Drop acid and see rainbows

[@AceNallawar]

thanks to NumberPhile, who got me to ComputerPhile, who got me to Tom Scott, who got me to Steve Mould ( who got me to mould effect )

[@SteveMould]

+Ace Nallawar yay! Love those channels.

[@oberdiah9064]

That's exactly the same thing I did :D

[@AceNallawar]

Steve Mould And I love your channel, it's amazing.

[@AceNallawar]

Oberdiah It's a chain of awesomeness

[@gamehelp16]

Let me bring you to standupmaths then :)

[@thecheapskate6187]

This is the best clickbait I've seen

[@SteveMould]

+The Cheapskate I wasn't sure if i could get away with it!

[@Kram1032]

literally what it says on the tin

[@OhSoUnicornly]

Think you saved it by talking about serious climate change at the end. No one can fault you when you're talking about saving the earth in the same video as dropping acid. ;)

[@ShurikB93]

Click bait done right!

[@_yuri]

OhSoUnicornly what's the difference

[@geooceanology9604]

If you have not got universal indicator you could try this with diluted red cabbage juice. And if you also don't have dry ice lying around the house you could just blow bubbles through a straw and the CO2 in your breath will acidify the water.

[@SteveMould]

+GeoScienceEd nice!

[@xja85mac]

There isn't much CO2 in your breath to acidify water quickly: you'll end up hyperventilating. Try yeast+sugar+warm water to produce CO2 instead

[@geooceanology9604]

you would be surprised how quickly the colour change will happen. Although if you dilute the cabbage juice with tap water from a hard water area or that has been softened with sodium carbonate then the higher alkalinity of the water buffers the pH change

[@lightdark00]

GeoScienceEd for a slow color change ferment some honey or sugar and let the gas exhaust to a tube like shown.

[@amneenja5720]

GeoScienceEd are you saying that my breath stinks

[@marlintheodorehippo2914]

Your videos are genuinely making me get back into my science GCSE, I was failing due to learning issues (I require a lot of personal attention during class) but you've managed to cause me to seek my own way of learning the stuff I need to pass. Can't thank you enough!

[@SteveMould]

+Marlin Theodore Hippo that's brilliant! I'm so glad.

[@nathanielb2814]

+Steve Mould loved your show at the NEC!

[@SteveMould]

+Nat Torpedia thank you!

[@elon6131]

"slowly turning my hand into soap" yeah that seems fun

[@kutsen39]

He definitely dropped acid

[@anujmchitale]

The pun on the video title is legendary.

[@KoenigKillHD]

came for the lsd stayed for the ocean acidification

[@kay486]

Shouldn't you drop the bass before dropping the acid?

[@Edgewalker001]

My old chemistry teacher explained it pretty simply as: Acids - Proton givers. Bases - Proton takers. It's a nice rule of thumb to remember, especially when more advanced stuff comes along, like isoelectric focusing.

[@TheBeaverCo]

Saw you give a talk at a maths conference a few months ago, got me into science videos. thank you so much

[@SteveMould]

+ABeaver Co great!

[@andreasvalen8802]

Thanks for uploading a new video Steve! Really really really liked the one about gravitational waves!

[@SteveMould]

+Andreas Valen thank you!

[@commander-fox-q7573]

The worst part is that I have to explain everything you are doing, to my four year old sister, in terms she will understand 😂.

[@Satchboy71]

That was trippy! Steve is my science pusher!

[@richardaversa7128]

Hofmann would be proud

[@chrisakaschulbus4903]

two years and only two likes... underrated coment, i give a thumbs up :D

[@fasefeso9432]

You should have pour that from a beaker in the end to see what happens.

[@RedHotBagel]

But the main question remains: Why does the rising CO2 form the rainbow?!? And why does it form this way around? Shouldn't there be more CO2 at the bottom of the tube near the dry ice? I guess it is because the surface area of the bubbles grows, the further up and the finer they get - but I could be wrong. Any suggestions Steve?

[@xpndblhero5170]

1:51 - Never knew dropping acid would sound so much like a bong rip..... 😏

[@Commandelicious]

I think the first 30 seconds are the best that has happened to me this month so far.

[@imveryangryitsnotbutter]

Instructions unclear; I am now a glass of orange juice.

