All right, so yeah, we got a lot of full slides today So I'm going to try to go through most of them fast and the ones that I think have the more intricate details We'll cover a little more in depth. So I'm going to introduce some those of us who might not be super familiar need a little refresher a little bit about stego Stegonography and kind of Eventually get to this point where we're applying some old techniques to new technologies and that's basically what this project I've been working on essentially coming up with a file system that operates within other data And we'll kind of take it to the next level and consider the ramifications of doing something like this as well as you know, what if somebody's already doing it so Just to kind of get things going, you know stego might be something as simple as somebody posed to classified ads says hey Wanted a single white female whatever right? That's all entirely code that really means something else or it might be something more subtle Something that's part of another message I'd say you've got inside the little tiny period of a letter on a printed letter You've got a bunch of little tiny ones and zeros that are real subtle to the human eye But if you know what you're looking for you can decode those and there's your message so the More interesting at least from where I'm coming from Ways to implement stego would be using something you might be a little more familiar with like taking the image or some other content and Finding some either unused space in that media Something that might be reserved for comments or metadata something about the data Instead of the actual content itself or maybe you can tweak it a little bit so that the original content is still represented It still describes the original thing it was doing, but yet you've tweaked it enough that it actually has another subtle meeting so Usually most people and they think of stego think of it that way they think of okay We've taken the least significant bit the little tiny piece of information That doesn't make as much of a difference as the rest of that say talk about an image a pixel the very very Least significant bit that represents that pixel color and we're gonna Do things a lot differently than that, but it's important to understand that the That somehow You can have data that isn't as important as the other data and then that's what we can leverage to either hide more data in such as a serial number watermarking or actually Exceed or normal storage capacity it is kind of the way I'd like to think of it So like I was describing the classical digital steganography Excuse me steganography You can do that a couple of different ways I like to think of it even though there's much more clever and interesting ways to do it But say you've got some number representing the color or say it's an audio sample It's represent numbers representing the magnitude of that audio sample If you just round off that number and even number when you're going through the media could be a zero and an odd Could be a one real simple. You don't have to think about real complicated Encodings here. So that's kind of what I'm basing the rest of this talk on is this very simple Description of steganography. Yes, you can get much more complicated. You can get much more clever you can Use other techniques to compress more data into the data you've got This particular project I've been considering actually for the couple of years now you know the growth of What's unfortunately called the web 2.0 new media environment? Sites let you upload videos prime target. You can cram a lot of data in a video file. They take a lot of data and We can also leverage that I also started considering the ramifications of of you know what we consider a viral marketing somebody downloads a video And forwards it around Well, doesn't that be great if I wanted to have my data mirrored by innocent bite or excuse me Not innocent bystanders. I shouldn't say but you know by the random public. Sure. You can maintain my backups for me As well as you know the actual marketing aspect of it where you know privacy concerns Okay, what if somebody's already tracking these videos with some sort of water marking under the hood and people are forwarding around You know what kind of One, how would you do it and then to what kind of issues come into play because of it? One of the issues considering this kind of a mechanism say you take a video upload it to Pick on YouTube today YouTube comm you upload it. It will convert it. It just does it re-samples things compresses the audio and does other things And if you just have your Secret code Encoded with just something simple like that least significant bit mechanism. I mentioned the Your code will actually be destroyed mostly because of the compression and the tweaking and the changing that they do to the video So that's probably the biggest issue we have today that I'm going to address is how do you make? that Stagnographically encoded data survive one maybe even two or three or four conversions between different things Hmm we can do it a couple of ways we can try to Pick something that when we upload to the the system that's hosting in any way that it's not going to do as much Conversion okay, it's not going to tamper with the bits too much If we can pick that from the get-go will be doing pretty well as well as if we include enough redundancy of our message in the Host media itself will be in pretty good shape So this is the kind of thing we start thinking about when we talk about distributing this day go Keep in mind too though that there are other ways to encode data. I like to use The misspelling of the blog comments right if you spell the with the TEH that could represent a one and for all the Zeros just that regular English text or whatever language you want to pick the regular spelling could represent a zero So at the human eye, you know, that doesn't look like a message is encoded But if you've expected that you can now decode the message Of course the conversion here would be if there's an online you're submitting it be an online form and it does the spell check for you would be an issue or For example using double spaces instead of single spaces your browser renders HTML If it's not a non-breaking space, it will just collapse those white spaces into one And it human eye doesn't matter you download it though, and now you can see that there's extra bytes there So we can use these in combination. Maybe even alternate between the classic media image audio video encoded messages Or maybe we just use and Consider this an out-of-band type and coding to represent maybe the structure that we're storing The actual data in this is how we can find the data. We're looking for Of course, it's pretty hard to prevent and to police all the blog comments, right? So it's going to more than likely than not Not be tampered with talk about the upload the conversion is usually not going to be as damaging So it's a good candidate for our structure for such a file system So to kind of Throw a few ideas out there stego FS as it's still I guess I should call it pre-alpha. It's still well, I Wouldn't want to hand it out Which is why I don't have a link to download it yet because I still have a lot of work to do on it But it does do a few things it does use URLs and the first version had a duly linked list so It would actually have a URL that pointed to this block a URL that pointed to the previous block a URL to point into the next block and that way if You were navigating through you could find okay yet more data yet more data and now you can tie everything together So your URL could be a blog comment and then the next one could be Maybe a video or whatever Originally, that's how we were doing it But for the example, I'm going to show here. I'm actually going to use a Flash video on YouTube that I Actually picked one that was already up there that I anticipate nobody will see So there's you know less funny business going on and I go ahead and I encode one bit per pixel and store some extra Some extra bits to make sure and check that those bits haven't been converted Generally what I'm talking about here is is what we call for error correction, right? So there's been especially in the last couple of weeks. There's been some interesting News articles a little bit of press coverage about for error correction. There was a thing a few days ago It was either digger slash. They're talking about the Viterbi engineering school Viterbi Named after the guy who came up with a lot of the for error correction. We use this stuff in data communications all the time It's not new The one I'm actually going to use I'll show in a minute is actually a hamming code based off of dr. Richard hamming Work so because I think that's the easiest one to understand My point is though we're going to try to prevent if we lose one or two pixels one or two bits Because they've resampled the video or they've stamped a watermark of their own over the top of it We can still fill in the gaps We can also extend this across Things So consider I might have multiple frames of video for example I could Have it mirrored repeated through multiple frames now if You know one of those maybe my error correction isn't good enough on one frame if I average it with the next frame I might be able to figure out what it was supposed to be So if you want to look up some more information and It's late in the afternoon your eyes are rolling back of your head or whatever Here's where I suggest looking most to go to Wikipedia's entries for a hamming code is really good and look up some of these other terms These techniques are being revisited quite a bit now because of you know the progression in quantum cryptography Quantum computing and other things So it's it's it's a hot topic now. I'm using a a stego in media example, but the error correction techniques Are definitely alive and well today So for our hamming code, I'm gonna encode one byte. Okay, it's gonna be hexadecimal ff and For this example here of the underlines that I have in this first bullet point each underline is Going to be a parody bit the first one the very first zero position is going to check every other bit Include itself actually starting counting with itself include and check every other bit and this is going to be an even hamming code So we're going to want to have an even number All right, so if we take ff, right, that's eight ones essentially in binary So to figure out what our first check bit should be we look at every other bit So the course will come back to our self later We skip a bit the next bit is a one the very first bit of the data that we're actually storing Is a one so we've got one so far we skip another one Which is a happens to be a blank so far the next bit We've got a one and so on we actually end up with five ones And that's odd, but yet we're doing even parodies so we need it to make it even so we actually place a one in Our check bit state now if any one of those bits has been flipped to a zero We can now detect that but the key to this Forward error correction is actually in the layering of the different check bits, okay? Take the second one for example if we check the second bits going to check two and three six seven ten and eleven so The same thing applies we added up we happen to get another five ones, so now we store