lasers in space, lightsabers, what do you think about when I say space and airborne laser platforms? Death Star? What else? What do you think about when I say laser based propulsion for space travel? Freaking complicated navigation math with way too many variables. Okay, no seriously. In the next talks we will learn what's really behind those terms. Peter Buschkamp will teach us not only basic physics but he will also teach us about the boundaries of lasers in space. And we will learn about space travel with lasers which absolutely sounds like science fiction but apparently is already a reality. Peter Buschkamp works for the infrared group of the Max Planck Institute for Extraterrestrial Physics where he's building the world's most sensitive instruments for space observation. He's also active in the Munich Freifunk Community where he's building backbones and he was the head of the public astronomical observatory in Bielefeld. Are you sure about the Bielefeld part? Yeah. Please give a warm hand for applause for Peter Buschkamp. All right. Yeah, this is essentially a follow-up talk from last year. I don't know who was there last year. I talked about how to shoot lasers into the sky and use them for astronomical purposes, essentially to correct the atmosphere above us to get clean and undisturbed images here on the ground and not just from space telescopes on satellite platforms. So this year it's lasers in the sky. It's only 30 minutes. Sorry.  What is actually now already flying above our heads? What is what some people think should be flying soon above our heads? And some others are pure speculation. So first we'll talk about laser propulsion. Actually, this is the second reason how this talk came to be because I was talking to Liz and she wanted to do something about interstellar and interplanetary colonization. I said, okay, cool. Maybe we can combine it and then talk about also about photonic propulsion and so on. And then we just skipped it into the next talk to have more time for other stuff in the other talk. After that, we're talking about laser brooms, how to clear up the skies above us with lasers. It's going to be about laser sensing, which is routinely employed every day. If you look up the weather on your smartphones, there's a fair chance that you will be looking at some refined laser data that has been taken either from ground into space or from space to ground. And to finish, we'll talk a bit about laser communication. Of course, this is something a lot of people here in the audience are also interested in. It's the KS Communication Congress after all. And this is something that takes place above our heads, is being built right now and is actually pretty exciting. So first, let's talk about laser propulsion. Laser propulsion is a method of pushing something forward with just light. How does this work? Well, I mean, photons are not just there to illuminate things, which they do a pretty great job in. They also, of course, carry momentum. It's just a tiny bit. It's the energy divided by the speed of light. But still, there is a bit of momentum being transferred from a photon when it hits some surface. To get a rough idea how much this is, if you are in Earth orbit, you get the amount of photons from the sun, which is equivalent to the so-called solar constant, which is 1,361, I guess, if I remember correctly, watt per square meter. This translates, then, if you have a solar sail which you put into Earth orbit and just let the photons from the sun push it forward, which is equivalent to, well, it depends a bit on your orientation of the sail. And if it's a black sail, the photons get absorbed, or they get ideally reflected, if you have so, that means if you have an inelastic collision or an elastic collision for the physicist here in the room. But roughly, you get around 7 micro Newton. That's not much. Of course, this is not much. Well, you can scale up your sail. It's not just 1 square meter. Maybe it's 100 by 100 meters. The point is it may be just a very tiny fraction from each photon, but there are a lot photons, and this is for free. So if you maybe have a mission which you just want to push far away and you have time on your hands, maybe this is something you want to do because this is constant.  You don't have to bring huge amounts of propellant into space for that. This could maybe an option. Is this pure science fiction right now? No, actually not. This is a representation of a test solar sail satellite from the Japanese space agency, which has been launched in 2010. It's called Icarus. And there you get a rough idea of what this actually looks like because if you just, well, this is just a sail with something in the middle. But yeah, this is actually flying right now. They hope to, they last communicated with it in 2014. They hope to communicate in the next year with it again. And what you see here is in the middle, for example, there is the little payload. So some experiments, a little transmitter to communicate back to Earth. And these blue stripes you see around the middle. These are actually solar cells which then produce the electricity for the experiments on board. How big is this thing? It's 14 meters by 14 meters. So this is not much, but it's a nice technical demonstration platform. Of course, if you want to go really into serious propulsion with that, you'd rather look maybe at sails which are 100 meters by 100 meters or even a kilometer. We don't have a real clue yet how to make them, how to bring them into space, what to use actually as the sailing material, how to unfold it properly, but we'll eventually get them. Another thing you could be thinking of is of course not the sun, but of course to shine a big laser on this, maybe a ground-based laser, maybe a space-based laser. There is, of course, project star shot. It's going through the media all over the place right now. This is a very interesting concept which uses a ground-based or maybe a space-based laser. And of course there you have targeted and directed laser light so you don't have the one over R squared problem when you get far away from the sun. This is an option. Another option using lasers in a similar manner is not to just push the sail forward with your laser, but to use the laser actually to transfer energy to your