[@aniruddhdeshpande7319]

I'm Very Angry It's Not Butter!! Thank you for not saying: got dick stuck in beaker

[@imveryangryitsnotbutter]

And thank you for saying it for me. ;)

[@SteveMould]

+I'm Very Angry It's Not Butter!! I appreciate your username.

[@NearbyTowels]

I feel you might appreciate this as well, then. I certainly do. www.funbull.com/funny-pictures/Funny-Pictures/Faith,-Reason,-Hope-1550.jpg

[@Duncan_Idaho_Potato]

These existential margarine names could seriously get out of hand: -"Whither Butter?" -"You will not be punished for your butter, you will be punished by your butter" -"He who fights with butter might take care lest he thereby become butter. And if you gaze for long into a tub, the tub gazes also into you" God, I don't even want toast anymore.

[@deano43]

I’m pretty severely colourblind, but I’m sure it was amazing 😂

[@Christo012345]

Steve, thanks for the heads-up! But this must be the saddest video you've ever made :-(

[@madkirk7431]

And if you smoke it, you can hear rainbows!

[@DenisRyan]

"Fun fact"?!? No! Bad Steve! Don't turn your hand to soap! That's very naughty.

[@kaki00105]

this video went from dropping acid and seeing rainbows to a psa faster then... well an acid psa

[@Hellefleur]

I'm not an idiot Rick, I'm not gonna dro- *smash*

[@xja85mac]

It's been demonstrated that carbonic acid doesn't exist as a molecular entity. It can be represented as H2O•CO2 and it immediately loses one proton or both to give hydrogen carbonate and carbonate respectively.

[@shinrakishitani1079]

Clickbait that both parties benefit from, well done

[@millesmedegaard]

The best title I've seen in a long time

[@Graeme_Lastname]

It's a shame the only people in a position to do anything about it refuse to do so.

[@magicandmagik]

Why dont you.. DROP THE BASE?

[@joehindley6185]

"I couldn't find a bung" 10 seconds later a test tube with a bung appears

[@austinbryan6759]

He meant for the top portion which still has no bung

[@Kassidar]

So, to see a rainbow, you needed to go through dry -eyes- ice

[@icanfast]

This video with a giant beaker has all the suspense in the world. Yed nothing was poured out of it, what a bummer.

[@EmperorZelos]

Steve, you are slightly wrong, the proton does not exist on it's own, it joins with water forming H3O+

[@SteveMould]

+EmperorZelos good point, thank you.

[@EmperorZelos]

Welcome, entertaining video. Keep up the good work!

[@KarlFFF]

Even the H3O+ ion is a simplification and doesn't exist on its own. As recently as 2010 it has been suggested (based on infrared spectroscopy) that the proton is dissolved as H13O6+. If you wanna know more you could look up solvation of hydronium. However, personally I find it somewhat misguided to try to attribute a single ion to acidity. It's convinient for calculations, but it will never reflect the chemistry. Water is such a dynamic system with its autoprotolysis so it is constantly changing, which is why I find a single ion label to be misguided. It is however interesting to consider how big an ion that can be attributed to the dissolved proton as it tells something about how far out the dissolved proton is communicated.

[@EmperorZelos]

oh interesting, got a source?

[@SteveMould]

+Karl Frederik Færch Fischer so interesting!

[@nimmen]

This is the exact same way you can diagnose a head gasket leak in a car. I always wondered what kind of solution those test fluids were. You fill the tester with this blue fluid, press it on the coolant fill neck and suck air through it. A change in colour would indicate exhaust gas (CO2) escaping from the combustion chamber into the cooling system.

[@lsd25records]

Drop acid and see rainbows...ok did that ..now what do I do ??

[@domcarter2327]

Was gonna stop binging your channel for the night but that video title made me laugh out loud

[@whatthefunction9140]

Next time ask your mate to find your bung. Its probably behind you.

[@joeKisonue]

Luckily we are diluting the ocean water with fresh

[@benonp3622]

i like this channel.. so calm

[@encodedpr]

Underrated puns

[@mjallenuk]

Fantastic ... I can't wait to show this to my kids! Explaining it too them might be a bit more difficult at 5 and 8...