another One and I'm not going to go through everything else on the slide, but the point is We've got this pattern and how do we actually detect and correct when something's wrong real simply if We go through and add up the bits that lie Okay if we go through and check and say that the the bit to that's supposed to check these other ones doesn't add up and The eighth location also doesn't add up we add those together Well it happens to be that bit ten now is the one that was damaged and that's just the very simplest way I can describe you for error correction. We're using 12 bits to describe eight bits and Well 12 total bits to describe eight bits of data and that can let us detect a couple of mistakes and always correct at least one Now we can add and keep going there's extra tricks make it more complicated to correct more than that many bits But now if one of these pixels has been tweaked in our stegode Image frame from the stegode video. We might be able to correct it Now notice I didn't add 12 bits to the image. I'm just rounding off choice ones. I want to One thing I like to consider too in doing this is how was you know how to extend it from other materials See we have a history of really poor actually stegobiographic techniques A lot of them are pretty bad if you just Google and try to find a stego tool It's probably not going to be very good unless you you pick something really clever There's easy ways to detect a lot of these tools That detect what appears to be a use of the tool let's say By doing things like looking for near duplicate colors if we've tweaked just that one in zero throughout the whole image Then there's gonna be a lot of colors. They're almost the same but not quite and yes I'm over generalizing, but you get the idea It's easy to detect and then because we're putting in a pattern that changes the pattern that's already there the compression Capacity changes of the content to host media. We're looking at so of course we can just go real low-key and only encode in very select places and it'll be a lot less likely to To not just be detected, but it's going to be a lot less likely to Be damaged in a lot of ways if you're not replacing everything and just replacing some things especially on real quiet to frames like it's not a whole lot of of Color in that frame you're going to want to be more subtle so it's less likely to Like I said get detected but also to be damaged when the things start getting compressed and the online engine as we're doing in this Example goes through and tries to make colors, you know, oh, this is the close gray to that gray So let's make it the same gray and so the video takes up less space, right? That's kind of the way it works If we encode very sparsely we're not going to have that damage happen in that way Um So again remember we can store things in the data itself we can store data about our data And we can store things Well, let's say what could we store we could store something like a serial number by using stego We can now say hey, I upload this video to YouTube if I want to find out when somebody tracks it Someone's downloaded it where they got it from I can now look at Their copy compare it to the one I encoded and I know which one they had But the other thing I want to kind of expand on is what if we use a visual watermark? To hide our data in that is you know how you go to YouTube, right or whatever my space whatever you do There's the YouTube logo in the bottom of the video Well, what if we make a YouTube looking like image to hide our stego in See when you use something like like YouTube Most of these things will do a matte layer in the player that doesn't actually encode in the original media stream So that if you actually were just to download it, there's no logo and there's no watermark from YouTube there But so if you're viewing it YouTube's logo is over the top of your stegode one, but when you download it there it is so some techniques like that and actually what I'm going to demonstrate is Just like a kind of like a barcode a watermark It this was an interesting topic to try and prepare for because how do I show you something that's designed to hide? It was a real hard one to to think up. So we'll get there shortly though Excuse me All right, so Mostly what I've been covering so far is making one frame survive conversion. That is one image one point in time survive that Take for example, say you've got a video you're uploading that's at 30 frames per second and the engineer uploading to decides to hey, let's take it down to 15 frames per second well, that's going to chop out every other frame that you have and If there's not a If the ratio between the two frames per seconds is not evenly divisible divisible Now you're going to have a problem where there may be new artifacts created When they take two frames and average them together So to make our encoding survive the resampling We're going to want to mirror between the frames the encoding that we're using Okay, so we can survive drop frames and we can survive That extra bit of information that sometimes is added when people resample at a non divisible rate so Just kind of illustrate that why don't I just pull up the Here is a video. I upload YouTube last week. I have up here in the Upper left The watermark now. I know you can't see that so I have a magnifier. I'm going to bring as I start playing this All right, this is the upper left corner here of the video as it's playing This is the same ff encoding that I showed you with the hamming code. We have actually three Semi-transparent Bits and then we have a black bit Which is going to represent that zero and then continue on the pattern But I've actually done it three times in a row as the video is here is playing We can average those frames ourselves and Figure out, okay, what is the most? Unique, you know, okay, this is gray most of the time see right now. It was pretty damaged there at that second But I can take this do three different independent Samples across the whole video and I can Figure out what is most likely to be the ones and zeros and now I've basically survived this ff encoding across everything All right, so that's kind of the idea now. I've just done this in the black area So it's a little easier to see and I use the the 50% transparent with white but you can use and Choose the colors very well and hide it in a more appropriate part. That's part of the image and not up in the In an easy to find place. Okay, that's just for demonstrated purposes. So That's what the stego fs tool encoded the bite ff with All right, all right, so we're talking about that Now it's not super obvious, although if you know what you're looking for you could see a lot of that You might you know do some other interesting things one of the things I was kind of contemplating doing that wish I had more time to do this but you know use the You know the old-time real to real type film that would show the patterns the streaks in the film I use those and actually have them represent a barcode as the video is going by You know you can do all sorts of techniques like that to store this You don't have to have it as blatantly obvious as a demo I just had to try to make it so pretty much everybody could see it for today So you can also add parody across the frames I just talked about mirroring the frame so far, but you could parody the frames themselves and either a hamming code in yet another Dimension across the frames As a different way Take for example here, we've got the two bites encoded Just an XOR example not real Creative nothing new just something we're doing in a different way that I haven't really seen anybody do before in this dimension so I Still have to rewrite a lot because I haven't used the actual libraries what I had so far was just command line scripts glued together so between image magic and FFM FFM peg Here's what you could do to rep replicate exactly what we did here We're going to run the convert command to create This is The code the the gray because it was 50 percent transparent white and black and using black fill points and Here these points are the zeros in the first command line option here Or excuse me the first line To create an intermediate image now. This is the watermark image. We will actually Use and then what I do is I create a third image or excuse me I create another image that has it three times and then I go ahead and make sure I've enforced the transparency and Create my actual watermark that FFM peg with the video hook library, which is getting rewritten It'll be interesting to see the newer version that comes out after Google summer of code But in this way and actually this particular one I ran on Windows With FFM peg and not on anything else So it works quite well to create the coded M peg and this is a At that point we upload it to read it of course you've downloaded it And I'm not gonna bother going you showing you scripts to download but downloads it Strips out everything saves it as individual PNG files goes through and peels off where we've placed that watermark Which again, I think the more interesting use would be to to make it look like the YouTube logo or something that would be hidden Overlaid with the matte version of the YouTube logo and then we can go through into our averaging to our parody checks and whatever I you know didn't have enough space to show you everything On the slide of course, so this is basically what Stego FS and its current state does Inside of a fuse module Fuse being that the file system for user land So to kind of reiterate we have that frame As an image we've peeled that off okay, if In that particular frame it's damaged We can try to repair it inside the frame or try to repair it by referencing the next frame or the previous frame Okay, or some other out of band in coding, right? We still have the audio We haven't been playing with we might have other things we've stored somewhere else Maybe we've mirrored the entire video somewhere else with a different Provider we've uploaded one to YouTube one to my space. Let's say Okay We can prevent detection or Well, at least make it a little less obvious if we don't just obviously choose those those colors in that spot We can also extend it to too many other Excuse me many other ways Another aspect of this is I don't have to just store the URLs right I could ask Google to find them for me or I could Make it a little more dynamic in another way trying to extend the concept we've gotten there's some other interesting things we can do By the way, I've got a Already got a link to this presentation the one on the disc for the con is not Complete there's been a lot of changes since then so you're probably on a download I've already got it up here if you want to download the full power point already the boot on comm slash resources we have Though to consider All right So you can hide stuff inside of videos. Yeah, what's new? Well, we're trying to do it in a way that's easily accessible inside of a file system format now You might not be interactively, you know editing a file Very well, it's not gonna be practical to edit a file, right? It's you're gonna have maybe multiple videos It's gonna have to download if you edit it and make it right It's got to upload you've got to wait five to 20 minutes depending upon the provider It's for them to compress re-encode it make