During the first five episodes of this series we've discussed explosions of all sizes, where the energy output is successively matched by the ejected mass, the density of the swept-up ambient medium, and finally by the characteristic pressure or stress of this medium, which can be a gas like air, a liquid like water, a solid like soil, or even the near vacuum of interstellar space. The dynamics of explosions are governed by this set of four mechanical parameters: energy, mass, density and stress. We call this set the "explosion domain". In this sixth episode on the physics of explosions we see how the possible pairs of mechanical parameters of the domain lead to six regimes outlining the possible trajectories of explosions in space and time. We see how the four possible trios define systems of objective units, which are much better suited to the description of explosions than the meter and second. Finally, we show that the combination of the four parameters of the domain lead to a dimensionless quantity indexing each explosion and delimiting two qualitatively different categories of explosions: the supersonic detonations and the subsonic deflagrations.

*Video Content*

On this page, you will find the pdf slides used in the making of the video, together with some films, gifs, images and plots used in the video. Feel free to use this content in any way you see fit.

A link to the datasets we used is available at the end of this page, together with the references associated with this video.

Slides

A6_SLIDES_compressed.pdf

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Films

GIFs

Images

Plots

References

New:
Tang (1999)
Slow Mo Guys

And from previous episodes:
Mack (1946)
Mack (1947)
Bainbridge (1976)
Taylor (1950a)
Taylor (1950b)
O'Connell (1957)
Schmitt (2016)
Nguyen (2017)
Porzel (1957)
Kingerey (1962)
Aouad (2021)
Hargather (2007)
Kleine (2010)
Porneala (2006)
Campanella (2019)
Grun (1991)
Xiang (2017)
Trinity and Beyond
Greg Spriggs and the curation of nuclear atmospheric tests:
https://str.llnl.gov/october-2017/spriggs
https://www.youtube.com/watch?v=pWpqGKUG5yY&ab_channel=LawrenceLivermoreNationalLaboratory
LLNL Nuclear Test Films Browser:
http://blog.nuclearsecrecy.com/misc/llnlfilms/

More on Trinity:
Source of the Trinity footage and pictures: Los Alamos National Laboratory https://www.lanl.gov/ https://www.atomicheritage.org/history/trinity-test-1945 https://www.atomicheritage.org/profile/julian-e-mack https://www.atomicheritage.org/history/high-speed-photography
More nuclear tests:
https://www.atomcentral.com/ https://www.sonicbomb.com/ https://www.youtube.com/channel/UCFbzthhT2eRcBpEPc5FPGtQ

Authors:
Marc-Antoine Fardin (Institut Jacques Monod, CNRS, Université Paris Cité)
Mathieu Hautefeuille (Institut de Biologie Paris-Seine, Sorbonne Université)
Vivek Sharma (Department of Chemical Engineering, University of Illinois at Chicago)

Acknowledgements:
Anna Part (Atomic Heritage Foundation, National Museum of Nuclear Science & History)
Greg Spriggs (Lawrence Livermore National Laboratory)