Messing Up the Fluorescence of Tonic Water - in several ways... 

Thunderf00t used them to get a clear view of liquid nitrogen and I was amazed

Got a box of them for a family member a few years ago. They love them for hot drinks. The glasses ended up being more durable than I expected.

I've owned some for years, and have exclusively used them for cold drinks. I never understood the hot drink only marketing. I'd wager far more cold drinks are consumed overall, and a cold drink that's warmed up is far worse than a hot drink that's cooled down.

@@Sypher474 The physics actually favor the cooler drink. First evaporation over time will tend to cool the liquid to the dew point. In my house right now, this alone will maintain a drink about half way from room temp to freezing and in a drier environment can be closer to refrigeration temps. If colder still is desired, ice contains a massive amount of cooling power, take it down to freezing, and will act as a buffer for the duration of the consumption. A third issue is that the temperature difference between room temp and a cold drink vs a hot drink is greater for the hot drink. The rate of energy exchange is on the order of the fourth power of that delta. As a separate issue is the comfort of holding an uninsulated container. A thin metal cup full of ice and near freezing water doesn't bother most to pick up and take a sip. A fresh hot chi or coffee is another story and is likely to end up with significant discomfort, possible spills, leading to minor burns. All the above and the smartest thing is to just use insulated containers in all situations.

I have a set and I love them for any kind of drink though you are right they keep stuff hot for a very long time

Exactly! After making this video, I appreciate the fluorescence of tonic water even more. It is so lucky that it happens to be a near perfect environment for quinine fluorescence :) Thanks for the early watch.

Thanks, CrazySprite. Well, it is! But it is also surprisingly easy to turn off. Quite a coincidence that tonic water happens to have near perfect conditions for the fluorescence of quinine. More videos to come.

Glad you like it, septicop! Believe it or not, but I learn a lot by making these videos too. Researching deeper into a subject that I usually would. Much more to come!

might burn it

Interesting. I am considering making a video in the future where I test quinine more precisely under different pH-values. Just need to purchase a pH-meter for it to make sense... Thanks for the early watch and suggestion!

That's what he said 😊

yes but not back to its original fluorescent level as the baking soda neutralizing the acid in the original would have created a sodium salt! (Sodium citrate in this case).

@@TheChipmunk2008 without chloride ions, would that even make a difference ?

Thanks! This video turned out better than I thought when standing in a dark room doing relatively long and repetitive experiments... The magic of editing - cutting down to the essence :) Much more to come, JustPyro.

You sure did, GQuack! I have lost count of how many of my videos include clips with quinine x) Probably more to come in the future. It is a chemical that keeps on giving for me. Just wish, I liked the taste of it... More videos to come!

@@brainiac75it's also very useful for my mother, she drinks it to prevent leg cramps

Very, very early indeed DJ Adventure :) Thanks! Greetings back from neighboring Denmark.

I was waiting for him to lower the pH to get some more out of it. Getting less is less fun.

So at 6:27 you are mentioning the exact issue I have with current quenching definition. Quinine can have different forms pH dependent. My problem is that for example HCl and NaCl solutions are totally different, we don't say NaCl is the same molecule as HCl after adding NaOH. For organics same argument goes for acetic acid and sodium acetate. So why should we name a product of quinine reaction with a base, different form of quinine?

And for NaCl, i totally agree. NaCl (in my modified definition) is a proper fluorescence quencher.

at the very least, salt should reduce the fluorescence by simply being an impurity (increased volume of non-fluorescent material in general, diluting the effect). its hard to say for sure beyond that without knowing what mechanism the dyes use to fluoresce. this is complicated by the use of a green highlighter rather than a yellow one! since pretty much every yellow highlighter uses pyranine, and only pyranine as its fluorescence source. im fairly certain green would use a mixture of pyranine and whatever blue fluorescent chemical they use, but i know a lot less about that, blue fluorescent dyes seem really complicated! pyranine changes its fluorescent properties based on pH similarly to quinine, except at a different and wider range of pH values, making it a potential choice for measuring the pH of solutions. when in an aqueous solution along with salts, i think it exhibits some sort of quenching still, but im not a chemist and all the stuff i could find online simply mentioned that salt interferes with the pH readings when in solution with pyranine. from what i read, it always made the pyranine appear MORE acidic than it should, which means it was quenching, since more acidic = less bright with pyranine. but i might be interpreting that wrong, im pretty bad at chemistry. im basing this primarily off of the free portions of this paper: www.sciencedirect.com/science/article/abs/pii/S1010603008001767 which says that the presence of salts in their solutions decreased the apparent pKa of the pyranine. with a lower pKa meaning more acidic, that should mean the pyranine fluoresced less. but later, they say that the presence of salts was making the solution overall appear more basic. the only way ive been able to reconcile these claims in my head is that somewhere in the paper, theyre subtracting the apparent pKa of the pyranine from the solution, and since that pKa reading is more acidic than it should be, the remaining solution is appearing less acidic, or more basic than it should be. which makes sense, when using pyranine to measure the acidity of something, you want to be able to mathematically eliminate the added dye from your solution, since you likely dyed a sample of a larger solution and dont want the pyranine included in your final result. as for the blue dye, thats where my research kind of got stuck. fluorescent blue dye in markers seems to be usually a mixture of non fluorescent dyes and brightening compounds. essentially "stealing" the fluorescence of other compounds and reflecting them into the blue spectrum. i assume that means they'd just add non-flourescent dyes to yellow dyes to make it green, but there is a lot less information on that, at least that i could find easily. blue fluorescent compounds are generally not as affective at converting ultraviolet light in to blue light anyways. since we are taking the high energy state of ultraviolet light, and moving it the least far down into lower energy color in comparison to the other dyes.