# Numberphile

## Pi

1. 3:14
1

### Calculating Pi with Real Pies - Numberphile

by numberphile 289,929 views

How accurately can we calculate Pi using hundreds of REAL pies?
Subscribe to Numberphile: http://bit.ly/13O3ZTL

Extended version of this video (director's slice) at http://www.youtube.com/watch?v=x4kyFKyCMv0

This video features Matt Parker: https://twitter.com/standupmaths Matt believes this is the world's most accurate pie-based Pi calculation.

More Pi videos: http://bit.ly/W4oDN1

Filmed and edited by Brady Haran
Extra camera: James Hennessy

Learn how the music from this video is based on Pi: http://periodicvideos.blogspot.co.uk/2013/03/pimusic.html

Clearly these pies were used for educational purposes... However during production of the video, Numberphile donated £314 to a local charity to provide food for people in Nottingham at times of crisis.

Behind-the-scenes blog and extra photos: http://periodicvideos.blogspot.co.uk/2013/03/pipies.html

We filmed this video at Meadow Lane, home of Notts County FC.

Website: http://www.numberphile.com/
Tumblr: http://numberphile.tumblr.com

http://www.youtube.com/nottinghamscience (Science and behind the scenes)

2. 5:34
2

### Pi and the size of the Universe - Numberphile

by numberphile 240,343 views

Pi is famously calculated to trillions of digits - but Dr James Grime says 39 is probably enough. All our Pi videos: http://bit.ly/W4oDN1

An extra note from Dr Grime: "Since pi39 ends in 0, you may think we could use pi38 instead - which has even fewer digits. Unfortunately, the rounding errors of pi38 are ten times larger than the rounding errors of pi39 - more than a hyrdogen atom. So that extra decimal place makes a difference, even if it's 0."

Website: http://www.numberphile.com/

3. 4:56
3

### How Pi was nearly changed to 3.2 - Numberphile

by numberphile 271,049 views

The State of Indiana nearly passed a law which would have made Pi equal 3.2 - strange but true. More Pi videos from Numberphile: http://bit.ly/W4oDN1

This video features Dr James Grime - https://twitter.com/jamesgrime

The video about squaring circles is being edited and will be coming soon.

A note to potentially disgruntled viewers about making this video longer to include the subsequent lengthy discussion about squaring circles: http://periodicvideos.blogspot.co.uk/2013/03/continue.html

Website: http://www.numberphile.com/
Tumblr: http://numberphile.tumblr.com

4. 6:28
4

### Sounds of Pi - Numberphile

by numberphile 224,788 views

Professor Philip Moriarty attributes some sounds to Pi in a discussion about its randomness and the Feynman Point.

OUR PI VIDEOS ---
ALEX BELLOS AND ROGER DISCUSS ITS HISTORY
BOUNCING BALLS AND A STRANGE PROPERTY
MATCHES HELP FIND PI
THE SOUND OF PI

Phil has put the LabVIEW code at: www.nottingham.ac.uk/~ppzpjm/SoundingPi.vi

Website: http://www.numberphile.com/

5. 6:28
5

### Pi and Buffon's Matches - Numberphile

by numberphile 199,199 views

Dr Tony Padilla's unique (and low budget) twist on the Buffon's Needle experiment to learn the true value of Pi.

OUR PI VIDEOS ---
ALEX BELLOS AND ROGER DISCUSS ITS HISTORY
BOUNCING BALLS AND A STRANGE PROPERTY
MATCHES HELP FIND PI
THE SOUND OF PI

NUMBERPHILE
Website: http://www.numberphile.com/

6. 13:14
6

### Pi and Bouncing Balls - Numberphile

by numberphile 267,394 views

Professor Ed Copeland on a strange occurrence of Pi involving bouncing balls.

See his calculations at: http://www.flickr.com/photos/numberphile/6976718861/in/photo­stream

Check out a computer simulation at http://periodicvideos.blogspot.com/2012/03/pi-and-simulated-­bouncing-balls.html (made by a viewer!)

OUR PI VIDEOS ---
ALEX BELLOS AND ROGER DISCUSS ITS HISTORY
BOUNCING BALLS AND A STRANGE PROPERTY
MATCHES HELP FIND PI
THE SOUND OF PI

Website: http://www.numberphile.com/

7. 9:42
7

### Pi - Numberphile

by numberphile 349,631 views

Some stuff about Pi, the "celebrity number'. This video features maths-loving author Alex Bellos (http://alexbellos.com/) and Professor Roger Bowley from the University of Nottingham.

Alex's brilliant book can be found at...
US: http://www.amazon.com/dp/1416588280/ref=cm_sw_su_dp

OUR PI VIDEOS ---
ALEX BELLOS AND ROGER DISCUSS ITS HISTORY
BOUNCING BALLS AND A STRANGE PROPERTY
MATCHES HELP FIND PI
THE SOUND OF PI

NUMBERPHILE...
Website: http://www.numberphile.com/

8. 11:12
8

### Tau vs Pi Smackdown - Numberphile

by numberphile 197,576 views

Steve Mould (tau) and Matt Parker (pi) go head-to-head. See these guys live at http://festivalofthespokennerd.com/ (very cool show!)
Bid for this brown paper: http://bit.ly/SZctkX
And check our Pi videos: http://www.youtube.com/playlist?list=PL4870492ACBDC2E7C

Mat Parker: http://www.standupmaths.com/
Steve Mould: http://www.stevemould.com/

Numberphile Website: http://www.numberphile.com/

http://periodicvideos.blogspot.co.uk/2012/06/here-are-my-cha­nnels.html

9. 9:43
9

### Tau replaces Pi - Numberphile

by numberphile 276,471 views

Should Pi be replaced by Tau? Professor Phil Moriarty thinks so.

See our collection of Pi videos at: http://www.youtube.com/playlist?list=PL4870492ACBDC2E7C

See ViHart's Tau video at: http://www.youtube.com/watch?v=jG7vhMMXagQ

Tau manifesto: http://tauday.com/

Professor Phil Moriarty is a physicist at the University of Nottingham. His "scrawls" from this video can be seen on Flickr at: http://www.flickr.com/photos/numberphile/

Website: http://www.numberphile.com/

10. 6:28
10

### Pi with Pies (director's slice) - Numberphile

by numberphile 82,288 views

A 6'28" version of our "Pi with Pies" calculation. See this full description for more information.

Videos features Matt Parker who tweets at https://twitter.com/standupmaths

The Pi-inspired music in the video explained: http://periodicvideos.blogspot.co.uk/2013/03/pimusic.html

Our full collection of Pi videos at http://bit.ly/W4oDN1

While the pies are usually delicious, this batch was not for consumption (even by hungry students, for those who suggested it!) but we feel they were used in a fun way to make people think about mathematics - perhaps some people who would not otherwise take an interest... To mark Pi Day we instead donated £314 to a local charity which helps feed people in crisis.

If you'd like to make a donation, here are some suggestions:

Matt is a supporter of Depaul UK, helping young homless people. You can donate through their website: http://www.depauluk.org/

Numberphile's donation was to a local group which does not have online donation facilities.

However here are some other options...
http://www.wfp.org/
http://www.foodcycle.org.uk/
http://www.napsoc.org/

Numberphile also raises money for cancer research if you'd prefer - donate here: http://www.justgiving.com/numberphile-charity

Special thanks to Pukka Pies (for the pies), Notts Country FC (for hosting us) and the football channel Copa90 (for helping us out) - http://www.youtube.com/user/Copa90football - plus James Hennessy for being second camera!

Website: http://www.numberphile.com/