it available and so you even know where it is so that you can reference It in the file system, so it's not something you interact with Like a normal file system, but we use the file system As a mechanism to store inside of there and then now stego fs could do all that stuff we need to do for us Extending it though, what else could we do? Well video uses keyframes Basically when you're skipping ahead in the video with the progress bar, whatever you want to call it The way that you can do that is because they've keyed in frames that kind of show approximately where in the video it is They're not really content Sometimes you could well you could if you wanted to make a video with no keyframes. I think you might have to have one to start with I'd have to read the standards, but See if you can even start with one without any But you could use say one keyframe If the next keyframe is with less than five seconds, that's a zero if the next keyframe is over ten seconds That's a one now you're not gonna store a whole lot of data there But you know you haven't manipulated the video at all all you've done is you've changed the way people can seek in the video And of course there's other things there's metadata inside the video the mpeg standards allow you to put in some comments and There's other things you can do to hide data But I think the one I'm probably gonna try next is to to make a watermark of my own look like another company's watermark So that when they're watermarks overlaying mine, you're not gonna see my watermark But when you actually download it and view it you see mine what you think is theirs So I think that's probably the way I'll have the next demonstration go The other thing to consider too is it's not just in the media content We can have anything we can signal and reread We can store something in you know just like think of a dynamic RAM Every time you read RAM you have to rewrite to it DRAM Well, what if we had something like a spoofed DNS request? and then With the reply comes back or it resolves to our DNS server that Represents a zero or a one now. I'm not talking about tunneling or using DNS as a covert channel as you probably have heard of it before Which is a great technique, but I'm still thinking along the timing realm, right? I can spoof a DNS thing see the result Or shoot don't spoof it Just do it if the result Excuse me comes back in less than you know five seconds or more than ten seconds again now those could be zeros and ones all day long Now that's a lot of overhead for encoding ones and zeros, but you're not actually storing anything anywhere The problem you would have is you'd have to constantly refresh That data right you'd constantly have to resend the DNS traffic to keep that media live But now on the wire you've got a file system That's never actually stored anywhere So that's kind of one of the things I hope to add in the stego FS before I release it is Some of that it's still very pre-alpha quality. It's especially with the video sites It changes so often that it's really difficult to Squeeze the most out of it actually last week the demo. I showed you on you with YouTube video Never once showed any kind of variation. It always was the same. I thought that would be a very interesting demonstration It looks like I just hard-coded that on every frame, but Anyway, it's a moving target. So I hope to add in some of these extra features But you get the idea we can still extend this into other forms anything we can store We can store more stuff in is what I'm saying Now as I started to work through some of this material I stopped to think about, you know, other companies watermarks and I thought about well What if they're already doing this? It's pretty easy to encode in watermark and serialized things and I know people who do forensic investigations I do too, but I mean some of the people I know of that have this have encountered and have been investigating people who Have had material that's been serialized in a stigma graphic type way But what about the viral marketing aspect of people trading around things now maybe using something maybe not a full file system version But they're still storing those blocks in they're using it redundant Blocks redundant bits Not so much ooh now they're doing that. Yeah, we probably were paranoid about that already But what I found is I can tell how they got it That is if you download something from YouTube, I can tell if my number Was that pattern I showed you it looks different when it comes from YouTube than from my space So I can tell you where you got it from I can also if I make it robust enough my pattern I've been playing with a little more. I Can have you I can tell that you download it from YouTube first and then re-uploaded it to my space and Then record it to an AVI file I'm trying to see how far I can I can take this before it gets crazy But that started to kind of freak me out a little bit And the more I work with it the more I find I've over complicated the problem. It's so unbelievably easy to do that So, you know, there's some large privacy concerns here So basically I Just tried to apply some old techniques to what we cook, you know, unfortunately call new media Considering the impact of of some of the problems we deal with today, that is we're running out of space in a lot of ways I mean as a security professional type person I can never keep enough tracking information and Sometimes those relationships are what I'm really concerned with not the actual serial number. I just want to know how you got it right so kind of like We'll like what the perturba guys did with Maltego, right the relationships is the data That's what we really want not so much the data itself. Yeah, it's important, but sometimes the relationship is more important So I'm you know in considering this aspect that we can use those relationships For example, I talked about the relationship with respect to time with the keyframes and it's DNS traffic To encode those ones and zeros so even though we're physically only got so much space in storage to store something We can actually store more than we can have physically stored on the device itself that way if we pick the relationships appropriately so And that's not a foreign concept either the Relationships between hashes and rainbow tables and the chains and everything that goes on there I'm not gonna get into that but essentially what I'm talking about is creating a reduction function of The data and the relationship itself with steganograph steganographic techniques So it's easy to consider how you might be able to extend this to other current problems like Some of the issues we have quantum computing if somebody reads something they've tampered with the data, right? It changes when they read it For error correction very important I have a few things I'm going to eventually put up a link on blue notch comm slash resources where you can download The Python module once I try to add in some more things But I do have a copy the presentation there that's current If you want to look at some of the flash video source originally I wrote it in in pearl for the the older FLV codec Standards, but since YouTube moved MP4. I thought that was kind of starting off in the wrong foot So I just dropped it all started off getting more in-depth with Python as the framework. I'm using and and Using MP4 as my tests But these techniques of course apply to other ones if you want to look up the hamming code probably the easiest place to start is this Wikipedia article and I Did run across somebody else doing something a little similar. There's a virtual dub filter Which you can look at on this URL. I could never get it to work, but it's interesting concept They show a good demonstration of hiding a message and then adding the redundancy that would survive Converting from an AVI into another format So it's basically a different way of explaining some of the things I've explained today That's pretty much all I had Q&A and 104 right so Go over there for questions unless you want me to play the rest of the hacker videos trailer. No Yeah All right, I don't know if the sound works very well in here, but why not just for fun Thanks guys If you can maybe you can see a little better now in full screen you see the the watermark I've got up in the upper left. Yeah, so all right I'll let it play I guess that maybe that would make everybody clear out the room if I play the hackers trailer All right. Yeah, I tried to find something. No one else would be viewing so that when I was Doing my test I could tell if if I was the only one going and fetching these files. So Obviously, no one ever watched this besides me so I'm taking over a TV network All right, I'm not gonna play any more my hard drives pegged for some reason so all right, that's all I got. Thanks I'll see you in 104


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Today we are going to discuss Plato's famous parable, the parable of cave. As I have been discussing about the dichotomy that is there in Plato's philosophy of mind, the dichotomy between the forms and the particulars. Particulars are there in the world and forms are there in a independent world. So, this dichotomy is something very significantly related to Plato's theory of mind and that can be little explicated through the help of this famous parable called the parable of cave. Now, let us see what is this parable of cave. Plato explains that there is a cave and there are some prisoners kept inside the cave for a long time and this prisoners hand and legs are tightly bound so that they cannot even move, they cannot even turn and see things what is there behind them. So, what the prisoners used to do, they were together and they were looking at the world. Now, between the world and the prisoner, the prisoners were dwelling inside the cave. Behind them there was fire, there was a fireplace where the fire was there and this prisoners used to do the work. They used to see their shadows that is reflected on the wall. The shadows were created by the fire. It is like this, suppose there is a cave and in the cave now you have to come down. The cave has a small entrance, entrance here and the prisoners are say for example, there are prisoners who are kept here and there is this fireplace. Now, because of this fire in the world of the cave there were some shadows. So, shadows were created by the existing fire. The prisoners, they were not aware of this fact that the shadows are created by fire. They only have this impression that whenever they used to move from here to there, the shadows were also moving. So, when they used to move from here to there, the shadows were also moving. So, for them shadows were leaving beings like the prisoners who were dwelling inside the cave. So, the movement of their bodies, the movement of the bodies of the shadows are quite similar. Hence, the prisoners were living inside the cave. The prisoners started believing that the shadows are real phenomena. Now, if shadows are real, then Plato asked these questions. How does one make the distinction between reality and appearances? Because for Plato reality is something different from appearance. Now, how does the prisoners find that there is something called a reality and that is beyond the appearances? How does one encounter such a reality?  