Sister blog of Physicists of the Caribbean in which I babble about non-astronomy stuff, because everyone needs a hobby

Tuesday, 18 June 2019

Just some balls

I found this on MeWe, which has the extremely annoying quality of not having public posts so I can't link back to the original. Anyway, this is a very nice little illusion which benefits from being seen in high resolution. If you focus carefully on any ball and try and ignore the lines, you can see that they're actually all the same shade of beige. But if you just casually look at the whole image (especially if you unfocus your eyes), they look like vivid red and green and purple (or at least they do to me anyway).


Here they are again with the lines removed :


The original author of the post adds the provocative comment :
Our brains fill in a picture of reality based on context. This contextual rendering happens visually as well as cognitively, which is probably why the people or person who define an argument have already won that argument, and why gaining control of the narrative is so sought after.
This is appealing, but is it true ? I'm not entirely convinced. Yes, our default comparisons are relative, since we don't have absolute standards to hand by which to judge everything. But we don't all do this in all situations. In his excellent introductory course, psychologist Paul Bloom gives an example of someone wanting to earn an amount of money defined not by his own goals but by what his peers are earning. And yet while some people do this, others don't. No-one goes in for science to make the big bucks; no-one goes in for unskilled labour to make slightly more than their peers. It would be very interesting to examine under what conditions people default to relative comparisons and when they default to their own innate standards. An example can be seen in yesterday's chart : note the strong mismatch between what the public search for and what the media report.

In this particular case, we shouldn't forget that we are capable of establishing the true colour through careful and controlled analysis. It's a nice example of just how wrong our first impressions can be, but perhaps a more optimistic message is that we can reach the truth at all despite the difficulties.

As far as defining the argument goes, I'm not sure. In some ways it's a very good thing to be as specific as possible - the more vague something is, the harder it is to refute. Specificity is a crucial part of a scientific methodology, because specific claims (especially numerical ones) can be objectively tested. If claims are successfully refuted, people can and do change their minds.

The difficult part, to which no general guide can be given, is what to do if they don't. Sometimes there can be legitimate reasons - one might only realise after the fact that a theory carries implicit assumptions that invalidate the test, not so much shifting the goalposts as realising that they were somewhere else the whole time. Whereas at other times people do indeed simply redefine the argument to suit their own agenda and are not really interested in the truth at all. Steady State theory comes to mind as a classic example of shifting the goalposts, whereas dark matter seems much more like a case of trying to find out where the goalposts really are*.

* I still plan to write a post to explain that more properly, but I'm making an effort to get back into CGI again right now.

Finally, while controlling the narrative is generally something to avoid, exploring the narrative is essential. That is why history continues to be interesting, because new perspectives illuminate the past in different ways. Examining narratives from different perspectives is an enriching and sometimes mind-wrenching experience. Yet for all that, establishing fact is possible, albeit, as Plato put it, often rather difficult. We should not lose sight of the simple premise that some things are right and some are just plain wrong.
On this account no sensible man will venture to express his deepest thoughts in words, especially in a form which is unchangeable, as is true of written outlines... Only when all of these things — names, definitions, and visual and other perceptions — have been rubbed against one another and tested, pupil and teacher asking and answering questions in good will and without envy — only then, when reason and knowledge are at the very extremity of human effort, can they illuminate the nature of any object.

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