For me, I think I still think there's women here in the U.S. You know what's so I'm still out there and I still have hope for them, but dang it's hard. Hypothetically, you get a time machine. We love the time. So you get a time machine and you can put it like this. You can go back to one of three points in history, either before you met your ex-wife, midway through dating her and potentially deciding I'm going to marry her or right after what happened happened and you were in that dark place and you could go back to one of those three times and talk to Corey of that time. Which time would you go to? Hands down before all of it happened. Hands down. And what would you say?  You need to be single. You in college just do what you just take your days by days. Just don't even worry about nothing. Folks on yourself, folks on your studies, folks on what you want to do and everything will come later. You're still young.  So I would say that would definitely be the point. Just focus on yourself, focus on your studies, have experiences and just live life, you know? That would be my main tip. And then that probably would change the narrative of a lot of things. Definitely hands down, that's what I would do. Honestly, I just feel like when it comes to dating for anybody that's watching, I think everyone should just take their time, no rushing. Be true to who you are for both parties, men and women. And really do a good job at vetting people. Everybody just gets so fixated on how they look, how the sex is, that they don't really vet people and understand if this person is truly compatible with what I'm looking for in my lifestyle and where, not what it is, but where I want to be too. And you know, I think that's one thing we didn't hit on when I know, I'm gonna say a story real quick. Talk to me. So I remember I was talking to this girl one time. I was like, she is solid. We talking everything going good. And I was like, usually if I see that this woman have potential and things like that, I'm not trying to rush to have sex. Usually I'm rushing to have sex. If I know I don't want to do it, I'm out.  I'm truly, truly interested in it. So, you know, I'm truly interested in her. We taking it day by day. And then I remember one day she reached out to me and she was like, I don't know if you're interested in me because you haven't tried to have sex with me yet.  And now it's like, ah, that's interesting. But I say that because I know that sometimes sex can cloud things. And sometimes if we rush into it too quick, if we want something to be everlasting, it might mess up what we currently have going on. So I say that to say it's like, properly vet people and that comes with it. Not saying that you shouldn't have sex on the first day or whatever. If it's a vibe, it's a vibe. But also understand that sometimes, you know, being physical too soon can potentially, you know, mess things up and mess the trajectory up on certain things. Have you seen the Bronx Tale? No. Bronx Tale, it's this old mob movie. But his dude, he was dating this black girl. He was Italian. Yeah. But his OG told him he was like, because this was probably in the 70s or something like that.  You open her car door letter in the car and then you swing around back to get into the driver's seat. And if she reaches over to unlock the door, then she's really riding with you. But if you have to unlock the door, she's just there for the ride. So like, what's your go-to, because when you say vet, right, do you have a go-to? All right. So I do this. I take it to the swimming pool. You know what I'm saying? Like, what's your go-to? Right. This is what I do to really see, or maybe just low level, high level, to really see if she, you know, I keep... I would say mainly do conversation, you know, whether that's in person on the phone, whether y'all FaceTime or whatever. Like really having a conversation and truly see like, who this person is, who this woman is. Because like we said earlier, what's being perceived may not be the reality. So you have to make sure it matches up. And that's my job. You know, I feel like as a man, you should do a great job at vetting to make sure if you're going to get in a relationship or you want to take things seriously, you should have done your job as a man to make sure you ask the right questions before you lock it down. Because once you lock it down and you ain't asked those questions and these things start to come up, it's a little challenging. Yeah, it's a little challenging. So I would say asking the right questions into your point, it's like little things. Like you said, I wouldn't say per se the car door thing, but yeah, because it's so automatic now. So it doesn't work. It doesn't work. I would say little things like her interaction with the waitress or her interaction. Like if my order was messed up, how she handled that situation, like little things like that to see like, how would she handle these situations once they come up in everyday life and just taking like mental notes and not talking about attendance, not me positioning these things to happen. It's just like as we're dating or as we're, you know, out, I'm just taking mental notes as the time go on. And then I just usually do like go back home, think to myself like, she handled that pretty well. Oh, she didn't handle that well. Okay, I'm taking mental note on that. And then once we get to a certain she ain't handled that well. I know she not really the one for me because I'm looking for a woman that's going to be able to handle these certain situations with grace versus turmoil, whatever may have happened. How would you know when you're ready to take that leap again? Oh, that's a good question. Honestly, it just got to be a right fit. And that's one thing I do think, well, that's one thing I do appreciate about the situation that happened. I am more vigilant on what I expect out of my next potential wife and long-term partner. So I just know, I know, I know, I know it's going to take me all day to explain exactly what I'm looking for and what it needs to be. But I know what I didn't have and what I need now in order to take that next step. Yeah. So like in hindsight, I look back at that situation and be like, well, yeah, this happened. But were you fully happy too? You know, and then I took a look back and be like, well, this is what I'm going to need in the next marriage or this and that in order for it to go smoothly. All right, I just thought of one more question. Oh. It's a debate right now. Some people say they're more marriage ready men. Some people's black men. Some people say it's more marriage ready black women. Having been married and having been outside, how would you, how would you, where do you fall on that spectrum? Like who do I feel? And you feel like it's more ready, equipped to like, I think the assumption is women, right? Right, right. So maybe answer, is it, is it that simple? I think the assumption is women just because it's women. And that's the way we've been programmed.  