3
Quite Easily Done
http://sms.cam.ac.uk/collection/1157706
A weekly homemade series of puzzles, tricks and mathematics from James Grime of Cambridge University.
1440
2012
Fri, 07 Dec 2012 15:35:09 +0000
Thu, 21 Jul 2011 12:28:15 +0100
en
smssupport@uis.cam.ac.uk
Quite Easily Done
http://sms.cam.ac.uk/collection/1157706
http://rss.sms.cam.ac.uk/itunesimage/1167292.jpg
http://video.search.yahoo.com/mrss
Quite Easily Done
A weekly homemade series of puzzles, tricks and mathematics from James Grime of Cambridge University.
Quite Easily Done
A weekly homemade series of puzzles, tricks and mathematics from James Grime of Cambridge University.
Cambridge University
Dr J R Grime
http://sms.cam.ac.uk/collection/1157706
Quite Easily Done
20110721T12:28:15+01:00
DAMTP
no

10000 YouTube Subscribers and Wisdom of the Crowds
ucs_sms_1157706_1183874
http://sms.cam.ac.uk/media/1183874
10000 YouTube Subscribers and Wisdom of the Crowds
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
Mon, 31 Oct 2011 18:31:49 +0000
maths,math,mathematics,problem,puzzle,probability,statistics,wisdom of the crowd,Francis Galton
108
University of Cambridge
Dr J.R. Grime
7fe8cd2d49f5c9a477102e76f6e239cd
8b951cf8a18e90d66495fc8b435e5c91
20354561851107cdc4d622455ce90ee6
QED Gold: Originally uploaded 12th June 2011
Competition is over I'm afraid,...
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
Cambridge University
173
maths,math,mathematics,problem,puzzle,probability,statistics,wisdom of the crowd,Francis Galton
http://sms.cam.ac.uk/media/1183874
10000 YouTube Subscribers and Wisdom of the Crowds
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
Competition is over I'm afraid, but you may still like to play.
Here's a photo of the jar: http://tumblr.com/xqt2yusc39
Here is the text of Galton's original paper http://tomayko.com/writings/galtonsox
Even better here is a pdf of the original paper http://galton.org/essays/19001911/galton1907voxpopuli.pdf
20111031T18:32:00+00:00
173
1183874
true
16x9
false
no

28 Minutes Later  The Maths of Zombies
ucs_sms_1157706_1183112
http://sms.cam.ac.uk/media/1183112
28 Minutes Later  The Maths of Zombies
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.
Wed, 26 Oct 2011 12:30:40 +0100
maths,math,mathematics,problem,puzzles,zombie,model,infection,James Grime,Thomas Woolley,Horror,Halloween
108
University of Cambridge
Dr J.R. Grime
f371477305a28d8ba6a2ea03adecfcc0
45b1101e830c87cb27777bc9c4d2b5ab
ad00b1d594e81699a6d83363f17976a7
So, to survive a zombie attack you need to run. In the long term we need a...
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.
Cambridge University
118
maths,math,mathematics,problem,puzzles,zombie,model,infection,James Grime,Thomas Woolley,Horror,Halloween
http://sms.cam.ac.uk/media/1183112
28 Minutes Later  The Maths of Zombies
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.
A zombie attack can be model as an infection, like an outbreak of flu or measles. This was first done in 2009 using a simple SIRmodel by Robert Smith of Carleton University, Canada. This model looks at the numbers of susceptable, infected and removed population. In this the infected were zombies. Read that paper here http://mysite.science.uottawa.ca/rsmith43/Zombies.pdf
However this model did not consider the spread of the zombie infection spatially. In this video we introduce Thomas Woolley, who has modelled the shambling movement of zombies as a 'random walk', also known as the 'drunkard's walk', starting from the hospitals and the graveyards [to be published, Mathematical Modelling of Zombies, University of Ottawa Press, 2012]. Using this assumption we can calculate that anyone within 100 metres would have at most 28 minutes before they encounter their first zombie. Now, if we were able to slow down the zombies by half then the time to an encounter is doubled. But, is we double the distance between us and them the time is quadrupled!
The number of zombies depend on the rate at which they can infect us compared to the rate at which we can kill them. If we can kill them faster than they can infect us then our survival just comes down to a race of who becomes extinct first. We need a large population more deadly than they are. Either way we are going to suffer heavy losses.
Another way we can slow down the infection is by removing the human population. If they can't infect us then their numbers can't grow. This could mean killing our fellow humans  but we do not recommend it. We don't need to help them speed up our extinction!
So, to survive 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.
20111026T12:30:51+01:00
118
1183112
true
16x9
false
no

Benford's Law  How mathematics can detect fraud!
ucs_sms_1157706_1164837
http://sms.cam.ac.uk/media/1164837
Benford's Law  How mathematics can detect fraud!
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!
Tue, 16 Aug 2011 23:09:45 +0100
math,maths,mathematics,problem,puzzle,statistics,probability,Benford,newcomb,logarithm,finance,fraud
108
University of Cambridge
Dr J.R. Grime
3b88472bf3df23d70d18ad578f4b20e2
6af9ef511d1c5e0e118ae052ceb13baf
548c9666632d0c5b9dbf3cea167123fe
Benford's Law is a truly surprising fact about the frequency of numbers when...
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!
Cambridge University
659
math,maths,mathematics,problem,puzzle,statistics,probability,Benford,newcomb,logarithm,finance,fraud
http://sms.cam.ac.uk/media/1164837
Benford's Law  How mathematics can detect fraud!
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!
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!

