Always nice to see our professor doing well. I say 'our' professor even though I have never been Uni of Nottingham student, but for all of us around the world he has been also our professor through all these years.
@c641162 жыл бұрын
if they need an explanation as to why he IS our professor, well then, he ISNT their professor lol. cheers.
@jeevahacoelho65562 жыл бұрын
*soviet anthem plays in the background
@PlzReturnYourShoppingCart2 жыл бұрын
I really like seeing that he is doing well too
@InvisibleJiuJitsu2 жыл бұрын
he taught me when I was at Notts uni :)
@Bassotronics2 жыл бұрын
He is awesome.
@CookedMeat2 жыл бұрын
Accidentally discovering a new element in 1800: "Huh not sure what is this but neat." Accidentally discovering a new element in 2020: "Guess I will have cancer then."
@moosemaimer2 жыл бұрын
"We haven't entirely nailed down what element it is yet, but I'll tell you this: it's a lively one, and it does NOT like the human skeleton."
@oldcowbb2 жыл бұрын
i don't think you can accidentally discovers a new element in 2020
@gubgubgub2 жыл бұрын
@@moosemaimer control group isn't going to like that
@gubgubgub2 жыл бұрын
or is it beam counters? i can't remember it
@bgezal2 жыл бұрын
@@moosemaimer Moon dust is a helluva drug.
@tekuaniaakab20502 жыл бұрын
This is similar to the story of the discovery of Vanadium. A Spanish-Mexican scientist discovered the element in Mexico and sent it to Europe for analysis, where they (incorrectly) told him it was just chromium. About 30 years later a Swedish scientist rediscovered it and named it Vanadium. The original proposed name would have been “erythronium” which os pretty cool
@kanishkmukherjee082 жыл бұрын
Chemistry students are diabolically thankful of this elements non-existence(erythronium)
@Freshbott22 жыл бұрын
@@kanishkmukherjee08 why?
@amiralibazdar32062 жыл бұрын
@@Freshbott2 Vanadium is just much much easier to remember
@ThePppp892 жыл бұрын
Unrelated to the story, but wouldn't a Spanish-Mexican just be... Mexican?
@雀-t6c2 жыл бұрын
@@ThePppp89 I’d say Spanish-Mexican is fine if he moved to Mexico after being born in Spain. Not really sure what it means
@johndododoe14112 жыл бұрын
If Nipponium had prevailed, 113 Nh would probably have been named for the prefecture, city, university or person discovering it. Similar things happened with other groups discovering multiple elements, such as the Bohr dynasty from Copenhagen/Hafnia.
@AaronOfMpls2 жыл бұрын
Or all the rare earths named after Ytterby, Sweden, where their ores were first discovered: Yttrium, Ytterbium, Erbium, Terbium ... and then Holmium (after Stockholm, closest city to Ytterby) and Scandium (after Scandinavia in general) because they ran out of ways to get an element name out of Ytterby itself.
@Anonymous-df8it2 жыл бұрын
@@AaronOfMpls What about Ytbium, could they have called Scandium that?
@mushyomens68852 жыл бұрын
@@AaronOfMpls damn didn't know about that, thanks!
@dominiccasts2 жыл бұрын
That or something like Yamatonium, if we were still going with names for Japan.
@RedHairdo2 жыл бұрын
All elements are named the same way: Moronium.
@Rubrickety2 жыл бұрын
I think the professor may have achieved new peak hair. Soon he will be indistinguishable from a giant dandelion. I am in awe.
@christmassnow34652 жыл бұрын
Mendelev never stopped amazing me: back when the sub-atomic particles were poorly understood, his way of thinking was as revolutionary as Einstein's theories. It is worth a video of its own talking about his researches.
@notforwantoftrying12 жыл бұрын
I think the Professor's hair has reached its most extreme extent ever
@Yora212 жыл бұрын
It has reached maximum entropy.
@polbecca2 жыл бұрын
They say the Professor actually invented being a scientist.
@phoule762 жыл бұрын
I love the manga tear that he's shedding in the drawing.
@SolarWebsite2 жыл бұрын
I would love a video about the island of stability. A deep(ish) dive in what it is and especially any recent progress towards finding/creating and elements that may constitute that island. Thanks!
@bretscofield2 жыл бұрын
would be interesting, yes.