When you outside. When you outside, man. Whoo. Cause like in my single life, I kind of came across like women. That's like some legit solid women. For me. And I came across women that was like, damn, you really like that? Huh? So I don't seem both sides now. So. Whoo. I still would side on the women though. I was still a side on them. But is it far? Is it, is, is, are they winning by that wide of a margin? No. Okay. No, no, no, no, no. Not by that. No. But just from my experience of dating, I think it was more, you know, women that I've dated where I can say, Oh, she seemed solid. And I just made a decision like either I wasn't ready or either she just didn't fit. Like, What you trying to do? Yeah. What I'm trying to do and like what, what's going on. So that's just from my experience. So, but you know, I have friends, homeboys and several groups. Do people talk about marriage like that? Nah. You know what I'm saying? Like, but that's not to say men aren't ready. But you know, I just feel like those conversations typically don't come up in those groups like that. That's right. I don't think, I don't honestly, bro, I don't think women these days are as interested in it. In marriage? Yeah. Definitely not as much as it was back in the day. I think they liked the idea of it. I think, I think it's one of those things where like back in the day it was a little bit more cut and dry because I needed, as a woman, I needed this man to buy property to do this, to do that. And now nowadays women feel like they don't need a man outside of what he can do for them. So I think if we were being honest and I interviewed these women and it's like, it really doesn't sound like you want the responsibility that comes along with this institution. Yeah. You just want the value. It's a lot of responsibility. Yeah. Because honestly, when we think about it, technically if a woman get married to a man, that commitment, that union, the valves, to death, to health, whatever. So basically if they get married tomorrow and this man, the next day, need to be on the hospital bed for the rest of his life, she got to be there to take care of him. I don't think not a lot of women like that no more. Not a lot of women will look like, yeah, I'm going to be, I'm going to ride for him on his hospital bed at that long. And that's sad, but that goes to show you like where the marriage kind of shifted, you know what I'm saying? Back in the day, that woman go stick by that bedside with that man, but nowadays a lot of, I feel like a lot of questions would be like, damn, what, what, what my everyday life going to look like now? Or how my life got style going to change now that he not able to do this or how will this look like if we try to do this and that? Now we can't really do that. Did I really shine up for this?  How you feel about the passport, bros?  They too masculine. They too this. But you can still find some of those traditional values in Africa and Asia and South America. How do you feel about their kind of approach? And they just saying, I work in tech, you know what I'm saying? I don't have to be here. You know what I'm saying? I'm out. I'm going to go to Brazil and just chill on the beach. I mean, I feel like it's to each his own. I feel like if you feel like the type of woman you're looking for is not where you at, it's okay to go where you need to go in order to find that type of woman. For me, I think I still think there's women here in the U.S. You know, so I'm still out there. I still have hope for them. But dang it's hard. You know, so I still think it's hope. It's just about finding the right, the right groups and things of that nature. And even if you find the right groups sometime, it's still some bad apples are there too. So it's nothing concrete these days, even if you do go somewhere else, it still isn't concrete that you're going to find what you're looking for and what's going, you know, cater to your life the best. So what risk you want to take?


Bernie Sanders campaign manager Faiz Shakir appeared on CNN and he was asked about Bernie Sanders claim that Corporate media is biased against him and he had a pretty interesting conversation with CNN's Brian Stelter where he brought up some of the points and criticisms of corporate media that I've been talking about on this program for years and This was fascinating. Let's watch What is the the heart of the critique about what Sanders calls the corporate media? What do you want people like me to do differently? Well, Brian, this isn't a personal commentary on you or any other journalists There's many wonderful talented journalists out there But in about you know a minute or so or two minutes or so you're gonna cut to commercial breaks And you're gonna see some pharmaceutical ads You're gonna see a lot of ads that are that are basically paying your bills and the bills of this The entire media enterprise and what that ends up doing is incentivizing you and others to make sure that you're asking the questions and driving the Conversations in certain areas and not in certain areas right now, you know, What evidence do you have of that? I don't actually know what ads run during the breaks. I actually don't see the commercials I don't know what runs And I'd already so I've reached out to Phil Griffin the head of MSNBC and happy to talk to Jeff Zucker and others It isn't about you Brian But about how these media structures are set and operated and the biases that I believe are Embedded within them about I think that's really interesting segments worthy, right? I mean, that's really interesting where you're covering and what aren't so what do you think is not being covered that needs to be covered more What are those topic areas? Well, I mean one one classic area of course is you know We're going across the border right now talk about prescription drugs Do you know why you pay so much more ten times more in America on prescription drugs than any other country? Does anyone know that or understand why do you know what the Trump administration is doing about that? Do you even know who the head of the Health and Human Services Secretary is? Do you know his background that he worked in the pharmaceutical industry? I mean these like I think Donald Trump turns out these tweets and attempts to distract all of us And there isn't a basic conversation around the fact that he's betraying the working class by having Selected a group of people to run his government who come from industry who benefit industry and that story is not told From the press don't you know all that from reporting? No, I that's not how I know it. I've done my own research and we've done our own research to know it But reading stories, but reading news stories about it Yeah, and I would argue to you and you know this well Brian the TV is a certain medium that has an influential power And I and I'm making more of a critique here of what media TV media decides to cover and it tends to be a game It tends to be a gotcha We're I appreciate that Donald Trump's tweets are important and we'll have a conversation about that But it also belies a conversation that he doesn't want to have And and I think that that's what I think I you know me Bernie Sanders a lot of us feel yeah It gets obfuscated is that many viewers lives, right? Many viewers agree with you. Yeah, the objects of sensationalism It's a problem. You know the question is whether it's I think effective for you all to call it out Maybe it is Trump has won support from his fans by attacking the media. Maybe that's what you think will work as well I mean so we're not playing a game here All right, it is it is truly based out of conviction and sincerity that we do see biases operating against the campaign But also against the issues we care deeply about you rarely see pundits on TV talking about the value of Medicare for all You see a lot of people criticizing Medicare for all You don't see the people talking about the value of canceling all student debt You see people criticizing it and why is that right? Just ask yourself it's you're taking on corporate power You're taking on the established You know establishment across the board and all we're arguing for is can we have a fair shake? So that was great work to Fieze he said basically everything that I would have said had I been in that situation So he first starts by calling out these perverse incentives that are created by Advertising dollars going to CNN Because if you obviously have a large multinational corporation spending millions potentially billion dollars billions of dollars advertising on your network You know, you might not necessarily be as inclined to criticize them as you would other companies And then to that Brian Stelter responded by saying what evidence do you have of that?  