teaching the subsequent generations likewise.

[anecdote]
My alma mater, Melbourne University & the Medical Faculty in particular, just three years ago had a huge bunfight about the teaching of anatomy to the medical students. The proposition was to cease this plank of teaching in-house, and out-source to a software group. I kid you not. The primary reason was simply cost cutting, apparently to cut face-to-face teaching salaries in favor of new salaries in the admin areas. More clipboard supervisors from the numpty basket to ensure the boxes are being ticked on the social agenda lists. We all need supervision there, right ? { .... and if you object then what are you hiding, eh sport ? } If done blatantly it would have failed so naturally that needed a gaggle of cover stories, and so the discussion ranged far and wide, many fires were set, the smoke drifted across the valley and finally the armies were drawn up for battle. The do-ers on one side and the sit-on-yer-back-siders on t'other. As Wellington said, it was a close run thing, and last time I heard at least we fortunately we still have trained anatomists in play. These human teachers can answer questions of substance. The computer programs cannot eg. "Why is the triquetral bone sometimes slightly rotated with respect to .... " etc. But it is a generational thing, so we age and die, and I guess another run at the topic in future may succeed.

I was fortunate enough to fail paediatrics the first time through in 1983. At my very first ever viva-voce I went to water and babbled. The written was fine. So I had to do it all again from square one onwards. I got to learn it all twice. I got to meet, examine and play with children far more than my peers. Paediatrics has since been one of my strengths. Now I've heard some recent graduates proudly proclaiming that they have avoided examining so-and-so many children. T'is seen as a virtue to not acquire physical signs ( which are pure gold in paediatric diagnosis 'cos they can't tell you what's wrong ). The trick apparently is to order the blood test, do the scan and refer onwards. Say nice heartwarming things to the parents, keep up a nice pat socially aware dialogue with them. Really ? Make sure that you demonstrate to them that you are not a something-ist while you ignore their sick child's plight. Do keep up the chit-chat while the kid is turning blue behind you .... practice hard at that ... because you'll have even more to say at the Coroner's Court.

The best service you can do for the family is to pay close attention to the biology of disease and physiological dysfunction absolutely irrespective of how you feel with regard to your standing rated against social parameters. That's the point of having doctors, independent thinking focused on the best health outcome under the circumstances. The clock always is ticking. A key skill from way back.

Be afraid people, be very afraid.
[/anecdote]

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Jim1348
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Computers do some things very

Computers do some things very well, or at least fast. My current theory of evolution is that humans will adapt to support them. We may lose thinking abilities in other areas, but what we don't know can't hurt us (that we know of).

Mike Hewson
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For whatever my opinion may

For whatever my opinion may be worth : I am deeply impressed by the investigative mechanisms in place with the LSC. They have clearly thought very carefully about the sorts of human failings that may elicit trouble in such a large collaboration. See for instance Big Dog, and more recently their response to rumor*.

I have just discovered this recent amazing article in Science on the matter of investigator bias. I say 'amazing' on several grounds :

- finally the elephant in the room is being talked of rationally without the usual shouting-down-blitzes and label-grenade-tossing ( but we'll see I guess ).

{ Beware the table-pounders that never seem to answer the question as put. The best lies are nearly the truth. Most online 'science' discussions are essentially parodies, often self-parodies. What I have seen are thoroughly infested/drowning with hypothesis myopia, texas sharpshooting, asymmetric attention, just-so storytelling and many more without the participants evincing the slightest knowledge that they are doing that. Sort of a "I think, therefore I am right" paradigm followed by "damn the torpedoes .... ". }

- it has appeared in Science, arguably ( IMHO ) one of the worst offenders.

- it reveals difficulties across the board/levels and not just in the high profile/public/political topics that many have bunkered down on.

- it frankly explains how the 'cognitive signals' in intellectual echo chambers may build to the level of frenzy. From then on no useful work can be done.

- it reveals ( for the current generations at least ) the tried and true solutions which have been known all along. So maybe there is hope after all ! :-)

Editorial : I think it is worth saying that the base case for human thinking is indeed mythic. I reckon this is uncomfortable to admit. We have 'happy hormones' that can literally reward us for that. We like that feeling and more so if it is a shared experience eg. we drink ethanol in company for that very aim. The tribe calls us always, so it takes effort and will to abstract from that preset. It is not that the hoi polloi are stupid. Not sheeple at all. It's just that those with low sociability** ( from whatever cause and however clever ) have a far lower threshold to not give a crap about the prevalent trend, and hence stride off from the group with the type of mindset that has been so fruitful in research. Many science practitioners will attract a personality label that at least implies mere non-conformance, perhaps some with implicit derogation, and all unnecessarily so. Science is a very recent arrival for humans. So we need places like the aptly named Perimeter Institute for example, to help us pick up the trail again when we realise that we were waddling around with our heads up our bums.

Cheers, Mike.

( edit ) In a general sense E@H is largely within the 'blind data analysis' wing of LSC. For example this is reflected in the processes we have to allocate work units, or the preset rejection/validation criteria for the returned results, the pre-arranged criteria for signal significance, plus the methodical stomping across the relevant parameter spaces, to name but a few practises in play. This 'metronomic rigour' is the baseplate of the strategy that has consistently produced the many discoveries.