Here's a good article by Ted Hill: http://web.williams.edu/go/math/sjmiller/public_html/BrownClasses/197/benford/Hill_1stdig.pdf
Hill, TP. The FirstDigit Phenomenon. American Scientist 86 (4), 358363. (1998)
Here's a list of papers http://www.benfordonline.net/list/chronological

This law was first notice in 1881 by the astronomer Simon Newcomb, then again in 1938 by the physicist Frank Benford. They both noticed that the starting digits of a lot of real world statistics do not appear evenly but follow a logarithmic distribution, for example this would mean numbers that start with a 1 appear over 30% of the time.
A quick appeal to intuition will show this is true for data that grows exponentially (geometrically). If something grows by some multiplication factor, you will soon see that the distribution is logarithmic, i.e. that numbers starting with a 1 appear 30% of the time. This explains the law for a lot of things that grow in this way, like prices and populations. Yet this law also appears in other types of growth, including factorials and Fibonacci numbers.
However, remarkably, this law also describes what happens when you take data randomly from a variety of sources, such as you might do if you took numbers from a newspaper. Although this data comes from a variety of distributions, not just from exponential growth but many other distributions, yet still follows Benford's Law. Although Benford observed this fact in his original paper, it was not proven until 1995 by Ted Hill.
However, you can still prove Benford's Law without knowing this. If we can assume Benford's Law exists, then it must be scale invariant, i.e. it would not matter which units we choose to make our measurements in  kilometres, miles, feet, centimetres or whatever. As I prove in this video, the only distribution that is scale invariant must be the logarithmic distribution. Hence Benford's Law is logarithmic. This proof was first put forward by Roger Pinkham in 1961.
In 1992, Mark Nigrini wrote his PhD thesis on the detection of income tax invasion using Bedford's Law, and his ideas are applied in the detection of fraud.
We see Benford's Law in observational data because real data can be a complex mix of many distributions and because it is the distribution achieved when data is repeatedly multiplied, divided, or raised to integer powers. And, once achieved, the distribution persists under further multiplication, division, and raising to integer powers.
20110902T16:28:44+01:00
659
1164837
true
16x9
false
no

Can you crack the combination lock?
ucs_sms_1157706_1197907
http://sms.cam.ac.uk/media/1197907
Can you crack the combination lock?
The sequence 11221 contains all 2digit combinations using the numbers 1 and 2.
Can you find a sequence that contains all the 3digit combinations using the numbers 1, 2, and 3. What is the shortest such sequence?
Can you find a sequence that contains all the 4digit 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 4digit combinations using the numbers 0 to 9. The sequence is 10003 digits long (yes I misspoke in the video!)
Fri, 16 Dec 2011 01:53:43 +0000
maths,math,mathematics,problem,puzzle,combination,lock,break,crack,sequence,combinatorics
108
University of Cambridge
Dr J.R. Grime
c2b3586f1c60b4221007b3675614ef51
673935e7725668b1edf1e76760461ae3
7b7a26f2e6556f433bbb201f46856bcd
The sequence 11221 contains all 2digit combinations using the numbers 1 and...
The sequence 11221 contains all 2digit combinations using the numbers 1 and 2.
Can you find a sequence that contains all the 3digit combinations using the numbers 1, 2, and 3. What is the shortest such sequence?
Can you find a sequence that contains all the 4digit 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 4digit combinations using the numbers 0 to 9. The sequence is 10003 digits long (yes I misspoke in the video!)
Cambridge University
173
maths,math,mathematics,problem,puzzle,combination,lock,break,crack,sequence,combinatorics
http://sms.cam.ac.uk/media/1197907
Can you crack the combination lock?
The sequence 11221 contains all 2digit combinations using the numbers 1 and 2.
Can you find a sequence that contains all the 3digit combinations using the numbers 1, 2, and 3. What is the shortest such sequence?
Can you find a sequence that contains all the 4digit 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 4digit combinations using the numbers 0 to 9. The sequence is 10003 digits long (yes I misspoke in the video!)
20111216T01:53:56+00:00
173
1197907
true
16x9
false
no

Can you crack the combination lock?  Solution
ucs_sms_1157706_1198283
http://sms.cam.ac.uk/media/1198283
Can you crack the combination lock?  Solution
The sequence 11221 contains all 2digit 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.
Sun, 18 Dec 2011 02:39:33 +0000
maths,math,mathematics,problem,puzzle,combinatorics,lock,code,break,crack,sequence,De Bruijn,Lyndon words,graph,hamiltonian path,eulerian path
108
University of Cambridge
Dr J.R. Grime
3bab82aaf7f01ffdaa33915df0043629
6903adc56a2d4455fa8b4f3b6a1c647b
dfbde3ebd4d33a2a89256fc630d13eea
The sequence 11221 contains all 2digit combinations using the numbers 1 and 2....
The sequence 11221 contains all 2digit 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.
Cambridge University
728
maths,math,mathematics,problem,puzzle,combinatorics,lock,code,break,crack,sequence,De Bruijn,Lyndon words,graph,hamiltonian path,eulerian path
http://sms.cam.ac.uk/media/1198283
Can you crack the combination lock?  Solution
The sequence 11221 contains all 2digit 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 2digit 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 first two involve making diagrams called graphs, and either taking a path that visits every node of a graph (a hamilton path), or a path that visits every edge of a graph (euler path). The third method is an algorithm for making 'Lyndon words' which if you string them together will make our De Bruijn sequence.
De Bruijn Sequences: http://en.wikipedia.org/wiki/De_Bruijn_sequence
Hamilton Path: http://en.wikipedia.org/wiki/Hamiltonian_path
Euler Path: http://en.wikipedia.org/wiki/Eulerian_path
Lyndon Words: http://en.wikipedia.org/wiki/Lyndon_word
There is an efficient method of generating a list of all Lyndon words of lengths that divide n, using the digits 1 to k, which involves a lot less crossing off. This is the method I used to make the final sequence in the video. I did not describe the method in the video, so let me describe it here:
Start the list with a sequence of n 1s, i.e. 11 . . . 1. We will generate successive words until we reach kk . . . k. For any word A = a1a2 . . . an, the successor of A is obtained as follows:
1. Let i be the largest value such that ai is less than k
2. Let B = a1a2 . . . ai1(ai + 1)
3. Then the successor of A is the first n characters of BB . . . B.
We then decided to reject, replace, or keep the successor of A depending on the value of i:
1. If i does not divide n, the successor of A appears earlier on the list under rotation. Generate a successor to the word before removing it from the list.
2. If i divides n but not equal to n, the successor of A is periodic. Generate a successor to the word then replace BB . . . B with B. Replace 11 . . . 1 at the start of the list with 1.
3. If i = n we keep the successor of A.
This creates a list of Lyndon words, of lengths that divide n, written in lexicographic order.
Together, this list creates a De Bruijn sequence of length k^n, containing all the combinations of length n (if the sequence wraps around) using the digits 1 to k.
Ok then, here's an extra one for you to try. Use the algorithm to give me a sequence containing all 6digit combinations using the numbers 1 and 2. So combinations like 111111, 112121, 211122 etc. The sequence is 64digits long (if you let the sequence wrap back to the start).
20111218T02:39:44+00:00
728
1198283
true
16x9
false
no