@klausolekristiansen2960Ай бұрын
There is a very pronounced island of stability at elements 90 and 92. Both have isotopes that are very much more stable than anything else above 83.
@mealex3032 жыл бұрын
Im guessing You will only wear that coat... PERIODICALLY ? LOL
@anarchyneverdies35672 жыл бұрын
😂😂😂😂😂
@Hemigloopilop78902 жыл бұрын
I love little tidbits of trivia like this. It really helps bring a humanising character to what is essentially a property sorted database (the periodic table) and helps tell a story of chemistry.
@RDEnduro2 жыл бұрын
Ogawa had a great mustache, thank you for the lesson Professor!
@Hexakinase2 жыл бұрын
5:24 This hits me in my field, as well. It's amazing that our forebears were able to accomplish so much with so little.
@samitabbakh84092 жыл бұрын
I think this applies to all fields. I'm an electronics engineer, and I can't even imagine how people used to do electronics designs back in the old days.
@johndododoe14112 жыл бұрын
@@samitabbakh8409 Well, first they looked in the data book for a nice integrated tube. If not listed or too expensive, fall back to basic pentodes, then simplify to triodes or diodes.
@ifitsrusteditsmine2 жыл бұрын
This Professor always brings a smile to my face
@auroraourania71612 жыл бұрын
I feel like Ogawa deserves to have an element specifically named after him, given that he didn't get this credit during his lifetime. Hopefully his name is put on one of the ones found in the future.
@WhyDoThat2 жыл бұрын
It isn't just about finding something in science but properly identifying and understanding it.
@astphaire2 жыл бұрын
nah
@natalieisagirlnow2 жыл бұрын
the chart is full, what can they find?
@slendeaway77302 жыл бұрын
@@natalieisagirlnow It's not 'full', the row has just been completed. We can keep synthesizing atoms with higher and higher numbers of protons in them, but at this point they're so unstable and have such short half-lives that it's highly difficult to even detect them. The periodic table makes predictions, so we could hypothetically theorize an infinite amount of atoms and their properties.
@Abigail-hu5wf2 жыл бұрын
@@WhyDoThat But, as pointed out, the second discoverers of rhenium ALSO believed they had identified technetium. Both were wrong in the same way. So this can't be the only part of the story. I would be a little wary that perhaps an element of racism played a part, honestly - it's not impossible.
@darthrainbows2 жыл бұрын
I'm curious, if the way to determine the element present in the salts involved calculating its atomic mass, how could Re be confused with Tc, given the huge difference in atomic mass between them (186 vs 99 (roughly))?
@Anonymous-df8it2 жыл бұрын
Can't let this comment get buried!
@Owlrrex2 жыл бұрын
It was mentioned that there was a mistake in the formula of the salt. Given the weights are almost exactly a factor of two apart, having twice as many atoms per molecule in the wrong formula would give you half the expected atomic mass, no?
@weckar2 жыл бұрын
@@Owlrrex Let's also not forget there's a second part no every salt. So he thought he had 2Np-X, while he actually just had Np-X. It is also possible he misidentified X.
@LucarioBoricua2 жыл бұрын
That's close-ish to a 2 to 1 ratio, which is really difficult to measure with the techniques that were likely available at the very start of the 20th century.
@giordy90132 жыл бұрын
So happy to see the Professor back in his university studio, it makes the video much more scientific
@BlackWolf42-2 жыл бұрын
Thank you for the image at 2:56 !! It helped bring to light the chem techniques used to find and isolate new elements. Intriguing af
@u.v.s.55832 жыл бұрын
When Sir Ramsey discovered a noble gas, he realized that all good names were gone.
@kansascityshuffle85262 жыл бұрын
1908 the same year a Japanese biochemist invented MSG
@wombatkins2 жыл бұрын
Ah, the King of Flavor!
@BackYardScience20002 жыл бұрын
Please do more videos about elements that might have been or that never were. It fascinates me that so many were named and published about, but we're never actually discovered and disproved when the real discoverer published about them. Like Veritasium. The name of that KZbin channel is the name of an element that never really existed. It was named, used in tables and everything. But then it was proven that specific discoverer didn't really discover it. So then the element was, I guess dismounted (?) From the periodic table and a new name was given to the true discoverers element and now the old name is used as a KZbin channel name. I'd love to hear more stories like this about elements that were named, but weren't actually discovered or people were mistaken on what they've actually found. Some very interesting stories are there to be told and shared with the world. I'd love to see and hear the professor talk about them. 🙂
@mushyomens68852 жыл бұрын
owo i always thought veritasium(name of channel) was just a made-up name from the Latin word veritas (truth) and not that there was some history behind it
@gcewing2 жыл бұрын
Do you have a reference for this? Everything Google is finding for me says it's just something that Derek made up.