Are you not? That's just human nature Second of all, even if you don't see the commercials and you probably don't even know all of CNN's advertisers Brian Stelter You were hired specifically because you won't rock the boat Your bosses know that you're going to read whatever's on the teleprompter And you're not really going to challenge power in a meaningful way Otherwise you wouldn't have been hired because think about it There's a reason why people like Medea Benjamin for example of code pink hasn't been hired to be you know CNN's foreign policy corresponded It's because the defense contractors that advertise on CNN probably wouldn't feel too comfortable spending money on a network If there was an explicitly anti-war message being broadcasted relatively frequently They'd spend their money elsewhere now since this is the case This creates incentives for CNN to not hire people like Medea Benjamin It's why MSNBC fired Phil Donahue for being against the Iraq war It's why you know Gerald Friedman and Matt Brunig are never brought on to talk about health care Because if they start bringing on these voices that actually Say things that go against the interests of companies that may want to advertise on CNN well then that Costs them money Because if you are actually telling the truth about health care for example about Medicare for all You don't even have to advocate for Medicare for all But if you're just laying out the basic details and facts about Medicare for all since the facts are not going to be Beneficial to health insurance industry executives. Well, then if CNN does that for example CNN will lose out on advertising dollars. They know this Brian Stelter knows this.  It's just that he is you know He's in that bubble to where he truly probably believes that he's doing something great And he's probably better than most CNN pundits even though the bar is so low But I mean the point is that CNN, you know, it's not like they never do good work It's just that they disproportionately most of the time will choose to play it safe now Brian Stelter then actually surprisingly admitted that sensationalism is in fact a problem because Sensationalism is what drives ratings which means that advertisers flock to CNN in the event their ratings are high based on sensationalism Because they want their ads placed on the networks with the most eyeballs watching It's why advertisers continue to flock to Fox News in spite of all the numerous Controversies that you see with you know, Laura Ingram and Tucker Carlson espousing straight up just white supremacist rhetoric the advertising dollars go where the eyeballs are It's as simple as that but an issue that's inherent with sensationalism is that when you have a sensationalist bias Does that yield you better ratings? Yes, but the issue is obvious I mean other more important news topics end up getting ignored for you to cover something that is just more sensationalist For example, how often do we hear about the war in Yemen the genocide? That's being carried out by Saudi Arabia and they're using our weapons How often do we hear about the health care crisis not very frequently because you know These aren't necessarily the topics that are sexy that will yield Good ratings for CNN so they stay focused on the more safer subjects that you know We'll get them the most ratings and in turn get them the most advertising dollars You know and the thing that was weird about this exchange was that Brian Stelter questioned whether or not it's effective To call out, you know the sensationalism issue in other words He's asking, you know, is it helpful to your campaign to bring up, you know Some of these problems that are inherent with corporate media. That was kind of a weird question to ask Basically saying do you really think it's gonna help you if you criticize me someone in the mainstream media and the aggregate corporate media? That was weird But faiz responded saying you rarely see pundits on TV talking about the value of Medicare for all You see a lot of people criticizing Medicare for all and really this is one of the main issues because it's not just that You know, they're not talking positively about Medicare for all They don't have to advocate for Medicare for all. They just are expected to lay out the details of Medicare for all What it does and doesn't do but they don't do that instead the media which is supposed to be educating people is actively spreading misinformation Oftentimes pushing talking points that come directly from the health insurance industry why Maybe it has something to do with the fact that they have Advertisers in that industry now again, you know I don't expect Brian Stelter to know the ins and outs about all of the advertising dollars that are flowing to CNN But I do expect his boss to know I do expect executives at CNN to know and certainly if they need to They can rein him in if he starts going to rogue it starts actually speaking too much truth to power and towards the end That's why I think that faiz really nailed it because he said look, this is what it's about These networks these corporate media news outlets, they don't want to challenge the status quo Which is why you oftentimes don't hear from voices that are really speaking truth to power. I mean we never hear from Bernie Sanders unless they're taking an adversarial stance against him We're not hearing from progressives running for Congress like McKayla Wilkes Anthony Clark Shea hid but our we're not hearing from them We're not hearing from people who are actually challenging the status quo and it's because CNN doesn't want to challenge the status quo because there's this perverse incentive to put profits Over educating the people like ideally speaking, you know the news and their job should be to educate people, right? That's their one job make people more educated so that way they have as much knowledge as possible When they enter the voting booth, but this just demonstrates how capitalism corrupts everything it touches It's that corrosive because rather than focusing on the delivery of news CNN is focused on ratings because they care more about profits and You know news and corporate media isn't the only thing that capitalism has corrupted. It's corrupted our entire democratic process So now money equals free speech like do you understand the problem here now? The solution is you know, we need to invest more in indie media as Individuals we need to try to support these shows and like them whenever they post videos and The good thing about indie media is we're not as susceptible to the forces of capitalism But that's not to say that indie media is perfect because you know oftentimes these are channels like mine run by one person So human error can and oftentimes is an issue oftentimes these new shows are personality driven Oftentimes we have our