spacecraft. And this is so-called laser-energized, laser-based propulsion. This is nothing like a sail, although this might look like it. I like these 60s and 70s space art. So on the very left you see a laser array here in some orbit around one of the moons of Jupiter. I think it should be Io because of the geyser there. Anyway, so this is sending out a powerful laser beam to one of these reflectors on the spacecraft itself in the front. Again, there's the payload at the very rear. Again, there's the engine. In the middle there's everything else. And so what we do here is we do have propellant on board. But unlike in the chemical rocket where we use the propellant for the energy and also the debris from the propellant, the dust and what comes out after the reaction for the thrust, here we use some external means of energy transfer on a propellant which gets then pushed out of the nozzle of our propulsion system and then pushes the whole thing forward. If you think of a normal jet engine, it's the same. Air is the medium and you use kerosene as the energy to actually drive the engine. Another very interesting thing which is being discussed in the scientific literature right now is the so-called photonic laser thruster. And for some applications, also in military application, there is the great wish for having formation flying satellites which also maybe are flying together like this and then they expand into a nice formation and have a nice long baseline between them and they should get together again for some radar, for some interferometry of radar on the ground to see where you know all this kind of stuff. This can be done with tethers or to just have a rope between those but if you have small satellites, you maybe want to think about something else and this is then what you do so you have a laser between those two vehicles, the mission vehicle and the resource vehicle can also be of comparable size, doesn't matter. The interesting thing is here, you do reuse the photons. It's not just that you shine them on a reflecting surface like on a sail or as we've seen in the other case but you have them actually enter like a laser cavity. There are mirrors to each side of this and so you reuse the photons and this is very efficient in pushing two small masses out of each other and then if you just switch it off they will self-gravitate together again. This is a very nice thing to have formation flights. At least it's proposed. It's not yet demonstrated in space but we'll soon we'll see this. Laser brooms. If you look at the earth from far away or maybe not even so far away within the orbit of our moon around earth and if you exaggerate a bit this is how it looks like. Earth is enshrouded by junk right now. This junk has been put there by us. We have 50 years of space exploration, upper stages of rockets, having collided, tanks being ripped off, satellites who have collided and this makes up a huge amount of space debris as it is called. There are around 30,000 objects of the size of 10 centimeters in space around earth. About 700,000 of the size of one centimeter so some thumb size and over almost 200 millions of them smaller than one millimeter so the ring you see here is the of course the geosynchronous orbit and in low earth orbit you also see this. Is this a problem? Yes, this is a problem. Here you see a nice image from ESA. I think it was in this September 2016. Sentinel-1A is one of the new class earth observation satellites from ESA and actually on the left you see how one of the solar panels looked like before the impact and then on the right you see there was some space debris hitting the satellite and there's about 40 centimeters in diameter damage on one of the solar panels and this roughly corresponds to some space debris junk piece of around five millimeters or even less. We have to think about if now space traffic is increasing and how to get rid of this. One concept is to actually shoot up this from the ground. Of course not in a matter that you now destroy these pieces and just split them up in even smaller pieces. This is not what we want to do. Of course not because we want to reduce the size. How do we reduce the size of these things? Well, if we get them into an orbit that they will just gradually go down in earth atmosphere and just burn up in the earth atmosphere problem solved. This is actually what is being proposed right now and if you take a commercial high power laser around five to ten kilowatt which you can buy and put it on a decent telescope you could move the orbits or the orbital velocity of space debris of around one to ten centimeters by one millimeter per second in only shining your laser at it. Again it's like a solar sail. It's just pushing the stuff with photons. It will have a slightly different orbit.  Of course this has also been proposed from space. Actually this is the same guy who is now in this project Starshot project. Lubin et al and Cosmo et al in 2015. If you want to look up those papers they're quite interesting reads. For example this is a proposed satellite that flies now in deeper space. They did not just think about deflecting space debris but also here targeting asteroids. This is a platform which has big arrays of solar cells to power the onboard lasers and then we just shine this laser at the asteroid for quite some time. It could be here. It could be maybe 10 years if we identify the threat to earth early enough. This is easy. Also by the way if you're interested in this stuff there is a conference about planetary defense conference. Just look it up so you can take part. People are discussing seriously about this. What you do then is not to just push the asteroid with your photons but here asteroids very often contain frozen material, frozen gases. So you supplement those gases and actually while the gas supplements from the asteroid itself it creates a bit of thrust of course. It's just like a little chemical rocket thruster and that gradually pushes things out of the way. This is the so-called D star light mission as it's called. There's also a D star which then proposes to have a dedicated shown on the left a laser platform with even more powerful lasers and then have an array of mirrors somewhere in space to direct this for example to an asteroid. Maybe this just needs half a day each day for five years to be deflected so it will not hit us in 30 years from now and then we turn this mirror in another direction and just to push a bit our spacecraft our solar sail spacecraft like the project star short thingy which we want to push through space. This could be done. It's shown here in detail how you would do this with an asteroid as yeah as said you just supplement the the gases there and use them as thrusters. This is of course not what we do have in space right now. It's being proposed. What we do have in space right now is laser sensing. Laser sensing is so-called LiDAR. It's light detection and ranging like radar and what we do is we do have a transmitter on a spacecraft. It shines down into the atmosphere.  