Imagine a situation where one of the prisoners tries to remove the circles and tries to turn and he turns in such a way that he is able to free himself and then started climbing up the steps. Now, once he goes on climbing up the steps, he reaches to a point that is the point at the entrance and then he finds there is a dim light coming through the entrance. He comes out of the cave finally and when he comes out of the cave, he is not able to see anything. He is not able to see anything. Why is it that the prisoner is not able to see anything? Now, Plato says, since the prisoner was kept inside the cave and the cave was a dark place, it was a dark chamber, hence the prisoner had no scope to see the light and when the prisoner came out of the cave, he finds that there is tremendous light and the light is so much he is unable to open his eyes and see things and then Plato says, slowly and slowly the prisoner starts opening his eyes and tries to see what are there in the world. Plato's explanation here is very interesting that is, the prisoners makes an attempt to go out of the cave and the prisoners is not able to see the cave and the third is the prisoner sees the things as they are. So, when the prisoner starts seeing things as they are, he has this impression about the reality that is different from the shadows, which are experienced by the prisoners who are dwelling inside the cave and he is one among them. Now, since he is out and able to see the things as they are, he is able to make this distinction that the shadows were only appearances and there is a reality beyond these appearances. Now, Plato's parable suggests that reality is, as it is, independent of the basic particulars, the basic particulars which are changing. So, there is something, there is an underlying principle and that can be seen or that can be known through what we call Plato called intuition. Now, intuition gives us some kind of a knowledge, knowledge about the reality. Plato says, so one has to prepare himself. Plato is talking about preparation. Now, what kind of preparation the prisoners are ought to be doing? Now, unless you prepare yourself, you will not be able to see your soul, you will not understand what the soul is. So, soul has a goal, the goal is coming out of this darkness. So, there is this epistemological exercise, there is this epistemological exercise in Plato, where the soul is aspiring, the soul is aspiring to know what is reality. Now, this aspiration demands some kind of a preparation. Preparation is through, we can say, contemplation, reflection. The soul uses a conscious being, must reflect on things that are experienced. So, this experienceable phenomena are real or not, needs to be understood and that is why Plato talks about this parable. So, the parable is a very suggestive one and it suggests that when the prisoner understands that there is a reality and this reality is something different from the appearances. Plato talks about truth. So, it is the truth which has been known and truth is universal for Plato. The light of the sun is a kind of a metaphor used in the parable to talk about truth because you are not able to see truth as it is, you are not able to see the reality as it is. Hence, what is necessary is that the self slowly and slowly comes to know what is been given to him and what is the reality. So, this parable has both an epistemological and ethical concern. As I said, truth and good are one in Plato's metaphysics because the epistemological enterprise and the ethical enterprise in Plato go together. Now, the prisoner who is aware of this fact that the shadows are not real phenomena and reality is something different than for Plato, he has this moral responsibility. In fact, the prisoner who is an enlightened one has this moral responsibility to go back and tell the other prisoners or free the other prisoners who are in the dark, who still thinks that the shadows are real. Now, look at this idea of steps. Steps are nothing but struggles with a lot of hardship you need to climb up. So, climbing up is talks about some kind of an upward movement. It is a movement which signifies the freedom of the soul. Now, the soul cannot be bound by the behaviors that are caused by the body. Body or bodily activities cannot bind the soul. The soul frees himself and he frees himself because he puts him in this struggle and so this realization is a kind of an upward movement. Plato talks about the hierarchy of ideas. Now, goodness being the highest ideas, the idea of good is one of the highest ideas in Plato talks about how does one understand ease of them, kindness, justice, freedom of goodness. All these are nothing but the ideas, ideas that represent virtues. Good being the most abstract idea is realized by realizing the other ideas. So, when one realizes what is compassion, when one realizes what is justice and then above all, one realizes what is goodness all about. So, one transcends these layers, these hierarchies and finally he is able to know what they are all. Ideas are united. They are not discrete phenomena. They are united because it is the soul which is working as a kind of a uniting principle, as a unifying principle, connecting this all experiences and understanding the content of these experiences. So, Plato's notion of soul which is akin to the forms is something very significantly analyzed by the board in this paper and one must look at the famous parable and try to see that how the parable of cave has got an epistemological aspect and also an ethical aspect. They are part of the whole story to talk about what is reality, what is appearances and how the reality is different from the appearances. The knowledge about the reality can be known only through the forms. Forms are the pure ideas. Therefore, Plato is talking about dialectics. So, the dialectical mode of analyzing, reflecting, questioning, suspending gives us knowledge and this dialectical mode of knowing is nothing but an intuitive mode of knowing. So, Plato gives importance to intuition or reason as a source of knowledge. So, there are since experiential knowledge and there are intuitive knowledge or rational knowledge, dialectical knowledge, knowledge that involves dialectics. Now, these two sources of knowledge are different in the sense that the knowledge about the particulars, the knowledge about the world is directly given to us like for the prisoners the shadows were directly given and for the prisoners the things in the world as he goes out things are directly given. Now, these two givens are representing two different kinds of realities and that can be discerned and analyzed with the help of reason. So, reason plays an important role constituting Plato's epistemology and ethics. So, therefore, we need to look at the question, what is the locus of the reason? Does reason reside in the function of sense extends organs or does reason reside in the soul? For Plato the soul is a rational entity. It is not only a conscious entity, but also a rational entity. I am just using this term entity little differently just to make sure that there are physical entity and there are mental or spiritual entity. Now, this idea of entity is always referred to the physical entities, but this notion of the spirit in Plato or the soul in Plato is something spiritual in the sense that it is the locus of the reason. So, therefore, the knowledge and the knowledge about the virtues, the intuitive knowledge, the rational knowledge and the knowledge of virtues are one, they are identical for Plato. Plato also shows that this conscious activities in which the soul is engaged in differentiating the appearances and the reality, whether it is a cognitive activity or a psychological activity. For Plato it is not merely a psychological activity, it is purely a cognitive activities because the soul is contemplating on the forms, what is the nature of the form? Now, this idea of contemplation is something very significant and that can be associated with Descartes idea of introspection, self-reflection, soul contemplates in order to have this self-knowledge, to know what is this identity all about is there a self. So, the idea of a self or self identity can be derived with this contemplative attitude of the soul. Plato does not associate with the physical activities, there are physical activities when Plato compares the activities of the person with movement of the chariot. Now, there is a chariot which is analogous to the notion of body, the chariot represents the body, the body has some kind of movement and this movement is caused by the chariator. So, in this connection one can find that the soul is the chariator, soul is the mover, it is the soul, it is the chariator and the soul which is causing intentional voluntary actions. So, soul as a chariator is the source of movement, these movements are self movement, the soul desires to move like the prisoner, the prisoner desires to move out from the cave, the prisoner could turn, now this idea of a turning is something very significant, it is significant because the reality sometimes are constructed, it is constructed by different sources. So, for example, in today's world the reality is largely constructed by the medias. So, most of the time you are accepting whatever is told to you, whatever is informed to you, but Plato's appeal is you must examine these informations, you must examine these opinions which are created by the mass media and then only you will have the possibility to know whether the information is correct or incorrect, whether the information is well justified or ill justified. So, this idea of a justification, justifying the opinions or what Plato calls doxers is an important element of Plato's discourse of epistemology. So, therefore, there must be a desire of the self of the person, the self must intend to do, intend to reflect, intend to contemplate so that he or she comes to know what is knowledge. What is truth? Unless the desire is ignited, Plato says the knowledge about truth is impossible, unless the one is prepared the knowledge about truth is impossible. So, you have to put the soul in such a condition in which this desire is strengthened, the desire is accumulated, it is broadened enough to realize what is truth. So, this idea of knowing as a kind of a cognitive activity and not a psychological activity is something very significant, because the notion of good, the notion of the ethical is purely a conceptual knowledge. It is not a knowledge which will be derived by seeing ten good acts. No, the lawyer who is is witnessing suppose ten cases where the justice is given, by then he does not really have the knowledge of what justice is all about. No, unless and until he contemplates, unless and until he puts himself in this dialectical process of the journey, the journey of knowing, knowing the truth, he would not enlighten himself. Hence, knowing is a cognitive activity, it is not mere psychological activity for Plato. Now, it is a cognitive activity, Plato says that the one who knows, the one who aspires to know and knows is a lover of wisdom. Now, philosophy as we know is the love of wisdom. Now, this idea of wisdom is something very significant. It is significant, because it is not only an epistemological discourse, but this discourse also talks about the ontology of truth. It is not merely an epistemology, but it is also an ontology that talks