Welcome to George H. Smith's Excursions into Libertarian Thought, a production of Libertarianism.org and the Cato Institute. I'm Rand on Aristotle. According to Aristotle, there are certain people who are free and certain who are slaves by nature, and it is both to their advantage and just for them to be slaves. As David Brian Davis, a leading historian of slavery, noted in Inhuman Bondage, The Rise and Fall of Slavery in the New World, this conclusion by Aristotle would have an immeasurable influence in western culture. Even in the 1200s, at the very time when chattel slavery was disappearing from northwestern Europe, Christian theologians revived and made extensive use of many of Aristotle's propositions. It is significant that Aristotle's theory of slavery formed the framework for the momentous debate in Spain in 1550-51 between Juan Ginez Sepulveda and Bartolomé de las Casas on whether American Indians had been created to be natural slaves. And while it would be absurd to blame Aristotle for all the uses to which his writings have been put, he did eventually provide the conceptual basis for much 19th-century Southern pro-slavery ideology and scientific theories of racial inferiority. Aristotle's defense of slavery was based on the theory that some peoples were congenitally incapable of reasoning and so were intended by nature to be slaves. These natural slaves, certain tribes of barbarians, were inferior both mentally and physically to Greeks. Inferior peoples are suited only for the menial duties of life, so they should be treated as animate articles of property, as we would treat domesticated animals.  Moreover, slavery, in addition to being just, actually benefits the inferior classes, since it enables them to partake of the superior abilities of their natural masters. Einran detested racism, which she denounced as an evil, irrational, and morally contemptible doctrine, and slavery needless to say was an enormous evil. Now, given that Aristotle was quite possibly the most influential defender of slavery and racism in the history of western civilization, should we therefore conclude that Aristotle himself was evil, irrational, and morally contemptible? This conclusion might seem justified, given how Rand condemned Kant as the most evil man in mankind's history, but this is not how Rand assessed Aristotle. On the contrary, she described Aristotle as a philosophical atlas who carries the whole of western civilization on his shoulders. She continued, Whatever intellectual progress men have achieved rests on his achievements. Whenever his influence dominated the scene, it paved the way for one of history's brilliant eras. Whenever it fell, so did mankind. In Rand's generally favorable review of the book, Aristotle, by the distinguished historian of philosophy, John Herman Randall Jr., she took issue with Randall's shocking assertion that Aristotle is an advocate of the welfare state. Rand curtly replied, Whatever flaws there are in Aristotle's political theory, and there are many, he does not deserve that kind of indignity. Professor Randall, who stresses that knowledge must rest on empirical evidence, should take cognizance of the empirical fact that throughout history the influence of Aristotle's philosophy, particularly of his epistemology, has led in the direction of individual freedom of man's liberation from the power of the state, that Aristotle, via John Locke, was the philosophical father of the Constitution of the United States, and thus of capitalism. If anything, when Randall characterized Aristotle as an advocate of the welfare state, he was being unnecessarily modest. In maintaining that the state is both natural and prior to the individual, Aristotle sought to justify a kind of political organism, an approach that Rand would have labeled collectivism, that would profoundly influence Hegel and other statist philosophers. In addition, Aristotle's doctrine that the state grows naturally from the family became the major argument of later philosophers who rejected the liberal argument, as found in Locke and many other political individualists, that legitimate governments must be grounded in the consent of the governed. And although the particulars of Aristotle's ideal state are somewhat less repulsive than the unvarnished totalitarianism defended by Plato, Aristotle set no theoretical limits on the power of the state to dictate the lives of individuals, down to the minutest details. As Ernest Barker, a distinguished historian of Greek political thought, put it in regard to Plato and Aristotle, the limit of state interference never suggested itself as a problem for their consideration. Plato's austerities are famous, but even Aristotle can define the age for marriage and the number of permissible children. Whatever has a moral bearing may come under moral regulation. Aristotle's political views were the reverse of the theory of limited government defended by liberal individualists. Rather than begin with the good of the individual and build his theory of the good society on that foundation, as we find in theories of natural rights and social contract, Aristotle employed the typical collectivist reasoning that the good of society is paramount, and from there he worked backwards by inferring that since what is good for a community is also good for its members, any laws that restrict individual freedom for the good of a society must also benefit its citizens. Hence, when Aristotle proposed laws that should govern an ideal state, he didn't view their effect on personal freedom as important enough even to consider. As a philosopher who had discovered the conditions of a good society, he merely needed to call for the codification and enforcement of those conditions in the form of coercive laws. As I wrote in a previous essay, Aristotle explicitly repudiated the notion of limited government that was defended by some of his contemporaries. He quoted the Sophist Lycophron as saying that a government exists for the sake of alliance and security from injustice, and that laws should serve as a surety to one another of justice. Aristotle disagreed. Rather than confine itself to this negative function, the enforcement of justice, the state should actively promote the good life. In order to promote the good life and maintain social order, the state should inculcate civic virtue. Those who care for good government take into consideration virtue and vice in states, whence it may be further inferred that virtue must be the care of the state, which is truly so called. This concern with civic virtue was the basis for Aristotle's plan of a comprehensive system of state education, one explicitly based on the Spartan model. It would be difficult to overestimate the influence of Aristotle's defense of racism, slavery, and political collectivism on Western philosophy, politics, and culture. For centuries his doctrine stood as major obstacles to the development of theories defending the equal rights and freedom of individuals. Yet according to Rand, Aristotle is the father of individualism. It took centuries of intellectual philosophical development to achieve political freedom. It was a long struggle, stretching from Aristotle to John Locke to the founding fathers. The system they established was not based on unlimited majority rule, but on its opposite, on individual rights. Moreover, to this day everything that makes us civilized beings, every rational value that we possess, is the result of Aristotle's influence. It is quite astonishing that Rand could make claims like this, while blanking out the deleterious influence of Aristotle's political ideas. To credit Aristotle as a father of individual rights and political freedom is absurd, as are some of our other claims, such as our simplistic assertion that the Renaissance was a rejection of Plato in favor of Aristotle. How can we account for these serious, indeed perverse, lapses in historical judgment? The major culprit here was Rand's belief that a philosopher's metaphysics and especially his epistemology trump everything else, that his fundamental view of reality and his theory of knowledge will ultimately determine his influence on later thinkers. Aristotle's moderate realism, to use the conventional label, was essentially correct according to Rand, so it follows that Aristotle's influence must have been good, whereas the irrational epistemology of Plato, and later Kant, must have been bad. As Rand wrote in a letter, the crucial difference between Plato and Aristotle lies in their respective theories of knowledge and in their views on the nature of reality. That is the root. Their ethics, politics, etc. are the consequences. Or, as Rand put it in, for the new intellectual, No matter what remnants of Platonism did exist in Aristotle's system, his incomparable achievement lay in the fact that he defined the basic principles of a rational view of existence and of man's consciousness. Strangely perhaps, Rand's view of the history of philosophy resembles, in some respects, the approach of Hegel, who viewed the history of philosophy as the inevitable development of the inner logic of ideas, especially in the field of metaphysics. For Hegel, the intentions and purposes of individual philosophers were largely irrelevant to how philosophical theories emerged from their metaphysical premises. It was almost as if the history of philosophy could be written with only incidental references to specific philosophers, who were but waystations on the inevitable journey of ideas to their logical destinations. According to Hegel, as philosophical ideas became objectified in the traditions, culture, and institutions of a given society, those ideas will profoundly influence the intellectual perspective of the members of that society. Of course, the similarities between Hegel and Rand should not be pressed too far. For one thing, among many, Hegel believed in the deterministic progress of philosophy, a notion that was absolutely foreign to Rand's way of thinking. But both thinkers were fond of what I can only describe as a priori history. Instead of looking as impartially as possible at how the ideas of one philosopher actually influenced other philosophers, both Hegel and Rand began with the a priori premise that certain types of ideas, Hegel focused on metaphysics ideas here, whereas Rand put more stress on epistemology. Must as a matter of logic surpassed the influence of all other ideas, such as those found in political theory. Thus, if Aristotle's rational epistemology did not prevent him from defending racism, slavery, and statism, this could only be because Aristotle himself did not understand the logical implications of his own epistemology. And if later defenders of racism, slavery, and statism were profoundly influenced by Aristotle's theories, this was only because they too did not appreciate that such theories were inconsistent with Aristotle's theory of knowledge. Aristotle's rational epistemology must have had a benevolent effect on Western civilization, whereas his political ideas were in effect non-essential errors. It should be said that Hegel, who was one of the most knowledgeable historians of his era, executed as a priori history of philosophy more successfully than Rand managed to do. Although Hegel sometimes tailored his history of philosophy to meet the demands of his a priori premises, he never falsified the historical record. I wish I could say the same about Rand, but I cannot. Her admiration for Aristotle, which was justified in many respects, got the better of her, sometimes causing her to distort the facts of history with gay abandon. So far as I know, she never once mentioned Aristotle's defense of racism and slavery, much less the tremendous influence of that defense on later thinkers. Instead, as quoted above, she claimed as an empirical fact that throughout history the influence of Aristotle's philosophy, particularly of his epistemology, has led in the direction of individual freedom, of man's liberation from the power of the state. Although this may have been true of Aristotle's influence in some instances, as a generalization, it is a flagrant distortion of the historical record. Is there a logical relationship between the epistemological theories of a philosopher and his political theories? Although this connection may be plausible in some cases, as when historians link William of Occam's pioneering theory of individual rights to his nominalism, according to which only individuals exist, any such relationship must be decided on a case-by-case basis. Such matters are far too complex to admit of sweeping generalizations based on a priori assumptions. I shall explore this and related problems in my next essay. Thank you for watching.


