Help, our train home is making 9 quintillion stops.

2019-11-29

[public] 669K views, 33.8K likes, 401 dislikes audio only

Stand-up Maths

Thanks as always to Jane Street! Here is that blog post about 63-bit numbers.

https://blog.janestreet.com/what-is-gained-and-lost-with-63-bit-integers/

My book is out in North America on the 21 January 2020. Pre-order now!

http://bit.ly/humblepi

Here are the numbers:

9,223,372,036,854,775,798 stops

2^63 = 9,223,372,036,854,775,808

7FFFFFFFFFFFFFF6

111111111111111111111111111111111111111111111111111111111110110

Here are the tweets:

Neil Codling @neilcodling

👀 Help, our train home is making 9 quintillion stops.

EIZrPtbW4AA3UL2.jpeg

https://twitter.com/neilcodling/status/1190757074164170758

Daniel @drawRect

Replying to @neilcodling

Thanks for the tweet. What version of the app are you using? I thought we fixed this bug AGES ago.

https://twitter.com/drawRect/status/1191033767760158720

Lia Buddle @LiaBuddle

Replying to @neilcodling

Had the same thing in 2017...

EIc4CNJXsAATexO.jpeg

https://twitter.com/LiaBuddle/status/1190982241914101760

Matt Parker @standupmaths

Thanks everyone who sent me this amazing tweet! So, as always it’s probably a binary overflow problem and sure enough 2^63 = 9,223,372,036,854,775,808 which is close!

https://twitter.com/standupmaths/status/1190940255974760448

We have a free Think Maths magic trick activity that teachers can use to introduce their students to binary.

http://think-maths.co.uk/standupmaths-videos?yt-trains#train-stops

CORRECTIONS

- None yet, let me know if you spot any mistakes!

Thanks again, as always, for Jane Street being my principal sponsor.

https://www.janestreet.com/

Thanks to my Patreon supporters who help make these videos possible. Here is a random subset:

Icaro Fonseca

Timothy Lombard

Andy B

Nokui

Peter

Tracy Parry

Brandon

Lindsay Miller

Support my channel and I can make more maths videos:

https://www.patreon.com/standupmaths

Filming and editing by Alex Genn-Bash

Music by Howard Carter

Design by Simon Wright

MATT PARKER: Stand-up Mathematician

Website: http://standupmaths.com/

Maths book: http://wwwh.umble-pi.com

Nerdy maths toys: http://mathsgear.co.uk/