about that yes, there is truth and there is also a lover, there is also a knower who knows the truth, who enlighten himself. He is a lover because he is a keen to this virtue of knowing. He cultivates this spirit of knowing and enlightening and that is why Plato's epistemology is very much linked with the ontology and ethics. So, these three, in fact, constitute some kind of a triangle where you have epistemology, this will be ontology and ethics, because knowledge about the truth or goodness is very much linked with the ontology and ethics. This is a kind of a highest virtue according to Plato. So, this is a kind of a knower or the lover. The lover talks about what unless there is a reality, unless there is something there, but the knower would know. So, ontology is also part of epistemology. The ontology of the forms because knowledge is a conceptual knowledge. It is through forms you have the knowledge about the basic particulars, such as the things in the world, the things in the world, the copies of the forms. So, this epistemic concern of the knower is something very significant when we talk about Plato's notion of truth and the knowledge of forms. This idea of a cognitive action, that knowing is a cognitive activity, shows that there is a kind of a power of a forming cognitive act. Soul has some kind of a power. Soul has some kind of a power and this power is intrinsic to the soul. It is the power which causes voluntary actions. So, the source of intentional action is due to the existence of the soul. Soul is not absolutely merged with the world. Now, the kind of relationship say for example, the forms and the particulars are having or the soul is in between this. Soul is akin to the forms and it is through the forms I know the particulars. Say for example, when you talk about the form of horse, horse is a basic particular. A particular horse can have this horseness which is the form of the particular horse. So, to identify the horse, that horse is different from cow, elephant, giraffes, zebra, etc., is due to the very fact that I have this idea about the horseness. Now, who has this idea? The soul has this idea. Soul is a keen. A keen is some kind of a, it is not a predicate of the soul. The soul is by virtue of this relationship with the form. The soul is able to identify, the soul is able to identify a particular as it is. Now, so this identity relationship is a kind of a knowledge. So, and that is possible through the soul. The keen is not a predictable if there is no differentiation. Now, if there is no differentiation, then how do we talk about the knowledge about the particulars and the knowledge about the forms? The conceptual knowledge is a knowledge where the soul is more associated with. The soul cannot be part of the world. Soul cannot be identified with the world. No. Unless an entity has some specific features. So, soul has certain specific features. Otherwise, it would have been identifiable. It is this differentiable differentiation is possible because the soul is associated with the forms. So, the relationship between the forms and particulars is apprehended through the soul which has certain spontaneous movement. Now, this idea of movement has been discussed in later philosophy which talks about freedom. The self is free to act. So, it is the freedom of will as Kant would call it, which talks about or which is the source of action. So, the spontaneous movement of the soul implies that the soul is free. Soul is the creator of the movement. Soul is an intermediary between the two realms of existence as I said. It is in between this. It is here you have ideas and here you have particulars. So, there are particulars. There are things in the world. There are things in the world and soul is in between this. It tries to relate to ideas and relate to the things in the world. So, hence soul is an intermediary between the two realms of existence. The eternal ideas, ideas which are universal, ideas which are universal and different from this mundane particulars, particulars that are there in the world. Let us summarize what is the metaphysical position of the Plato's notion of soul. So, the theory of soul says that every living actions are to be examined. The Socrates famous slogan and unexamined life is not worth living. As I mentioned earlier that in Plato's philosophy, you will find that epistemology, ontology and ethics. They are the three foundations of the entire philosophy and they are related. There is a kind of a triangular relationship. They constitute a kind of a structure in which they revolve. Socrates famous slogan that an unexamined life is not worth living is very clearly maintained and discussed by Plato's theory of soul. So, the soul has this desire, the soul has the higher aspiration to know what it is, to talk about its own self-knowledge and self-identity. Hence, it needs to contemplate on its activities and this contemplation is a kind of an examination. We need to examine it. So, there is a kind of a presupposition in the theory of soul that an unexamined presupposition of living for an examined life. So, an unexamined life is not worth living. The ethical aspect of ontology speaks about the living of virtuous life. So, the ontology not only tells us that there are forms, forms like goodness, justice, compassion, courage, etcetera, but how does an individual live through these virtues? How does one inculcate these virtues? The individual inculcates them, puts them in the reaction and tries to see the meaning through the cultivation of these virtues. Now, unless one cultivates the virtues, one would not be able to examine what they are, what is been given to them and what is responsibility. So, there is some kind of a responsibility and this is what we call the moral responsibility. It is the responsibility of every individual to know what he or she is. Now, for Plato, that is the metaphysical principle of the soul. The soul has the desire of knowing, know the truth. So, soul is a metaphysical reality for Plato. Now, it is a metaphysical reality, the soul as Plato tries to show us, transcends its engagement with the empirical world. We are all engaged with the empirical world because we are all performing actions here and now. Our actions have history, our existence has a history. It is history because it is happening in time. It is we are here now because our existence has got some special temporal location. Now, what is important is that we need to transcend this engagement, this interaction with the world in order to know what is the reality. Like the prisoner had to transcend the engagement that they were having with his fellow prisoners thinking that the shadows are only real, but the shadows were not really real. He had the responsibility. He could turn his psyche in such a way that he could go out and could contemplate on these two experiences, the experiences that he had when he was dwelling inside the cave and the experiences that he can count it when he moved out of the cave. And with that reflection on reflective mind, the platonic notion of soul gives us this impression that it is a kind of a transcendental principle. The ideas by degrees vacate their position of transcendence and are seen to be dependent upon the soul. So, it is the activity of the soul that transcends various knowledge claims, various engagements and tries to realize what is the ultimate truth. So, soul is the center of gravity in platonic systems. So, when we talk about epistemology, when we talk about Plato's ontology, when we talk about Plato's ethics or the theory of values, where we locate soul, the soul is the center of gravity. It is there the center and these three are revolving around the soul. So, in a platonic system of morals, ontology and epistemology, the soul constitutes the center of the gravity. However, it does not eliminate Plato's dualism. Even if Plato is thinking that soul is the center of all this engagement, it is engagement with the morals, engagement with the mundane existing particulars and it is engagement with the forms. This notion of a soul as a center of gravity does not deny Plato's dualism that there is a world and the world of particulars and there are forms independent of this world. So, this ontological dualism is not denied, is not eliminated because the soul is only akin to the forms. They cannot be part of the particulars. The soul through forms tries to know the particulars, try to identify the particulars that yes, this is what it is. So, this notion of dualism is very much part of Plato's philosophy. Now, one can reconstruct Plato's dualism, robot try to reconstruct Plato's dualism. Now, what kind of reconstruction robot does? He says the soul which is at the center of all this activities could be a subjective factor of knowledge and it is antithetically related to the object. So, that kind of dualism between the subject and the object, the knower and the known are very much there in Descartes, in Kant. So, there is a kind of a dualism which probably Plato could be the source of it. Now, let us read in what way robot tries to see, tries to interpret Plato's dualism, tries to reconstruct Plato's dualism. He writes, I quote, in somewhat similar fashion referring to Kant, Plato having postulated soul as that in which mind and wisdom are contained, argues from the soul which acts as organising principle in the individual to a supreme soul in the universe from which souls of individuals derive their being. So, it is with this we would like to conclude that soul is an organising principle. Soul is a unifying principle, hence it is a metaphysical principle, principle which connects to ideas, connects to the particulars and tries to realise what is the supreme virtue. So, it is that where you find Plato is talking about how soul is the source of all kinds of motion. The platonic notion of motion or movement as I was talking about freedom is some kind of a rational movement. It is, it is coming to a rational movement, the movement which is articulated by region and when it is expressed, it is expressed through physical action, hence one can also notice it is affinity with the body, soul is independent of the body and soul is related to the body. Soul is independent because it is the cause of its own motion. So, the mortal soul is as Plato says is the trunk of the body and the immortal soul is the soul which has the reason, the spirit and also can be divided into this three category reasons, spirit and the appetites. There are three forms of activities where activity of the chariot and the activity which of this horses who are pulling the chariot. So, the chariots, the soul has the power to control the movement of the horse. At the same time, the chariot in itself represents a kind of a composed organic system like the our body is and the soul who is there in the body controls its movement, that is how chariot controls the movement and directs this horse towards the body. So, chariot controls a kind of a destiny. So, there is this notion of a destiny in Plato's philosophy. Destiny is to realize truth. So, truth is an ultimate and we need to realize following a dialectical process. This is the process which is cultivated through imagination and reflection. It is a knowledge which is conceptual not sensory. So, this will conclude Plato's discussion on the notion of soul. Thank you.


