Anyone tried running colossus on 175W metal halide lamp?

[Percolation]

The lava is driven by heat and since the lamp is trapped inside the base, the heat produced should equal to the wattage of lamp.

Metal halide lamps are much more efficient, so a 175W lamp would produce heat almost comparable to a 200W lamp, but much more light output making the lamp much brighter. 

I don't see why it wouldn't work.  Anyone tried it? 

[Percolation]

Given 200W 120v lamp, using the v^1.6 formula, used by lighting engineers, the lamp is 184W @ 114v and 216W @126v
So, the lamp can vary in output as much as 17% within the +/- 5% tolerance allowed by utility. This doesn't prevent the lava from working does it?

Now, assume 175W MH is burning 175W. It will get the same amount of heat to the globe, except the unabsorbed energy radiating out as visible light.

Remember that even with incandescent light, some of its power is actually escaping as near IR and IR light.

[MagicLamp]

Still, the incandescent will output more heat than the MH even at the low end of the utility voltage, and what's more, most of it will be absorbed by the globe rather than shine through it.

This also raises other questions such as how efficient the MH is at radiating heat away from itself (e.g. LEDs are notoriously bad at radiating heat, and this results in them internally overheating rather than heating their surroundings).

The bottom line once again is that there is no advantage in using MHs or other "efficient" forms of lighting with lava lamps: lava lamps are one of the few(?) applications where you actually WANT the heat along with the light, and the good old incandescent offers both in a convenient and resilient package.

Furthermore, most other kinds of lamps would just die prematurely if forced to operate in a closed fixture with their surrounding ambient temp getting over 50 C, while an incandescent just shrugs it off, as it has practically zero airflow requirements and can work even inside an oven.

[Percolation]

LEDs are notorious at expelling heat as a radiant energy. The heat generated is spread out to a heat sink that is naturally or fan cooled depending on power. Just like computer processors, they can not handle high temperature.

MH and incandescent lamps are both good at sending out heat as radiant energy. Filament is yellow to bright yellow hot.
HID quartz glass capsule gives off visible light, in addition to a large amount of radiant heat from bright-orange glowing hot quarts glass.

Anything will radiate heat fine as long as they get hot enough.

[MagicLamp]

Yeah, not all light sources can get hot enough without destroying themselves first, though ;-)

I don't care if LEDs also radiate heat well at 200, 500 or 2500 C, if the plastic will have molten long before that, and the junction will be FUBAR even before ;-)