Traveling Day Quiz

Off once again into the wild blue yonder. So today a quiz, inspired by the Cnet article whose over-stated title is “Researchers build DNA neural network that thinks.”

The piece was a review of the paper “Neural network computation with DNA strand displacement cascades” by Qian, Winfree, and Bruck.

Basic idea:

Here, building on the richness of DNA computing14 and strand displacement circuitry, we show how molecular systems can exhibit autonomous brain-like behaviours. Using a simple DNA gate architecture16 that allows experimental scale-up of multilayer digital circuits, we systematically transform arbitrary linear threshold circuits (an artificial neural network model) into DNA strand displacement cascades that function as small neural networks.

They made a brain in a bottle composed of about a hundred neurons, designed for the special purpose of playing a quiz game:

The team trained the neural network to play a memory game in which it would correctly “identify” four scientists based on specific yes or no questions–for instance whether the scientist was British.

Players dropped DNA strands representing an incomplete set of answers into a test tube. The network then provides the answer–the identity of the correct scientist–by fluorescent signals.

When presented with 27 different ways of answering the questions, the DNA “brain” responded correctly each time.

The game is thus like twenty (or twenty-seven) questions, with the focus of trying to discover whether the scientist is British.

Here’s our quiz: think of the shortest list of yes-no questions you can ask to discover whether a scientist is British. Puns are acceptable. Good luck!

My solution to the twenty-questions is below, but hidden by an HTML comment. If you open this page’s source code, look for the word “SOLUTION.” Don’t reveal what this is in the comments below; I’ll reveal it tomorrow.


  1. Bernie

    I assume you exclude the question, “Is the scientist British?” ?!!

  2. Rich

    “Was the scientist British” is one of the original questions. I shall have to check the solution to understand the question as at the moment I is confused.

  3. Eric Anderson

    The paper is behind a pay wall, which I’m not going to plunk down for. Anyone have a free copy?

    This is very interesting research, and I don’t mean to detract from the work, but as Briggs points out, the news headline is over the top (do authors not have any say in headlines, or do they just let the sensational headline stand in order to get a bit more notoriety?). The paper abstract, revealingly, puts ‘think’ and ‘intelligent’ in quotes, and seems to be talking about a series of gates that have built into them the information needed to distinguish different nucleotide combinations. In that sense, it is like an extremely simple computer program in the AI area and I can’t tell whether there is anything interesting at all in the architecture — probably a very old approach, similar to what AI folks were doing 50-60 years ago in the computer world.

    The unique aspect seems to be applying this to molecular systems — using gates to recognize specific DNA strands. This I do think is very interesting and worthwhile area of research, in which it looks like we’re just now scratching the surface. Will be interesting to see where this heads in the coming years.

  4. Chuckles

    ‘Are you French’ should do it?

  5. Bernie

    Of course, if it is a British Climate Scientist we may never know the answer because he will refuse to answer the question, claiming IP rights, confidentiality, or a letter from his mum.

  6. bob

    Do you believe in Global Warming?


    Does your mother look like Secretariat?

  7. Gary

    Drink beer warm?

    3 words — short enough?

  8. GregO

    Should Liebniz be given any credit for co-inventing the calculus?

    No? Do you drink beer warm? (sorry Gary – your question is too good not to copy!)

  9. John Whitman

    Only one question needed.

    Should peas be put in your mash?


  10. Bernie

    The Irish drink their beer warm as well – and I would be very wary about calling an Irishman British, especially if he has been drinking warm beer!

  11. j ferguson

    Are you sure about the Irish? I spent 18 months in Dublin 2000, 2001. Guinness was reliably served at 45F, at the brewer’s insistence. Their Ales and Lagers were also chilled. Maybe in the country it’s different.

    Spent a week in London this spring and found that Bitter served at whatever (not chilled) was quite good and the temperature seemed not to matter. I also came to appreciate why they used to wonder why we liked the “fizzy” stuff.

  12. Bernie

    j ferguson:
    I was in Ireland two years ago – Kerry, Wexford and Dublin – and recall many old fashioned pulls and ads saying casked beers. Guinness is certainly now from chilled barrels. Personally, I like my Guinness chilled – but wherever the beer is from a cask it will be warmish – cellar temperature. But after all, most cellars in England and Ireland are going to be in the 55-60 dF range – which is neither warm not cold.
    I tend to buy only English, Scottish or Irish beer plus Grolsch when it gets really hot – but if you haven’t tried it, Abita Amber from New Orleans is my new found favorite. It is a bit more expensive than Bass, Newcastle, Smithwicks here in Massachusetts. Really good American beer is very difficult to find.

  13. TomVonk

    OK , I understand that this is meant to be fun .
    But , seriously , the qualification of British is equivalent with the citizenship of Great Britain .
    However anybody can become a citizen of Great Britain – f.ex a Frenchman born in New Caledonia .
    So the only question able to treat this problem is “Have you or can you have a UK passport ?”
    But perhaps what was meant was not to discover whether a person was British but whether he was born in UK from a 10 generation lineage of persons all born in UK .

  14. j ferguson

    I can see that you’ve made more of a study of than did i. I was so overcome by discovering that the tab for Guinness could be included on my expense account, that I sort of lost it. SWMBO joined me for a long weekend and we circumnavigated the place, but I think i never tried anything beyond Smithwick, Kilkenny (IIRC) both of which were delicious. Non-carbonated ales, if I’m not completely confused on this, seemed delightful at any temperature.

    I’ve also discovered that Guinness is wonderful at any temperature during the rare failures to properly stock our ship-board fridge. I much prefer the cans with the widget. How about you?

    I suppose my suggestion of asking “Bitter?” would only detect an Englishman. The affirmative answer would be insufficient unless you could include the smile with the “Yes.” you really don’t need the other 26 questions.

    Ah well.

Leave a Reply

Your email address will not be published. Required fields are marked *