I think what's really important is that a person feels accepted and they feel safe because this is happening for a reason, so if somebody isn't speaking it's happening for a reason and whilst it's important to meet the person where they are, so you know if it's a child that's absolutely stunned into their own silence we need to help them with that but how we help them might not start off by looking at speaking so I think you know I speak to a lot of parents who can feel very out of control and the way that they try and take control the way that they try and help is say come on speak to me I want to hear what you've got to say and actually that person can communicate what they want to say without saying without actually speaking and so for me I would very much say that a person needs to feel safe they need to feel understood and they need to find their own ways of communicating I think we have to be very aware to not reinforce the idea of perpetuating safety behaviors silence is one of them but to enable the person to make the changes that they want to make and you know a good question to start with might be like do you want to do you want to talk right now is that something you want to work towards and and establishing where that person is in that relationship so you're on the same page at the same time and you can do that in a number of different ways you know flashcards with full writing or you know eye movement and all those kinds of things and so I think I think safety and relationship is really really important but I think everybody's different and I think it's about you know taking the time to understand that in that given moment and seeing it as an opportunity because some of the most the deepest connections we can develop between other humans can happen in those moments of silence so not to be afraid of them really because if we're supporting someone you know especially kind of parents or teachers we can we can perpetuate the fear by being scared ourselves whereas actually we can you know we can embrace that person and all that they are and and help them and we just have to see the opportunities as they're presented to us


Okay, so Pierce brought something really, really interesting here, which is how many contracts don't receive a bid. The last time I checked, it was right around like 57% of all contracts had one or no bidders on it. So it was somewhere around 57% of all the contracts. So when you're looking at all of these things and you think like so many people are bidding opportunities, bidding contracts, that's not the case, right? Just because there's a lot of opportunities doesn't mean people are actually responding to them. My very first contract that I was awarded with the help of the Department of Interior was an opportunity that I reached out to a small business person, the Ostebu, and I gave him my capability statement, always be prepared, that's the first thing, always be prepared. I reached out to an Ostebu, gave him my capability statement, and she says, hey, I have a project right now, it was FedBizOps at the time, she says on FedBizOps, and this was like two years ago, and again, like my first call, and she said, I have a project on FedBizOps and I put it out twice, no one's bid it. Would you look at it? And I'm like, sure, I'll take a look at it. She's like now, so all right, she sent me the information, we're on the phone, and I looked at it and I'm like, yeah, it looks good, she goes, well, can you give us a price? I'm like, absolutely. They extended the bid due date so that I would price the job, and what do you think happened? I was the only person that bid it. But imagine how do you, it's almost impossible to have that kind of information available unless you are calling and speaking to people in the offices, letting them know who you are and what you do, they can't give you those opportunities.


The first speaker will be Vanessa Gable talking about river incision across the lithologic boundary. Thank you. So what I want to tell you all a little bit about today is the work that I've been doing trying to understand how fluvial incision gets expressed across lithologic boundaries. And the area where I'm studying this is the High Plains of North America. So to get everyone oriented here, what we're looking at in this figure is a DEM of the modern topography of the study area looking to the northwest. So the high red peaks are the southern Rocky Mountains in Colorado. And as you move to the north and lose some elevation you're moving into Wyoming. The sharp break and slope that you can see is the area that I'll be referring to as the mountain front throughout this presentation. And this broad flat surface to the east are the High Plains. Now what I've outlined in white here is the preserved surface of the Ogallala formation. The Ogallala is a mid to late Miocene formation with an end deposition date around 5ma. And it's significant because it captures a time when the plains switched from being in an aggregational mode to a degradational mode. So as the Ogallala is being deposited, the plains are capturing sediment. And after the end date of Ogallala deposition, plains that are traversing the mountains or rivers that are traversing the mountains start to incise into that surface. And what you can see from just a cursory study of this DEM is that incision has really been focused around the mountain front streams have carved deeply below the Ogallala in that location. And the amount of material that's been eroded seems to attenuate quite rapidly as you move east. And so I'm interested in understanding why incision into this surface occurred in the style that it did. So when I say style, I mean both the magnitude of incision as well as the spatial extent. So why is it focused at the mountain front? So to answer this question, we need two things. We need a paleotropographic reconstruction so that we can actually quantify how much materials been removed. And then we also need a numerical model so that we can test different erosion scenarios. So for our paleo surface reconstruction, what I've done is interpolate between the Ogallala formation where it is well preserved on the plains and sparse patches of fluvial gravels that are found within the mountains. What the presence of those gravels in the mountains suggests is that at the time of Ogallala deposition, the sedimentary systems were much more continuous. So we graded from high elevations in the west to low elevations in the east much more smoothly than we do today. And so when we do this interpolation between the gravels and the Ogallala formation, the surface that we can reconstruct supports that hypothesis. And so the surface that you're looking at now will be used as the initial condition for all of our subsequent model runs. We're using a landscape evolution model that where the change in elevation at every point in our model is the sum of an amount of material eroded minus an amount of material deposited at that point. Erosion is governed by the stream power theory where the area and slope are calculated within the model, but the erodibility efficiency is a user defined value. So what I've done for my model setup is define a low erodibility for the mountains representative of granitic rocks and a higher erodibility for the plains more representative of sandstone. For the deposition calculation deposition is a function of the sediment flux and some effective grain size. And that effective grain size is a value that we really don't know either. So in addition to testing different values of erodibility, I'll be testing different values of an effective grain size. So what we want to do in these model runs is basically start with our initial reconstructed topography and erode it towards something that looks looks more like the modern topography. In order to evaluate our model performance, we need to understand what that sort of difference that we're looking for is. So what you're looking at here is a DM of difference where all the areas that are lighting up our places where material has been removed in the modern. So this green curve is just showing us the amount of material removed so we see up to around 400 meters of elevation removed right at the mountain front. And as we go into the plains, essentially no material being removed so no elevation change between the ancient and modern landscapes. So, when we run our models, what do we see. So what I've tested for in just these preliminary results are three values of an effective grain size moving from point zero one up to 100. And in each of these we're also looking at three amounts of contrast in erodibility between the mountains and planes from the planes being 10 times more erodible than the mountains up to 30 times more erodible. What we see in these top two plots is that the model appears to be quite insensitive to the contrast in erodibility and the shape of the surface that we produce is is also quite insensitive to the contrast in erodibility and the effective grain size that we choose. What this what these curves tell us where it's below the modern curve closer to the mountains and above the modern curve on the plains is that rather than getting focused wells of incision we're getting a much more dispersed erosive signal. That's like distributed down river valleys. So this really isn't capturing the focused well of incision that we're looking for. What the grain size really does seem to control is the runtime of the models. So much so that when we move to this bottom plot, we see something that looks more promising for the erosive signal, but the grant, but the runtime is exceeding 5 million years so we're running for too long. So where do these results leave us? Basically what we know at this point is that we need to more fully test the parameter space of both the erodibility and the effective grain size. There's going to be a range of solutions that give us the curve that we're looking for. The model seems to be insensitive to a contrast in erodibility, but it's also possible that the contrast is just much higher than what I've shown you here. So basically another possibility is that we need some additional forcing to replicate the modern topography, whether that means honoring, differing erodibility values in stratigraphy or inducing some sort of external forcing like tectonic tilting or climate change. So with that, I'll take any questions. Great. Thanks, Anessa. And as a reminder to folks, please raise your hand if you'd like to ask a question. I can't see the chat or I'm not sure if, okay, no one's raising their hand. So I have a question. When you were talking about the different erodibility for the mountains and the plains. Yeah. How were you doing a sort of an abrupt transition or were you a step function or were you doing a more gradual transition? And did you have problems with numerical stability? Yeah, it is an abrupt transition. And so that is one of the things that I, yeah, it's an abrupt transition. So that in itself is, you know, probably not particularly realistic. And also what I'm kind of starting to think about on this last slide is honoring stratigraphy. So I think one of the things that might be going on is that closest to the mountain front. You completely removed the Ogallala and started to incise down into the pier shale, which has a much lower erodibility, even than the Ogallala. So, so using one erodibility value for the plains is probably not particularly realistic way to model it. Thanks. And we have one more question from Nicole. Yes, Brini. She says, great job, Vanessa. Maybe I missed it, but how did, how did you initially estimate erodibility? Yeah, so the initial estimate of erodibility is, so I've kept it constant for the mountains and just varied it for the plains. And that value that I used for granite is taken from an average value published by Katie Barnhart and others earlier this year, where they basically combed the literature for different values of erodibility that people have used for different lithologies and compiled them all. And so I took an average value from that work. Thank you.