@BackYardScience20002 жыл бұрын
@@gcewing after researching, you're right. I did find where "Veritas" had been considered for an element name at one point, but was ultimately rejected due to it not coming from the original discoverer. That's what I was thinking of, where he talked about that. Thank you for pointing that out and for being on the ball with the research.
@im_outtahere2 жыл бұрын
Fun fact: element 100, fermium, is the last element that can possibly be made in macroscopic quantities. However, the heaviest element to be seen in macroscopic quantities was the one before fermium, element 99, einsteinium.
@MGSncB2 жыл бұрын
Isn't it theorized that there might be an island of stability somewhere?
@michaelbloom53422 жыл бұрын
@@MGSncB Yes. But we aren't anywhere close to it yet.
@leppeppel2 жыл бұрын
Me, reading the title: "huh, did scientists jump the gun on element 113?"
@lewismassie2 жыл бұрын
I happen to know that 'Nippon' and 'Nihon' are both correct ways to write 日本 in english characters, so both element names are essentially the same
@موسى_72 жыл бұрын
Hey guys, isn't strange that Nihonium is not ニホンイウム but ニホニウム? Doesn't make sense, since Nihon is Japanese for Japan, and it is ニホン, because the n and i are part of two separate things, Nihon and ium.
@colmonhs2 жыл бұрын
I missed you professor! Hope you have a lovely 2022 🥰
@defeatSpace2 жыл бұрын
Since elements already use Np and the Japanese word for Japan, chemists should recognize element 75 as Ogawanum or Og for short.
@kasuha2 жыл бұрын
I don't think we would have both Nippoinum and Nihonium in periodic table, in japanese Nihon and Nippon are two alternative readings of the same word 日本 meaning Japan. Having one already in the periodic table, the newer element would certainly get a different name.
@photonicpizza14662 жыл бұрын
We have terbium, ytterbium and erbium, all named after the village Ytterby in Sweden, so I wouldn't rule it out.
@kasuha2 жыл бұрын
@@photonicpizza1466 Yes, but we don't have Ytterbium, Ytterbium and Ytterbium. There's a difference.
@MGSncB2 жыл бұрын
Just being curious - is there a reason behind the difference? Regional accents, or maybe a quirk of the language?
@موسى_72 жыл бұрын
@@kasuha Nihonium isn't written with kanji. In fact, it doesn't make sense in Japanese; ニホニウム instead of ニホンイウム
@lafcursiax2 жыл бұрын
An excellent book on this and many other cases of "almost-discovered" elements, as well as discovery claims that were later disproved, is The Lost Elements by Marco Fontani, Mariagrazia Costa, and Mary Virginia Orna.
@syrupfin78902 жыл бұрын
I'm so jealous of that hair tho
@mateuszcielas33622 жыл бұрын
actually one video about how in the olden days people could discover new elements would be great, i cant wrap my head around how they could do so not knowing some stuff
@maxresdefault_2 жыл бұрын
I would love to hear the prof. explain the complete history of Phlogiston. Love stories of scientific advancement
@highpath47762 жыл бұрын
One was done (by another channel?) when speaking of Hydrogen - actually that might be a BBC Radio expisode (search the sounds website)
@owentan63222 жыл бұрын
I'm really hoping the next element discovered would be something like jacquenium (Jq) such that all letters are used in the periodic tables..
@zucc47642 жыл бұрын
That would be truly groundbreaking, as it would unlock a heavier level of elements. It would have its own row in the table
@jpdemer52 жыл бұрын
Mendeleev actually did use "J" for iodine (iodine is "Jod" in German.) For some reason, the English name and initial become the standard.
@castform572 жыл бұрын
Fun coincidence relating to the happi coat: in finnish, happi means oxygen, and it is pronounced the same way as the coat, はっぴ
@glenngriffon80322 жыл бұрын
Much as i would love to see him get his due credit for the discovery i bet chemists are happy they don't have to distinguish between "Nipponium" and "Nihonium". That could get confusing.