own biases that may solely you know, what we're trying to communicate with regard to information You know, we still there's this sensationalist bias in YouTube as well because we're trying to make sure that we put out video and news that generates clicks So clickbaits a problem. So I mean, it's not perfect, but certainly Indy media is better than corporate media in the sense that you know, we are able to dissect The truth from the bullshit so we can use you know a factual basis That's created by real journalists and then use our commentary to give people kind of like a jumping off point and get them to Not maybe take what we say But ideally to think for themselves and construct their own opinion and be more informed overall as they enter the voting booth So overall corporate media is garbage Because you know, we live in a capitalist system where we all have the desire to make money because our survival is Contingent on us making money and you know, if you're already rich Then you want to make more money because that's just the perverse incentives that capitalism creates and in corporate media It's no different their goals to make money not to deliver the news not to be objective and not to educate people And so what faiz is doing here is calling that out and saying hey do better, but it's tough You know, how do you do better when their whole model and survivability hinges on them? You know not speaking truth to power not rocking the boat. It's tough How do you get them to actually see the light? Well, we need indie media to grow so, you know, they're forced to compete with us, but I mean we're just We're dwarfed in comparison with these corporate news shows, right? We're dwarfed they have billions of dollars. We don't have that We can't compete, right? These are not Million-dollar enterprises here these indie news shows are scraping by with patreon dollars and advertising From YouTube the good news is, you know that tie between Advertisers and us is severed by using YouTube as kind of a proxy But I mean the same time, you know, it's not it's not reliable So it's just it's tough, right? The goal ultimately is to get people to think for themselves based on an educated opinion that they form But you know when there's so many bad faith actors so many capitalistic forces that want them to take the position that would yield You know a profit for them whatever special interest that may be, you know People are getting conflicting opinions on things that may not necessarily be in their interest. So it's tough We're fighting information warfare here and a gigantic disinformation campaign But we've just got to keep pushing through and you know shining a light on this just so that way maybe the viewers of CNN see Oh, maybe advertising dollars do create perverse incentives for CNN And maybe I shouldn't take everything they say is gospel if we can just kind of get people to think in that way Maybe plant that seed. I think overall we'll all be better off Slashed humanist report to support the low-radix humanist report sad my views a much higher


Alright, welcome back everyone. Another video on the basics of graph. I want to talk about how to extend graph or generally how you can add macros and make your own commands in case something is a little too long or you want to abbreviate something or really just make it your own thing. I'm also just going to talk about some other formatting stuff I didn't touch on in the last video. So here we have another document. Again, we're using the MS macros. I'm still compiling to PDF and here is our document here. We have some headings. We have some text, paragraph text. One thing I don't think I mentioned in the last video. So in H starts a section. So in H for introduction, in H for formatting. Both of these sections start with in H. You can also use SH and what SH is, is a unnumbered heading. So you'll notice the numbers disappear if we recompile this. So if you're the kind of person who either doesn't want numbered headings or maybe you need a heading that isn't numbered, you can easily use SH to get what you want. So that's just one minor note. Let's talk about some other formatting before I talk about making your own macros. So we talked about bold and italics in the last video. One thing I didn't mention that is sort of important about the bold and italics macros is let's say the last word of this sentence is bold. And I won the word bold to be bold. So you'll notice here, well first off, if I put a period on the next line, it's gonna read the period as just being, you know, a command or something. But let's say we replace it with an exclamation point. You'll notice that this exclamation point, there's actually a space between bold and the exclamation point. Now in some languages that's actually how they format it. It's not how we would do it in English. That looks very silly in English. Now the thing about the bold command is if you want to add something directly to the end of this, you have to add it as the second argument. Notice if we redo this, you'll see that this exclamation point is at the end, but it has not been added as, I mean it's not bold and there's no space between it. So that's what you want to look for. Or if let's say we want to end a parenthesis here. One other thing about bold commands and italic commands is they can take three arguments where the first one is the thing you bold, the second one is the thing that goes directly after, and the third one is the thing that goes directly forward. So we can put a parenthesis here as well, and you'll see that this is now bold in parentheses. So that works as well. And I think we can easily, we might have to put that in quotation. No, I guess not, okay. So we can do pretty much what you expect. Okay, so that's bolding. That's one thing I just failed to mention in the last video. But another thing as well, let's talk about some other formatting. So one thing we can do is underline, underline text. Okay, so again same formatting here, the periods at the end because we don't want it underlined. But you'll see that this is now underline text. Another thing that Graf can do pretty easily is create boxed text. So I'm really missing that key, box text. So that is something else we can add in here. So it's pretty good at formatting that relatively well. So this is just some other minor things you can add into your knowledge, your knowledge of what kind of stuff you can do in Graf. But let's make a new heading here. And we're going to talk about macros, okay. Now before we talk about macros, one thing we need a reason to make around macros. So here's a good one. Now you can make list items in Graf. And these are pretty easy to make. But they're a little, by default they're a little, they leave some to be desired. Now to make lists or list items, you do IP. And so this is a list item. Here is another and another. And another. Okay, so if we compile this though, you'll notice that our list, okay, things are indented. They sort of stick out. They're on their own individual line, but they don't have like a bullet point. They don't have a number. They don't have anything else like that. Now the typical way of adding bullet points is the IP command can take an argument, which is this escape sequence. And that means bullet. So I can manually add these to each of these. Or you notice there's a big difference between the bullet and the text by default. That's a little weird. But the third argument, or I guess the second argument of IP is a text width that, whatever width you