Connect The Towns
ucs_sms_1157706_1157733
http://sms.cam.ac.uk/media/1157733
Connect The Towns
What is the minimum distance to connect four towns?
Thu, 21 Jul 2011 13:05:09 +0100
maths,math,mathematics,problem,puzzle,minimum,smallest,connect,towns,cities
108
University of Cambridge
Dr J.R. Grime
67daa5451722978b0d0592a5836d2869
083ad236a025ddbb88d663f448af3f19
4b199bd848c067b440886006b140fdc7
What is the minimum distance to connect four towns?
What is the minimum distance to connect four towns?
Cambridge University
90
maths,math,mathematics,problem,puzzle,minimum,smallest,connect,towns,cities
http://sms.cam.ac.uk/media/1157733
Connect The Towns
What is the minimum distance to connect four towns?
20110826T16:25:07+01:00
90
1157733
true
16x9
false
no

Flipping 10 heads in a row
ucs_sms_1157706_1169380
http://sms.cam.ac.uk/media/1169380
Flipping 10 heads in a row
Sun, 04 Sep 2011 20:49:45 +0100
maths,math,mathematics,problem,puzzle,probability,statistics,coin,Derren Brown
108
University of Cambridge
Dr J.R. Grime
7056767e47ecf5cbf8e4f389d045d996
299c254c57c5978b70e89194c5550de6
d535308b49cf25219cdb34efee88de91
Cambridge University
82
maths,math,mathematics,problem,puzzle,probability,statistics,coin,Derren Brown
http://sms.cam.ac.uk/media/1169380
Flipping 10 heads in a row
20110905T09:06:54+01:00
82
1169380
true
16x9
false
no

Flipping 10 heads in a row: Full video
ucs_sms_1157706_1169397
http://sms.cam.ac.uk/media/1169397
Flipping 10 heads in a row: Full video
Even unlikely events happen given enough opportunities.
Sun, 04 Sep 2011 22:04:19 +0100
maths,math,mathematics,problem,puzzle,probability,statistics,coins,Derren Brown
108
University of Cambridge
Dr J.R. Grime
2efbf7751dd43169e074639306a7a1ec
3ac8197dd8bc2f3708a736ead629da20
b58e3c5ee96a4efaadc9a67ca037037e
Even unlikely events happen given enough opportunities.
Even unlikely events happen given enough opportunities.
Cambridge University
310
maths,math,mathematics,problem,puzzle,probability,statistics,coins,Derren Brown
http://sms.cam.ac.uk/media/1169397
Flipping 10 heads in a row: Full video
Even unlikely events happen given enough opportunities.
20110905T09:07:28+01:00
310
1169397
true
16x9
false
no

Game of Nine
ucs_sms_1157706_1171238
http://sms.cam.ac.uk/media/1171238
Game of Nine
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.
Thu, 08 Sep 2011 21:01:48 +0100
math,maths,mathematics,problem,puzzle,game,investigation,strategy
108
University of Cambridge
Dr J.R. Grime
a132d94257f60eca702b6c298f0c2aa5
75dbb8dd65d6a30a0914011a2fae9048
b81fcf6a4e5978df70fa56f0d0e9dd92
Here is a game for you to play and investigate. Is there a winning...
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.
Cambridge University
125
math,maths,mathematics,problem,puzzle,game,investigation,strategy
http://sms.cam.ac.uk/media/1171238
Game of Nine
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.
20110909T17:18:11+01:00
125
1171238
true
16x9
false
no

Game of Nine Solution
ucs_sms_1157706_1172626
http://sms.cam.ac.uk/media/1172626
Game of Nine Solution
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.
Fri, 16 Sep 2011 01:18:10 +0100
maths,math,mathematics,problem,puzzle,game,investigation,strategy,magic square
108
University of Cambridge
Dr J.R. Grime
2452945f7d99f0a43a283a7b4f5a9a89
590c2e35a03a17fe76ce5acc488d7ad0
2738eec29c950383c0c6fcfa5a3534fd
Solution to my 'Game of Nine' video: http://youtu.be/ue4Baa8Mhn8
Each player...
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.
Cambridge University
120
maths,math,mathematics,problem,puzzle,game,investigation,strategy,magic square
http://sms.cam.ac.uk/media/1172626
Game of Nine Solution
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.
20110916T01:18:20+01:00
120
1172626
true
16x9
false
no

Make a Postit Note Dodecahedron!
ucs_sms_1157706_1181466
http://sms.cam.ac.uk/media/1181466
Make a Postit Note Dodecahedron!
How to make a Postit 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
Fri, 14 Oct 2011 12:33:26 +0100
maths,math,mathematics,problem,puzzle,fun,origami,modular,dodecahedron,platonic,regular,solid,shape,postit note
108
University of Cambridge
Dr J.R. Grime
29ce9fa5222f94b73f67cd5a5f618744
8743ea1e58e75c8be1c24b93c9708674
37f4a0f02e8774aa10cd08f4a0fa7485
How to make a Postit Note Dodecahedron. Fun and beautiful! If you make one...
How to make a Postit 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
Cambridge University
357
maths,math,mathematics,problem,puzzle,fun,origami,modular,dodecahedron,platonic,regular,solid,shape,postit note
http://sms.cam.ac.uk/media/1181466
Make a Postit Note Dodecahedron!
How to make a Postit 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
20111014T12:33:37+01:00
357
1181466
true
16x9
false
no

