Quite Easily Done: Recent Episodes
Cambridge University
A weekly homemade series of puzzles, tricks and mathematics from James Grime of Cambridge University.
A British couple discover the remains of a WWII carrier pigeon behind their chimney. It was carrying a coded message. Code experts believe the code used was something called a One-Time Pad Cipher, and that the message will remain unbreakable, why is that? http://www.bbc.co.uk/news/uk-20456782
A description of how I broke the code: http://www.singingbanana.com/codechallenge2012.htm
Here's another excellent explanation from Rule The Web (http://www.youtube.com/user/rtwvidz) http://ruletheweb.co.uk/blog/2012/03/singing-banana-code-challenge-2012/
QED Gold: Originally uploaded 4th February 2011
Take a random pile of coins. If I tell you how many coins are heads and how many coins are tails, can you separate the pile into two piles with the same number of heads in each. And can you do this with your eyes shut?
Take the same number of coins as there are heads. Call this pile 1. Then;
Total number of coins in pile 1 = Total number of heads
In other words, if h1 and t1 are the number of heads and tails in pile 1, and h2 is the number of heads in pile 2, then;
h1 + t1 = h1 + h2
Cancel h1 on both sides and you will see that the number of tails in pile 1 will be the same as the number of heads in pile 2. So, if you turn over all coins in pile 1 you will now have the same number of heads in each pile.
QED Gold: Originally uploaded 31st January 2011.
Take a random pile of coins. If I tell you how many coins are heads and how many coins are tails, can you separate the pile into two piles with the same number of heads in each. And can you do this with your eyes shut?
QED Gold: Originally uploaded 6th February 2011.
The Möbius Strip is a strange mathematical shape which is a loop with only one side and one edge. For more information see wikipedia: http://en.wikipedia.org/wiki/Mobius_strip
This is not a new idea, and for this and more mathematical valentines ideas see this blog: http://individual.utoronto.ca/sck/vday.html
Send your entries to the Enigma Project http://enigma.maths.org Challenge ends on the 1st of March 2012. And check out NRICH: http://nrich.maths.org (February 2012 is code month)
cipher: VA BT LS EG OT XK PB BH CI FV GA YC QG BP UW IH QD OE DI HL CQ YC QG BP EI LZ GA GB IZ PS AZ DQ NI CY UY EA AI UA BF BV OV QA ZS DP QD PG QM PS WL QY DH BD TL VZ PL LW AH GZ BP IM NI KP DZ QU DH FP CI FV RT SB BP BV XO BE BQ PG KO GE IK KO NA OS DG DG DA OX PO GE LZ GA OP FL WU PU UT WF BV IC HF EQ SP NA UX DC BV
crib: "EXTRA LARGE FRENCH FRIES"
QED Gold: Originally uploaded 26th February 2011
Top Trumps is a popular game were players compare stats on their favourite subject. But I wondered, are all packs of Top Trumps the same? Is there a formula? And if there isn't could I devise a mathematically perfect version of Top Trumps. This is my genuine investigation into the game Top Trumps: Best of Bond.
I have a board that uses the numbers 1 to 90. I fill the board with Othello piece, they are black on one side and white on the other. All the pieces start black side up. First I flip every second number, so 2 becomes white, and 4, 6, 8 and so on. Then I flip every third number, then every fourth number, until finally I flip every 90th number. Which numbers end up black side up and why?
Music by Ghostly Dust Machine http://freemusicarchive.org/music/Ghostly_Dust_Machine/Bad_Panda_79/Ode_To_A_Baby_Snowstorm
QED Gold: Originally uploaded 28th April 2011
A common question, why does 1=0.999...
If you want to know more, Wikipedia has a good article on the subject http://en.wikipedia.org/wiki/0.999...
Join the discussion on YouTube http://youtu.be/G_gUE74YVos
QED Gold: Originally uploaded 21st May 2011.
A silly one, and this time not about mathematics but a fun physics demonstration.
The sequence 11221 contains all 2-digit combinations using the numbers 1 and 2. A sequence such as that is called a De Bruijn sequence. I show you three methods to find such sequence.