@phileo_ss2 жыл бұрын
And it would probably be most confusing to us Japanese people!
@tom_something2 жыл бұрын
Some scientific experiments need a _lot_ of helium. Well, even some party planning projects need a lot. But if you're a scientist who needs only a small amount, then I guess having another element that slowly releases alpha particles is pretty handy, because you don't even need a gas cylinder to contain the resulting helium. I'd like to think that if "Nipponium" had caught on, then "Nihonium" would have had a different name. To people in Japan, "Nihon" and "Nippon" are essentially synonymous. Their differences, as I understand it, are essentially contextual. It would be like having "Americium*", which there is, and also having "Unitedstatesium". But like, imagine that their pronunciation is also a little bit similar. *In this example I pretend that "America" exclusively refers to the United States. Again, the hypothetical construct is based largely on context.
@jeffreyblack6662 жыл бұрын
Yes, some might think it is a bit ridiculous. Almost as ridiculous as "hypothetically" naming 4 elements yttrium, terbium, erbium and ytterbium after some hypothetical town called Ytterby.
@ChemistryinaNutshell2 жыл бұрын
I love your chemistry history videos. Thanks for what you do!
@TheFinktron2 жыл бұрын
Nihonium should have been named Japonium with the symbol ”J”. We then would have had a J for making people’s names from chemical symbols.
@victorcristian83382 жыл бұрын
Today is his birthday, 16th December! Happy birthday Sir Martin Poliakoff! Best wishes!!
@johnkristian2 жыл бұрын
I don't know how it has taken me such a long time to get this, BUT HIS HAIR IS AMAZING!
@maineeveryday39912 жыл бұрын
Poor Professors right eye is clouding over with cataracts. 😕. We love you!
@2112jonr2 жыл бұрын
What a lovely, and thoughtful gift :-)
@inigoromon19374 ай бұрын
Being a non native English speaker It IS a joy to listen to the professor and understand so many clever things.
@Brittunculi2 жыл бұрын
I haven't seen you for ages, Your hair,Mygodium ! Massive 🤣😘
@AzngameFreak032 жыл бұрын
I'm sure I subbed to you when you were 10k views. Amazing to see now what has happened. Wish you well Periodic Videos man.
@donaldinnewmexico2 жыл бұрын
Hi, Professor. *Happy* *Holidays*
@markanderson37402 жыл бұрын
I am so happy just to see your face, smiling and healthy. You are among my favorite humans :)
@ALSPEHEIR2 жыл бұрын
Nipponium, Germanium and Italyum. 3 elements that combined, create some explosive results.
@douglasstrother65842 жыл бұрын
... especially when combined with Americium!
@ALSPEHEIR2 жыл бұрын
@@douglasstrother6584 Actually Americium is pretty much inert all the time. It only reacts with _Peer-Harborium_ .
@douglasstrother65842 жыл бұрын
@@ALSPEHEIR XD
@TheCleric422 жыл бұрын
And you’re forgetting about that other element synthesized in Japan: Hiroshium!
@OGWk1097 Жыл бұрын
😂😂😂
@jamesbarisitz47942 жыл бұрын
Interesting sidebar to the history of the table! Thanks. 😃
@JustAPersonWhoComments2 жыл бұрын
Rhenium (Latin: Rhenus meaning: "Rhine") was the last-discovered of the elements that have a stable isotope (other new elements discovered in nature since then, such as francium, are radioactive). The existence of a yet-undiscovered element at this position in the periodic table had been first predicted by Dmitri Mendeleev. Other calculated information was obtained by Henry Moseley in 1914. In 1908, Japanese chemist Masataka Ogawa announced that he had discovered the 43rd element and named it nipponium (Np) after Japan (Nippon in Japanese). However, recent analysis indicated the presence of rhenium (element 75), not element 43, although this reinterpretation has been questioned by Eric Scerri. The symbol Np was later used for the element neptunium, and the name "nihonium", also named after Japan, along with symbol Nh, was later used for element 113. Element 113 was also discovered by a team of Japanese scientists and was named in respectful homage to Ogawa's work. Rhenium is generally considered to have been discovered by Walter Noddack, Ida Noddack, and Otto Berg in Germany. In 1925 they reported that they had detected the element in platinum ore and in the mineral columbite. They also found rhenium in gadolinite and molybdenite. In 1928 they were able to extract 1 g of the element by processing 660 kg of molybdenite. It was estimated in 1968 that 75% of the rhenium metal in the United States was used for research and the development of refractory metal alloys. It took several years from that point before the superalloys became widely used.