[@davidonfim2381]

Why in the world does the solution near the top start getting acidic first, and the increased acidity gradually moves down? You'd think the pH would decrease faster near the bottom, given the fact that the bubbles start out as pure CO2 at the bottom, but near the top they should be partially composed of water vapor. In addition, the pressure at the bottom is higher, so more CO2 should be able to diffuse into the solution. Not only that, but it should also be colder near the bottom, since that's where the dry ice is, so the solubility of CO2 in the solution should be higher near the bottom. Is it because the pressure of the water above should keep the CO2 bubbles near the bottom smaller, meaning there's a smaller surface area for CO2 to diffuse into the solution? Or maybe it's that the bubbles break up into smaller bubbles as they travel up?

[@TemptedsX]

Man I love your videos, keep up the great work. Really interesting and informative content.

[@SteveMould]

+Tempted sX thank you

[@BradleyArsenault]

I may or may not have been on acid when this video came on the top of my feed. The irony!

[@LexiconOne]

Just discovered and subscribed to your channel,I must say the quality of your videos is astounding.The voice works and video editing is top notch.The science stuff is the cream on top.Thanks for making these videos.

[@SteveMould]

+LexiconOne thank you!

[@joedoe3688]

impressive you didn't debunk me. So I can conclude, I'm not wrong?

[@JonesP77]

Dropping some acid? I highly recommend this. You may get a mystical experience, which you urgely need. For sure!

[@chrisakaschulbus4903]

i always think it would be so cool to trip at those places from those science youtubers... so many physics toys to interact with ^^

[@JonesP77]

@@chrisakaschulbus4903 Yeah, this would be soo funny, just some toys and you can interact with them and everything would be so interesting and colourful and... :-D Im very excited when im on the Psy-trance festival "Psy-fi" in Netherlands this year. Its one of the most beautiful places to take some psychedelics! ^^ On this festival i had by far my absolute best days of my entire life!

[@chrisakaschulbus4903]

@@JonesP77 even though i'm not quite sure if i like to trip around other people, but i think i will go to such an event sometime in the future :D

[@corrigenda70]

But why is the world's coral recovering so massively?

[@FitnessTips4Ux]

Ooooooh in the water. Yeah that'll do it too I suppose

[@DanielHarveyDyer]

Why does the top end of the tube acidify first? I would have thought the concentration of HCO3 would be highest at the bottom, closest to the solid CO2. It would make sense if the top of the tube was closed, so CO2 rises up through the tube, gets trapped at the top and then dissolves. But reference to Steve saponifying his hand leads me to believe that the top of the tube was open. What have I missed?

[@ptarmigan1356]

I am wondering this too. Maybe the gaseous CO2 takes some time to dissolve/react and is near the top of the tube by then, and it builds up starting at the top of the solution, despite the top not of the tube not being sealed? In this case if the tube was sealed it would build up from the top even faster, but even with the end open, the rate of loss of HCO3 from the solution to CO2 in the air is not as fast as the rate of new HCO3 being contributed from below, so at least to start with, it builds up.

[@DanielHarveyDyer]

The carbon dioxide bubbling through is already in the gas phase though, so it won't have any difficulty leaving the tube. Each bubble ought to dissolve as it rises. I would expect the dissolution rate to be proportional to it's surface area, and as it loses volume over time it ought to dissolve more slowly towards the top of the tube than the bottom. Additionally, carbon dioxide is more soluble in cold water. As dry ice is cold, I would expect the bottom of the tube to be colder than the top, and therefore dissolve more carbon dioxide. Maybe there is more dissolved carbon dioxide at the bottom, but the equilibrium reactions that produces the colour change are affected by temperature: 2 H2CO3 + (Bromothymol blue) ⇌ 2 HCO3- + H2(Bromothymol blue)+

[@SteveMould]

+DanielHarveyDyer my guess, it takes a little while for the dry ice to reach the bottom so the top has had co2 dissolving it for longer. I feel like that can't be the full story though.

[@DanielHarveyDyer]

It looks like the dry ice is already at the bottom by 2:01 but the colour doesn't develop until 2:11 or so. Or are there small bits floating at the top, and only the big lumps sank?