The sequence 11221 contains all 2-digit combinations using the numbers 1 and 2.
Can you find a sequence that contains all the 3-digit combinations using the numbers 1, 2, and 3. What is the shortest such sequence?
Can you find a sequence that contains all the 4-digit combinations using the numbers 1, 2, 3, and 4. What is the shortest such sequence?
Then, can you break this lock? By which I mean, find the shortest sequence containing all 4-digit combinations using the numbers 0 to 9. The sequence is 10003 digits long (yes I misspoke in the video!)
QED Gold: Originally uploaded 28th May 2011
Solution the the First to get a head problem
QED Gold: Originally uploaded 19th December 2009
My true love gave to me Triangle Numbers.
QED Gold: Originally uploaded 24th June 2011
We reveal the answer to my Wisdom of the Crowds competition. I asked you to guess how many jellybeans were in a jar. How close was the wisdom of the crowd, but first we need to answer - which average should we use?
QED Gold: Originally uploaded 12th June 2011
Competition is over I'm afraid, but you may still like to play.
Here's a photo of the jar: http://tumblr.com/xqt2yusc39
So, to survive a zombie attack you need to run. In the long term we need a fortified society, but if the barricades fall we need to reduce the speed of infection, slow them down, and be more deadly than they are.
QED Gold: Originally uploaded 17th July 2011.
Watch the tutorial by mismag822 http://www.youtube.com/watch?v=4BZFx1eUOFs
Originally posted by zachcloseupmagic http://www.youtube.com/watch?v=-vUiXp6HGXs
How to make a Post-it Note Dodecahedron. Fun and beautiful! If you make one yourself send me the photo! Email address in the video.
Follow me on Facebook/twitter etc http://singingbanana.com Thanks to Colin Wright who taught this to me. Follow Colin at http://solipsys.co.uk or on Twitter: @colinthemathmo And thanks to Julia Collins for the headache. Follow Julia and Haggis the sheep at http://haggisthesheep.wordpress.com and @haggismaths
QED Gold: Originally uploaded on YouTube on 14th July 2011
Watch the tutorial by mismag822 http://www.youtube.com/watch?v=J8shpCoZHdY
Watch the trick performed on Penn and Teller's Fool Us http://www.youtube.com/watch?v=yJwbBP1akY8
A look at the Trinity College clock with Hugh Hunt.
For more information: http://www.trin.cam.ac.uk/clock
Solution to my last video: http://www.youtube.com/watch?v=lAmhA_SmzsI
This puzzle was given to me by Rob Eastaway http://www.robeastaway.com/
Books by Rob Eastaway (I do recommend them!) Amazon UK: http://amzn.to/pSsLYO Amazon USA: http://amzn.to/qWAQvI
QED Gold: Originally uploaded 5th August 2011
A video of me reading my original blog post out loud http://singingbanana.tumblr.com/post/6629627960/whats-the-probability-you-live-in-an-odd-numbered
The original Facebook poll: https://www.facebook.com/home.php?sk=question&id=218841344812765&qa_ref=qd
Solution to my 'Game of Nine' video: http://youtu.be/ue4Baa8Mhn8
Each player takes it in turns to pick a number, the first to pick three numbers that add up to 15 wins.
With this simulation you don't even need a friend! http://gammahoo.de/gameofnine Thanks to GammahooX for making it.
QED Gold: Originally uploaded 1st June 2011. Survey ends October 2011 so there is still time to take part!
Take part in our survey at http://www.favouritenumber.net
Here is a game for you to play and investigate. Is there a winning strategy?
Each player takes it in turns to pick a number, the first to pick three numbers that add up to 15 wins.
With this simulation you don't even need a friend! http://gammahoo.de/gameofnine Thanks to GammahooX for making it.
Benford's Law is a truly surprising fact about the frequency of numbers when studying data such as prices, populations, rivers, even street addresses. And if someone's accounts do not follow Benford's Law then they may be committing fraud!
Some simple maths filmed at the Mathematical Association annual conference dinner, 2011. With thanks to everyone involved.
What is the minimum amount of road needed to connect these four towns together? Known as the Motorway Problem or Steiner Problem. An experimental solution.