Good evening everyone. This is Mahesh and I should really be thanking you all to organize this story in this community And I'm really glad to be here cool, so obviously I'm talking about React life cycle methods and they're probably Few months back we got a big news by Dan Abramow mostly that a lot of Component life seconds are breaking deprecating Changes he launched hooks which Kean talked about and a lot more things are happening, right? So probably the agenda of today's talk Major least two Week together will take a deep dive in what exactly is React life cycle methods. What are the new changes? I'm not gonna talk about the older one because that's sort of has not and not be in context or we should not Care much about that. What was earlier? So it is all about what are the changes and the from The moment a component renders or it starts to what happens until it is unmounted We'll talk everything about it. Just even before I start. I just want to know that how proficient we are on react Life-cycle methods are so that I can Decide that how much deep should I go is it experts any experts? Everyone's laughing Okay, oh one expert. We have got one expert. That's great. Okay, so immediately. I'm thinking just medium So even I can relate that. Yeah, it's not that straight forward. So let's try to jump into it Okay myself. I'm Mahesh. I am full-stack developer and I love react here And I'm a storyteller. So I do share or some podcasting on YouTube. That's a Hindi language So that's Indian. So you would not understand and I'm a blogger I am quite active in medium.com my few of the blogs have got published in multi language Right rest API guidelines react component life cycle methods and few other stuff. You can follow me on medium Let's be connected. I'm open source contributor as well. Like I have got to couple of NPM library like in hooks and Using tooltip react tooltip and yes in India just before Singapore. I was in India I did couple of a lot of react training in India as well as South Africa So, yeah, and I'm ex-mikin see and right now I'm walking in a starter. I'm a tech lead That's me on a summary Let's start. Let's start our deep dive Before we start with the what exactly is component life cycle method. This is the one-line intro of react There's the official introduction of react. That says react.js is a JavaScript library for building user interfaces If you see I did bold user interfaces. So in react, we only create user interfaces What is into user interface user interface is any area any zone where user goes Interacts and basically he commands. So that's why it's an interface which is Led by the user and we as a developer we provide that playground for the user to Interact with our app. So that's it user interface now cool Why should we discuss and why should we know about? react life cycle method that's Before you've been going into it Knowing that is really important because you should know the value and then we should be doing Why exactly we are learning and why exactly you should be listening to me on this talk? So maybe I just want to Put out put one analogy that how exactly react looks like. So if you see this is a bunch of television and The every television has got its own connectivity to power its own connectivity to maybe Compact displayer so that you can control every of the television on its own and this whole Combination is react every small Television is a component and you can control individual component on its own right so so For example, why how what is the role of? Life-cycle component methods for example, you want to program your all the television that whenever you start television number one It should show up this is television one and this of this brand and then it starts Displaying and then probably you want to control on the television number three that whenever it starts Whenever someone changes the channel, it should show a different message so that you can have more control and these are components We'll come back to on this again Taking the same analogy on the interface so we can actually divide the whole Every portion of it as a separate component and each component has got its own control for example whether show or not or for example when you When you click on follow button it can actually call up API so so the other components need not know about what exactly the other component is doing Now as I was saying that you can actually Connect every television with its own compact displayer and that's why if you hear a lot mounted Did mount will mount so you can actually imagine that whenever you mount a disc on the compact displayer That is will mount a dead mount or This analogy is just to set your expectation that whenever we will talk about Did mount will mount did update how exactly we can relate with with the Compact displayer so whenever we say mount so you what do you exactly do you take a disc compact CD and then you mount it on the player and it plays from there. We'll come back to on it again Okay, why life cycle is important because though that was more about setting up the context now We shouldn't discussing we should be discussing why life cycle is important Everything everything in this universe goes through a life cycle you Maybe any company any tree Everything goes to us life cycle method it takes birth it grows it grows and one fine day It starts degrading and one fine day it will die And scene happens with our react component as well. So it Will prepare itself to mounted or to get birth Onto the browser and browser is that Area or that player where it is going to mounted or going to be played around and then It will update get the updates That is where it grows because it's taking new update by clicking off the button taking new props setting up Changing the state that is updation and then one fine day when you close that model for example or close the website That is where it is it is unmounted Okay, and to apart from that also Why we understand that right that it is important and why it is important because if you know That if you know the hook points that at this point of time something is going to happen You can plan better right for example, maybe take yours your example when you are about to get birth Your parents did plan some stuff for you, right? You are coming or maybe you were not that welcomed That is another story if you would okay, so Whenever you're getting going to get both your parents are planning that okay one fine day All the toys all the clothes needs to be there And when you are going to good get to the school and your parents know that at this point of time My child is going to the school. I need to search a better school Imagine if your parents never knew that what time you are getting birth or what time you are about to go to the school Then they cannot plan efficiently and same happens with us also as For example, let me give you the example of YouTube for example, you want to optimize your YouTube app and Obviously YouTube buffers and takes Battery and it takes your network bandwidth as the resource which comes into buffer the video now if the user Switches back to another app. Then actually you can track that whenever this app is out of focus I can stop the buffering. I can stop taking the battery. This way you are optimizing your apps and If you know all the hook points Where and what thing is happening? You can plan accordingly in a better way, you know very much efficient efficient way, okay So that is that is why it is important and we should be talking about it in detail. Okay talking about phases These are the three phases Mounting updating unmounting as I talked about told you that whenever your component is about to Mount on the browser You get one set of function where you can perform something That is where the that phase is called mounting phase when it is It is still not mounted yet But it still it is in the process and then when it is mounted already now For example, if the button clicks on if the user clicks on some button So it is updating it is getting updates whether that is a state update via props or some some others some other way So that whole phase is called updating and last is unmounting obviously when the Component is going to unmount or get close for example If you hit back button or if you hit submit button it should go to next page or if you hit the close button in a model So that model is going to close so you can do some some stuff. So we'll we'll go in deep in that Okay, this is the end state don't get confused or don't get In a problem that what exactly is this because the same was my reaction when I started with React that what exactly this diagram or what exactly the whole life cycle component is So this is our industry by the end of this talk my target is so that we together should be able to understand Decode every part of it. I know few of people already know but I'm still talking in a journalizer so that everyone Is on the same page. So by the end of the talk, we should be able to understand this diagram Okay, what is it matter? I already talked about we should know the hooks so that we can better optimize it This is again the same analogy which I tried to put that every component has its own control for example You as as a person has got your own control and I as a person has got my own control So we can finally run our Life-cycle methods for example When I am ready to go to school in the similar way you will get your own when you are ready to get go to the school That's why everything is separate every component is separate Okay to now because we are going to get the deep dive in the each of the methods of life cycle of the react life cycle let's Imagine that we are going to build a Contra music player some music player so that we can better understand that in which use case Which method is going to be used? Let's start with mounting. So mounting is that phase Where on the browser the dorm or the component is still not mounted? It is preparing itself to get mounted on the browser for the first time So the first function is obviously constructor As we know in even in oops also the construct is the first function that gets executed Where you can do the steps like setting up your first state initial values and you can set you using the Default props you can also set the default props as well So for example if you want to do a start your music player with a value of volume 70% and state as a spouse You can set here so that your component whenever mounts on the browser. It is starts with this value So we should it's pretty straight forward initially in the previous version of react that is 16.3 and below there was another method called component will mount and What exactly happened that comp and if you see that component will mount and the constructor are Pretty much same so constructor also call gets called first time before render component will mount also gets Called first time only one time before mount so and even there was a huge discussion going on that We should merge it and finally in this 16.4 we merged it and we have got only one that is constructor The next method is static get derived a state from props Let's try to decode it if you see this method is used for getting the derived a state from props now What is the use case a lot of times as react developers? our state depends on prop For example when you pass a prop as a function and then you Your your component depends on the props and you want to sync it so this is that case for example That's why the the name is pretty much very clear that get derived a state from props So we want to get a new state from props whenever the whenever state is dependent on prop for example You are setting this state age value from date of birth, which is coming from your props So you will do some processing You will take the date of birth current date minus and do the number of years or age and that you will set it to the state So that that kind of conversation or that kind of conversion happens in this particular method This is just to give an example for example And this is a static so you do not get the access of this And you you will get you will be getting the props and a state only So you can actually do you can compare that a state dot value is not equal to props dot value then you actually return a new state and You can also return a null when it is null it does nothing when you return a valid object It merges with your original estate Whatever you started with on the constructor so for example, if you say your Props is dependent or you states is dependent on props and that is a function which processes something So this is that use case when you're you want to sync your state with the props and do some calculations on processing Next method after constructor and then one method gets called get a state Get get derived a state from props and then actually the render happens in the render This is that method where equivalent HTML DOM is generated and then it will be sent to the browser So render is the final method Everyone knows that because we start with render, right? and then Actually mounting happens after render processes one particular object with your props with the states and everything it generates one Dom and then it mounts it and one another function is called that is component did mount as the name suggests that component did mount It says that component has already already been mounted to the browser and what is the use case of this? for example, you want to access the Dom and you want to use jQuery library to set the graph or maybe D3 library to set the graph on this value so whenever you want to access One particular or Dom it has to be bound mounted on the browser First so that's why all the