# How does a Lava Lamp work? **URL:** \ **Category:** Factual Questions\ **Created:** [July 27, 2002, 7:43pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144 "2002-07-27T19:43:32Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 27, 2002, 7:43pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/1 "2002-07-27T19:43:32Z")
The gravity of the molten wax blobs and the oil/water/whatever surrounding medium it moves through, are close enough that it will cool enought by the time it reaches the top of the lamp away from the heat coil at the bottom, that it will fall back down. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 27, 2002, 7:47pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/2 "2002-07-27T19:47:55Z")
Sorry, that should be “specific gravity” of the molten wax blobs, not “gravity”. ---
**Author:** ![manhattan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manhattan/32/7_2.png) [@manhattan](https://boards.straightdope.com/u/manhattan)\ **Post date:** [July 27, 2002, 8:06pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/3 "2002-07-27T20:06:15Z")
I’m lost. Is this supposed to be an answer to another OP? ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 27, 2002, 8:28pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/4 "2002-07-27T20:28:14Z")
It seems the OP disappeared but the title is self explanatory and astro answered it pretty well. I was going to say about the same thing except I did not know it was wax and I was hoing to say goo. _\__ ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 27, 2002, 10:28pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/5 "2002-07-27T22:28:49Z")
Cecil on [How do lava lamps work?](http://www.straightdope.com/classics/a2_359.html) ---
**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\ **Post date:** [July 27, 2002, 11:09pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/6 "2002-07-27T23:09:50Z")
Heat coil? I thought it was a light bulb. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 27, 2002, 11:42pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/7 "2002-07-27T23:42:14Z")
> [@](#): > > \*Originally posted by postcards \* > \*\*Heat coil? I thought it was a light bulb. \*\* You are correct, the initial heat source is a light bulb. I should have said “radiating coil”. There is a free floating metal coil at the bottom of the glass container that picks up the bulb’s heat and evenly distributes it throughout the wax. You don’t usuallly see the coil because it is sitting inside the pool of wax at the bottom of the container. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [July 27, 2002, 11:43pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/8 "2002-07-27T23:43:46Z")
It is. See Cecil’s column above. And be sure to only use 40 watt bulbs. Higher wattage scorches the wax and turns it into unsightly hard blobs. ---
**Author:** ![manhattan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manhattan/32/7_2.png) [@manhattan](https://boards.straightdope.com/u/manhattan)\ **Post date:** [July 27, 2002, 11:46pm UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/9 "2002-07-27T23:46:30Z")
> [@](#): > > \*Originally posted by sailor \* > \*\*It seems the OP disappeared… \*\* Doh! Space – the final frontier. These are the voyages of the moderator **manhattan**. Should figgered that one out on my own. Carry on. ---
**Author:** ![aha](https://avatars.discourse-cdn.com/v4/letter/a/eada6e/32.png) [@aha](https://boards.straightdope.com/u/aha)\ **Post date:** [July 28, 2002, 12:34am UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/10 "2002-07-28T00:34:54Z")
Yes very strange indeed about my original op. It just disappeared. Anyway I now know much more than I did about lava lamps. Thanks guys! aha ---
**Author:** ![Mudshark](https://avatars.discourse-cdn.com/v4/letter/m/f04885/32.png) [@Mudshark](https://boards.straightdope.com/u/Mudshark)\ **Post date:** [July 28, 2002, 8:26am UTC](https://boards.straightdope.com/t/how-does-a-lava-lamp-work/121144/11 "2002-07-28T08:26:03Z")
I thought the metal was to prevent the glass from cracking due to the heat.