In this video we want to prove that Equal chords of the same circle are equidistant from the center and here We have a diagram where we have two chords a b and pq and the center is o and we have drawn perpendicular from o to pq and a b and why have we drawn these perpendicular is Because we know that the distance or the shortest distance between a chord and a point or a line and a point The perpendicular distance and that's why we have drawn the perpendicular distance. What we need to prove here is that if Pq is equal to a b then o m is Equal to o c right, so this is what we need to prove How are we going to do this is first of all trying to collect all the information that we have What I can see from the diagram is that clearly pq is Equal to a b because it's given to us We are going to use a knowledge point that the perpendicular drawn from the center of a circle to the chord Biceps the chord so from our knowledge of geometry We know that m is a midpoint of pq because o m is a perpendicular from the center of the circle to the chord and similarly C is the midpoint of a b since o c is the perpendicular to a b and No is a center of the circle and with all these knowledge points. Let's see if we can prove O m is equal to o c now Let us first of all try and complete a triangle and why I like to draw the triangles in such Circle proves because if I can complete a triangle where o m and o c are the sides of those triangles Then it becomes easier for me to prove that the triangles are congruent And then I can show that o m and o c are congruent and because I can see different elements that are already equal I think this approach of making a triangle first and trying to show them congruent is going to work So we have completed two triangles one of them is triangle o m q and The other triangle is o c b So we mentioned in triangle o m q and triangle o c b what we see is that there are two right angles One of them is o m q major angle o m q is equal to major angle o c b And both are equal to 90 degrees And we know this from construction Right because we already know that these are perpendicular. So the angle is 90 degrees So can we say that the triangles that we're considering are Right-angled triangles Now we go ahead We have already mentioned one of the points the next point that we can consider in both of these triangles is side o q Right o q Is equal to side o b and why is that this is because both are Red eye of same circle and we already know that the red eye of the same circle are equal So we already got the second point in the two considered triangles Now, let's see if we can find something else We already know that p q is equal to a b right and therefore The half of both of them should be equal as well We already know m is the midpoint of p q and c is the midpoint of a b and therefore Can I say p m is equal to m q and because both of these chords are equal I can also say that this is also equal to ac and b c And we only want to highlight m q is equal to b c right and so We will just keep m q and b c here, right? Let me just write it well. So m q Is equal to b c and I can say this is deduced knowledge from the fact a perpendicular drawn from Center to the chord bisects it you won't really have to write Such a long reason in the exam, but I'm just writing it for you to understand This is a deduced knowledge from the given point as well as something that you know from the geometry So we have got three elements in the two triangles that we considered to be congruent or to be equal And it is enough to show that the two triangles triangle o m q is congruent with triangle O c b and which test that we used here We showed that these both are right angle triangles and the hypotenuse o q and o b are equal, right? So this was the hypotenuse, right? And we already showed One other element of both the triangles to be equal as well, which is m q equal to b c and therefore this is hypotenuse side test and since triangle o m q and triangle o c b are equal All the other corresponding elements of both the triangles are going to be equal and therefore o m corresponds to o c I can say that o c Is equal to o m and this is exactly what we wanted to prove at the top and therefore The equal chords of the same circle are equidistant from it


Show you how it's all done, but I want to make a little drink because it's date night Got some ice in here. This is drop-tine bourbon Drop-tine bourbon whiskey finished in brandy barrels. This is a great product And this is a product made by people like us who do the kind of things that we like to do Hence the name drop-tine little honey, I Didn't have any regular club soda, which is what I would normally put in here Little iced tea couple of cherries Now you can muddle these cherries you can mash them up if you want or not little lemon juice So you've got the tartness of the lemon juice. Of course, you've got the bourbon in there Give it a good shake glass of ice I'm not one of those people that looks at the cocktail menu when I go to a restaurant But I know some of you are but You know, I kind of surprised myself for that I'm just kind of throwing stuff together and I thought the tea would work well I'm gonna drink the whole thing


People say it happens fast. I didn't imagine how fast. I think it was just after 1230-ish that I heard alarm sound. I thought it was our clock alarm.   I don't want to imagine what the alternative looks like. If we had had a better system in place, it could have been a less destructive story. That's the house but we got out of life. We're here today to launch the CFA and Fire Rescue Victoria campaign, Silence is Deadly and it's a message to all Victorians about having smoke alarms, working smoke alarms, having them installed in the right place and also importantly having them interconnected. Fire services in Victoria responded to over 32,000 residential fires in the last 10 years so it can happen to anybody at any time. 18 Victorians die every year because of house fires and a lot of those are shown that they don't have working smoke alarms so we really encourage everyone not just to have working smoke alarms, that's really important but if you can get interconnected smoke alarms because if one smoke alarm goes off the rest detect the same and they all activate at the same time.


Hello, everybody, hooded Cobra Commander 788 here, and I'm back with another Vintage GI Joe toy review. This time we will be looking at the 1983 Gung Ho. Before we get started, I want to remind everybody to go ahead and smash that subscribe button. And if you liked this video, go ahead and give it a thumbs up. If you hate this video, go ahead and give it a thumbs down, I'm okay either way. If you're watching this video from any website other than YouTube, I would greatly appreciate it if you take a little trip over to the hooded Cobra Commander 788 YouTube channel and hit that subscribe button because I've got a lot more great GI Joe vintage toy reviews and comic book reviews coming up and you don't want to miss it, so please subscribe. This action figure is the GI Joe Marine Gung Ho, who was released in 1983. And this was one of my favorite GI Joe action figures. I know I say that almost every week, it seems like every GI Joe action figure was my favorite GI Joe action figure, but in this case I really mean it. I really had a fascination with Gung Ho, and I still really enjoy the action figure today. As I said, Gung Ho was released in 1983. He was also sold in 1984 and 1985. He was discontinued in 1986 when he was replaced by the new GI Joe Marine Leatherneck. Now the words Gung Ho are an anglicized Chinese expression gong hei, which means work together. The American usage though has the meaning of either being enthusiastic or overzealous. The phrase Gung Ho, however, is associated with the United States Marine Corps and Gung Ho's codename probably came from the 1943 movie entitled Gung Ho, starring Randolph Scott, and that movie featured a unit of the United States Marine Corps. I actually had a copy of the movie Gung Ho on VHS Cassette when I was a youngster, and that movie started a long fascination with the United States Marine Corps in general, and Gung Ho in particular. It's worth adding that since this figure came out in 1983, he predated the Gung Ho movie with Michael Keaton that came out in 1986, so the Michael Keaton movie doesn't have anything to do with this at all. Let's start as we usually do by looking at Gung Ho's accessories. Gung Ho came with what the card described as an XM-76 grenade launcher, and this appears to be roughly based on the M79 40mm grenade launcher, which was a real-world weapon used by the US military for a long time, including the early 80s when Gung Ho would have come out. The main differences between the M79 and this XM-76 is that the M79 did not have this handle, it was held more like a shotgun, and it didn't have this kind of ridged portion right here, but other than that it's not a bad representation of the real-world weapon. Now when a lot of kids got the accessory, they thought it was a shotgun, and I guess it kind of looks like a shotgun, but really they're not too far off, because the M79 was capable of firing a lot of different types of rounds, including buckshot and flochette. Gung Ho's other accessory is his very large backpack, which is in the same color as the rest of his uniform, and it really is much larger than other G.I. Joe backpacks that came out with the figures at the time. One problem that I have with this backpack is that there are no straps or web gear on the action figure that would hold this backpack up. Now maybe the backpack is supposed to clip onto the vest itself, the sculpting on the vest certainly does not indicate that, but even if it did, Gung Ho was wearing an open vest and this obviously heavy backpack would just pull the vest right off of his shoulders. For that reason, I don't really care that much for this accessory, I don't think it's very necessary, of course you need it in order to have a complete Gung Ho, but it's really not my favorite and I don't consider the backpack essential to the character of Gung Ho. Let's look at the details of the figure itself, and the first thing that you notice is the light blue, almost aqua blue color, which seems like an odd color scheme for an infantry trooper. I think that Hasbro when they designed this action figure had in mind the traditional role of the Marine Corps, which was to be