calculations all the processing of graph or you want to use high chart or some other Library which accesses is Dom then you need to do all this processing and component did mount Because just just try to understand You have got your reactor world where and if you want your high chart to take the Dom Then high chart doesn't know what react is or what their internal processing is happening He high chart only knows browser Dom which we see in the elements in the console of the probe So that's why now once the component is mounted We are pretty much sure that my component is on the browser and another library can access the Dom to do some processing or modify it Okay, so this is just a quick deprecated methods which Have been deprecated from 16.3. So component will mount has been removed Complaint will receive the receipt props has also been removed Component will update is also removed. We'll talk about these two fun these two function in next life cycle And right now it is not totally removed. It is just prefix with unsafe and in react version 17. It will be removed So you're free to use and why they have done that so that you can slowly migrate to new life cycle methods or using hooks and all and Just to remind why this is again important if you want to totally understand hooks Then also understanding of react life cycle method methods is really important because hook is is Is the side product or The result in to make make your whole life cycle method is a little bit of easier That is that is the hope so we should be understanding late react life cycle better So coming to that particular diagram We have already talked about constructor then after constructor we call get derived in straight props then it renders and then It commits to the browser it sends to the browser and then finally we run component Did mount now we are going to talk about updating So this particular process this particular phase is then the component has been mounted already and render function has ran At least once or the first time So when we start the with updating updating can happen by Basically three rough base one is when you change the props props if you do not know what is prop prop is like function parameter So component is a function and props is a parameter So if you change the parameter of props then it will update your react component or when you change the state The internal state of your component then it will update the Component another way is another function that is force update You can from any point of time you can forcefully update your react that is force force update Which is not recommended bad practice. So we'll talk about the Update by props and update by state. So the first function is obviously called get derived a state From props. So this is the same method which we talked about when you want to sync your props and state And do want to do some processing. This is the first method that is get called and then after Get derived a state from props. The next method is called should component update as the name suggests It says that it expects true or false, right? So it is a question. Should it update the Component so yeah, so you can for example Your any render of component processes a lot of values and it goes through a heavy cycle And you want to get control on that whether I Every time some prop or state changes do I want to re-render the component or not? So you can control that thing in this particular function should Should component update and if it returns false then it will not go to the render It will not reload or it will not be remounted and if it returns true Then it will go to the render and remount it and if you do not write this function by default it returns true So we have more control But using we should be using it very carefully. This is again not recommended even by the official reacting But some cases we need to so there's just a quick example in the should component update you get the Next props and next state and the current state and current prop is available in this So you can do this dot props of this dot a state and you can do comparison and you can actually return a boolean to have a More control on a component rendering So this is what I'm talking about from the diagram that after we get a new prop or we change by set a state We get the get it get derived a state from prop after it passes We go to the should component update if it is true It will go to render if it is false. It will stop over there Updating phase obviously then after the after this particular Function the next function that is called and this is again newly introduced in 16.4 get a snapshot before update this is When I started on the day one when I tried to understand this was pretty fine This took a little more time to actually understand it I hope that I'm able to convey the same what I understood feel free to question me back if you do not get it So get a snapshot before update. Let me first tell you the use case. Why and the bench do we need to use this? This is One of the very rare function you will use but it's important to know for example you are doing a tooltip and While your tooltip is moving you change some state and your component reloads then there is at the worst condition There is potentially some chances that while you are moving it and the component reloads You will lose the track that where or you will you will face few of the laggings That because while you were moving it it re updated and as the react Versaildom works that whenever at in a binary tree in a tree of a component whenever it sees Delta It deletes all the child and it re Reattaches all the parent so at worst case for example if you're moving the tooltip and something gets update you might lose this Animation you might lose this flow. This will be not a smooth and same applies for your Scroll bar as well for example if you are Scrawling up and down and you are showing a list and at that point at some point of time if API responds you back And you update the state at some point of time you might lose the track So get a snapshot before update is a function where Before writing to the browser you get the previous state and you just wire it up I'll let you know I will talk about it. So Let me tell you can show you a quick example So you can see here that I got get a snapshot before update and as the names suggest that I want to get a Snapshot of the component before it actually updates so that I can continue after it is updated I think you will get it. So we get the props.  It's only once but did update will happen Any number of time update is happening, right? So this is that component component did update So in component did update whatever you return here You will get here a snapshot and here you can set that current is crawl height is from the snapshot So just think that you were moving a tool tip and here the update is happening Before actually rewriting on the browser. You're taking the current is snapshot and it updating it and you are passing it to the newly updated DOM The older is snapshot so that you can wire it up As simple as that try to make it simple, but yes, this is the definition and this is where it is going to be used Does it make sense? Yes, no Or should I repeat? Yes, please Then Yeah, yeah, you got it, right so big because On every because you see this particular function will get called on every update on every update This might not be the condition that I want to I am installing so you your If this condition is not met you did not lose your Flow then you're returning null and if it is null then that you are skipping that from that condition and Whenever on that specific case you are handing over or you are continuing that flow Okay, so this get a snapshot before update as the name that get a snapshot Before actually updating it so that I can hand over after it is updated as simple as that And obviously the next function is component did update now as I was repeating that component did update Mount will happen only once and after rendering or mounting whenever you update wire state or wire prop It will always call that did update so that you can again now the use case for this you can again what if in component did mount you said the Highly D3 or high charts library to access the dome and now whenever something has changed now You should be again telling high chart that now update again. So this is that function in did update now You will get a notion that we are duplicating few of the things in didn't mount and in did update We are again duplicating it then obviously you can Solve it in various ways like passing a call back passing a function or taking out in a separate file something like that but that can be solved and Then obviously and after did update before did update we get the render So it happens the render and then get a snapshot before update and then it did update Yeah, so I talked about did update. So maybe let's have a quick look What exactly and where we are in terms of our end goal? So mounting we understand constructor happens and then we call get derived state from props And then in mounting the render gets called then here is that process in the browser It is writing it is committing to the browser and then it calls the component did mount After it is mounted then updating starts update can be done by three ways new props or Changing the state by calling set a state or force update when you do force update it directly Goes to it again passes through this function and then it directly goes to render It does not go to should component update because you are saying that falsely updated and it does not call the did update When talking about new props and set a state Should component update we talked about if it is true it goes ahead if it is false it stops there Then render calls then get a snapshot before update now you see that here is the Function Moment where commit is happening commit to the browser So component did a snapshot before update It takes the previous snapshot and handed hands over to component Did update so that you can wire it up Cool. Does it make sense? Now the next next is unmounting so when you are closing the model or when you want to close or collapse this This particular component This is where that function is get called and the use case is pretty much a straightforward Maybe you want to destroy all the charts you want to Remove the linkage or remove the library high chart library. You want to clear the user session You want to log out the user all those clearing stuff happens here and obviously If you see in this particular diagram in unmounting there is no component did unmount Do we need that? We cannot actually for it's similar like when you are about to die Just let me know i'll come you and give you water or some kind of food And then I say that when you died then come back to me tell me that when you died So obviously if something is unmounted they cannot come and tell us so that's why after will unmount there is no did unmount Cool Integrate api call. Okay. Yeah, this is important. So now in the whole life cycle thing There's one of the very important question. Where do we integrate the apis if you want to call api? So that should happen component did Amount mostly, but there are some other use cases for different kinds of use cases, but it should be here why here And even when component will unmount was there in the react. So a lot there were a lot of confusion around the whether it should be in component will unmount will mount or component dead mount So the straightforward answer is that For example, if you're doing server side rendering as well, so server side rendering will call constructor will call throughout the Render it will not commit and it will not do the dead mount So if you put in constructor or Some other Function before committing it to the browser Then on the server side rendering when you are generating your html files for seo Optimization it will try to call the api even if it is not loaded on the browser So you should be doing on this part. That's why this particular lower Side is mostly when it is on the browser did update or did mount So please make sure that you integrate your apis in Dead mount and obviously You want to call api once and not every time component update mostly But there are some other use case on every button click you want to get response in that case It will be did update But whenever the use case is that you just want the api call on load it should be going here in dead mount Does it make sense? Yes I'm answering Okay, okay. Cool. Thank you. That was it and Yeah Stay in touch I'm new to Singapore just two months back. I moved here. So let's be connected. I'm happy to Discuss more. Let's get over some coffee or invite me on some dinner. I'm happy to join Cool. Thank you so much. And there is a quick feedback form if you can feedback Give me some feedback that will be helpful took for me. You can either scan or you can take the tiny url Thank you so much guys. It was pleasure. Thank you. You're on for inviting. Thank you


This study examined the effectiveness of different treatments for intrahepatic recurrent hepatocellular carcinoma, RHCC, after hepatic resection, HX. It found that the prognostic factors for overall survival, OS, and disease-free survival, DFS, included the duration of disease-free interval, DFI, less than 1.5 years, type of Retreatment, Transarterial Chemoembolization or Transcatheter Arterial Infusion, TAI, age, younger than 65 years old, and perioperative red blood cell transfusions. Additionally, the repeat HX group had the best outcomes compared with the other two groups. This article was authored by Michinori Matsumoto, Katsuhiko Yanaga, Hiroaki Shiba, and others.


