In another question I asked if the Saltwater float present in a specific youtube video was capable of determining any differences in mass between the faces of a die in determining the balance of a group of dice, and was met with very good results and a positive affirmation that yes, it was very possible to do so.

Which led me to believe that there was a possibility that denser liquids might have the possibility of testing the balance of the dice even better, with much less mess. This led me to go through and search the densities of many liquids to determine which would be best for the job.

  • Water came in at ~1g/mL at room temperature, which was the medium for the test initially.
  • Saltwater was at about ~1.028g/mL. Dice were able to float in this.
  • Galium has a density of ~6.028g/mL. I assume based on the huge difference in density that dice would float extraordinarily well on Liquid galium, and since it's a liquid metal at slightly above room temperature, it would be great to run the test on.

So the question is this:

Would running the same test using Liquid Galium instead of Saltwater allow one to determine the balance of a die easier than running the test with Saltwater?

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    \$\begingroup\$ I'm closing this question as off-topic because it is no longer about RPG expertise, but is rather about physics and engineering. \$\endgroup\$ Jan 24, 2018 at 1:42
  • \$\begingroup\$ What if a DM suspects a player of using loaded dice? Isn't it of interest to detect and do something about cheating? \$\endgroup\$ Jan 24, 2018 at 2:37
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    \$\begingroup\$ If a dm suspects cheating ask how to deal with suspected cheating. \$\endgroup\$ Jan 24, 2018 at 2:57
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    \$\begingroup\$ Related meta (note that at time of writing the consensus is leaning towards this being on topic, contrary to the closure. This may change as the debate evolves, however) \$\endgroup\$ Jan 24, 2018 at 3:23
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    \$\begingroup\$ Regarding the rollback: Changing a question in response to an answer, in a way that springboards off the answer to ask a different question & simultaneously invalidating the answer one is springboarding off of, isn't what editing is for. That's a new question, not an edit. \$\endgroup\$ Jan 25, 2018 at 5:50

1 Answer 1



First of all, gallium is a lot more expensive than salt water. It's also solid at room temperature, so you'd need to wait until a hot day and make sure the liquid metal was entirely molten and not lumpy or otherwise semisolid. Then, you'd want to partially submerge your dice in the gallium so that they are floating with the substance both above and below them for best results, which has two huge problems. First, you can't easily adjust the density of Gallium. Second, you can't see a die submerged in gallium because gallium is not transparent. Neither of these problems is easily resolved.

This means we will, of necessity, be forced to use the less accurate version of the salt-water test, with the dice floating at the top of the liquid rather than in full suspension. Since the differences in density between the atmosphere and gallium are even bigger than between air and sea water, and because gallium at near-room-temperatures flows like molasses, this is basically just not going to work. It's theoretically possible to use it, but the process would need to take hours for the die to settle, and you'd need to use the chi-squared test or something to differentiate between sides, since a simple poke is unlikely to result in the die flipping properly even with significant weighting.

It would be practically impossible to use gallium for this test at all, and even though you (with training and equipment and some modifications to experimental methodology) could, it would be patently false to claim that doing so is easier than using salt water.

Basically, your premise is wrong. It is hard to do the saltwater test, but that has nothing to do with water being too not-dense. It has to do with it being difficult to get the density exactly right for your dice. If you have really dense dice, gallium would be a better choice than salt water, but only because the dice would not float in salt water at all. Really, what you'd want to use is another variably dense solution, probably a different kind of salt. Lye could work well and is cheap, but has obvious safety issues, and still won't float steel or tin or copper dice. Looking through some material lists, liquid iodine seems to be the only sorta-kinda-see-through liquid that's commonly available and dense enough to float a heavy die. It still won't float a solid metal die, though, and it it's only liquid around 20 degrees hotter than the boiling point of water, so there's safety risks involved here, too, plus iodine gas is mildly dangerous (i.e. burns mucus membranes on exposure).

Ultimately, if your dice don't float in salt water, just use math. The chi-squared test is easy and reliable and it'll take two hours tops for extremely high reliability for a whole set.

  • \$\begingroup\$ With a melting point of 85 F it would not be overly hard to fully melt gallium. I've done it many times just so my kids and their friends can see a liquid metal safely. I agree with everything else. \$\endgroup\$ Jan 24, 2018 at 2:16
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    \$\begingroup\$ @TimothyAWiseman Sure! I'm don't mean to be arguing that it's hard, just that it's harder than putting table salt in a cup of water. You can melt gallium in your hands, but you need to put it in a vessel to float the dice in and keep it liquid, so that's probably going to need a laptop battery or a really hot day or something (?anything?). I guess if you live somewhere it's regularly over 85 then that part wouldn't be a problem. Just... water+salt. It's hard to get easier than that. \$\endgroup\$ Jan 24, 2018 at 2:32
  • \$\begingroup\$ I live in Las Vegas, melting gallium is very easy in the summer. Anyway, I fully agree with your general answer. \$\endgroup\$ Jan 24, 2018 at 6:07
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    \$\begingroup\$ When writing "20 degrees", could you specify the kinds of degrees? I know that pretty much every country in the world uses the SI system, but maybe you are part of the minority. \$\endgroup\$
    – Tommi
    Jan 24, 2018 at 6:49
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    \$\begingroup\$ @Sandwich I recommend you ask that question, then (this one is currently about gallium/density specifically. You could edit it, but it'd be a completely different question at that point, so that'd be a little bit annoying, plus this question is useful, because I suspect "use something denser!" might be a common reaction to reading the other piece). You may want to wait until meta consensus is reached, though. Actually, I see that SSD rejected an edit in that direction. You should ask another question, then. \$\endgroup\$ Jan 25, 2018 at 6:33

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