This mechanism shrinks when pulled

How an unlikely physics paradox controls these counterintuitive structures. Use code veritasium at https://incogni.com/veritasium to get an exclusive 60% off.

If you’re looking for a molecular modeling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV

▀▀▀

A huge thank you to Paul Ducarme and Bas Overvelde at AMOLF for showing us around.

Check out their research on counter-snapping structures here - https://ve42.co/CounterSnapping

For more on Braess’s Paradox, check out these great videos by Up and Atom (https://youtu.be/cALezV_Fwi0) and Steve Mould (https://www.youtube.com/watch?v=Cg73j3QYRJc)

▀▀▀

0:00 What happens if you cut this rope?

1:41 The Spring Paradox

4:59 New York’s Perplexing Discovery

6:29 Road Networks and Traffic Flow

8:40 Braess’s Paradox

14:29 Snapping

17:16 This object shrinks when you stretch it

▀▀▀

References:

Ducarme, P., Weber, B., Hecke, M. van, & Johannes. (2025). Exotic mechanical properties enabled by countersnapping instabilities. Proceedings of the National Academy of Sciences - https://ve42.co/CounterSnapping

Braess's Paradox via Wikipedia - https://ve42.co/BraessWiki

Braess, D., Nagurney, A., & Wakolbinger, T. (2005). On a Paradox of Traffic Planning. Transportation Science - https://ve42.co/Braess2005

Schäfer, B., Pesch, T., Manik, D., Gollenstede, J., Lin, G., Beck, H.-P., … Timme, M. (2022). Understanding Braess’ Paradox in power grids. Nature Communications - https://ve42.co/Schafer2022

Kolata, G. (1990). What if They Closed 42d Street and Nobody Noticed? New York Times - https://ve42.co/Kolata1990

Youn, H., Gastner, M. T., & Jeong, H. (2008). Price of Anarchy in Transportation Networks: Efficiency and Optimality Control. Physical Review Letters - https://ve42.co/Youn2008

Nicolaou, Z. G., & Motter, A. E. (2012). Mechanical metamaterials with negative compressibility transitions. Nature Materials - https://ve42.co/Nicolaou2012

Counter-Snapping replication package - https://ve42.co/CSPackage

Images & Video:

Earth Day Festivities via VHS Music Rarities - https://www.youtube.com/watch?v=0awPgHjn2nY

Earth Day Speeches - https://www.youtube.com/watch?v=RMDI3kXpeQ8

1990s New York via NYC Nostalgia - https://www.youtube.com/watch?v=0YaFxTw0VqM

42nd Street Closure via Trainluvr - https://www.youtube.com/watch?v=gELde63Fzio

42nd Street Traffic Operator - https://ve42.co/NYCTraffic

Dietrich Braess via opc.mfo.de - https://ve42.co/BraessOPC

Dietrich Braess via Wikipedia - https://ve42.co/BraessWikiPic

Belt Buckle via Mingda Hardware - https://ve42.co/BeltBuckle

▀▀▀

Special thanks to our Patreon supporters:

Adam Foreman, Albert Wenger, Alex Porter, Alexander Tamas, Anton Ragin, armedtoe, Balkrishna Heroor, Bertrand Serlet, Blake Byers, Bruce, Charles Ian Norman Venn, Dave Kircher, David Johnston, David Tseng, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, Jeromy Johnson, Jon Jamison, JT, Juan Benet, Keith England, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Robert Oliveira, Sam Lutfi, Tj Steyn, TTST, Ubiquity Ventures, and wolfee

▀▀▀

Writers: Gregor Čavlović & Derek Muller

Producer & Director: Gregor Čavlović

Editors: James Stuart & Trenton Oliver

Camera Operators: Sander Mook, Dylan Meanwell, Fabio Albertelli, Casper Mebius & Gregor Čavlović

Animator: Fabio Albertelli

Illustrator: Jakub Misiek

Additional Editor: Peter Nelson & James Horsley

Researchers: Darius Garewal & Gabe Strong

Thumbnail Designers: Ren Hurley & Ben Powell

Production Team: Rob Beasley Spence, Tori Brittain & Matthew Cavanagh

Executive Producers: Derek Muller & Casper Mebius

Additional video/photos supplied by Getty Images, Pond5.

Music from Epidemic Sound