Well, today we're looking at some projects I've been working on. I've got a lot of projects up on GitHub. If you go to github.com forward slash metal x1000 is where I post all my code. If you go there and click on repositories, you can see all my different projects that I have up. And this week we're looking at some simple 2D games I've created for my daughter. Who is to? Most of them are educational and fun. Some are just fun. They are using Phaser 2D, which is a great library for creating HTML5 games. They all use, or most of them use a template I've created called Phaser Game Template, which I reviewed last week or went over last week. That source code is there if you're going to create your own games. And the games we're going to be looking at, there's the Little Bo Peep one. There's the Open Piano one. There is the Toy Record player. And there is the Elephant one, the Pink Elephant. And then there's the Apple Tree, which is actually one of the first games I created. It does not use the template that I created, but it's still using Phaser 2D. And the code on that one is really, really sloppy. But it's functional and actually has more features than most of the other games. I spent a lot of time on it learning new things. Now you can find all the source code. Again, here at GitHub. But if you want to try the games out, and if you have a modern browser, and I mainly have tested these in Chrome on both my Linux desktop and on my Android device, I know that there's the little bit I've been able to try it out on Android, Safari, seems to have some issues with some of the games. If anyone has an iPhone device with Safari, and would like me help fix this code, I would encourage me to troubleshoot stuff when I don't have the device in front of me. And I have not tried Chrome on iPhone or iPad to see how it works, but I'm assuming it will work well.  I don't have a nice menu or page set up yet, and hopefully there will be more games here later on. But all these games are live and ready to go.  The first one we'll look at is the Little Bo Peep one. Click on that. It has a quick little load screen.  You can't click on the sheep here, but there's two game modes. There is Play the Main Game, and then there's Sheep Pile. I'll click on Play the Main Game. Then the game goes full screen then. And you can hear me saying a little nursery rhyme with a high-pitched voice. And again, these are simple, created for a two-year-old, so they're very simple. Basically, if you click on the right side of the screen, Little Bo Peep will move to the right. The more you click, she'll go a little bit faster. If you click the other way, she'll go the other way, and she'll eventually slow down and come to a stop if you stop clicking. But the point of the game is to just chase the sheep around, and when you get to them, they jump and run away. So you can try to catch the sheep. And just like in the nursery rhyme with Little Bo Peep, they'll... If you chase them, they'll run away. That's the point of this. If we click Exit, little game credit there. If we click Sheep Pile, this one, again, a little rhyme this time that I made up. But you can move mouse cursor over the sheep, and it's... The point of the game is to tickle the sheep. So like on a tablet, you would use your finger, and you would chase these sheep around. And every so often, when one reaches one side of the screen, another sheep will come in. They all have various speeds, and that's that game. And if we go back now, we can also see Open Piano, which is a very simple piano, which is really designed for a touchscreen the way I designed it, because it's not clicking it to whatever the mouse is over, so it's hard to play a song with the mouse. So on a tablet, it works nicely. Pink Elephants is a game to work on colors. If you click... The point of the game is to click on the elephants, which pops bigger elephants into smaller elephants. And when you click on a smaller elephant, they disappear. And if you ever miss, it creates a new elephant and tells you the color. This is another one that does not work on iPhones, on Safari properly, that I've checked, because I'm using one image and using code to adjust the colors, and apparently that does not work. So all the elephants are the pink color, regardless of what it says. Other than that, I think the game works. I think mainly the issues I have on iPhone, iPad devices with Safari is full screen mode is not working quite right. Again, Apple Tree. This one's meant to go in vertical mode on a tablet. So you'll have black sides here, but you can add apples up to 10, and then they fall. So you have some physics with gravity there. If you click the owl, he says, whew. You can add five yellow stars, and then they bounce like the apples do, although they don't make a noise. You have a blue bird if you click over here, a green parrot on that side, and flowers, different colors on each side of the tree. And when you get to 10, after a few seconds, they all wither away. So the point of this game is just to teach kids how to click the screen and also teach them numbers and colors. And the last one is the toy record player, which on a tablet or phone sometimes can take a little bit of time for the music to load, even though it's preloaded to the device. It takes a little while because they're longer sound files. So if you click on one and it takes five seconds for the sound to load, once it loads to the RAM, it tends to load no problem, but you can see you can click on these records and it plays the song, says the name of the song with a nice little rotating animation there. And you just have your normal kids songs here. And there's always an info where you can learn about the program and a main menu button. So I just wanted to bring those to your attention in case you have kids that are free and open source games I've created. And I hope that you enjoy them. Again, the source code is at github.github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com, github.com. And if you want to try the games out, filmsbychrist.com, forward slash games, forward slash kids, hopefully in the future I'll actually have a page here that looks a little bit nicer than just a default index for a page. But again, all these games, once you load them in Chrome, you can easily add them to your desktop if you click your menu button, click add to home screen, you'll add them with a nice icon based on their favicon, and they'll be in offline mode, so if you're traveling and you have a tablet that doesn't have internet access, once you've loaded them, they're basically installed and you're good to go. As always, I thank you for watching. If you enjoyed these videos, be sure to like, share, and subscribe. If you enjoy the games, be sure to share them, I appreciate that. If you have any suggestions on the code, I would love to hear them, or at least see them I should say. If you're going to make some changes, let me know, I'll be glad to add them if they improve the game. And of course you can fork it on GitHub if you wanted to. And as always, I hope that you have a great day.


I have any, what data fees recommend, continuum or rhythmic? So everybody always says, well, rhythmic is better. Well, technically there's more data to it, but more is not always better. Sometimes you want less and continuum, just in my opinion, personal opinion. Now, again, they could have changed this, but from the studies I have done in the past, they're always like, well, rhythmic comes in a little bit faster. Well, what happens is some of their unaggregated order system thing, or everything is individual, it just taxes your computer more.  If you want to tax your computer less and still have the same, then continue. So this follows Occam's razor principle. So when two answers, then the simplest solution is the best solution, then you're going with this one right here. Continuum. So right here, aggregated quotes. If you're on the R-Trader, you cannot have that on. You've got to set it to off. Again, I don't use that. I have a CQG data feed with my broker. I have a couple of brokers. The trader now is going to buy data. Oh, you're trying to figure out which one. So you want the CME data bundle? Top of book. Yeah, you see the one that says CME group? Top of book, level one. That's the one you want right there. $12 a month. Let's see. Barbecue says Interactive Brokers doesn't give historical data. So every time you start them into your charts are blank. Ooh, that doesn't sound fun. Okay. So in that case, let me show you a little bit of a trick. So since Barbecue says about that up here, let me bring this over here. So there are some options you can get deep into. You can talk to an illustrator about that on using one for historical and one for live. But yeah, if the Interactive Brokers doesn't have historical, my thing I would say is so multi broker license and then use a secondary for historical. You have one for historical and then one for real time. You can set that up. It's just a complicated setup under your connections. But you can talk to the illustrator on that or Google that if you want to do that.


The coach says, can you guys talk about this? Like, it's pretty heavy rain. And all the ums say, let's just play. One fan stays. She's in her poncho. One fan stays to watch the scene that unfolds. Ball slips out of her hand. Now the tying run goes to third base. The catcher tries to crawl it. It slips. And they're like, come on, blue. Like, it's pretty rainy. And the very next pitch slips again, gets away. Catcher tries to grab it, tries to throw it. Slips out of the catcher's hand. Tying run scores. And everyone's like, what is going on? What are you doing, blue? It's raining.    And she gets ejected. Meanwhile, the catcher in the background, we don't really see this, but she throws her glove. She throws her mask. And her and the batter step to each other. And then quickly the catcher retreats. Umpire throws the catcher out.