Maths Problem: Connect the towns solution (Motorway Problem)
ucs_sms_1157706_1164688
http://sms.cam.ac.uk/media/1164688
Maths Problem: Connect the towns solution (Motorway Problem)
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.
Tue, 16 Aug 2011 19:14:42 +0100
maths,math,mathematics,problem,puzzle,motorway,steiner points,minimum tree,connect
108
University of Cambridge
Dr J.R. Grime
5b2184fc36d13d2148ba38fa006b1fbf
67c7b50ec6dd0e96f0066eef7b908955
3169a056ba07d68ea0b229cb39247cea
What is the minimum amount of road needed to connect these four towns together?...
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.
Cambridge University
335
maths,math,mathematics,problem,puzzle,motorway,steiner points,minimum tree,connect
http://sms.cam.ac.uk/media/1164688
Maths Problem: Connect the towns solution (Motorway Problem)
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.
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.
With thanks to Scott Grandison of the University of East Anglia for all his help! And David and Neil of the workshop for making the props!
Reference: Problem solving with soap films: Part I, C Isenberg 1975 Phys. Educ. 10 452 http://iopscience.iop.org/00319120/10/6/314
More information from wikipedia: http://en.wikipedia.org/wiki/Steiner_tree
If you liked this, you'll also like "Slime Mold Grows Network Just Like Tokyo Rail System" http://www.wired.com/wiredscience/2010/01/slimemoldgrowsnetworkjustliketokyorailsystem/
20110816T19:14:52+01:00
335
1164688
true
16x9
false
no

Maths Puzzle: Back to Black
ucs_sms_1157706_1205465
http://sms.cam.ac.uk/media/1205465
Maths Puzzle: Back to Black
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
Thu, 19 Jan 2012 13:37:08 +0000
maths,math,mathematics,problem,puzzle,numbers,factors,divisors
108
University of Cambridge
Dr J.R. Grime
33d378b917c8401c10c01d45707c4707
1843544fb786c5d60ca00ab8ebd5dd0b
866c45a23a0ec784fae756e715f43dce
I have a board that uses the numbers 1 to 90. I fill the board with Othello...
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
Cambridge University
347
maths,math,mathematics,problem,puzzle,numbers,factors,divisors
http://sms.cam.ac.uk/media/1205465
Maths Puzzle: Back to Black
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
20120119T13:37:21+00:00
347
1205465
true
16x9
false
no

Maths Puzzle: Coins
ucs_sms_1157706_1215891
http://sms.cam.ac.uk/media/1215891
Maths Puzzle: Coins
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?
Mon, 20 Feb 2012 01:44:19 +0000
maths,math,mathematics,problem,puzzle,coin,trick,challenge,scam
108
University of Cambridge
Dr J.R. Grime
bdcb4c8f81f1814959bc04c81dbb14a4
aeff75d79ddbbfdea11eed06850cb73e
3d7085d52693892fa4f70bea2ccc1f67
QED Gold: Originally uploaded 31st January 2011.
Take a random pile of...
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?
Cambridge University
96
maths,math,mathematics,problem,puzzle,coin,trick,challenge,scam
http://sms.cam.ac.uk/media/1215891
Maths Puzzle: Coins
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?
20120220T01:44:31+00:00
96
1215891
true
16x9
false
no

Maths Puzzle: Coins Solution
ucs_sms_1157706_1218639
http://sms.cam.ac.uk/media/1218639
Maths Puzzle: Coins Solution
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.
Sun, 26 Feb 2012 12:19:55 +0000
maths,math,mathematics,problem,puzzle,coins,challenge
108
University of Cambridge
Dr J.R. Grime
e829f42d5cd41ad8c6b44113b9e2b94b
9def94eef73f8615a9d38334bb9201f0
a8d752bc3ab52cfb219343fabf51a4bf
QED Gold: Originally uploaded 4th February 2011
Take a random pile of...
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.
Cambridge University
190
maths,math,mathematics,problem,puzzle,coins,challenge
http://sms.cam.ac.uk/media/1218639
Maths Puzzle: Coins Solution
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.
20120226T12:20:08+00:00
190
1218639
true
16x9
false
no

Maths Puzzle: First to get a head
ucs_sms_1157706_1189122
http://sms.cam.ac.uk/media/1189122
Maths Puzzle: First to get a head
QED Gold: Originally uploaded 25th May 2011.
Let's get ready to rhumble...!
Sun, 20 Nov 2011 23:34:27 +0000
maths,math,mathematics,statistics,probability,coin,problem,puzzle
108
University of Cambridge
Dr J.R. Grime
6cebabb15b9529826140cb78189ed73a
bdcdcc931edb65bde0efa6736b027dd9
b401a4b23b5f6b79331a77146bc9d3b8
f841dcab1d9d5c371db66f073336b319
QED Gold: Originally uploaded 25th May 2011.
Let's get ready to rhumble...!
QED Gold: Originally uploaded 25th May 2011.
Let's get ready to rhumble...!
Cambridge University
70
maths,math,mathematics,statistics,probability,coin,problem,puzzle
http://sms.cam.ac.uk/media/1189122
Maths Puzzle: First to get a head
QED Gold: Originally uploaded 25th May 2011.
Let's get ready to rhumble...!
20111120T23:34:39+00:00
70
1189122
true
16x9
false
no

Maths Puzzle: First to get a head solution
ucs_sms_1157706_1194087
http://sms.cam.ac.uk/media/1194087
Maths Puzzle: First to get a head solution
QED Gold: Originally uploaded 28th May 2011
Solution the the First to get a head problem
Tue, 13 Dec 2011 12:39:10 +0000
maths,math,mathematics,problem,puzzle,game,coin,probability,statistics,tree diagram,geometric,series,sum
108
University of Cambridge
Dr J.R. Grime
72b2d6121e4401d78269e8051ce130ec
534328deada0034ad057239a63c0f4ec
439c5419edac99e3f2efecd5d906410f
QED Gold: Originally uploaded 28th May 2011
Solution the the First to get a...
QED Gold: Originally uploaded 28th May 2011
Solution the the First to get a head problem
Cambridge University
242
maths,math,mathematics,problem,puzzle,game,coin,probability,statistics,tree diagram,geometric,series,sum
http://sms.cam.ac.uk/media/1194087
Maths Puzzle: First to get a head solution
QED Gold: Originally uploaded 28th May 2011
Solution the the First to get a head problem
20111213T12:39:23+00:00
242
1194087
true
16x9
false
no