@9peppe2 жыл бұрын
It's the same story with controlled fission. First made by Fermi and his team in Rome, who never realized they'd done it. They were looking for Neptunium and Plutonium, which they called Ausonio and Esperio, and never realized that bombarding Uranium with neutrons had split the nucleus.
@drishtantsen37242 жыл бұрын
Wow, so good to see you again professor! The algorithm brought me to you
@skyty02 жыл бұрын
Weebs: 😴 Physicists: nipponium Weebs: 👀
@drumkommandr97792 жыл бұрын
@5:30 This sounds like a challenge for @NileRed
@scrotiemcboogerballs19812 жыл бұрын
If it wasn’t for the professor’s hair I don’t think I would believe anything he talked about lol jk love watching thank you all for everything you do
@adamdaichendt38382 жыл бұрын
Id call it the frazzled dazzle.😆Not in a rude way by any means of course.👍
@eeronasi65162 жыл бұрын
I work in asbestos removal can you make a video about asbestos
@killtrigger912 жыл бұрын
Nipponium sounds like what katanas in all anime is made out off.
@TheFrozenedge32 жыл бұрын
Clicked for the hair, stayed for the video.
@rubiks62 жыл бұрын
That was fun. Thanks again, Professor.
@Rencol6662 жыл бұрын
Where else can we see real thorium next to fidget spinner :D
@cm14612 жыл бұрын
Thank you Professor Poliakoff for keeping doing these amazing videos! I had the pleasure to meet the Professor at the UoN before covid and he is truly friendly and funny as we can see in the videos! All the best
@pollywanda2 жыл бұрын
Has anyone studied the spacing of hair filaments in an oxygen rich atmosphere and the increased chance of flammability when near a heat source?
@curiousnerdkitteh2 жыл бұрын
I saw this video and that outfit and got really excited that there's literally a channel designed to nerding out about the periodic table's history. At the demonstration on the shirt sleeve I instantly subscribed.
@debdude1232 жыл бұрын
Professor, you were there during the Manhattan Project, can you recall those times when suddenly so many new elements popped up out of nowhere?
@douglasstrother65842 жыл бұрын
You Chemistry Geeks need to write the lyrics to "Atom from Tokyo" with apologies to Deep Purple!
@manjunathanulaganathan91522 жыл бұрын
Okawa should be recognised for his contribution. Interesting video professor.
@Shad0wBoxxer2 жыл бұрын
That is awesome! Thank you for the lesson
@_Solaris2 жыл бұрын
His hair looks better than ever.
@ChamaraVFX2 жыл бұрын
Im Sri Lankan and it's first time I'm hearing about Thorianite.. wow
@jaysartori90322 жыл бұрын
What a great teacher Professor is he inspire me to fall back in love with Science and art!
@ah93382 жыл бұрын
This guy looks like science
@DeconvertedMan2 жыл бұрын
Science works no matter were you are from
@tncorgi922 жыл бұрын
Unless you're from a red state in America.
@DeconvertedMan2 жыл бұрын
@@tncorgi92 unhelpful. :P
@dooman2302 жыл бұрын
wholesome video
@zachb20462 жыл бұрын
Thank the Universe and all it's elements this timeline still has an awesome professor going strong! Thanks for the video
@vanderburg.M2 жыл бұрын
Hi guys, I've always wanted to know how older chemists worked out what elements were contained in samples and the chemical compositions of organic molecules without the use of modern spectroscopy. In this video, you mentioned that some chemists made salts with known elements and unknown ones to work the left over molar mass (which would indicate what the weight of the unknown element). Would you do a video on all this?
@alanh86642 жыл бұрын
so delightful
@wearegoingtogoseeyousoonid18912 жыл бұрын
This man’s an icon
@richross47812 жыл бұрын
That was a fascinating story.