Okay, good. All right, so talk to Chantel. We were trying to figure out some presentation we could do for Science Circle and I thought of the eruptions of the volcano in Hawaii in Kilauea and thought I would talk a little bit about volcanoes. So I'm going to start out really simple and then we'll progress and get into the concept a little more detail as always feel free to interrupt. I'll be keeping track on the nearby chat so you can always type a question in there and I have a problem stopping and I'll do the best we can to answer them. Like I said, I'm going to start off simple. I want to summarize some of the results that volcanologists have come up with. And at the very end, I want to talk about some research that I've done with James Mass in university on some igneous rocks and ancient volcanoes in northern Virginia that is leaving a whole bunch of geology stump. Maybe some of you who are on Science Circle give us some suggestions as to how to resolve it. I'm Bill Schmackenberg in real life. My email address is up there. Feel free to email me if you have further questions or comments that you want to do. Right. So, like I said, we're going to start off some real basic stuff. Magma that comes to the surface is considered lava inside the volcanic chain. It's considered magma. And I think there's an important distinction to be made between these two. Magma that forms on the outside of the earth cools relatively quickly creates fine grained igneous extrusive rocks like basalt. Magma that's inside the earth is like inside of a thermos jug. It cools very slowly forming coarser grained igneous rocks like granites. And it's the igneous rocks that tell us so much about what volcanoes were like in the past. I'll be saying more about them in a little while. Alright, some of the gases that have been measured from volcanoes include carbon dioxide, hydrogen sulfide, ammonia, what? Well, H2O, but not liquid form, but mostly in high pressure steam that's coming out. The explosive gas methane and cyanide, which is poisonous. One of the things that scientists have noticed is that we don't get any oxygen coming out of volcanoes. The intense heat inside the magma chamber forces the oxygen forms CO2 or sulfide gases. And this may have been important early in the history of the earth. It was probably volcanoes that formed our initial atmosphere and then later on as a result of terraforming processes and bacteria, the carbon dioxide is converted into oxygen. I'm going to give it a few minutes here to res. Alright, we also recognize a different solid material called pyroclastic material that shot out of volcano. The finest material is the size of flour, less than a quarter of a millimeter in diameter. Then the next size up is typically rice grains, a quarter to five millimeters cinders, which are the size of golf balls, and then anything larger than that are considered volcanic bombs. If you think of a volcano sort of like, yeah, that's true. If you think of some, think of volcanoes as sort of like a cannon. These things are fired out. They don't explode, but they're sort of like cannonballs. There are four types of volcanoes that me that geologists typically recognize. There are the shield volcanoes, which are very wide at the base, but they're not very tall. For example, Hawaii.  So just lava just sort of trickles down the side of the volcano. The fastest flowing lava is on the earth are only just a couple of miles an hour. So you can quickly and easily run away from them. Then we have the cinder cone volcanoes. They're the exact opposite. They're very narrow at the base and very tall. For example, some of the Mexican volcanoes are like that. They're a little more destructive. We're more violent. They shoot out rock particles. You get pumice coming out of them. When I worked at the University of Chicago, we did a field trip to the Southwest part of the United States to a cinder cone volcano. And it was sort of weird. I remember rolling in to the camp site. It was late at night. Couldn't see anything pitched to tent slept. Got up the next morning and the ground felt really weird and got outside walked around and the best I could describe it was like walking on on black popcorn is what the cinder cones are like. There's some of the most recent, by the way, and the southern part of or well Southwest part of the United States, in some case, only a couple of million years old. Then we have composite type of volcanoes, which are a mixture of rock and lava Mount St. Helens is an example. And then the fourth and probably the most violent type of the called areas are cauldron shaped volcanoes. The Greek islands and Melodia gene are a really good example of these.  It hits the hot molten magma inside pressure builds up and then boom, they explode outward. Other examples of called areas would be Yellowstone Park, for example, that's erupted 20, 30 times when they go off. They're extremely violent and that's something the USGS is concerned about is a eruption of a super volcano. And Vic says walking on cinders and why I felt like walking on glass and there's all the heat up your shoes. And that's not good. All right, so I have here pictures of four different types of volcanoes. So you see shield volcano in the upper left hand corner, very wide, not very tall. Cinder, I wish I had a different shot of this because it's looking down on the cinder cone volcano. And it really doesn't do the perspective right. Like I said, they're very, they went upside down ice cream cone. You got the idea of a cinder cone. And then there's Mount St. Helens as a composite example and then a caldera volcano in the lower right hand corner. All right, so one of the things that I think are really interesting that geologists and volcanologists have been discovering is we now understand why it is that some volcanoes are relatively mild and others are extremely violent when they go off. And there's a series of factors that we've identified dealing with volcanoes that tend to control how violent they are. The first one is gas pressure. So if you think of a volcano like a can of soda, if you pull the top of the can of so you. Okay, it's rapid release of carbon dioxide gas. And that's sort of what a volcano is like. And one volcanologist here in Virginia told me that the release of pressure is actually more important than temperature with dealing with volcanoes. So the higher the gas pressure, obviously that's inside the volcano, the more violent they tend to erupt. The second factor is the number of vents. We know that there are holes in the sides of some volcanoes, more vents, the less violent the eruptions like taking an ice pick and jamming it into a can of soda. You're going to release the gas pressure more slowly than if you don't. The third factor is viscosity, also known as resistance to flow. We've all seen different fluids flow. For example, if you look at water, if you pour it on an inclined plane, it tends to flow very quickly down the plane. If you think of something like molasses, if you pour that on inclined surface, it tends to move very slowly. So we say that molasses has very high resistance to flow, whereas water doesn't. And lava is very similar to that. Some lovers are, you know, are very runny and some are very sticky. Yeah, as some totes says, you can look at as the internal friction of a fluid, which is fine also. And even the fastest flowing lava is like I say on the earth, they're only a couple of miles an hour. You can just easily walk away from them. So it turns out volcanologists are more concerned about the viscous lava flows because they can form dangerous volcanic plugs on the top of a crater of gas pressure can build up. And then that's when you get these very explosive discharges. Mount Pinatubo that erupted in the 19 days is a really good example of that of a pyroclastic flow with a material just flowed out very quickly. Those are probably the most dangerous pyroclastic flows can travel over 100 miles an hour.  And the question then becomes, and here's to me is one of the most exciting discoveries that volcanologists have made is that you can determine how violently a volcano erupt based purely on the mineralogy of an igneous rock. I thought this was fascinating when I was a graduate student, I heard volcanologists in Chicago talk about this. It turns out that you if you have light colored, what are known as the felsic murals, things like quartz, that's in fells bar say must bite Micah. If those are the predominant minerals that are present in the magma or lava. Those tend to be very thick and be very viscous flows. But those are the most dangerous. So light colored igneous rocks to believe when they erupt are very dangerous. On the other hand, if you have a lot of dark colored minerals, for example, all of the period scenes ampoules, the so called mafic minerals that are present in igneous rock. Those are the ones that tend to be very running. For example, you tend to see those in the Hawaiian flows. And the last thing I have here is temperature. So what we've noticed is that in general, the higher the temperature. Well, you could argue it one or two ways. And I actually, when I do this as a PowerPoint in my, in my, in my classes, I have students vote on this. And I sometimes have students say, well, the higher the temperature, the more violent is higher the temperature, the more gentle it is. Yeah, I mean, a couple of ways of looking at and it depends upon the other factors, right? If gas pressure is the most important factor, right? Then it becomes a matter of gas laws. I'll make Mike show happy about this. Obviously, if you've got complying gases inside the crater, and you start increasing the temperature, you're going to, you're going to pump up the pressure. All right. On the other hand, if that's yeah, I just said that. Okay. If on the other hand, this is the more important factor in a volcano. As I bump up the temperature, what's going to happen is I'm going to make the law, the magma is runnier. It's the analogy I sort of like to make there and think of it this way. When I got up this morning, I had waffles. So my wife keeps the maple syrup in the fridge to keep it fresh. But I took it out. I think as hard as it rock. So what do I do? I nuke it. Okay. I heat it up and that becomes nice and running. And the same thing is true. Okay. With temperature inside a volcano. Okay. The higher the temperature, the runny it is and the more gentle it tends to erupt. And you sort of see that, you know, you look at the flows and why you're talking about 1200 degrees Celsius. So when they come out there, they're pretty running sort of a lot of us. If you look at the ones in Italy, Japan, those are the more business flows. They're a lot cooler, maybe 500, 600 degrees Celsius. Or right. Yeah, somewhere in that range, I would say. Right. So it is sort of interesting that we're getting a feel as to the factors that control volcanic violence. All right. And we've got a question from Astrid. How does the gas permeability of the gas through the rock come into this and the gas escape from the rock? That's a good question. And sometimes it does. And sometimes it doesn't. There are the silver salts. Okay. In which case. In which case, you know, the gas has clearly escaped from it. There's pumice. Okay, which is fired out at very high speeds from volcanoes where the gas is actually trapped inside the air pockets of the rock. There was an interesting study that I saw that he was done at the University of New Hampshire. And when their volcanologist presented this years ago in Chicago, and what they did was they wanted to know the altitude of the Rockies. And the way they did it was very clever. They went out. They went, first of all, they went to Hawaii. Okay, that must have been a tough job. Getting the grant for that. So they go to light and they measure the air pressure at the top of different volcanoes. And they get a relationship between the amount of trapped gas in the vesicular