Mentally Unsolvable (?) Card Trick Tutorial
ucs_sms_1157706_1182545
http://sms.cam.ac.uk/media/1182545
Mentally Unsolvable (?) Card Trick Tutorial
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
Mon, 24 Oct 2011 01:06:03 +0100
maths,math,mathematics,problem,puzzle,magic,card,trick
108
University of Cambridge
Dr J.R. Grime
3d9477d870fd189339299f490c77ddae
5ba17a31bede20faad55be7603a42519
6989fc6f3fd9a15e355bd401cf1a225a
QED Gold: Originally uploaded 17th July 2011.
Watch the tutorial by...
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
Cambridge University
382
maths,math,mathematics,problem,puzzle,magic,card,trick
http://sms.cam.ac.uk/media/1182545
Mentally Unsolvable (?) Card Trick Tutorial
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
20111024T01:10:16+01:00
382
1182545
true
16x9
false
no

Möbius Strip Hearts (For Valentine's Day)
ucs_sms_1157706_1212013
http://sms.cam.ac.uk/media/1212013
Möbius Strip Hearts (For Valentine's Day)
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
Mon, 06 Feb 2012 10:19:51 +0000
maths,math,mathematics,problem,puzzle,mobius,Möbius,moebius,geometry,nonorientable,klein bottle,valentine
108
University of Cambridge
Dr J.R. Grime
4d1a40713a2a0233baf19801b37f88d7
45a3a8f63df58e2f669bd0c8a2b1e1b2
209bea844843ecb5887b9decfdb791b6
QED Gold: Originally uploaded 6th February 2011.
The Möbius Strip is a...
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
Cambridge University
207
maths,math,mathematics,problem,puzzle,mobius,Möbius,moebius,geometry,nonorientable,klein bottle,valentine
http://sms.cam.ac.uk/media/1212013
Möbius Strip Hearts (For Valentine's Day)
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
20120206T10:20:04+00:00
207
1212013
true
16x9
false
no

Puzzle: Mathematical Ants
ucs_sms_1157706_1174913
http://sms.cam.ac.uk/media/1174913
Puzzle: Mathematical Ants
A little puzzle to pass the time...
Thu, 22 Sep 2011 23:31:16 +0100
maths,math,mathematics,problem,puzzle
108
University of Cambridge
Dr J.R. Grime
b45918c52f2df91d5b55dcd325514a5e
b3afad1846d15c041696808e3e57229d
8d7caae4089621e2b7ea55605aefc35f
A little puzzle to pass the time...
A little puzzle to pass the time...
Cambridge University
93
maths,math,mathematics,problem,puzzle
http://sms.cam.ac.uk/media/1174913
Puzzle: Mathematical Ants
A little puzzle to pass the time...
20110922T23:31:25+01:00
93
1174913
true
16x9
false
no

Puzzle: Mathematical Ants Solution
ucs_sms_1157706_1174930
http://sms.cam.ac.uk/media/1174930
Puzzle: Mathematical Ants Solution
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
Thu, 22 Sep 2011 23:49:40 +0100
maths,math,mathematics,problem,puzzle
108
University of Cambridge
Dr J.R. Grime
8e21a802be69a4332009dfac77c0fada
9d69b521865f76493386af19eb9aa854
1b3e8a0df9c04c745c7a00bad403f514
Solution to my last video: http://www.youtube.com/watch?v=lAmhA_SmzsI
This...
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
Cambridge University
107
maths,math,mathematics,problem,puzzle
http://sms.cam.ac.uk/media/1174930
Puzzle: Mathematical Ants Solution
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
20110922T23:49:51+01:00
107
1174930
true
16x9
false
no

QED Code Challenge 2012
ucs_sms_1157706_1211194
http://sms.cam.ac.uk/media/1211194
QED Code Challenge 2012
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"
Thu, 02 Feb 2012 19:41:04 +0000
maths,math,mathematics,problem,puzzle,code,cipher,cryptology,alan turing,james grime,simon singh,competition,enigma project,nrich
108
University of Cambridge
Dr J.R. Grime
d9ee2d38bd691a015b47e497e751f65f
96c07a0b73e8c14ac54d02c5f2372469
b27c975848602a35e6f2d2443a0cbe27
Send your entries to the Enigma Project http://enigma.maths.org Challenge ends...
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"
Cambridge University
217
maths,math,mathematics,problem,puzzle,code,cipher,cryptology,alan turing,james grime,simon singh,competition,enigma project,nrich
http://sms.cam.ac.uk/media/1211194
QED Code Challenge 2012
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"
20120202T19:41:16+00:00
217
1211194
true
16x9
false
no

QED Code Challenge 2012: solution and winners!
ucs_sms_1157706_1221446
http://sms.cam.ac.uk/media/1221446
QED Code Challenge 2012: solution and winners!
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/singingbananacodechallenge2012/
Mon, 05 Mar 2012 00:32:19 +0000
maths,math,mathematics,problem,puzzle,code,cipher,challenge,cryptography,cryptology,playfair
108
University of Cambridge
Dr J.R. Grime
ce3b49678c4e0b6feae34f58cbcbcde1
4b28ce2dcfda32eb1bc42060389bc9ae
376431ee87eea126eb7ecddaee484d49
A description of how I broke the code:...
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/singingbananacodechallenge2012/
Cambridge University
547
maths,math,mathematics,problem,puzzle,code,cipher,challenge,cryptography,cryptology,playfair
http://sms.cam.ac.uk/media/1221446
QED Code Challenge 2012: solution and winners!
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/singingbananacodechallenge2012/
20120305T00:32:33+00:00
547
1221446
true
16x9
false
no

Simple Maths
ucs_sms_1157706_1164773
http://sms.cam.ac.uk/media/1164773
Simple Maths
Some simple maths filmed at the Mathematical Association annual conference dinner, 2011. With thanks to everyone involved.
Tue, 16 Aug 2011 20:02:28 +0100
maths,math,mathematics,problem,puzzle,addition,trick,fun
108
University of Cambridge
Dr J.R. Grime
073ecfda00e1ad2e026094f979422b40
1cdc7cd2d00b2c93873897720d8e9c01
70b461503286556c03fde471d6644993
Some simple maths filmed at the Mathematical Association annual conference...
Some simple maths filmed at the Mathematical Association annual conference dinner, 2011. With thanks to everyone involved.
Cambridge University
111
maths,math,mathematics,problem,puzzle,addition,trick,fun
http://sms.cam.ac.uk/media/1164773
Simple Maths
Some simple maths filmed at the Mathematical Association annual conference dinner, 2011. With thanks to everyone involved.
20110816T20:02:38+01:00
111
1164773
true
16x9
false
no