infantry troopers on naval vessels. So they gave him kind of a color scheme that would be more of a camouflage at sea. Despite this attempt to portray Gung Ho as kind of fulfilling the traditional role of the Marine Corps, a lot of collectors just don't like this light blue color scheme and I can understand why, it just seems rather odd. Of course in the comic book, this light blue color was just recolored green anyway, and Gung Ho, like a lot of other action figures that came with blue plastic, is subject to yellowing. And as the blue plastic yellows, it has a tendency to turn a light green. And you know what? That actually doesn't look too bad on this action figure, it's one of those rare cases when the action figure being in less than perfect condition actually improves the look of it. But I'm happy to say that this one is still a bright blue. Now you can't really tell, I don't think that it's coming out too well on my camera because my camera seems to make things look more yellow than they actually are, but I can tell you that looking at it here in person under the bright lights, it is still a vibrant light blue. As you can see, Gung Ho is wearing a vest with no straps or anything like that, it's an open vest. He's got some grenades, some green grenades. He's got some muscles sculpted onto his chest and abdomen. Also on Gung Ho's chest is the feature that got me interested in this action figure when I was a kid and that is his huge tattoo. He has the Marine Corps emblem tattooed on his chest, also known as the bird, ball, and chain. And I think this is kind of courageous on Hasbro's part to release action figures with tattoos. This is the first one that they released that had a tattoo. I don't know if most parents would want their kids toys, encouraging them to get tattoos, but nonetheless Hasbro went ahead and released this really interesting and unique looking action figure. Now when Gung Ho appeared on the GI Joe Action Stars cereal box, they actually covered up this tattoo with a t-shirt that had the Marine Corps emblem on it. Also later versions of Gung Ho have played a little bit with the tattoo. There's a version of him out that has a much smaller tattoo that's higher up, but quite frankly I think the whole idea of tattoos is that they stay where they are. And so I know that you want to change his wardrobe around a little bit, but you can't just move the tattoo around, it just doesn't make sense. On his legs, Gung Ho has a very nicely sculpted pistol and a holster. On this side, he has on his boot a knife and grenade rounds for his grenade launcher. And that's really cool. I really like it when the sculpt of the action figure coordinates with the accessories. On his wrist, he has a green watch with some decent detail. That's kind of rare, not a lot of action figures got watches, so that's nice. That's another nice detail. Gung Ho's boots were actually reused for Duke. Just recolored, but there's the same knife, the same boots. Gung Ho's pants were camouflaged, and that's another thing that I really like about this action figure. Back in 1982 and 1983 we had precious little camouflage on these G.I. Joe action figures, so this was like a bonus. Let's take a look at the articulation for Gung Ho. He had the typical 1983 G.I. Joe action figure articulation, which meant that he could turn his head side to side. Later G.I. Joe action figures, starting in 1985, had a ball joint at the neck, so they could also look up and down, but back in 1983 they could just do that. The action figure was held together with a rubber O-ring that's looped through the center of the action figure, which allowed him to move at the torso a little bit. His arm at the shoulder, he could swing up like that, and he could swivel all the way around. He had a hinge at the elbow, so he could move his elbow about 90 degrees. He had a swivel at the bicep, which allowed his arm to swing around all the way around. This was referred to as swivel arm battle grip, which was introduced in 1983. The 1982 G.I. Joe figures did not have that swivel, they only had the hinge at the elbow. His legs could move apart about that far, and he could move his leg at the hip about 90 degrees, and he could bend his knee about 90 degrees. On his head, Gung Ho has a Marine Corps utility cover, also known as a utility cap, that is olive drab, and sculpted on there looks like an anchor, even though for the Marine Corps it would be the same Marine Corps emblem. So fascinated was I with Gung Ho as a kid that I actually went to an Army surplus store and got a hat exactly like his, and I would wear that around the neighborhood. Yeah, I was a little bit of a dork. Let's take a look at the file card. The file card was printed on the back of the card on which the action figure was packaged. This is the front side, you can see a little bit of the card art, and on the back it had this little biography, and you were encouraged to cut that out and keep it. It says he's a Marine, and a Marine is not a specialty, it's actually a branch of service, but I don't mind the Marine designation on here. Not every designation on the file card is the specialty of the character, for instance Stalker is a Ranger, which again is not a specialty. The Marine designation I think is to tell us what is distinct about Gung Ho among the G.I. Joe team. At this time he was the only Marine on the G.I. Joe team. Says his code name is Gung Ho, his file name is Etienne R. Lafitte, I hope I pronounced that correctly. His primary military specialty is Rekondo, and Rekondo is actually a combination of two words, reconnaissance commando, and the purpose of a Rekondo is to do reconnaissance missions deep into enemy territory. Secondary military specialty is Jungle Warfare, and training instructor. His birthplace is Ferre de Lance, Louisiana, which I believe is a fictional town, I don't think that really exists. Ferre de Lance is French for Iron of the Lance, and my best guess as to where this came from was maybe a 1974 movie by that name. The movie, I haven't seen it, but the synopsis doesn't make it sound very good. The best I could describe it is Snakes on a Submarine. His grade is E7, Sergeant. And this biography here says that he was born into a large backswamp Cajun clan. Gung Ho moved to New Orleans and won a reputation as a bare-knuckle brawler and a knife fighter to be reckoned with. Joined the Marines at 18 and graduated top of class from boot camp at Paris Island. Paris Island refers to Paris Island, South Carolina, which is the Marine Corps Recruit Depot, a training center for the Marines since 1915. Here it says he attended Airborne School, Rekondo School, and Marine Ordnance School. That expert all NATO infantry, small arms, and most Warsaw-packed infantry weapons, XM-76 grenade launcher, which of course is what he came with. This quote here from Zap, his teammate, says, All Marines are crazy, but Gung Ho is the hairiest, scariest, craziest jarhead that ever scratched, kicked, and bit his way out of that hole in the swamp they call Paris Island. So the file card really depicts Gung Ho as a real badass. Now he joined the Marines at 18, but by that time he had already won a reputation as a bare-knuckle brawler and a knife fighter before he turned 18. So at 17 he was knocking around New Orleans and knocking some heads. Honestly, if he hadn't joined the Marines and ended up in the GI Joe team, he'd probably be in prison. I think maybe that's what drew me to Gung Ho. I mean, he's a good guy, he's fighting for the right side, but he's also really tough, he loves to fight, and he can be brutal when necessary. And I think that is an interesting mix. That is my review of the 1983 Gung Ho, I hope you liked it, and if you're thinking of picking up a Gung Ho action figure, I hope you found this review informative. If you liked this video, go ahead and give it a thumbs up, as I said, and if you don't like this video, give it the thumbs down, I'm happy either way. Once again, go ahead and hit that subscribe button because there's even more great stuff coming up. Thanks for watching.


Hi and welcome to the session. Today we will discuss the following question. The question says, Rukhsar painted the outside of the cabinet of measure 1 meter by 2 meter by 1.5 meter. How much surface area did she cover if she painted all except the bottom of the cabinet? Before proceeding for the solution, let's recall the formula of total surface area of a cuboid. Which is equal to 2 into L into B plus B into H plus H into L, where L is the length, V is the width and H is the height of the cuboid. This is the key idea for this question. Now let's see its solution. In the question, it is given that Rukhsar painted all the cabinet except the bottom. So to find out the painted area, we will find the total surface area of the cabinet and then we will subtract the area of the bottom. Now as we can observe that the cabinet is a cuboid, so first of all we will find out the total surface area of the cuboid in cabinet. So for the cabinet, length that is L is equal to 2 meters, width that is B is equal to 1 meter, width that is H is equal to 1.5 meters. Therefore total surface area of the cabinet is equal to 2 into L into B plus B into H plus H into L. Substituting the values, we get 2 into L into B that is 2 into 1 plus B into H that is 1 into 1.5 plus H into L that is 1.5 into 2. And the unit will be meter into meter that is meter square. This gives plus 1.5 plus 3 meter square and this is equal to 13 meter square. The area of the bottom of the cabinet, so let us write for the bottom of the cabinet. Now the bottom of the cabinet is in a rectangular shape with length equal to 2 meters and width equal to 1 meter. So we will write length that is L is equal to 2 meters and width that is B is equal to 1 meter. Now area of the bottom is equal to length into and L is equal to 2 meters, so 2 meters into B that is 1 meter and this is equal to 2 meters square. We already know that the area painted is equal to this area of the cabinet area of the bottom substituting their values. Total surface area of the cabinet is 13 meter square and area of the bottom is 2 meter square. So 13 meter square minus 2 meter square is equal to 11 meter square. So rucksack has painted 11 meter square of the area of the cabinet and thus this is a required answer. With this we finish this session. Hope you must have understood the question. Goodbye, take care and have a nice day.