basalt versus elevation. And they found a relationship. And then they got basalts from the Rockies in the past. And they were able to determine how high the Rockies were based on the gas pressure in the vesicles. I thought it was a really clever use of using sort of pressure elevation changes. Okay, let's see. That was a part of the trivia question, right? Okay, so next thing I want to talk about is how volcanoes form. And there are multiple ways that we now recognize that volcanoes can form. Probably the most common way and the one I'm going to start with, as Rick has just said, is subduction. All right. And here you see a diagram of a typical subducting situation. So you have on the left-hand side of the slide a mid-ocean ridge. New seafloor material is being produced at the ridge. Agma is welling up like that. Seafloor material is moving to the side. As it moves to the side, eventually it gets denser and it's taken back down into the crust. And actually mid-ocean ridge or rifting tends to occur in the Atlantic, whereas subduction tends to happen mostly in the Pacific in terms of what's going on. And then what happens, if I can continue, what happens is water is taken down into the subduction zone or the trench. And as the water goes down, what it does is it lowers the melting point of the rocks. And rocks that are on the bottom of the crust tend to melt very easily. And as they're coming up, it forms the volcanoes. Typically the melt that comes from, they call this partial melting, is rich in more of the felsic minerals they melt at lower melting points. So things like quartz, potassium, phallospora, and the mycas. They crystallize out first, whereas the denser minerals, for example, your pyroxene soils and all of the enriched segments tend to be solid. So this is one way that we get it. So volcanoes around the Pacific, things like the Aleutian Islands off of Alaska and Indonesian islands, New Zealand. Any of the islands in the northwest part of the United States, such as Mount St. Alan's or in the Andes in the western part of South America, all really good examples of subduction. And I think scientists quickly grabbed onto this as one of the main mechanisms of which volcanoes. But there are other ways of doing it. So you can either form volcanoes as a result of rifting or by a subduction. And Bergen says, yeah, it's kind of nutty if the earth has a zipper. Bergen, it's funny you say that, I wasn't going to bring this up, but yet there are actually places where the earth is ripping apart. If it's town of Mid-Ocean Ridge, what happens is that magma wells up and fills the holes that are in between. There are other places on land where it's also unzipping. And my favorite example, really the only example that I know of that's doing that is if you look at Ethiopia in northeastern part of Africa, literally what's happening is Africa is being ripped apart. There's a rift zone that goes right through there. And as it proceeds, you're forming this valley. The technical term for it is called the lockogen or sort of a land sort of rift system, but there are places on land where you can actually see continents ripping apart. And that's important because sometimes I get asked, well, how do we know Pangea is superconduct ripped apart while it's happening today. Let's see, Vic says there's also an oceanic ridge extending from Iceland all the way around into the ocean. Oh yeah, the Mid-Ocean Ridge is extremely long. Iceland is the main part of it that's exposed above sea level. But yeah, it goes right down the middle of the Atlantic Ocean to the southern Azores. And then you're right, it wraps around Antarctica. All right, so next guy here. All right, when I was in college, one of the things that was being heavily debated is what do we do with Hawaii? Geologists really were bothered by Hawaii. It's a huge, long volcanic island chain. There are five islands that are most of all sea level now. You can also face the volcanic island chain all the way coast to Japan. There's a whole bunch of underwater seamounts that are on the bottom of the Pacific Ocean. And I remember as an undergraduate at Cornell going from geology class to geology class and the professors there just were heavily debating this. Some people wanted what was called a propagating rift. They thought there was a split in the Pacific sea floor, and Magma was welling up inside there. That one sort of, I think, fell by the wayside. The leading theory now is that we've got some kind of hot spot that's going on underneath the Pacific sea floor. There's some concentration of heat that's down there that's melting its way through the bottom of the Pacific plate. And it forms little seamounts on the bottom of the ocean that in turn works its way up to form volcanic islands. And we're not sure what's down there. I think it is that some kind of concentration of radioactive material that's down there. But again, nobody really knows as the Pacific plate drifts to the West. It drags these islands off of the, that's right. And we're going to say, Dallas forms the plate moves away from the hot spot. And you, in fact, there's a new one that's forming to the east of the big island of Hawaii. As of dot says, are there other examples of mid plate hotspots? Yes. And the best example of that that I can think of is Yellowstone. Yellowstone we think is sitting right on top of another hotspot as well. And you can, you can trace a series of volcanoes from Northwest Wyoming across Idaho. It's called the craters in the moon. The series of volcanoes that are millions of years old. And the cool thing about this hotspot is that we can use it. That's right. It's fair the path of the color of the river. We can use this to measure the, the rate at which the continents are drifting. So I just had my students do it and we did the Hawaiian island chain, for example. And students found out that it's drifting at a rate of about, I think the average was 3 inches a year, which is very high for a plate. Moving normally plates move maybe a couple of centimeters a year and inch a year. So for some reason we're getting a very high drifting rate off the line plate. All right. So we've got a couple of different models here. Okay. For how that forms. We've already talked about how Vic just brought up Yellowstone. So here's an example of how Yellowstone works. Basically it's a big volcanic crater system. The super volcano that's been erupted maybe 20, 30 times in the past. And mostly rhyolitic lava. That's why it's called Yellowstone. All right, let's see. Hawaiian chain is linear until you get back tens of a minute heads north all the way to the top of Chatscope. It's very evident from the sea mounts. Hey, maybe the plate moves because the hotspot reduces viscosity on the plate. That's an interesting idea. I never thought of that very gone. Right. We do know the plates move at different rates. We know the transform force allow them to move at different rates. It sort of decouples them from one spot to another. All right. And since you were bringing up Yellowstone, here's another graphic showing the Yellowstone volcano in red. And I wish I had a pointer here, but you can see it in there. And then there's a series of volcanoes that goes to the Southwest. So we can date them and measure their speed of movement. Okay. So those that's a modern plate tectonic theory. And now what I want to do is talk about some of the more ancient volcanoes. And here's one of my favorite ones I like to go to. This is ball knob that was that I took on a field trip. I just ran in my high school with my students. I'm fortunate being in Southwest Virginia that this structure is right behind the high school. It takes about 15 minutes to hike to the top of ball knob. I think I've got some other couple of pictures here. Yeah. All right. Yeah. Here's an example of a rock that we got off that I got off the top of ball knob. So you can see it's a classic sort of vesicular basalt. We've done a number of studies on this on this structure. We found that in terms of mineralogy, it's rich in amphiboles. And we're also starting to get some dates on it about 600 million years old. I'll say a little bit more about this history in a minute. And here's another picture that I took on the field trip just about a month ago. And this is a shot. I'm standing on the basalts that are here looking out over the valley. And in the background, you see grassy hill that's there. The class spent a night on bold mountain. No. Okay. Tagline. We're, it's like I said, it's a 15 minute hike to the top. We look around for about 15 minutes and then we come right back down. But it really is an outstanding example, an excellent way of doing field based science in the high school campus. We're very fortunate to have these schools have this opportunity. I've been running field trips to ball knob for about 30 years now. And when I first came to the high school, very little was known about this structure. I thought it was some kind of old volcanic stock, which was just pure guesswork. And over the years we've been learning a little bit more about each of these. All right. This is, this is a rock. This is a granite that was taken from Martinsville, which is south part of Virginia. Very different type of mineralogy, mostly quartz. And I see some dark minerals, maybe some pure scenes in there. Ball knob is about 600 million years old. This granite is called from what's called the Leatherwood granite. It's about 500 million years old. All right. And here are some samples of igneous rocks that I obtained from James Madison University. They were, they're cleaning up Memorial Hall. And they said, well, we've got all these rock samples left over. Do you want samples of them? I said, oh absolutely. So they sent me samples of these and I took some pictures. I also have some of my students go through and analyze them. This one was very interesting from going to Virginia. It's a rhyolite, which I didn't even know existed in our state. And it's more similar to what you see out in Yellowstone Park. Here are some examples of some other specimens. This is from molehill. This is about 50 million. Both the rhyolite and molehill samples are 50 from their ESEAN age and about 50 million years old. And again, the question is, you know, how did these rocks form? Some of them we're starting to understand others we're still having trouble with. And one of the things I had my students do was we went through and I had students use online gifts. And they clawed up the samples. And I don't know if you can read this, you may have to zoom in a little bit. I'm going to have to do it as well. But the first letter, we have about data from nine or 10 samples. Actually, Jamie, you has more, but they only gave us data on none. The first letter of the symbol that's next to each stops refers to the age. So if it's an E, it's ESEAN. It's about 50 million years old. If it's a late Jurassic, it's about 150 million years old. So we have volcanic rocks in Virginia that range widely in age and composition as well. The oldest English rocks that we have in Virginia go back about a billion years. And the youngest ones are about 50 million years old. All right, so what have we learned from this? You know, what do we know and what do we don't know? Okay, that's what I want to try and get into here. The, what do we know? All right, let's start off with ball knob. I'm going to go back here a little bit. Oops. Go back forward. Okay. Let's see. So we have a question from tagline. So Virginia area has been above sea level for at least a billion years old. Yeah, actually, the paleogeography of Virginia is very interesting. To the west of Virginia, you have the Laurentian super Laurentian Crayton plate. All right, so that's been around for you have millions of years. And what I tell my students and I think what I would suggest to you as well tagline is don't think of Virginia as it is part of North America today. If you want to try and visualize it, think