unusual chess puzzle !

sinbad68

With so much anger, tension and hate on this site, it would be good to lighten the mood here, here is an unusual chess puzzle !


On ICU homepage, we have the photo of joint irish champions sitting in front of the trophy in the link below. one of the light squares on the chessboard looks darker than other light squares !

http://www.icu.ie/images/1068


but the same light square now appears brighter than other light squares in this photo taken at almost 90 degree angle from the previous photo !

https://stbenilduschessclub.files.wordpress.com/2012/01/irish-champs-trophy.png

Q1- Which square am I talking about ?

Q2. What is this phenomenon called ?

Q3. Which 3 chess pieces on the board are contributing to this phenomenon ?

bduffy

Here's my guess: Would you be looking at the metamerism on e3?

sinbad68

bduffy wrote: »

Here's my guess: Would you be looking at the metamerism on e3?

e3 !!! . e3 is a dark square !. Read the question, in ICU photo (taken looking from white position ) a light square that appears darker than other light squares...... I give up, will give answer to question 1, it's the " C6 " square.Now, can anyone name this optical phenomenon and tell me the 3 chess pieces almost exclusively responsible here ?

bduffy

Well. ......going with c6, are we assuming that the issue is based on light scattering on the grain? It wouldn't be diffraction but there are a lot of optical wood tests out there including transillumination but at this stage I'm guessing again......��
Makes a change from the politics ��

Sparks

I'm finding it hard to see how this is a chess puzzle. Are the chess pieces wearing white/gold dresses or blue/black dresses?

Razzen

c6?
The checker shadow illusion?
The two knights and bishop on the surrounding light squares casting shadows?

Razzen

c6?

checker shadow illusion?

sinbad68

Razzen wrote: »

c6?

checker shadow illusion?

Yes, it is c6 , I posted the answer yesterday, BUT , it is NOT the checker shadow illusion which initially I thought as well !

https://en.wikipedia.org/wiki/Checker_shadow_illusion

Because I applied the paper hole test, where you make a hole in a piece of paper big enough to see most of the c6 square but not large enough to see the adjacent squares,( it's actually better to make 2 holes or more with one hole on c6 and another or more holes on other light squares, you need to put paper on screen and put a dot with a pen where to make holes and lift paper and make holes ). C6 is actually darker than other squares, so I sent this problem to a member of Mensa who teaches physics in college and he sent it on to another guy who deals with spectroscopy , etc and he came to the conclusion that the the darkened c6 square is actually due to a phenomenon called " shadow !" and with the light overhead being focused mostly to the right of centre on the board on the ICU image, 3 pieces were responsible. The pawn on d4 & e5 and the most guilty piece, the knight on d5.

Sparks wrote: »

I'm finding it hard to see how this is a chess puzzle. Are the chess pieces wearing white/gold dresses or blue/black dresses?

This is a puzzling over a problem involving a chess board and I added the word " unusual" which meant it is not your usual chess puzzle.:cool:

bduffy

Just checking that my initial answer (albeit a different square) doesn't still work: Metamerism is a phenomenon that occurs when colors change when viewed in different light sources (as maybe in this case)......
But really is it just a different percentage of light reflection depending on the relative orientation of the wood grain to the light source?

sinbad68

How many chess games were played in Ireland between 3rd of September 1752 & 13 September 1752 ?!!

Tim Harding

sinbad68 wrote: »

How many chess games were played in Ireland between 3rd of September 1752 & 13 September 1752 ?!!

Ha ha, none!
"Give us our eleven days!" cried the rioters - the United Kingdom (which then included Ireland) switched from the Julian to Gregorian calendar, an adjustment which involved changing the date.

cdeb

I've always liked that Greece didn't make that change until the 1920s, which means Prince Philip has two birth dates - one in the Julian calender which was in force in Greece when he was born there, and one in the current Gregorian calendar.

sinbad68

Tim Harding wrote: »

Ha ha, none!
"Give us our eleven days!" cried the rioters - the United Kingdom (which then included Ireland) switched from the Julian to Gregorian calendar, an adjustment which involved changing the date.

