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I was just sitting by a lava lamp when the question hit me.

2007-03-16 15:47:35 · 7 answers · asked by Bj 1 in Science & Mathematics Engineering

7 answers

I agree, they are "cool" (could have used a more appropriate word here!) and very mesmerising.

Wiki has a nice explanation of how they work.

The lamp consists of an illuminating bulb, a glass bottle containing a transparent oil and translucent wax (although other combinations may be used), and a metallic wire coil. The glass bottle sits on top of the bulb, which heats its contents. The metallic wire coil is hidden in the base of the lamp, on which the glass bottle is sitting.

The wax is slightly denser than the oil at room temperature, and slightly less dense than the oil under marginally warmer conditions. This happens because the wax expands more than the oil when heated.

When the lava lamp is turned on, the light bulb heats the bottom of the glass bottle which in turn heats the contents of the glass bottle in this vicinity.

Wax at the bottom heats until it melts, and eventually becomes less dense than the liquid above it. At this time, a portion of the wax rises towards the top of the container. Near the top, away from the heat source, the wax cools, contracts, and as its density increases it begins to fall through the liquid towards the bottom of the container again. This is a macroscopic, visible form of convection heat transfer, although it also occurs on a molecular scale within the liquid itself. The difference in temperature between the top and bottom of the globe is only a few degrees.

One mass of wax may rise as another falls. The metal coil at the bottom helps to overcome the surface tension of the individual wax droplets, causing the descending blobs to coalesce into a single molten wax mass at the bottom of the container. The cycle of rising and falling wax droplets continues so long as the bottom of the container remains warm and the top of the container remains cool. Operating temperatures of lava lamps vary, but are normally around 60 °C (140 °F). If too low or too high a wattage bulb is used in the base, the "lava" ceases to circulate, either remaining quiescent at the bottom (too cold) or all rising to the top (too hot).

2007-03-16 16:00:16 · answer #1 · answered by Anonymous · 1 0

I agree - 4 hours seems excessively long. Mine will start up moving interior an hour, tops. be sure you're making use of the right wattage bulb. Mine takes a 40 watt incandescent equipment bulb. a clean bulb will warmth speedier than a frosted bulb. the encompassing air temperature additionally will have an result, yet i do no longer recommend you keep it in a window, using potential for an develop in stress inflicting it to explode. there is a minimum of one documented case of someone getting killed from the shrapnel of an exploding lava lamp, yet he became making use of the range to warmth it up (Darwin award winner.)

2016-10-18 21:30:30 · answer #2 · answered by ? 4 · 0 0

It's a low melting temperature wax.

Doug

2007-03-16 16:12:34 · answer #3 · answered by doug_donaghue 7 · 0 0

it is a kind of plastic that is special to be heated and melt in water, it also could be wax i am not sure, its one of those.

2007-03-16 15:53:37 · answer #4 · answered by jlk15 3 · 0 0

The technical name for it is: Goop.

In laymans terms its:Goo.

2007-03-16 15:50:18 · answer #5 · answered by Anonymous · 0 1

wax

2007-03-16 15:50:15 · answer #6 · answered by Anonymous · 1 0

Its colored oil or wax I think.

2007-03-16 15:51:12 · answer #7 · answered by Pen 5 · 1 0

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