about Japan. Think about how there's a volcanic island arc off the coast of a continent. That's what Virginia was like. In fact, we probably had several volcanic island arcs off the coast of Virginia in the past. And getting a little bit off of track here though. All right. So what happened was that a billion years ago, North America and South America slam into each other. And you're all familiar with the Pangea story, right? Okay. That 200 million years ago, North American Africa slammed together and formed the superconduct Pangea. And what we've learned over the last couple of years is that there were other supercontinents prior to Pangea. If you go back a billion years, geologists are now speculating that there was a superconduct known as Rodinia. There was a different arrangement of the continents, though Virginia was right in the middle of North American, South America. Then what happens Rodinia forms a billion years ago, 600 million years, Rodinia starts to rip apart. Okay. And the crack formed right behind my high school. My high school was actually in the crack of the, we want to call it the rifting zone and want to be fancy. They call it the late protozoic rifting zone. That zone can be traced all the way, at least as far as Southern Virginia, right in a diagonal line, right through Maryland, all the way up to New York. Some of the rocks there are very similar. And over the last year or two, we're learning a lot more about how North and South America split apart. One of the things that we learned is as the crack develops, okay, the initial rifting involves very shallow volcanism, extremely violent volcanism. Right. So what happens is that you start firing out pyroclastic bombs in my neighborhood. As one geologist said, if you had been around when that initial rifting, there's no way you would have been able to survive that you would have been able to get away from that pyroclastic material. Right. Then as rifting progresses, what happens is the shallow rifting goes deeper and deeper. Okay, into the earth and you go to deeper sort of volcanism and you form the salts that you see around here. As I said before, if you have a lot of dark minerals in it, those are relatively quiet sort of eruptions. You form ball knob and grassy hill. Right. Keep in mind that Virginia was a lot narrower than it is today. Okay. I'm about 20 miles south of Roanoke to give you an idea in terms of geography. We were the edge of, we were Virginia Beach if you went back 500, 600 million years. Okay. Then what happens, let's go pay this. Okay, we've got this grand here. Then what happens is volcanic island arc sets up off the coast of Virginia. Right. And starts firing off ash material. In fact, we can find some of those layers in the Appalachian Mountains. And that arc gets slammed into North American welded onto the North American continent. In fact, that's how I got this salt was by sampling from that old volcanic island arc sequence that you see. And then after that, you form Pangea or the continents come together. Africa slams in the North America. You form the Appalachian Mountains. And then rifting occurs. Pangea rips apart, North America pulls apart away from Africa. And you start finding the salts that are formed that are. I would say early Jurassic and age, maybe 200 million years ago. If you go around Southern parts of Virginia around Martinsville where the museum is that I like to work, you can find the salts from that era. What's really tricky, and this gets to sort of the question that we have. Are these igneous rocks in Northern Virginia? Okay, these rhyolites that are 50 million years old. And these basalts that are similar in age. And we don't have a model right now to explain these rocks. All right. It's an enigma because what's happening is at this time, North America is splitting apart. We call it passive tectonic margin. Okay, North America, Africa, Europe, they're just pulling gently apart. And there's no reason why volcanoes should have been triggered from. Jurassic time, late Jurassic 150 to 50 million years. And yet they are, and it's not just like one, like I said from this map, we've got about 10 different locations in Northern Virginia. Where you can find these volcanic deposits. And there seems to be a pattern for some reason. You've got high silica. Orts and potassium fells for rich samples in the West. And then to have the more mafic. Amphiboles purexings and so on in the East. So I'm having a discussion right now with some of the geologists at James Madison University. And quite a few are where these could have come from. So asymptote says, but if land tears apart, doesn't that produce a deep riff that releases magma? That's a good question. There should be the most of the rifting though is in the mid-Atlantic Ridge. Okay, it's confined mostly to there. So certainly middle of Iceland, for example, or down the middle of the Atlantic Ocean, you get this crack. And then magma is welling up and filling it in. Could you get cracks further? And that's, that's sort of an interesting question. If you did, then, you know, why is it salt? So we're, why aren't we getting just the salts? Where are the, right? Look, one's coming from that seems to suggest some kind of partial melting, almost like subduction is going on. But in order to have subduction, you have to have the collision of plates, not the ripping apart of plates. It's in my mind, it's sort of, this almost brings me back to the 70s, late 70s and 80s, when I was sitting in Cornell, we were debating about Hawaii. And the question in my mind is, you know, do we need a third mechanism for generating igneous rocks and volcanoes other than mid-ocean rifts, subduction, and hot spots? All right. So, I asked, but in ancient Rodinia, wasn't there rifts that are gone now? Oh, absolutely. Rodinia, by the way, up with this, a local chef is spelled like that. And I was told it's a Russian, is KT still here? I was told that Rodinia is a Russian word.  Is there a translation from Russian into English? Because I ran into one of the guys, one of the geologists that was asked where Rodinia comes from. And Rodinia, from the Russian, being to beget or give birth, meaning motherland birthplace. There we go. Vic is faster. Okay. Interesting. I'm not like, Pangea means all lands. I get that. All right. But nobody is really sure about what Rodinia meant. But anyway, to get back to the question. Yeah, there are certainly rifts. Okay, from Rodinia. You go back 600 million years ago. Absolutely. Balnab is an example of rifting basalts that are there. If you go to the Catocta Mountains in Maryland, same thing, they are Rodinia rifting. Maybe some of the rocks around New York City are as well, although that's a little more questionable. But they're 600 million years ago. The ages don't work out here for the rifting of Rodinia. They're too young. The basalts and rhyolites we see in northern Virginia are only 50 to 150 million years ago. They're way younger than the rifting event of Rodinia. And even somewhat millions of years younger than the rifting of Pangea, even. Vic is putting in some Rodinia. Look at, what's the YouTube video Vic? Oh, Mark's Brothers. Okay. I have talked with other people. Some people have suggested that maybe this is not a geologic event. Maybe it's more of an extraterrestrial event. Some people said this could be a result of an impact event. Where some extraterrestrial object is slamming into the crust, fracturing it and causing these igneous rocks to come to the surface. That seems sort of unlikely to me. You'd expect to see some kind of cratering. Alright, so as some notes says, couldn't there have been a recent hotspot that's moved elsewhere? I remember when I took geophysics, we talked about moving hotspots. And the evidence that the geophysis told me is that most hotspots, once they set up, tend not to move. You know, the assumption that we make is that the hotspots stay in one place. And it's the plates that move over them. And I think, yeah, I don't know whether that's assumption or it's been proven. We sort of assume that because it makes it a lot easier to measure plate movement. If the hotspots are moving around on us, then we don't have a clue as to how fast plates are driving. But like I said, I remember this was discussed back in geophysics in the 80s and people were pretty clear that it wasn't moving around. Alright, couldn't that explain those rocks? What explains them? Moving hotspots? You want to move a hotspot around, ask them to explain the movement of the, or the placement of the igneous rocks? They kind of moved away from that spot. One of the things that I played around with is I sort of noticed that some of the youngest basalts are in the east and they get somewhat older in the west. So I tried to figure out if a simple plate movement could explain the location of those igneous rocks. If, for example, we had a hotspot or something. And the plate movement that you get when you play around with the scale is just way too high. Okay, to try and explain this away with just hotspots. I originally thought molehill, for example, was a hotspot. And I was quickly told by others that no, it can't be a hotspot. So it's sort of some kind of mystery that we have going on here. Anybody else have any other questions or comments? What is the main argument against molehill being a hotspot? I'm not exactly sure. It was one of the volcanologists that said that it might be based on mineralogical evidence. Jim Beard, I took to Jim Beard who was a volcanologist down at the museum and he didn't like the idea of a hotspot. He may have some mineralogical evidence. My concern, I still said, all right, maybe it is. But like I said, I tried doing some simple math and measuring the rate of North America and I got numbers that are way too high. Could they have been transported from somewhere else where the igneous rocks that are in northern Virginia, is that what you're asking, asymptote? Yeah, I don't think they are. Well, the structure of molehill is this. Basically, northern Virginia is mostly limestones. And what we found is that these basalts that make up molehill form the core of molehill. These basalts go right into the base of the mountain there. So we're pretty, in fact, we know for sure that they came from deep inside the earth. I had a chance to look at the rocks on molehill and not only do you find basalts, but you get all of the class that are in these basalts, which tell me that these things came up not from the crust. They're coming from the mantle. These are very deep-seated volcanoes that are coming up and could be as deep as 2,000 miles under the surface of the earth. So that's why I'm a little leery about saying that it's a great impact. How else would you make a basalt? And again, we get back to, you know, this involves the deep part of the earth. You know, it's not like you're saying, well, it's a meteorite, an asteroid impact, and these are melts from the impact event. Yeah, if somebody else has some other idea, please let me know. Because, like I said, there are a number of volcanologists in James Madison University. There have been geology conferences that have been held about these volcanoes where geologists get together and kick around ideas. But at this point, there's no consensus as to what formed them or why they're there. All right, Astrid says, continental plates and oceanic plates have different compositions. If that's true, can the plates move so that a hot spot can shift from an oceanic plate to a continental plate? Salt and olivine seem like ocean. Yeah, absolutely. Definitely, we know basalt. Oceanic plates are made out of basalt. Continental plates are made mostly from granites. And again, not so sure about shifting hot spots. The rhyolitic volcanoes that we're seeing in the west, Benton suggests that there's some kind of, at least to me, there's some kind of partial melting that's taking place. It just feels to me like there's some other mechanism, some other