Richard Wiseman

Where is the missing face?

Richard Wiseman — Tue, 22 May 2012 06:00:31 +0000

Mathematician and ace puzzler Martin Gardner died two years ago today. I thought it would be good to use the occasion to celebrate his work with a little YouTube video, and this is what I came up with….

Any idea about the solution? Feel free to spread the word!

Answer to the Friday Puzzle

Richard Wiseman — Mon, 21 May 2012 06:00:24 +0000

On Friday I set this puzzle…..

I am a member of a club in which every member either always lies or always tells the truth. Yesterday I had a telephone call from a member who always tells the truth and he said ‘Some members have just had dinner around a circular table, and each member said ‘I declare that the man on my left is a liar’”. Ten minutes later I received another telephone call from another member called John, and he said “I was at the dinner and there were 11 of us there”. Ten minutes after that I received yet another telephone call from a member called Tim, and he said “I was at the dinner and there were 8 of us there”. Either John or Tim was lying. But who was the liar?

If you have not tried to solve it, have a go now. For everyone else, the answer is after the break.

Well, the first assumption has to be that I am telling the truth. If that is not the case, then all bets are off and there is no answer. However, assuming this is the case, there must have been
(1) a mixture of liars and truth tellers around the table and
(2) an even number of people around the table.
(3) they alternate liar – truth teller around the table
Otherwise, everyone would not be able to say the sentence ‘I declare that the man on my left is a liar’.

So, John must be the liar. Did you solve it? Any other solutions?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

It’s the Friday Puzzle…..

Richard Wiseman — Fri, 18 May 2012 06:00:06 +0000

As ever, please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for theKindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

I give you the most unusual pareidolia I have ever seen…..

Richard Wiseman — Thu, 17 May 2012 06:00:53 +0000

As you have probably worked out by now, I am a fan of pareidolia. Yesterday I was sent this great photo….

It was taken by ace photographer Matthew Horwood, who very kindly gave me permission to post it here. It gets my vote as the most unusual pareidolia I have seen. What do you think?

Watch people vanish right in front of your eyes

Richard Wiseman — Wed, 16 May 2012 06:00:04 +0000

This is an animated version of a lovely old Victorian puzzle. Basically, you have to count the number of people in the image, wait for the piece to flip around, and count them again. The flip should happen after about 10 seconds (if it doesn’t, you might have to click on the image and have it open in a separate window)

My thanks to @DrBrocktagon for bringing it to my attention. 10 points to anyone who can explain why it works!

Two cats hugging…..

Richard Wiseman — Tue, 15 May 2012 06:00:09 +0000

@Letitia_Potorac brought my attention to this great ‘two cats hugging’ illusion….

So, time for a poll. Imagine that animals could fire guns. In general, would you trust a cat or a dog with a gun? Vote now and let’s nail this pressing issue once and for all.

Answer to the Friday Puzzle….

Richard Wiseman — Mon, 14 May 2012 06:00:47 +0000

On Friday I posted this puzzle….

Let’s play a little game. Imagine taking 4 playing cards out of a deck. Two of them are red and the other two are black. We mix them up and place them face down on the table. I am going to ask you to turn two of the cards face up. If they are both the same (as in, if both of them are red cards or both of them are black cards) then you win. Otherwise, I win. Is that fair?

If you have not tried to solve it, have a go now. For everyone else, the answer is after the break.

Nope, it is not a fair game. Let’s imagine you start off by turning over a red card. Of the three remaining cards, two are black and one is red, and so you only have a one in three chance of winning.

Did you solve it? Any other answers?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

It’s the Friday Puzzle…..

Richard Wiseman — Fri, 11 May 2012 06:00:10 +0000

As ever, please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for theKindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

Can you see the mad and sad face?

Richard Wiseman — Thu, 10 May 2012 06:00:38 +0000

This a great illusion by Humberto Machado. Can you see the mad and sad face in the illustration?

Feel free to leave clues for those struggling to see each face.

Watch as your eyes see nothing…..

Richard Wiseman — Wed, 09 May 2012 06:00:03 +0000

This is a great illusion. Look at the animated gif below. You should see a rotating blue grid (if it is still, click on it to open the image in another window). Next, simply stare at the flashing green dot. All being well, some or all of the yellow dots will vanish!

Did it work for you?