Straw Kazoo
ucs_sms_1157706_1200566
http://sms.cam.ac.uk/media/1200566
Straw Kazoo
QED Gold: Originally uploaded 21st May 2011.
A silly one, and this time not about mathematics but a fun physics demonstration.
Sun, 08 Jan 2012 22:31:34 +0000
physics,music,kazoo,experiment,kids,children,fun,vibration,frequency,pitch
108
University of Cambridge
Dr J.R. Grime
1723be53aa2b1ae04a5434f0abd536ed
fc46bc4f4fc4e228710548ba1460ef8f
5a6bbb04fbaf15e8e0058ca62965b73a
QED Gold: Originally uploaded 21st May 2011.
A silly one, and this time not...
QED Gold: Originally uploaded 21st May 2011.
A silly one, and this time not about mathematics but a fun physics demonstration.
Cambridge University
85
physics,music,kazoo,experiment,kids,children,fun,vibration,frequency,pitch
http://sms.cam.ac.uk/media/1200566
Straw Kazoo
QED Gold: Originally uploaded 21st May 2011.
A silly one, and this time not about mathematics but a fun physics demonstration.
20120108T22:31:47+00:00
85
1200566
true
16x9
false
no

Survey: What's Your Favourite Number?
ucs_sms_1157706_1171314
http://sms.cam.ac.uk/media/1171314
Survey: What's Your Favourite Number?
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
Sun, 11 Sep 2011 23:02:22 +0100
Maths,math,mathematics,problem,puzzle,survey,favourite,favorite,number,alex bellos
108
University of Cambridge
Dr J.R. Grime
809b6373cb05b65999c184cb1108c33e
1b224976357ebed33a211a5a6ca1a963
493546b50d1fafb9427fa07f837fd5e6
QED Gold: Originally uploaded 1st June 2011. Survey ends October 2011 so there...
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
Cambridge University
135
Maths,math,mathematics,problem,puzzle,survey,favourite,favorite,number,alex bellos
http://sms.cam.ac.uk/media/1171314
Survey: What's Your Favourite Number?
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
20110911T23:02:33+01:00
135
1171314
true
16x9
false
no

The curious case of the WWII carrier pigeon and the unbreakable code
ucs_sms_1157706_1358689
http://sms.cam.ac.uk/media/1358689
The curious case of the WWII carrier pigeon and the unbreakable code
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 OneTime Pad Cipher, and that the message will remain unbreakable, why is that? http://www.bbc.co.uk/news/uk20456782
Fri, 07 Dec 2012 15:34:45 +0000
maths,math,mathematics,problem,puzzle,one time pad,cipher,code,WWII
108
University of Cambridge
Dr J R Grime
fc250168cf3f3065ee55454c24d72eaa
3804220847f08e1941e3592f51871364
e90397dbcec464a9664fa0b097be2fda
940a06962a65640063347ba1cc87fe58
A British couple discover the remains of a WWII carrier pigeon behind their...
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 OneTime Pad Cipher, and that the message will remain unbreakable, why is that? http://www.bbc.co.uk/news/uk20456782
Cambridge University
383
maths,math,mathematics,problem,puzzle,one time pad,cipher,code,WWII
http://sms.cam.ac.uk/media/1358689
The curious case of the WWII carrier pigeon and the unbreakable code
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 OneTime Pad Cipher, and that the message will remain unbreakable, why is that? http://www.bbc.co.uk/news/uk20456782
20121207T15:35:09+00:00
383
1358689
true
16x9
false
no

The Maths of Christmas
ucs_sms_1157706_1194070
http://sms.cam.ac.uk/media/1194070
The Maths of Christmas
QED Gold: Originally uploaded 19th December 2009
My true love gave to me Triangle Numbers.
Mon, 12 Dec 2011 00:14:12 +0000
maths,math,mathematics,problem,puzzle,christmas,xmas,triangle,triangular,numbers,twelve days of christmas,handshake
108
University of Cambridge
Dr J.R. Grime
700b1ce0389c29227f5d013518e18e5d
7a1943250d398f457e06e3c7c78ebe46
7aaf9d142811f7833d0a45f5cd36e0aa
QED Gold: Originally uploaded 19th December 2009
My true love gave to me...
QED Gold: Originally uploaded 19th December 2009
My true love gave to me Triangle Numbers.
Cambridge University
244
maths,math,mathematics,problem,puzzle,christmas,xmas,triangle,triangular,numbers,twelve days of christmas,handshake
http://sms.cam.ac.uk/media/1194070
The Maths of Christmas
QED Gold: Originally uploaded 19th December 2009
My true love gave to me Triangle Numbers.
20111212T00:14:25+00:00
244
1194070
true
16x9
false
no

The Slide Rule
ucs_sms_1157706_1176569
http://sms.cam.ac.uk/media/1176569
The Slide Rule
No shoes allowed on the helter skelter.
Sun, 02 Oct 2011 20:54:32 +0100
maths,math,mathemathics,problem,puzzle,slide rule,calculator,vintage,logarithm,logs
108
University of Cambridge
Dr J.R. Grime
b2437d3a8c03d6acecfdc4ac0a5d20f1
9af47e94fccd24de2339df42a282fcbb
6ade0e754624e84d1a6efe0fb88f21b9
No shoes allowed on the helter skelter.
No shoes allowed on the helter skelter.
Cambridge University
436
maths,math,mathemathics,problem,puzzle,slide rule,calculator,vintage,logarithm,logs
http://sms.cam.ac.uk/media/1176569
The Slide Rule
No shoes allowed on the helter skelter.
20111002T20:54:43+01:00
436
1176569
true
16x9
false
no