want, whatever padding you want between these two. So you'll see that I can change these list items relatively easily. But one thing that would annoy you if you're writing this on the fly and you want pretty much, let's say you want all of your list items to look like this. You don't want to have to rewrite this over and over and over again. That's sort of a pain. So one of the things you can do is of course make your own macro. So that's something that's relatively easy to do. We can do it with the DE command. And these are non capital DE. And this is like defined. And what we can do is let's define a macro called BL. And we'll go ahead and say the macro is the definition ends with dot dot. So we'll go ahead and in that. Now we can define BL as just being whatever sequence we want to abbreviate. So let's say I don't want to have to type IP, you know, BU2 all that time. Now if we create this macro of BL, whenever we run BL, it's just going to reproduce that text. So we don't have to type it up over and over again. So well, first off, let's add another section heading. So there's something to break here. Here's a break. Just so you can see that that's there. Now let's try this out. So if I type in BL, so this is a bulleted item. Missing all the keys. Here is another something like that. So all we have to do is type BL. And since we've defined this macro, it just is reading this macro up here. And it works all totally fine. Okay. So that works more or less how you'd expect it to. Now I could move let's say this is sort of ugly where it is, maybe I can move it to the top of the document. You know, sometime in tech or other documents, it's nice to define things at the beginning, just so you know, you won't have to worry about where you define them. But another alternative is you could actually put this definition in a separate macro file. So let's do that. Let's open up, I'm going to open up, let's say macros, open up a document. And I'm going to take this definition and I'm going to put it into this document that just says macros. Okay.  And you don't want to have them clogging up every single document you have. You can just put them in one single thing. And now what we can do, oops, didn't mean to close that out. Now what we can actually do is well actually let's re one run it. And we'll see that now that the macros are gone, it's not going to know what to do with this BL stuff. So it's going to just ignore it. So you'll see that all of this got interpreted as part of the header. But anyway, we can add a macro. We can go here, or yeah, I gotta make sure I'm doing it right. So I think it's macros. Why did I name it? Name it macros. Yeah, whatever macros. Maybe I didn't let me double check. Actually, scratch that I stopped the video for a second. That's actually a more complicated way of doing it. Instead of doing it on the command line, one thing you can do is at the beginning of your document, let's say you all you have one rolling macro file where you keep all the stuff you need, you can actually just sort it or sort it source it at the beginning of whatever file you have. So I've named the macros file macros. I can just name it that at the beginning of my document. And then this file is going to read it. So whenever you have a document, you can just source it wherever it is. That's the easier way to do it. So you'll see now these bulleted items are indeed here. But the definition of BL, I mean, if we look for definition of BL, it's not there. That's because it's in, it's in the macros file, as we said, and we're just loading that up. So you can easily source and of course this, I mean, this is similar to using tech packages or something like that.  So that's pretty much all I want to talk about. I mean, obviously, we're not going into the specifics of all the things you can do with do with macros. But this is just to give you an idea of how to define them, how to use them, how to put them in a file, how you can customize this customized graph to do pretty much whatever you want it to do. So anyway, that's it. So I'll see you guys next time. Again, I'll do one on pre processing pretty soon. And yeah, all right, hope you enjoyed it.


In this lecture 9th, we continue to discuss spreading its interrelation with interfacial and surface tensions and we also try to obtain a certain theoretical insight into what happens at the surface especially from the view point of works of adhesion and cohesion. We will also try to obtain certain insight into design of products which may be motivated by some of the basic concepts that we will try to outline here. We begin with a quick recap of what we have done in the last lecture. We had looked at this particular measure of spreading. The spreading coefficient as it implies an incomplete balance that would remain as a residual of the balance of horizontal components of surface and interfacial tensions when you attempt to spread one liquid on another. So, if we were to think of spreading of an oil on water, the spreading coefficient would be given by this surface tension of water in contact with air which is trying to spread the drop minus the maximum action that the surface tension of oil or the spreading liquid and the interfacial tension between the spreading oil and the substrate which is water that tries to oppose the surface tension. The magnitude by which these spreading and restraining factors come out as a balance that is the net spreading coefficient. We realize here that when the contact angle that the oil makes and the angle that the interface makes with respect to the horizontal, even if they were to reduce to 0, they would not be able to exceed the sum total of this gamma OA and gamma OW as the restraining action. So, if this coefficient is positive, we would expect spreading. Now, depending on the magnitude of the spreading coefficient, we may have spreading which just occurs or it might be a situation where there is a strong tendency for the spreading liquid to spread out on the lower substrate liquid and then we got into the nitty gritties which rise for the changes which occur when time is given for the phases to get perhaps mutually saturated and it turns out that in many cases the spreading coefficient may be marginally positive in the beginning, but turns out to be negative at the end. So, this was one example benzene being attempted to spread on water where we find initially the spreading coefficient is positive 8.9 not very high, Ergs per centimeter square, but when benzene gets saturated with water and water gets saturated with benzene, the final spreading coefficient turns out to be negative minus 1.4 Ergs per centimeter square and this has predominantly occurred because of the reduction in the surface tension of water by about 10.4 dyns per centimeter. What physically it means is that there is a monolayer of benzene which occupies the surface of water and there is a certain orientation the benzene molecules exhibit on the surface making benzene unfavorable for further spreading. Then should there be some extent of spreading right over the surface in the beginning then because the final spreading coefficient is negative the system responds by retracting benzene into a very flat lens which is clear indication that under the final conditions the spreading is not favorable. And then we looked at a number of values of spreading coefficients and especially we make note of here spreading question for methylene iodide which is a very large negative value minus 26.5 dyns per centimeter. We will return to