* To be precise : the subsequent course of events within LSC is the same regardless of the actual scientific outcome. So the correct current answer to 'have we just found a gravitational wave ?' is 'that is a question for next year'.

** This is not a derogatory phrase, just descriptive. You could replace it with 'high independence index' if that sounds better. This is one of the troubles with sociology as a study : it is a value laden minefield if not understood properly. The language used can easily and casually trigger offense without such intent.

For an unbeaten roundup of this stuff as it applies to the gravitational astrophysics community then please look at anything by Harry Collins eg. Gravity's Shadow. It yields a great insight into why the investigative check mechanisms of the LSC exist in their present form. Basically some forty or so years ago gravitational wave research needed agreed methodology somewhat akin/related to :

Quote:
.... he didn't discover anything about the rats. In fact, he discovered all the things you have to do to discover something about rats.


For that matter IMHO many other fields of modern science could benefit quite well from the lessons described.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
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{ Yes, I am well known for

{ Yes, I am well known for dumping on String Theory .... }

I am currently working through a book Advanced Concepts in Particle and Field Theory by Tristan Hubsch from Cambridge University Press. It's a really good book. While the author is an admitted proponent of strings ( not the cosmic strings of GR ), he gives an outstanding introduction into the ideation that physicists go through when a theory is defined and tested against reality. In particular he weighs heavily against the philosophic crowd :

Quote:
1.1.3 Philosophers are not scientists
A second glance at this framework of thought reveals something extraordinary ! The scientific models described here, and systems of such models forming theories and theoretical systems, are improved and extended, but not literally falsified, i.e. proven to be unconditionally false! ( For the most part, it is rather our mental imagery and philosophical “underpinnings†of the scientific model that are taken too seriously, and may have to be abandoned as false.) Radical revisions of course do occur in scientific research – and not so infrequently – but that does not falsify established models and theories, only perhaps an unwarranted trust that those models and theories would be exact and absolute truths. Properly understood within their qualifications, models and theories of fundamental physics have not been falsified throughout the past three centuries, but have been and continue to be refined, extended and often united.

Quote:
Generally, physicists understand that quantum physics does not simply falsify classical physics, but extends it into a domain where classical physics is not sufficiently precise. Unfortunately, philosophers of science are not physicists. This pragmatic approach should be compared with a similar vantage point of philosophers of natural sciences such as Thomas S.Kuhn, where one needs to know that Kuhn obtained his BS(1943), MS(1946) and PhD(1949) degrees in physics at Harvard, where he lectured on history of physics 1948–56. However, Kuhn opines that theories ( and paradigms ) are chosen by the group of researchers that is more successful than others, and assigns this choice a degree of socio-politically pliable subjectivity. This seems all too alien to most physicists I know, and which I myself ( perhaps all too naively ) cannot accept for physics itself, nor any other science, but only and at most for the admittedly capricious socio-historical process of development in a particular subfield.


So if you like he outlines meta-theory : the theory about what we mean by theories, in physics at least. What does he say about String Theory ?

..... to which I will add that 'no indication to the contrary' and 'no contraindication has been found' merely means it has been constructed out of well tested theories ( quantum/relativity ... ) and so inherits that pedigree from same. No surprise really, but at least is a consistency check that all effective theories must pass ( this idea has a 'grandparent' in Niels Bohr's Correspondence Principle : that quantum mechanics should reproduce classical mechanics as the system scale goes to macroscopic ). Specifically I imply that any other theory also based on quantum/relativity/etc would also demonstrate that, if the extraction/extension has been properly done. I would also mention that the 'surprising abundance' is a number of order 10^500 !! This does not gel with later statements :

.... so there you have it. If a multiplier formed by the digit '1' followed by 500 zeroes is considered to demonstrate a "principle of parsimony in explanation" then can we be thankful they didn't try harder ? I would hope that one day it may be realised that the utter lack of reference to reality is the very reason why they have no disambiguation signal operating upon their 'solution set'. :-) :-)

Ah, think what you will. I would say it seems that to be one working in string theory requires

- an extraordinary type of twisted optimism and/or

- a willful suspension of disbelief and/or

- some emotional thrust propelling onwards despite very clear departure from the rigor that validated/realised the physics upon which it is based.

- a relaxed attitude to taking a long walk off a short pier. :-)

Later he talks of 'caricatures' that we hold in our minds like particles and waves. These are little ( cartoon ? ) sketches that we have and use as cognitive handles/summaries for what are often rather complex models in detail - which is where the rubber meets the road.

{ I certainly don't want to appear as some bloody armchair know-it-all ( too late !? ), but I do like to exercise some facility in critical thinking as it applies to other people's thinking. Certainly I suspect work that shows no evidence of self-reflection upon error. You really can't say that it is the task of others to quality check the work. That's the investigators primary responsibility ! }

Cheers, Mike.

( edit ) The main way to keep out of trouble with the various traps as disclosed here is I believe to focus tightly on the modelling. Some key thoughts :

- what is the data from which the model was abstracted ?

- how does the model operate to yield predictions ?

- what is the new data set to test those model predictions against ? { Hint : the best new data set is future observations ... }

- does one have sufficient intellectual honesty to carry out an iterative program to refine, or even discard, those models ? { Hint : 'purity' per se is not expected to be achieved, pragmatism rules, but perhaps exists as a goal to be approached asymptotically. }

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

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