@VeganSemihCyprus332 жыл бұрын
The Connections (2021) [short documentary] 💖
@polyquaternium72 жыл бұрын
Ahh Nipponium, made from 100% concentrated Otakus that haven been sushi fed daily and massaged by cosplay maids, forged in the bowls of Mount Fuji, folded a 1000000 times a by Edo era master smith and blessed thrice by a Kyoto Shrine maiden/J-pop star before being cooled in the finest Sake.
@eldstgilmorbarboydodellatb44132 жыл бұрын
💚💚💚💚 bookmark/ notes: def shirt spaces from early periodic table …..ect…..tbc…… -g-b, bot
@ExcelonTheFourthAvalonHeirs2 жыл бұрын
I can finally fulfill my dream. The creation of Nippon Steel. Sorry, I have too.
@NoName-qx6tc2 жыл бұрын
FYI japans endonym(its name in its language) is “Nippon” which is roughly pronounced “NEE-hon”
@philipfish502 жыл бұрын
Hi I have a photo what I took of a cloud and it looks exactly like the professor with the hair and everything how can I post it to you so you can see it thanks phil
@nowthatsjustducky2 жыл бұрын
I propose that we name one felonium, to show that even the realm of chemistry has a criminal element. All in favor?
@dextrodemon2 жыл бұрын
nipponium sounds like what like car geeks would call rare japanese 90s performance cars or something, like derived from 'unobtainium' 'did you see that rx-7 bro, that's some glorious nipponium, can't get those anymore'
@lanfrancoadreani92122 жыл бұрын
Nipponium Is a material used in the Japanese tree in warthunder
@موسى_72 жыл бұрын
Hey guys, isn't strange that Nihonium is not ニホンイウム but ニホニウム? Doesn't make sense, since Nihon is Japanese for Japan, and it is ニホン, because the n and i are part of two separate things, Nihon and ium.
@amanofnoreputation21642 жыл бұрын
"Sir William encouraged him to name it Nipponium with the symbol Np." Gigachad.
@meazle2 жыл бұрын
I have the same glasses as Prof. Poliakoff. It's nice to know I dress like the superstars.
@IIGrayfoxII2 жыл бұрын
I still cant see why we cant just rename it We renamed Wolfram to Tungsten and Tungsten still bears its Original symbol of W
@sockington12 жыл бұрын
...just so that the americans could call aluminium aluminum
@gomahklawm44462 жыл бұрын
We should NEVER allow elements to be named for/about nation states. It's disgusting.
@cherubin7th2 жыл бұрын
If Japan is really sad about it, they could just ignore the name Rhenium and call it Nipponium. Just how English people ignore the name natrium and call it sodium.
@موسى_72 жыл бұрын
I call it natrium to better remember the symbol. And copper cuprum. And lead plumbum. I only call it that when memorising things for myself, never when talking to other people. It makes certain things easier to remember. These names such as natrium are Latin. It's easy to associate plumbum with lead as you associate any word in one language with its equivalent in another. Connecting plumbum to lead is easier than remembering that the letters Pb link to lead; that's the case for me at least.
@amanofnoreputation21642 жыл бұрын
"...But there aren't any elements left to discover that we can name after Japan!" "Fine, we'll synthesize one ourselves!"
@melekeok2502 жыл бұрын
Still I Can't belive that is a Man on Earth who looks like every female teacher with 40 Yeats experience and Brian May from Queen
@brokentombot2 жыл бұрын
Nip this element in the bud. For Rhenium's sake. Or is it Technetium?
@NeonRabies2 жыл бұрын
I literally moved to Japan a few weeks ago, this is a great gift, thank you Periodic Videos :D
@موسى_72 жыл бұрын
Pray that they will be kind to you. I heard that they are unfriendly to foreigners, and that most foreigners leave. Please prepare so it doesn't end badly for you.
@nihonium2 жыл бұрын
that's almost me
@DerpyLaron2 жыл бұрын
I mean did he recorded a spectrum of it? Yes. Did he not understand the data correctly and thus not came to the conclusion that is needed for a discovery also yes. Maybe it's the analytic chemist talking here, but if you read the wrong thing out of it you didn't find anything. Someone else using the date you recorded retroactively fixed your mistake. It's tragic in this case, but that's science.
@icefire66222 жыл бұрын
But the team that was attributed with the discovery made the same mistake. They also assumed they had created element 43.
@jamesowens71482 жыл бұрын
KZbin didn't notify me about this video on my subscriber page.