this value a little while later in the light of what we are going to discuss today. Amyl alcohol on water exhibits a similar situation what it implies is that amyl alcohol would also retract into a lens under the final conditions situation might be somewhat like this. Physically it means that the oriented hydrocarbon layer is not favorable for spreading of amyl alcohol beyond a point and the amyl alcohol prefers to be in a random mixture of hydrophobic and hydrophilic parts rather than spread on the oriented less favorable monolayer which occupies the rest of the surface. So, spreading question in the beginning is about 44.3 dyns per centimeter, but in the final analysis it turns out to be minus 2.0 dyns per centimeter. And then we have other cases like carbon disulfide water where the initial spreading question itself is negative and would become further more negative going from minus 7.6 dyns per centimeter to minus 9.9 dyns per centimeter because the surface tension drops by this magnitude 2.3 dyns per centimeter which corresponds to an invisible monolayer of CS2 with this surface pressure pi equal to 2.3 dyns per centimeter. We may conclude for the last lecture that the saturation of liquids in general makes the final spreading question less favorable than what is implied by the initial spreading question. Then we briefly looked into the kinetics of spreading and benchmark the speed of spreading in context of the average speeds that we are familiar with our own movement on this planet. And these velocities of spreading or spreading kinetics are of importance in certain phenomena like kicking droplets or in the applications of anti foam agents. This was the apparatus that we had used where Tulk is used for visualizing what happens at the surface. And when you release a liquid spreading liquid from this glass plate into a surface or interface then it pushes the Tulk layer in this direction and we record the movement of that front with respect to time. And what we get is an initially changing distance versus time plot which changes slope then kind of stabilizes at a constant slope. And finally, we have the diminishing slope of distance versus time or the position of the interface versus time when the depletion arising out of either desorption into bulk of water of the spreading acetone like material or evaporation causes a fall in the rate of spreading. And typical Sine camera that was used in the past would have about 16 frames per second as the frame grabbing speed. Constrable precautions have to be taken in preparation of materials and that will reserve for later lectures. An important point here was that we tried to correlate the initial spreading rate for different liquids at surfaces of water or at interface between water and different liquids in presence or absence of surfactants. This was the case of a surfactant being used at an interface. And the last column reflected the measure of what the viscosity of adjacent liquids would do to the rate of spreading. So, trying to take that factor out we have here S by sigma eta where sigma eta would be at least the sum of viscosity of the underlying liquid and the liquid on top. In a rigorous analysis that should also take into account the viscosity of the spreading liquid. And we find that there is a good correlation between the initial spreading rate and this S by sigma eta. And when you compare the spreading at a surface against a situation corresponding to spreading at an interface likes between petroleum ether and water we find that there is a factor of 2 involved. The viscosities of the adjacent liquids tend to add up to an equivalent of diminishing the velocity of spreading by a factor of 2. So, that was our general conclusion that at oil water surfaces or interfaces the spreading is about half as fast as at air water surface. And since this cohesion S by sigma eta is a rough measure of factors controlling the rate of spreading we naturally come to a conclusion that a rate of spreading is equal to a constant times S by sigma eta. And the action of viscosity comes through the no slippage between the spreading layer and the liquid above and below it. In context of spreading from solids we noted that there is a very marked dependence on temperature and there is a critical temperature below which the spreading rate is extremely slow. The energetic is not favorable, but if you have temperature which is equal to or greater than critical temperature then the spreading is relatively rapid. Generally as you increase the number of carbon atoms in a homologous series the critical temperature increases. Another important point was what happens to the spreading when you contact a solid with liquid and where is the spreading occurring from? Where do the spreading molecules from the solid leave the surface of solid? It turns out it is not into the bulk of water but rather only at the periphery or at the three phase contact line where the solid has whole formation the molecules leave and then they occupy the position in the surface. And this can be demonstrated quite easily by placing a drop of water on a flat surface of solid steric acid. It just leaves an observable ring at the periphery with the inside of steric acid not dissolving at all practically. We just looked at the rates of spreading and the constants which characterize the spreading. In general the number of molecules spreading per second will be equal to constant times this perimeter into the driving force which is here the equilibrium spreading pressure minus the existing spreading pressure that gives the constant involved here of the order 2.4 to 3 into 10 raise to 12 molecules per dime per second. We concluded that lecture by noting that you can actually measure the molecular weight of protein by first having a monolayer of protein by touching a clean water surface by a protein crystal and withdrawing a hydrophobic fiber slowly through this surface there by depositing a monolayer of protein on the fiber by weighing the fiber before and after we know how much is deposition and from there we can actually figure out what is the molecular weight. We will go into the details of this kind of calculation measurement and calculation a few lectures later. Then we came to the relation between the surface and interfacial tensions and that will occupy most of our today's lecture and we began here looking at the thought experiment that Gibbs advocated. May be a little bit of information in way of digression I can pass on to you about this celebrated scientist Joshua Willard Gibbs. Most of you who have had exposure to thermodynamics at some level or other inescapably would have come across Gibbs's adsorption isotherm and various contributions. He was in a sense precision personified. So meticulous was he in his work as well as his day to day habits and so much was his punctuality that the, that was the point. The folklore has that people used to adjust their watches depending on when Gibbs would take his lunch break. You see that commitment and precision of work in his theories too. This is one simple example of how mind of a genius like of Gibbs really worked. This treatment of Gibbs in context of interfacial and surface tensions is something that I briefly introduced but will go into the details today. Gibbs started with the consideration of interfacial tension between mercury and water and like most of his subjects of interest he focused on equilibrium and he wanted to have a general deduction about interfacial tension in terms of surface tensions of the