[@wereoctopus]

Conjecture: CO2 is denser than air, so it's going to quickly displace the air in the top of the tube. There's not enough time while a bubble rises for enough CO2 to dissolve to affect the indicator. The majority of dissolution is happening at the top, and the agitation caused by the bubbling slowly mixes it down. I suggest repeating the experiment with the following variants: * Remove agitation: Put some dry ice in a conical flask, have tubing that runs the sublimating gas to just above the water level at the top of the column. * Minimise the surface area at the top that's in contact with CO2: either have a gas denser than CO2 sitting on top of the water in the column (butane would probably work and is readily available, though it poses an obvious fire hazard), or have a column that's very narrow at the top.

[@kaitlyn__L]

oh man, i've not seen this effect since early secondary school, when they called it "rainbow fizz".

[@pcfreak1992]

So does that mean we need to throw soap into the oceans? ;-)

[@AceNallawar]

what if I dump a lot of antacid into the ocean

[@SteveMould]

+Ace Nallawar you'd be a modern day hero

[@AgentMidnight]

Can ocean acidity be combated by introducing a Base solution to the environment? I'm guessing its far more complicated than that.

[@praveenb9048]

"Things that we like to eat or look at would disappear as well". It would be nice to see a sentence like that in *Nature* etc sometimes, at least in an abstract.

[@Blido]

I read the title and thought Steve will encourage us to do some LSD.

[@Maninawig]

So does that mean that if you leave a carbonated drink to flat, you'll reduce it's acidity?

[@mancheaseskrelpher8419]

When clickbait delivers, but not in the way you expected

[@rushthezeppelin]

So how did shelled creatures survive in the past when the CO2 levels were MUCH higher than they are now?

[@benedictifye]

Well played…..

[@ChozoSR388]

And it's funny to think that we humans ingest flavored carbonic acid quite regularly. I think my favorite flavor of carbonic acid is Dr. Pepper.

[@SFTV.]

Steve Mould reminds me of Neil Buchanan from Art Attack

[@thekingofdestruction5138]

I've been using acid to see rainbows before I saw this video... didn't learn anything new

[@kevinjpluck]

Would a warmer ocean return the CO2 to the atmosphere? Or is the carbonic acid permanent?

[@GodlikeIridium]

Best clickbait xD

[@ThingEngineer]

Did the top eventually turn red? What Universal pH indicator did you use? Great demo and simple explanation of acidity.

[@edderiofer]

No beaker ending?!

[@HyperionNyx]

1:49 I find it troubling that you equate H+ concentration directly to "acidity", because that's not technically "acidic". -log10 [H+] is pH - although flawed, at least it's what most people consider when thinking about acids/bases.

[@SteveMould]

+HyperionNyx I thought I'd been quite careful with my description. Not to say an acid is something with H+s floating around but that something is more acidic if it has more H+s floating around.

[@KnowArt]

buttt..... what up with the microwave video's that were coming?

[@SteveMould]

+Aldo next one is microwave video!

[@KnowArt]

Weeeeh!

[@IceMetalPunk]

+Steve Mould Careful, there's a lot of controversy about microwaves and cameras here in the US these days :P

[@DanWi90]

All those animal dissing pears... so sad😭😂

[@emilyno5647]

Lets stop ocean acidification together, everyone get your drain cleaner and dump it in the ocean NOW!

[@khalilamardjia7273]

your vidéos are getting better and better good job :)

[@Luxcium]

It's hard to make a shell 🐚 because if it would have been easier then it would have been harder (2:48 no pun intended?)

[@C0deH0wler]

It will kill off things "we like to eat and look at." Man, that is so sad XD

[@aidanwansbrough7495]

That's pretty cool!

[@spamsausage]

I'm glad Numberphile showed us this channel. I can honestly say it's probably in my top 10 for all my subscriptions. Great videos

[@TrashLock]

Well technically it's not a rainbow. It's missing the red part of the spectrum :(

[@TrashLock]

But maybe if I drop acid I'll see the extra colors?

[@SteveMould]

+TrashLock technically you're correct, which is the best kind of correct.

[@HolyMoses33]

I think I just learned something.

[@unoriginalusername1139]

i like how he responds to comments

[@KarlFFF]

Black thermo-beakers are the best for pouring cold chemicals (0:38) Didn't expect the mentioning of ocean acidification at the end, though in hindsight it a logical place to go. Did you watch that minute earth video yourself recently or what gave you the idea?

