h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

A curiosity. I'd be interested to know your first reaction...

Polarised sunspecs, idly viewing my LCD monitor through them.

'Normal' - light. Rotate. At about 45deg - dark (both my monitors, different brands, act the same).
Continue rotating... do you feel anything odd?

Your -first- reaction, please, and non analytical (if possible).

I don't have any polarised specs so can't check, but my *first* reaction would expect it to go alternately light and dark at 90 degree intervals as you rotate.

.... and apologies if this is the analytical answer ...

LCDs work by twisting the light from the backlight through polarising filters. The pixel is on when the light and filter are aligned, and off when they're not (no light gets through). So the display would go dark when the LCD filter and your specs are misaligned.

Yes, Dave, that's more or less my thinking.

However, I'll wait a while before explaining my 'fault' & my reason for asking... to see if anyone saw the same as I thought I did.

It's not very interesting really...beginning to feel a little silly, now!. A point of interest looking for company.

I'll hold of 'til tomorrow morning, so don't you do without your glass of something interesting.

Oh well.

Now I'm feeling -really- silly. Still, I said I would, so:

Rotating further, from 45deg, the 'other' dark spot wasn't there.
My first thought was 'Good grief! Must post this to SEx'.

The curious bit was that it took me a couple or three retries to click on and realise what had happened. The realisation was non trivial - I'd been 'expecting' it at 135deg.

(please remember, it was an idle playing - I was probably in a semi-dreaming state originally)

I reckon it had something to do with the dark spot being at 45deg rather than the expected 90deg & that that had set me all askew.

My reason for actually posting was that I have memories of two incidents where my senses (or interpretation thereof) had led me astray, one not really serious but under moderately dramatic circumstances and the other was dramatic and not far off traumatic.

I posted here 'cos of my first reaction, and because 'Ask' didn't seem appropriate.


Silly is as silly does

Nevertheless, Comments welcome

Not sure I understand - can you post what you saw in terms of: 0 - light, 45 - dark, 90 - light, 135 - etc, etc?

Traveller in Time not having state of the art TFT screens
"Well I am looking at one, just no polarisation filter at hand.

Guess it is a pixel defect in the polariastion. In the early LCD days you could see inverted colours shining through the 'darker' areas guess those defects have gone. "

Ah! Oh! Deary me.

Dave:

Both dark spots Were, actually, there and they were, as one would expect, 180deg apart.

My problem was that I didn't see the second dark spot where I 'expected' it, so to me at the time "it wasn't there".

The first dark spot would normally(?) be at the 'normal' position, specs horizontal.
In actuality it was at 45deg clockwise and the second was at 225deg.

I can see no other explanation than: The first dark spot having been found at an unexpected angle, that fact threw me completely (I was initially, I think, in a dreamy state - but obviously aware enough to be startled).

So far, I accept that it was a problem of perception and could have written it off as such - but:

I felt that really, the curious aspect was - that persuading myself that I'd been wrong was non-trivial - two more goes at it, maybe three.

At the time of my original post I was interested in hearing:

a) if anyone else would find similar and
b) if so, any comments.

Now, I ain't so sure. I'll put it down to ageing and general incompetence.

(If you set out to, you did wind me up!)

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Didn't intend to, , just curious

That's perfectly allright, Mr Blackeye.