two components when they are in equilibrium. He deduced that the interfacial tension between mercury and water would be equal to the surface tension of mercury saturated with water minus the surface tension of water saturated with mercury. Obviously, the surface tensions are with reference to air being the phase in contact with the liquids that we are considering. We had in passing noted Gibbs's thought experiment. What he had presumed was you would have two chambers connected through the vapour space. On one side we have mercury, on other side we have water and his argument was the following. This space would have predominantly water vapour. Obviously, there will be a few mercury atoms or molecules here too but predominantly is water and then he argues by saying that we need to focus what happens here. What happens at the surface of mercury when it becomes accessible to the vapour of water which is present in the other chamber and when you look at the unit area here at the surface of mercury, this is where he expects to find an answer which would be justification for this. Now, let us look into this thought experiment closely. On a clean mercury surface, we would have a very high surface energy. The surface tension of mercury is very high close to about 485 dyns per centimeter compared to otherwise exceptionally high surface tension of water which is about 72 dyns per centimeter. He argues this way that that high surface energy of mercury will tend to lower itself and it would do so by adsorbing whatever vapour is present in its vicinity which means from the saturated water vapour some water molecules would be adsorbed on the surface of clean mercury surface with its high surface tension. It is impressive that he could visualize what might happen and he could ascribe some of the not so obvious attributes to the thin film of water that would be deposited on the mercury surface in the process. He argued that the thin film of water which therefore would result on the surface of water might be thin enough on one hand to be considered as a part of the surface of mercury itself. On the other hand, he argues that it may be considered thick enough to behave as if bulk liquid water vapour would appear in contact with mercury. Now that is the part which is not so obvious whether this is true or not could only be checked in the face of experimental data. If that were true if those arguments were true the total surface tension or energy for mercury with adsorbed water should be equal to some of the surface tension of water which is present as a thin film and is part of the surface of mercury and the interfacial tension between mercury and water. That interfacial tension would have a value gamma Hgw where our thin film to behave like a bulk liquid water. But if you accept that then you at once see that gamma Hgw is nothing but gamma Hg saturated with water minus gamma w saturated with mercury and that is equation that we started out with. This is exactly identical with the equation that we have cited from Gibbs's deduction. In practice what happens to the surface tension of water? If water is also saturated with mercury that would happen given sufficient time for the two phases to achieve an equilibrium. It so happens that the surface tension of water is comparatively much lower and there is only a negligible effect on the surface tension of water because of presence of any mercury which might dissolve in it. And this relation advocated by Gibbs for especially mercury and water system has been tested at 25 degree centigrade and it gives you a value of 374 dynes per centimeter. Surface tension of mercury water system when we have these phases mutually saturated works out to be 447.6 minus 72 or about 375.6 dynes per centimeter. The measured value of interfacial tension between mercury and water of 374 against what is deduced from Gibbs's analysis is pretty much close to each other. In a sense that assumption which for most of us would not be very clear in the beginning that the thin film of water which is adsorbed on mercury would actually behave like bulk water is the same to be substantiated by experimental data. And when we question about the validity of such arguments for equilibrium between mercury and other organic liquids the same conclusion is reached. It is here that we run into a relationship I am certain all of you are exposed to some time in your chemistry courses and that is Antonov's relation. According to this the interfacial tension between two mutually saturated liquids is equal to the difference between their surface tensions when each of these liquids has been made saturated with each other. Antonov's relation in this manner is a generalization of Gibbs's statement. Gibbs's statement was deduced based on mercury water surface Antonov's relation is a general relationship. There are some caveats here one has to be aware. You may note in passing here that with respect to water and organic liquids the kinds of systems you often come across in practice the mutual saturation can occur extremely slowly sometimes as much as 10 days may be required to reach an equilibrium. This point is something most people are not aware of academicians are no exceptions. Let us say by B we indicate an oil phase then in terms of our chosen notations B W would be the phase B oil phase which is saturated with water. And by W B we would understand water saturated with the liquid given oil. To keep things simple let B be benzene. So, if you have benzene saturated with water according to Antonov's relationship gamma B W is the interfacial tension between benzene and water and that is equal to the surface tension of water saturated with benzene minus surface tension of benzene saturated with air. So, all tensions interfacial and surface tensions are when mutual saturation has been accomplished. This table gives you a set of values and sort of projects a certain result that we will try to establish in the next few slides. We see here for different oils benzene chloroform carbon tetrachloride toluene and methyl methylene iodide all at 25 degree centigrade. The surface tensions for water and the oil when they are saturated with each other and the interfacial tension between oil and water in these columns surface tension of water, surface tension of oil and interfacial tension. These are the major values for surface and interfacial tensions all at 25 degree centigrade. Last but one column gives you the difference between the surface tension of water and surface tension of oil when water is saturated with oil and oil is saturated with water. And the final column gives you the final spreading question for oil saturated with water and water saturated with oil using equilibrium values for surface and interfacial tensions that is the final spreading question. Now, we expect to see the validity of Antonov's relation or for that matter gives us deduction when we compare this experimental column against this theoretical prediction based on measured experimental surface tension values. So we see for benzene an exact agreement 27.2 dynes per centimeter. For chloroform it is 23.0 versus 24.3 some difference 1.3 is the final spreading question. For carbon tetrachloride again we have exact match for toluene again exact match for methylene iodide a stock difference very different values between these columns here. The interfacial tension is about 40.5 what is predicted by Antonov's relation is 19.6 the final spreading question is as we had seen earlier large negative value minus 24.2 dynes per