[@SteveMould]

+Karl Frederik Færch Fischer actually it was a friend of mine Andrea Sella. He's the professor of chemistry at UCL (look at me dropping names!). It's his demo actually, he let me borrow it. He does the demo to illustrate ocean acidification. I saw the minute earth vid while researching. It's a great vid so i thought I'd hand off to them instead of saying it all again.

[@KarlFFF]

It's a nice demo, kind of him to let you use it. If you like video ideas from inorganic chemists, then you might like this one (look at me promoting myself!). There is different fire extinguishers for different types of fires and this can be nicely demonstrated with burning metal. Traditionally this is done with magnesium as it looks impressive if you're there, but for a camera dense steel wool might do the trick without over saturating the sensors. Set fire to the metal and pour some CO2 on it from a beaker (CO2 is more dense than normal air so it is pourable), it should light up and glow more intensely. Then do the same with a spray bottle with water. Could do it to a candle first to show that it turns off the candle. And then finally turn of the burning metal by dumping baking-powder on it as that is what a powder extinguisher contains.

[@SteveMould]

That's a great idea for a video. Really counterintuitive that CO2 would make a metal fire burn more brightly. I've added it to the list!

[@KarlFFF]

I looked into it a bit and this will probably not work with iron or steel wool, so better just go for magnesium from the beginning. You might be able to get your hands on a fairly big amount of magnesium for very little money as it was once used for pipes. If you get a magnesium pipe it is fairly easy to make shavings of it with a dagger.

[@tempacc7042]

which way is up? it's not clear

[@Tonicwine999]

Haha, cleverly named video

[@photonicpizza1466]

I expected a VERY different video

[@mgsquared5204]

Sea animals are dying because of people dropping acid

[@cryojester]

Wait, so carbon dioxide and water react together, so what keeps the reaction from happening when you breath out underwater? Is it just that there's not enough time for the reaction to take place, or am I missunderstanding this reaction?

[@TechnoHackerVid]

I feel like this would be a REALLY late necrobump but just for completeness' sake, it does happen all the time. We don't really notice it because carbonic acid (H2CO3) is a weak acid and it doesn't have significant effects on the human body atleast at those levels, unlike stronger acids like Hydrochloric, Sulphuric or Nitric acid

[@cryojester]

@@TechnoHackerVid Makes sense, thanks for the response, even if it's late lol.

[@TechnoHackerVid]

@@cryojester glad to help xD

[@williamwatkins821]

Hey Steve, love your videos! I just discovered your channel, but it's super interesting and I'm hooked! I know it'll probably never happen, but if you're ever in Texas I would love the opportunity to get coffee with you!

[@0cramoi]

Truly amazing video! Just a question: where did you get that "50% of all carbon dioxide produced since the industrial revolution went into the oceans" (~ 2:20) from? I've never thought about so I searched that figure but found nothing. Can someone point to some research so I can read up about it?

[@iepineapple]

I've watched steve mould on LSD before, and he looks quite weird when you're tripping

[@chrisakaschulbus4903]

i think most people look weird on psychs ;)

[@Jbrimbelibap]

Ain't that supposed to be when you take acid ?

[@morphenominal]

We get the pun, guy

[@wouterpauwels614]

is there a specific reason universal indicator changes with the colors of the rainbow? I've always been curious about that

[@MarkTillotson]

Its specially chosen/formulated to give a wide range of colours to cover a large part of the pH range - hence "universal".

[@HarrySarge96]

this is high quality content

[@PeterLawton]

Go plankton!

[@ocircles738]

March 16th, 2017. Steve Facial Hair prognosis is at a 6/10 because of neckbeard, setting a downward trend from the record breaking 9.8/10 2-day beard the other day. We urge you to stay calm and indoors.

[@Fightre_Flighte]

When clickbait is actually healthy (for once)

[@ZorroVulpes]

I like the experiment and that you tied it in to real life. I think it's important for science communicators to show how the science is applied in the real world.

[@auds9738]

subscribed because of the excellent clickbait and suitably excellent video. good job

[@SteveMould]

+cheshire doge thank you!

[@lucasagua77]

i love your channel

[@Yezpahr]

inb4 the new algorithm sees the new rules and the old title.

[@princessjellyfish6057]

Yay Steve!