Thursday, 14 February 2013

A collection of Valentine's Day videos

Some Valentine's Day and romantically-themed videos from across my various channels!

Equals or Zequals

Due to some time constraints, I will be not be able to post a detailed blog about Zequals.

The estimation method is featured in a new book by Rob Eastaway.

Here is the main video on Numberphile:

And here are some extras:

In addition, my resident graph expert Dave Wiley (see previous blog) drew up two graphs to analyse the strength or weaknesses of zequals.

This first one shows what happens when you square a number.

The blue line is the true answer, the red line is a zequal plot.

See a hi-res version of this graph on Flickr.

The second graph is fascinating.

It shows what happens when you multiply two numbers (x and y axis) using the zequals technique.

White areas show where you answer is dead right.

Red areas show where your zequals answer is higher than the true answer... blue areas show where is it is too low!?

Again, a hi-res version is on Flickr.

Tuesday, 12 February 2013

Football statistics at Opta

My latest Numberphile video comes from a visit to Opta in London.

I spent a couple of days learning how the harvest and analyse statistics from football games.

Here's the first video - another is coming soon:

The video is essentially a statistical analysis of Andres Iniesta's winning goal in the 2010 World Cup final. (Spain beat the Netherlands 1-0)

Here's the graphic with all the stats on it:


Sam Green - the stats guru featured in the video - shared a couple of other nuggets with me.

The assisting pass by Cec Fabrgas was his 39th and final touch of the game. It was the 1,045th pass of the game and Spain's 657th.

Iniesta's successful shot was the 34th of the match, and Spain's last.

Thursday, 7 February 2013

A nice email from Warsaw

Emails like this make me much happier than any YouTube viewing statistics...

Dear Brady,

Thank you. I just wanted to say that.

Physics, maths, science... your videos are truly a university for me. I could watch them for hours and I do. 

Even though I don't really remember much after I know I'm learning, and most of all, I know I'm having fun. Though I'm a fan, I watched numerous of your vidoes on many channels, you still surprise me. 

Just today I was like: Words! He has a whole channel on words! These are, like, my second favorite thing on the world! 

And that's another thing. You provide videos on so many topics it's mindboggling. I would never thought that, when I was watching my first numberphile video (my fav channel to this day, on youtube, ever), that I will learn from you not only about numbers, but on words! biographies! 

I mean, once again, You are truly a university for me. 

Thank you, thank you, thank you. 

Dziękuje i wszystkiego najlepszego w życiu, jesteś wspaniałym człowiekiem, 

Leszek, Warsaw 

(shared with permission)

Friday, 1 February 2013

Popular Numbers

What is the most common "favourite number"?

This is something I recently stumbled upon in the course of making some Numberphile videos.

It all started in San Francisco at a YouTube EDU summit, where I met a bunch of clever YouTubers.

I took advantage of the situation and asked many of them: "What's your favourite number"?

Here's the resulting video:

I then invited the viewers to submit their favourite numbers, preferably with an explanation.

Thousands of people responded (and continue to do so!)

So with all this data, it seemed obvious some analysis should be done.

Unfortunately I lacked the time and skill for such an endeavour.

But fortunately a software writer named Dave Wiley (right), from Colorado, came to the rescue.

We had to draw a line in the sand (or we'd never have started) so selected the first 6,041 comments.

From these, Dave used a combination of programming and human checking to glean a list of 5,286 number choices.

Here's one observation Dave made about reading everyone's explanations: "It's people sharing a bit of themselves. I love these little glimpses into the way other people think."

How true.

So what were the results?

Well, the most commonly selected number was seven (238 votes).

Very close behind was three (225 votes).

Here are the numbers which achieved 100 votes:
  1. Seven (238 votes)
  2. Three (225)
  3. Forty-Two (204)
  4. Eight (202)
  5. Thirteen (200)
  6. Two (175)
  7. Four (174)
  8. Pi (152)
  9. Seventeen (130)
  10. Twelve (127)
  11. Nine (126)
  12. Five (123)
  13. Sixty-Nine (118)
  14. Twenty-Seven (113)
  15. Twenty-One (111)
  16. Eleven (105)
  17. Golden Ratio (100)
Notable numbers with fewer votes included Zero (98 votes), One (73 votes) and 666 (18 votes).

It was also interesting to note that odds slightly outperformed even numbers.

A normal arithmetic average is quite pointless (because some people chose HUGE numbers like Googolplex and the unimaginable Graham's Number).

But the median can be found quite easily and it lies at 16 (sixteen itself recorded 53 votes, by the way!).

And here are a couple more graphs (or here for higher quality):

  • Two people chose 40 and two people chose -40
  • Dave used a C++ program to extract numbers from the YouTube page, followed by manual checks
  • Many numbers were chosen because they represented people's birthdays
  • Two and powers of 2 were popular with computer scientists
  • Popular culture showed up often, such as Douglas Adams's famed 42 and the online slang 1337 (leet)
  • 18 negative numbers were chosen - the lowest was -47
Dave also wanted everyone to know he his best to "properly record every vote whether it was expressed in English, as a number, as a formula or as a programming constant".

Finally, here are a selection of the many fascinating contributions people made (click here for the full comments section and read ALL of them):

"I have synesthesia, and this question is very tough for me. I used to like 3, 6, and 7. But now I feel closer to 8 and 11. 11 is so pure and pleasant, and 8 is like a gentle gay uncle."

"267. I'm a synesthete and I just like the colour combination of those numbers ^_^"

"Ok 03, no it CAN NOT be just 3. I don't know why it just can't."

"88 because it is symmetrical. You can draw a vertical or horizontal line through it and it's the same. It just always seemed very round and finalized to me. (:"