Lava lamp

The lava lamp has captivated viewers for over fifty years. Shortly after discovering the lava lamp s prototype — a contraption made out of a cocktail shaker, old tins, and things — in a Hampshire, England pub after World War II, Edward Craven Walker founded the Crestworth Company in Dorset, England to develop the device. Over a 15-year period he perfected the lava lamp and mass marketed... 

Question 3.3 What Makes a Lava Lamp Work ... 

R. Hubscher, How to Make a Lava Lamp. Popular Electronics (March 1991), 31 also in Popular Electronics, 1992 Electronics Hobbyist s Handbook. 

Immiscible combinations are all around us. Oil and water is an immiscible combination as is the lava in the so-called lava lamps and chicken broth in chicken soup. Immiscible blends are actually a misnaming at the molecular level since they are not truly mixed together. But at the macrolevel they appear mixed, so the name immiscible blends. 

A system is a set of components that are being studied. Within a system, a phase is a region that has the same composition and properties throughout. The lava lamp in Figure 19 is a system that has two phases, each of which is liquid. The two phases in a lava lamp are different from each other because their chemical compositions are different. A glass of water and ice cubes is also a system that has two phases. This system has a solid phase and a liquid phase. However, the two phases have the same chemical composition. What makes the two phases in ice water different from each other is that they are different states of the same substance, water. 

The lava lamp is a system that has two liquid phases, and the ice water is a system that has a solid phase and a liquid phase. 

The lava-lamp model for the Earth s mantle (Albarede 8k van der Hilst, 1999 Kellogg et al., 1999) takes its name from that household curiosity of the 1960s based upon the fluid-dynamic properties of liquids with near identical densities. The model is based upon seismic observations of an irregular, deep boundary layer in the mantle at 1,600-2,000 km depth. 

FIGURE 3.34 The lava-lamp model for the Earth s mantle (after Kellogg et al.( 1999). 

Note OK, so we ll disclose up front that this experiment won t actually make a lamp. It will make a device with bubbles that rise and fall just like a lava lamp, but you ll need a flashlight or other light source if you want it to be illuminated. 

You should see colored bubbles move throughout the bottle, similar to a lava lamp. You can also add another Alka-Seltzer after the reaction has finished. 

Experiment 1.2 Lava lamp. When the lamp is turned on, blobs of heated wax ascend slowly from the bottom to the top where they cool and then descend to the bottom again, causing a constant movement of both phases. 

The fluid dynamics of all these operations is controlled by the buoyancy term Apg. If either p or g is zero, the system is controlled by surface forces. Under these conditions counter-current flow of the phases cannot occur, coalescence is suppressed and the droplet or bubble size becomes very large. In the absence of interfacial shear, heat and mass transfer coefficients are severely reduced. A good demonstration of this state of affairs is given by the Astro lamp (or Lava lamp), shown in Figure 3.1. 

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