plate tectonic mechanism at play here, other than just hot spots and rifting and subduction. What's going on? Any other thoughts or ideas? Some upward movement from below. I'll be interested to create a 3D map of the sphere of energy in the Earth. Okay, thanks, Katie, for coming. Sure, no problem. Yeah. Trimble knob is, I have samples from Trimble knob as well. And I think they're also basaltic. They're right next to molehill. But yeah, JMU sent me some samples from there as well. Sure. Thank you all for coming. I appreciate your time. I hope I've made this interesting. And like I said, if you have another ideas, then let me know. Oh, okay. See Bay has a question about the Hawaiian islands. All right, basically what happens is that as long as the Hawaiian island is on top of the hotspot, the hotspot can continue to generate magma and build the island up. So they start as sea mounts and then eventually when they get high enough, they get above sea level. Some of them get built high enough that they can withstand weathering erosion for millions of years. Then as the island moves off of the hotspot, weathering erosion processes start to kick in and the islands get eroded. Like I said, the five Hawaiian islands we have now are the remnants of probably about 20 or 25 Hawaiian islands that existed in the past. Most of them though have just been broken down by weathering and erosional processes that are going on. And what else we were saying? Oh, I want to talk a little bit more about Kilauea. It got really bad this summer. The eruptions that are current in Kilauea and there was a lot of damage done to houses and so on. Some of them Kilauea was erupting a lot more violently than people have expected in the past. And we think what's going on there is that sea level was getting into the magma chamber of Kilauea and pressure was being built up and you get these more violent explosions that are going on. But for some reason Kilauea was much more violent this summer than it was in the past. Could be. Yeah, Vic, you raise a really good point. And this is a topic that people have been asking about as well is, is it possible that a volcano could erupt in Virginia? And we do know that volcanoes can appear in the ocean. They want to appear off the coast of Japan, fishermen spied it and lasted for just a couple hours and that was destroyed. There was a farmer in Mexico that reported a volcano coming up in his farm. That must have been scary. And so I've been asked and I've asked some volcanologists is it possible that a volcano could erupt and some geologists starting to say yes. We do have volcanoes. We do have earthquakes in Virginia where there are earthquakes. You tend to see volcanoes. In fact, they're getting worse. The most violent earthquake that went off was in 2011 in mineral Virginia. And it was a magnitude 5.8 somewhere around there. There's also there are also some earthquake studies that are being done at Virginia Tech. And they found some very interesting results the last time I was at the conference at a conference there. What they're doing is looking at earthquake waves. And there's three types of earthquake waves P, S and L. Those earthquake waves travel have no trouble flowing through the earth right down practically to the core under southern Virginia, which is where I live. What they're finding though is that when they monitor earthquake waves under northern Virginia, E and L get through but not S. All right, low depth of 100 kilometers. Let's say that they're saying the S waves are stopping. And the question is what's stopping those earthquake waves from moving through northern Virginia. And when it comes to S waves, which are like shear waves, the only thing that geologists can think of is liquids. So that, yeah, exactly as I'm told. Okay, we're starting to get evidence that below 100 kilometers under northern Virginia, there's liquids down there. And 50 million years ago, those liquids came to the surface. They brought all the salt to the surface three miles away from Harrison Berg and James Madison University. So could have all came to rough. The answer is yes. Okay, it might take another 50 million years, but at least we know there's some magma that's down underneath there. In fact, in some spots, I'm wondering if it's a lot shallower like we have hot springs, northern Virginia. That's sort of interesting as to why there are hot springs under northern Virginia, but not southern Virginia. Can hotspots move vertically, not that I know of. Yeah, power cuten, that's right. Well, I guess if you're on a spherical earth, vertical and radial mean the same thing. Okay, gotcha. Oh, that's cool. Where do you live, S and T? Where's, I can even try and pronounce that. Awesome. Oh, that's interesting. Yeah, I heard. One of the things I talk about in my classes is the Mexico City Earth, Mexico City earthquake that happened, I believe it was back in 1985 was a magnitude 8. You know about that, S and T. We can talk about later. Oh, cool. Do you worry about, S and T, do you worry about a volcano coming up under your house? Good. Sorry about that. Yeah, that's very true as much as we think we're pretty much safe. Even in Virginia, I don't tend to worry about earthquakes and whatnot, but Florence came pretty close to our area. In fact, the initial forecast for Hurricane Florence put my county dead center in the middle of it and people started freaking out over it. School started to close early. College is closed early. It ended up that it went south of us through North Carolina and swept right around us, but it could have been close. I mean, we could have had the flooding that North Carolina had. Yeah, North Carolina is still flooded and Richmond got slammed with some really nasty tornadoes that spun out of that. So the earth is is a dynamic place. You just don't know what to expect. All right, I'm about, let's see, 11, 11 a.m. Pacific Daylight Time.  I'm going to head off to the college. I've got lesson plans to get ready, but I thank you all for coming. And for the questions that you've come up with in real life class this week, we lost like 11 instructional hours from Hurricane Florence. Most of you have my email address. If you don't, I'm going to put it in local chat. Yeah, feel free to email me. I check that every day. Bye, everyone. Hope you have a good day or a good night depending on where you are.


Hi, I'm David Cantor with the Law Offices of David Michael Cantor and I'm going to talk about juvenile disposition hearings in Arizona. Basically that's a sentencing in juvenile court. It can be done immediately after juvenile pleads or after they've been adjudicated delinquent at a trial. Now once that occurs the judge has 30 days at the latest to do the adjudication or disposition hearing if the juvenile is in custody and has 45 days later if the juvenile is out of custody. During that time we can set it for the predisposition report which will be prepared for the judge and we can also do our own disposition memorandum. We will file photos, letters, copies of awards, psychological reports, whatever it takes to get the lowest possible outcome on your behalf. Now the judge can sentence the juvenile depending on the felony and the severity for custody at juvenile prison or adobe mountain all the way up to the juvenile's 18th birthday. In addition the judge can require that a juvenile registers a sex offender up to their 25th birthday if it's a sex crime. Now if the judge gives probation the judge can order probation to occur all the way up to the 18th birthday. Now our goal is always to get the lowest possible sentence so if you or a loved one have been charged and not yet convicted or haven't even started in the system contact us. If you have been charged adjudicated delinquent and a sentencing's coming up at a disposition hearing contact us. Either way we're not going to charge you any money to meet with us it's free but it will take 30 minutes. We'll go over your case from top to bottom and explain what we can do on your behalf. We look forward to hearing from you soon. Take care.


Hey, Psych2GoFam! Welcome back to another video. Thank you so much for all of the love and support that you've given us. Psych2Go's mission is to make psychology and mental health more accessible to everyone, and you help us do that. Now, let's begin. An anxious avoidant relationship is one in which one person has an anxious attachment to another person who is avoidant. Anxious attachment generally comes from a place of seeking out closeness and intimacy with others. This person tries very hard to avoid rejection and abandonment. On the other hand, the avoidant person seeks a level of emotional distance that conflicts with their anxiously attached partner. Relationships like this are difficult to navigate when both partners have different and conflicting desires. Before we begin, here is a quick reminder that this video is for informative purposes only and should not be taken as relationship advice. If you relate to this video, please reach out to a relationship counselor or other professional for help. With that said, let's go over five signs of an anxious avoidant relationship. 1. Feelings of suffocation When you are anxiously attached to someone, you may feel an intense need to be close to them. You seek out ways to get closer and feel elated when you do. However, the avoidant partner may start to feel overwhelmed by the other person's intense desire to be near them. While the anxious partner wants closeness, the avoidant partner seeks distance. Too much closeness can cause the avoidant partner to feel suffocated. 2. Feelings of abandonment While feeling suffocated is associated with the avoidant partner, abandonment is more of an issue for the anxious partner. The avoidant partner requires a certain level of independence and emotional distance from the other. This can be problematic for the anxious partner since it bars their desire to be close. They may feel that their efforts are no longer successful and that their partner is slowly drifting away from them. 3. Concern over the relationship being one-sided The anxious partner may feel that the relationship is one-sided. They feel that the other person isn't putting in as much effort into the relationship as they are. This issue can crop up especially during a conflict where one person wants to get closer and work through a problem, but the other person wants to keep their distance. This may lead to an issue where one starts to antagonize the other. 4. Feelings of instability The anxious avoidant relationship does lend itself to feelings of relationship instability. If you are the anxious one, you feel that your partner is becoming distant and uninterested. If you are the avoidant person, you feel that your partner is too clingy and high maintenance. Neither one can get what they want out of each other and this causes mutual feelings of dissatisfaction. This can become an increasingly toxic situation and cause you two to lash out at each other in misunderstanding. 5. Emotional toxicity An anxious avoidant relationship is considered toxic. You want different things out of each other and may find yourselves fighting about meaningless topics. It can be antagonistic and you might place the problems of your relationship on one another. You and your partner's needs are incompatible with one another. This makes it extremely difficult to work through and resolve relationship complications. Did you find this video helpful? Did it help you recognize any anxious avoidant personality traits in some of your present relationships? Toxic relationships are difficult to navigate, so it's important to reach out to someone you trust if you think you need help. If you found this video helpful, please like it and share the video with others. Don't forget to hit the subscribe button for more Psych2Go content. The references and studies used are added in the description below. Thanks for watching and we'll see you in our next video.