Bubble rafts

A selection of experiments with bubble rafts modelling the behaviour of close-packed crystal structures, a technique pioneered by William Lawrence Bragg and JF Nye.

Bubble raft model

A short film demonstrating the creation of a bubble raft and highlighting that on manipulation, dislocations in the structure can be formed and repaired, similar to the close-packing seen in crystal structures.

Combinations of dislocations

The film shows a bubble raft model up close, highlighting areas of dislocations and gaps in the structure. It demonstrates that as a bubble raft is compressed, these areas of dislocation move in order to repair the overall structure of the model. It goes on to demonstrate crystal boundaries and recrystallization of the bubble raft model.

This film is likely to be an exert from a longer film on bubble rafts, possibly made in the 1940s -1950s by Lawrence Bragg.

Construction of a bubble raft

Possibly the first bubble raft film ever created, this demonstrates the structure and mechanical properties of a metal. It demonstrates the construction of a bubble raft, the geometry of a dislocation within a bubble raft and the compression of a single ‘crystal’ between parallel plates. It highlights each of the stages with the use of a photograph of a bubble raft which can be turned to various angles in order for the viewer to see any dislocations, ‘slip planes’ and formations of defects such as holes in the structure. It goes on to describe the result of covering a surface of a liquid with bubbles is to form a ‘polycrystalline’ raft composed of areas with different orientations and the development of ‘grain boundaries’. The film ends by describing and demonstrating 3-dimensional crystals and that with more than one layer of bubbles, different arrangements of close packing can be observed.

This film was made by the Kodak Research Laboratory in Middlesex.

For this film, and several others in our collection, we have tried to contact any known copyright holders and believe it to be an orphan work. If you are the rights holder, would like it to be taken down, or have any more information, please get in touch at richannel@ri.ac.uk.

Bubble model of a metal

The concept of bubble raft modelling was first presented by Lawrence Bragg and John Nye of the Cavendish Laboratory. Legend claims that Bragg conceived of bubble raft models while pouring oil into his lawnmower. He noticed that bubbles on the surface of the oil assembled into rafts resembling the plane of close-packed crystals.

This film was made by the Kodak Research Laboratory in Middlesex. It demonstrates the construction of a bubble raft, the geometry of a dislocation within a bubble raft and the compression of a single ‘crystal’ between parallel plates. It highlights each of the stages with the use of a photograph of a bubble raft which can be turned to various angles in order for the viewer to see any dislocations, ‘slip planes’ and formations of defects such as holes in the structure. 

For this film, and several others in our collection, we have tried to contact any known copyright holders and believe it to be an orphan work. If you are the rights holder, would like it to be taken down, or have any more information, please get in touch at richannel@ri.ac.uk.

Bubble model

This film shows bubbles being created via a constant stream of air being added just below a surface of a liquid. It then shows the larger bubble raft model under closer light, highlighting the creation of dislocations and fractures within the model structure.

This film is likely to be an excerpt from a longer film on bubble rafts, possibly made in the 1940s -1950s by Lawrence Bragg.

For this film, and several others in our collection, we have tried to contact any known copyright holders and believe it to be an orphan work. If you are the rights holder, would like it to be taken down, or have any more information, please get in touch at richannel@ri.ac.uk.

Experiments with the bubble model of metal structure

Lawrence Bragg begins the film by describing the close packing structure of metals. A demonstration goes on to show how bubbles on the surface of the liquid can show the same structure as metals; this is a bubble raft experiment.

The rest of the film, narrated by Bragg, uses bubbles to demonstrate the idea of dislocations in the structure of metals and how these occur at the points of greatest stress. The bubbles help to show how dislocations occur through rapid crystallisation and collapse through a structure to create a hole. The bubble raft is further used to demonstrate how dislocations can correct themselves by pairing up or leaving a vacancy in a row within a structure.

Crystal boundaries are further described and demonstrated through the use of a bubble raft, showing how they might exist where two extremes meet. This can be where angles are or where disordered deformations occur.

Excerpts from 'Metal structures'

A silent film excerpt from ‘Metal structures’, showing the demonstration of the close packing of atoms within structures through the filling up of a 3-dimensional pyramid shape with ball-bearings, which form a dense arrangement of congruent spheres in regular arrangement (or lattice-shaped).

Movement of a magnetic fluid and other film trims

A series of film trims showing the movement of a magnetic fluid beneath a glass plate, filmed under a microscope. Contained within the film there is also a computer model of a protein, produced by Michael LevittChristian Sander and Peter S. Stern at the Weizmann Institute of Science Israel.

Movement of a magnetic fluid and other film trims

A series of film trims showing the movement of a magnetic fluid beneath a glass plate, filmed under a microscope. Contained within the film there is also a computer model of a protein, produced by Michael LevittChristian Sander and Peter S. Stern at the Weizmann Institute of Science Israel.

The bubble model of a crystal at high temperatures

The film shows the apparatus used to form and film the bubble raft model on the surface of a soap solution. A perfect crystal lattice, a stationary dislocation and running dislocations are shown. An impurity atom, a bubble of different size from that of the bubbles in the mother lattice is also introduced and a dislocation is formed. The model is then set under vibration to simulate the heat motion in a real crystal.

The apparatus is reset to form a grain boundary separating two lattice grains of specified angle of misorientation within the model. The film goes on to show and describe the misorientation angles, boundary shifts and grain slides that occur due to temperature changes.

This film was photographed by Tomonori Zempo. It was supported financially by the Scientific Research Fund granted by the Ministry of Education, and technically by Prof. Yoshio Suge. It was directed by Einosuke Fukushima, Akiya Ookawa and produced by Einosuke Fukushima, Tokyo Metropolitan University Tokyo, 1958. 

For this film, and several others in our collection, we have tried to contact any known copyright holders and believe it to be an orphan work. If you are the rights holder, would like it to be taken down, or have any more information, please get in touch at richannel@ri.ac.uk.

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