centimeter. We will try to rationalize these data, experimental data in the phase of Antonov's relation. And in the process C whether we can get some more insight a very interesting result was obtained by Adam he combined Antonov's relationship with Dupri's equation. I am tempted to give you a mnemonic here if we represent Antonov's relation by A and Dupri's equation by D A plus D gives you A D A D for Adam. So you will never forget which relations go into which final result. We start with Dupri's equation. Dupri's equation gives you the work of addition between the oil and water W B W that is equal to gamma B W A plus gamma W gamma W B A. Minus gamma B W, gamma B W A that is the surface tension of oil saturated with water plus gamma W B A which is surface tension of water saturated with oil minus the interfacial tension between oil and water gamma B W. And then we plug in for gamma B W for gamma Antonov's relation. So we take the Dupri's equation and plug in for interfacial tension the expression given by Antonov's relation. So first two terms are identical gamma B W A plus gamma W B A minus for gamma B W we substitute gamma W B A plus sorry gamma gamma B gamma W B A minus gamma B W A. So when we substituted for gamma B W as gamma W B A minus gamma B W A we see that this gamma W B A cancels that turns into a plus sign. So we get two gamma B W A. Work of addition between oil and water is seen to be here equal to the work of cohesion of oil. This is something which I think we should analyze and understand. Gives a statement gives us the starting point to understand this. It would also help you understand why in this column there is some failure seen. Clearly this is approximate this is total failure right and we must understand why this is happening. We expect Adam's result to help us understand what is happening. I am sure some of you must be imagining the picture at the level of the interface. That is where the answer should lie. I will try to make it obvious to you. How is it that the work of addition between an oil and water comes out to be equal to work of cohesion of oil? Next diagram should make it clear. If we have benzene in contact with water our result is the work of addition between benzene saturated with water and water saturated with benzene is equal to work of cohesion of benzene. It implies that water must have retained a film very thin film of benzene. Something similar to the film of water which was postulated by Gibbs on mercury surface and that too would behave like the bulk of water and the Dupre's experiment which involves separation of benzene and water would lead to a separation of the two phases with benzene layer a thin benzene layer still sticking to water. If this is the case what is what has happened is the benzene has separated from itself. So, when you are looking at benzene being separated from water when you pull apart unit area of this interface you leave part of benzene on water. In effect you are separating benzene from itself and that will be the work of cohesion of benzene. That is what is written in words here the work of addition between two mutually saturated liquids is equal to the work of cohesion of the liquid of lower surface tension provided it has been saturated with the liquid of higher surface tension. There could be a certain projection which will serve the rule of another mnemonic here. You would never forget this if you look at the next observation and we will try to see if there is a projection for product development here. In my first lecture I listed out lots of common products which I stated would be influenced by interfacial phenomena surface phenomena at some stage either during their production or during their usage. I would like to bring from that that list this particular product adhesive. In general what attributes the adhesive should have and how does all that fit in into this mnemonic I am trying to explain to you. What has happened to separation of benzene and water when benzene is saturated with water and water is saturated with benzene is something similar to your observation when you try to pull apart an adhesive tape stuck onto a paper. You all seen that when you peel off this adhesive tape from paper it brings with it a thin layer of paper that is provided you have a proper adhesive. And what is that proper adhesive? The proper adhesive should have enough of its own strength that the bond is stronger than the bond it forms with the substrate. So, when you try to forcefully take away an adhesive tape it must be able to snap off a thin layer of paper and not snap off in the middle of itself. So, adhesive use on adhesive and adhesive tape must have enough of its work of cohesion to exceed the work of addition. So, to say in equivalent terms for liquids between the surface of the adhesive and paper. So, that work of cohesion must exceed the work of addition that is the only way that the adhesive will not fail. Talking about failures I am also tempted to tell you another aspect of this and we will try to confine it to the context of the adhesives. Sometimes the failures have as much to teach you as successes at times even more than successes. This is no greater a truth in the context of product development than in any other context. You could think of this for a moment what if our adhesive were not appropriate. We intended to make an adhesive which would serve the proper bonding with the substrate, but what if something goes wrong has that happened historically potentially creating a new product. In the light of what visualization I have asked you to make you can think of the post-it notes. Post-it notes probably were designed to have work of cohesion smaller than the work of addition. So, while we have temporary bond with the substrate paper when you take off a post-it note it would still be left with an adhesive layer. So, the adhesive layer must have snap form itself work of cohesion must have been lower than the work of addition and this would be possible a number of times. Unless this is possible a number of times the post-it notes would not be a successful product. There is a lot here than I intended to convey to you. I must tell you that such a simple thing as an adhesive tape a cello tape has been the instrument of experiments done by a couple of physicists each one all know that graphite is layers of carbon layer by layer structure. Nobody believed that you can take off individual sheets of carbon layers from graphite, but these physicists at Manchester actually managed to repeatedly peel off layers of carbon atoms from graphite and in roughly about 50 odd repetitions they could get down to a layer thin enough to be atomically thick. So, what was never theoretically expected was achieved experimentally and that is what has now created a great interest both in research and applications in the area of graphines. You can have attributes to graphene which are very different from you may otherwise realize in any other form of carbon. I will just complete this lecture by saying that in context of this benzene water interface there is a decrease in surface tension of water by about 15.5 units. So, the surface tension drops from 72 to 56.5 dynes per centimeter and this is not surprising because benzene is known to adsorb on water surface giving monolayers with this kind of surface pressure and it exactly analogous to the original suggestion by Gibbs that the adsorb film of water on mercury behaved as though a normal liquid water were in contact with mercury. We will stop here for today.