Well done Tim !. Last year I was asked......ok, I volunteered :rolleyes: to provide a few questions for a charity table quiz and gave 6 questions and said answers look easy but are NOT .The format for the question here was . Q: In Ireland, The following day after 2nd of september 1752 was what date ? The answer was 14 September 1752, and No table got it right , another question was. Q: Name the tallest mountain on earth? and every table said it was " Mount Everest" which was false! The answer is " Mauna Kea " located in Hawaii.
Everest has the highest point above sea level but Mauna Kea is much taller.

https://en.wikipedia.org/wiki/Mauna_Kea

Anyway, to my surprise neither the organiser nor the quiz participants were impressed with my questions

sinbad68

Both these clubs

Elm Mount & Phibsboro claim on their websites to be the largest chess club in North Dublin, which one is telling the truth ?

http://elmmountchess.com/

http://www.phibsborochessclub.com/about/

cdeb

Phibsboro were once upon a time I think. They've been passed out (in terms of number of league teams anyway) by Naomh Barróg, Malahide and Blanchardstown now. As well as Elm Mount of course.

sinbad68

In early October I posted a puzzle here ( First post on this thread ) where there was query about the photo of Irish champions on ICU homepage,

http://www.icu.ie/

whether the darkness on c6 square was the checker shadow phenomenon . One month after my initial post , the photo on ICU homepage appears to be the same photo but now brighter than before !.

October photo below
http://www.icu.ie/images/1068

November photo

http://www.icu.ie/images/1182

Am I imagining the change ? if not what happened here ?!

mikhail

sinbad68 wrote: »

Am I imagining the change ? if not what happened here ?!

Someone cropped the image. Is it so hard to believe they filtered it too?

sinbad68

What is happening here ?

The white king and queen keep swapping places several times during this video !, even when the game starts at 4:02 the King is in the right place and 3 seconds later it is in the wrong square ! prompting Fischer to correct the mistake later in the game.

Did they patch up several takes together to make the clip?
was there a Live audience ?

https://www.youtube.com/watch?v=LSWau3pTyIg

sinbad68

Photo from last benildus charity blitz ( you may need to click on it to enlarge)

One boy is subconsciously mimicking the same posture of boy beside him

Q1. What is this phenomenon called ?
Q2. Which boy is copying ? ( with reasoning )


https://stbenilduschessclub.wordpress.com/2016/03/17/conor-odonnell-makes-it-three-in-a-row/blitz-final/

bduffy

Are you suggesting that they're mirroring each other?
Still no response to the metamerism in the earlier post......I'd imagine the spectroscopy angle was a deflection (if you're into science puns ☺)

sinbad68

bduffy wrote: »

Are you suggesting that they're mirroring each other?
Still no response to the metamerism in the earlier post......I'd imagine the spectroscopy angle was a deflection (if you're into science puns ☺)

Yes this phenomenon is called mirroring. I did explanation to previous puzzle, read my previous response.

As for who is copying who,I am very confident the boy in dark green top is copying the boy in red shirt.

Stephen Brady has a habit of hovering his hand around his mouth, which started the chain of events here and prompted the boy in red shirt to subconsciously mimic him. The reason I believe the green shirt boy is copying is not just to do with the fact he is sitting behind the red shirt boy and can see his action.It is to do with vantage point.people when watching a game look for best vantage point and if you arrive early you get a good vantage point. The red shirt has a good vantage point in the photo and sitting on the table, he didn't just arrive and sit on the table, he was standing there for a while waiting for the game to start before he decided to make himself more comfortable and sit down. The green shirt arrived late and ended sitting on the chair and has a poor vantage point and can't really see what is going on the board and he saw the red shirt in that position ( right elbow resting on left wrist )before he sat down and subconsciously copied him in what in psychology in known as mirroring. Most kids in green shirt position would stand and squeeze themselves in, but this boy does not want to invade others personal space and shows a high degree of having regards for others.

Of note . Both players in the photo and the red shirt boy show blushed cheeks, I wonder if it is temporary and induced by stress & anxiety here and if not, is it what is known as " The curse of the celts" ?

bduffy

Interesting on the mirroring, but then I think we all do this at some stage...the cursed yawn that spreads!
As for the previous post, the spectroscopy pun was missed I think, but your friend may also have been incorrect.... (happy to explain why offline).
Happy Easter!

2bts

It looks like its c6 again this year (see http://www.icu.ie/images/1331) only this time front right (was back left in http://www.icu.ie/images/1068).

sodacat11

Someone please tell me that I am reading all this in a nightmare and that I will wake up any moment now

2bts

c6 clearly has a shadowy past!