The Trinity College Clock, Cambridge
ucs_sms_1157706_1175137
http://sms.cam.ac.uk/media/1175137
The Trinity College Clock, Cambridge
A look at the Trinity College clock with Hugh Hunt.
For more information: http://www.trin.cam.ac.uk/clock
Sun, 25 Sep 2011 22:41:24 +0100
maths,math,mathematics,engineering,physics,pendulum,trinity college,clock,cambridge university,hugh hunt,james grime
108
University of Cambridge
Dr J.R. Grime
cde61029f4ddef1409260ae298764298
20bd0beb75c7921625ff6b3106a66b5f
e5e61d13dbd55977ae887e082d4bf838
A look at the Trinity College clock with Hugh Hunt.
For more information:...
A look at the Trinity College clock with Hugh Hunt.
For more information: http://www.trin.cam.ac.uk/clock
Cambridge University
444
maths,math,mathematics,engineering,physics,pendulum,trinity college,clock,cambridge university,hugh hunt,james grime
http://sms.cam.ac.uk/media/1175137
The Trinity College Clock, Cambridge
A look at the Trinity College clock with Hugh Hunt.
For more information: http://www.trin.cam.ac.uk/clock
20110925T22:41:34+01:00
444
1175137
true
16x9
false
no

Top Trumps Investigations
ucs_sms_1157706_1208779
http://sms.cam.ac.uk/media/1208779
Top Trumps Investigations
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.
Mon, 30 Jan 2012 01:14:07 +0000
maths,math,mathematics,problem,puzzle,game,investigation,top trumps,probability,statistics,nontransitive,formua
108
University of Cambridge
Dr J.R. Grime
9c05427f17de7b231c8ea0c7edf3630c
6356ff3d4379ef083f89edc2bc87b7c8
bdacfc65a162219e05f3b63b81e5359c
QED Gold: Originally uploaded 26th February 2011
Top Trumps is a popular...
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.
Cambridge University
590
maths,math,mathematics,problem,puzzle,game,investigation,top trumps,probability,statistics,nontransitive,formua
http://sms.cam.ac.uk/media/1208779
Top Trumps Investigations
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.
20120130T01:14:19+00:00
590
1208779
true
16x9
false
no

Welcome to Quite Easily Done
ucs_sms_1157706_1169018
http://sms.cam.ac.uk/media/1169018
Welcome to Quite Easily Done
A short welcome to my channel.
Fri, 02 Sep 2011 21:57:23 +0100
maths,math,mathemathics,QED,Q.E.D,,Quite Easily Done,James Grime,singingbanana,singing banana,youtube,puzzles,problems,tricks
108
University of Cambridge
Dr J.R. Grime
f5e08bbdb2e2866521beb8a8c06dfcbb
ad1e855eed1680718108780e67af8121
fd152c16534e0b07990fee145dde4a62
A short welcome to my channel.
A short welcome to my channel.
Cambridge University
68
maths,math,mathemathics,QED,Q.E.D,,Quite Easily Done,James Grime,singingbanana,singing banana,youtube,puzzles,problems,tricks
http://sms.cam.ac.uk/media/1169018
Welcome to Quite Easily Done
A short welcome to my channel.
20110902T21:57:33+01:00
68
1169018
true
16x9
false
no

What is the point?
ucs_sms_1157706_1164721
http://sms.cam.ac.uk/media/1164721
What is the point?
"What is the point of mathematics?"
Tue, 16 Aug 2011 19:42:51 +0100
maths,math,mathematics,opinion,blog,vlog,discovery,beauty,elegance,creative,thought,science,physics,philosophy,truth
108
University of Cambridge
Dr J.R. Grime
2b2d303cbe489460df07134fe7494d86
58b9c5778cb0fbca75ca8b4fd2651cd0
e01dbe00bf455b24c305c42dfbd8b3db
"What is the point of mathematics?"
"What is the point of mathematics?"
Cambridge University
209
maths,math,mathematics,opinion,blog,vlog,discovery,beauty,elegance,creative,thought,science,physics,philosophy,truth
http://sms.cam.ac.uk/media/1164721
What is the point?
"What is the point of mathematics?"
20110816T19:43:01+01:00
209
1164721
true
16x9
false
no

What's the probability you live in an odd numbered house?
ucs_sms_1157706_1172660
http://sms.cam.ac.uk/media/1172660
What's the probability you live in an odd numbered house?
QED Gold: Originally uploaded 5th August 2011
A video of me reading my original blog post out loud http://singingbanana.tumblr.com/post/6629627960/whatstheprobabilityyouliveinanoddnumbered
The original Facebook poll: https://www.facebook.com/home.php?sk=question&id=218841344812765&qa_ref=qd
Sun, 18 Sep 2011 22:07:55 +0100
maths,math,mathematics,problem,puzzle,probabilty,statistics,confidence interval,hypothesis testing,normal,bell curve
108
University of Cambridge
Dr J.R. Grime
d7f665e1d8e0458a636ae41e296cc7b9
5e736b587e67d52d135132f1adf702cd
68a1510617c39f81171c57206adac8aa
QED Gold: Originally uploaded 5th August 2011
A video of me reading my...
QED Gold: Originally uploaded 5th August 2011
A video of me reading my original blog post out loud http://singingbanana.tumblr.com/post/6629627960/whatstheprobabilityyouliveinanoddnumbered
The original Facebook poll: https://www.facebook.com/home.php?sk=question&id=218841344812765&qa_ref=qd
Cambridge University
410
maths,math,mathematics,problem,puzzle,probabilty,statistics,confidence interval,hypothesis testing,normal,bell curve
http://sms.cam.ac.uk/media/1172660
What's the probability you live in an odd numbered house?
QED Gold: Originally uploaded 5th August 2011
A video of me reading my original blog post out loud http://singingbanana.tumblr.com/post/6629627960/whatstheprobabilityyouliveinanoddnumbered
The original Facebook poll: https://www.facebook.com/home.php?sk=question&id=218841344812765&qa_ref=qd
A video of me reading my original blog post out loud http://singingbanana.tumblr.com/post/6629627960/whatstheprobabilityyouliveinanoddnumbered
The original Facebook poll: https://www.facebook.com/home.php?sk=question&id=218841344812765&qa_ref=qd

More details:
The answer 0.502 falls outside what you would expect with 400000 coin tosses, with 95% of such experiments being within 200000 +/ 300. Therefore the difference 0.002, although small, is statistically significant. That is to say, extremely unlikely to be a simple variation due to chance, but a genuine difference. The conclusion is strong since 400000 is a large sample.
Using our data we have seen the answer appears to 0.502. And we have shown that answer is statistically significant. But justifying why it's 0.502 is more difficult.
I suggest in the video that there are more odd numbered houses due to streets with an odd number of houses. An argument that works brilliantly if the houses are in a row, or on a close, or a block of flats.
If the street has odd numbered houses on one side and even numbered houses on the other side, I am assuming that the majority of streets with. say, 100 houses have 50 houses on the even side and 50 houses on the odd side. But if the street had 101 houses I am assuming the majority have 51 on the odd side and 50 on the even side. This allows the numbering to be consecutive, and would be strange otherwise. For the same reason, if one side has a few more houses than the other side, I can imagine the long side will be the odd numbered side. If that it is not true, it doesn't change the fact that the statistical analysis shows the answer *is* 0.502, and we have already come up with enough reasons to explain it.
[Edit: That was my guess about two sided streets  and it may not be true! Here's a wikipedia article about house numbering http://en.wikipedia.org/wiki/House_numbering Houses are numbered with odd houses being on the left/right (depending which country it is) as you look up the street with houses in ascending order. As I said before, the statistics show that there are more odd numbered houses than even numbered houses, justifying that is secondary.]
A rough calculation might be to work out the average proportion of odd numbered houses in streets of size 1 to 1000. That is 1/1000 sum (4k 1)/(4k2) summing from 1 to 500. Which is 0.502. This is rough because it assumes the distribution of street sizes is uniform. We do not know what the true distribution is, only that it gives us an average of 0.502.
I believe exceptions will either be insignificant (e.g. houses without the number 13), or cancel each other out (e.g. streets with only odd numbers cancelling out with streets that only have even numbers).
[Edit: Here's a BBC piece about houses numbered 13 http://news.bbc.co.uk/1/hi/magazine/7779212.stm]
Whatever the truth, the statistical analysis shows that the average appears to be 0.502, with justifying that answer being secondary.
20110918T22:08:07+01:00
410
1172660
true
16x9
false
no

Whispering Jokers
ucs_sms_1157706_1180447
http://sms.cam.ac.uk/media/1180447
Whispering Jokers
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
Mon, 10 Oct 2011 01:14:11 +0100
108
University of Cambridge
Dr J.R. Grime
888a54c148c0592b57635ae7b0f12f19
77c8e8d61325bd2c69a3520b8a7ee43a
d4bc5ecb000a2041c766756f68f7528d
QED Gold: Originally uploaded on YouTube on 14th July 2011
Watch the...
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
Cambridge University
400
http://sms.cam.ac.uk/media/1180447
Whispering Jokers
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
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
To begin with, there are 54 cards. That's 52 cards and 2 jokers.
Let's call the jokers J1 and J2.
J1 starts in the J1th position;
J2 starts in the J2th position.
Volunteer 1 cuts 1/3 down the pack.
Volunteer 2 cuts 2/3 down the pack.
Call the chosen cards C1 and C2. They are in the J1th and J2th position plus or minus some difference.
Say C1 is in the J1 + d1 position;
C2 is in the J2 + d2 position.
The deck has been split into three packs.
Pack 1 has size J1 + d1;
Pack 2 has size J2 + d2  J1  d1;
Pack 3 has size 54  J2  d2.
Packs are now placed in order: Pack 2, Pack 1, Pack 3.
C1 is now in the J2 + d2 position;
C2 is now in the J2  J1 + d2  d1 position.
Reveal the two jokers.
J1 is now in the J2 + d2  d1 position;
J2 is now in the J2  J1  d1 position.
Remove the jokers. There are now 52 cards and the deck has been split into three packs.
Pack 1 has size J2  J1  d1  1;
Pack 2 has size J1 + d2  1;
Pack 3 has size 54  J2 + d1  d2.
After removing two jokers, C1 is now in the J2 + d2  2 position, (it is d1 down Pack 3);
After removing two jokers, C2 is now in the J2  J1 + d2  d1  1 position, (it is d2 down Pack 2).
Packs are placed in order: Pack 1, Pack 3, Pack 2.
C1 is now in the J2  J1  1 position;
C2 is now in the 54  J1  1 position.
20111010T01:14:22+01:00
400
1180447
true
16x9
false
no

Why does 1=0.999...?
ucs_sms_1157706_1203064
http://sms.cam.ac.uk/media/1203064
Why does 1=0.999...?
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
Mon, 16 Jan 2012 17:36:02 +0000
maths,math,mathematics,problem,puzzle,number theory,Analysis,decimal,notation
108
University of Cambridge
Dr J.R. Grime
8729b380c85d6160e2dfabfca16f1348
e1ca500793e36c50ae5817e1c7d50d13
cb13ab62e3af55b8c5b79003dd977312
QED Gold: Originally uploaded 28th April 2011
A common question, why does...
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
Cambridge University
130
maths,math,mathematics,problem,puzzle,number theory,Analysis,decimal,notation
http://sms.cam.ac.uk/media/1203064
Why does 1=0.999...?
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
20120116T17:37:24+00:00
130
1203064
true
16x9
false
no

Wisdom of the Crowds competition  the answer
ucs_sms_1157706_1187673
http://sms.cam.ac.uk/media/1187673
Wisdom of the Crowds competition  the answer
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?
Mon, 14 Nov 2011 11:59:49 +0000
maths,math,mathematics,problem,puzzle,wisdom of the crowd,Francis Galton,James Grime,David Spiegelhalter,statistics,probabillity,average,mean,mode,geometric,lognormal,normal distribution,logarithm,log
108
University of Cambridge
Dr J.R. Grime
be3fed6bfcf10c62e6ec8e6236e59a3d
0e744d05e216f6fa5c2a173dfba43bf8
d481bbd8f68ce37a8bb9d03cb1451918
60e6112546e5f2ed6053dd535991d143
QED Gold: Originally uploaded 24th June 2011
We reveal the answer to my...
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?
Cambridge University
453
maths,math,mathematics,problem,puzzle,wisdom of the crowd,Francis Galton,James Grime,David Spiegelhalter,statistics,probabillity,average,mean,mode,geometric,lognormal,normal distribution,logarithm,log
http://sms.cam.ac.uk/media/1187673
Wisdom of the Crowds competition  the answer
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?
20111114T12:00:00+00:00
453
1187673
true
16x9
false
no
1157706