So we know exactly when we started the pulse and where it is after a given time. So if the pulse travels down into the atmosphere it will of course traverse different parts of the atmosphere and thereby probe different layers maybe high clouds high winds more lower winds or something like that and it will back scatter and we of course know the time the light travels downward and upward and so if you make a graph of the signal intensity versus time we can learn about the different heights in the atmosphere. We cannot just do this with one laser we can maybe do it with two lasers and therefore use different wavelength that means looking at how the one wavelength is absorbed by the atmosphere and then looking at how the other wavelength is absorbed by the atmosphere and then correlate this and then maybe even learn something about the chemical chemical composition of the earth in our line of sight or we do something like Doppler shift measurements and there we can learn about for example how wind is blowing in the atmosphere so our timeline is essentially a set the distance from our spacecraft which then translates to altitude so a short is just means it's near to me it's the high atmosphere and the far away time signal is of course then the ground layer maybe. This is hopefully being launched next year this mission has been on the menu a bit longer it was a bit delayed this is ESA's new satellite for just profiling the wind and you see here an artist's description on the on the right the only actual instrument on this on the satellite will be this wind lighter and it will probe down into the atmosphere and give you exact measurements how the wind is blowing so this will then use this Doppler method where you send out a signal and just measure the the the shift in frequency from the return signal which is then influenced by if you have maybe hit something that is receding from you or coming towards you of course you have to calculate out the satellite motions itself and earth motion and blah blah blah and whatnot so this is hugely complicated and if you want to have a look at the instrument it's looking like this and this is another lesson we had this in in the talk before space technology is really really hard i'm not saying it's not possible it is possible it's it's it is being built but it's not just you don't just fumble something together and who has ever put i mean we have heard by andres talk about the the microscopes and how to build your own microscopes for for maybe doing laser microscopes to to enhance the resolution and how to build them on a on a on a on a typical optical lab bench here you do essentially the same but also you have to launch this thing and actually this is the most critical part because this will be shaken like hell and whoever has adjusted a laser ready resonator alone um mostly is not a fan of yeah just coming to my lab and kick my table a couple of times and let's see if it's still working this will be happening during launch and so you have to really make it perfect and test it and test it and test it and test it and test it again and when you think you have enough done enough testing you test some more um another thing of course you can make distance measurements this is used on the uh on the european um autonomous autonomous transfer vehicle the atv uh that docked to the international space station um this is how it looks like and there's a little lighter interface on the side and it sees the international space station then in false colors which mean this green stuff is very near near to me there's it's it's the flange where i have to dock and the red part is then is at the very back this is the trust structure of the international space station and the widest thing in the middle is one of the so-use capsules that is right now docking on the international space station so this is being used routinely now in space um and as said you can maybe see it in your uh weather app on your smartphone every day i'm not talking about this one this will be in the later actually maybe in the next talk you can also do gravitational waves and there you come have to communicate between different satellites not in terms of just exchanging data but you're actually flying a michelson interferometer in space and measure the relative distances between uh three satellites separated by thousands of kilometers in space to detect gravitational waves we'll learn about this in the next talk so in the remaining time let me briefly give you an overview of how our communication is actually affected by lasers in sky this is mostly developing right now so the first satellites who employ this on commercial platforms are already in space the next will be launched next year and the years after that um why do we want to do this laser communication i mean can't we just do the the the normal k a or q band uh radio frequencies which we are using i mean satellite tv it's it's working fine um the thing is of course with laser communications you do have a much higher bandwidth and that means you have several tens of gigabits per second port per channel it's very very efficient and this is actually interesting for space then again because you've learned in the previous talks that each kilogram you want to put into space costs you a real a lot of euros and so if you look at radio frequency you get about 0.5 megabits per second per watt so electrical consumption and kilogram if you're using it as a if you're looking at a laser communication system it's more in the range of 5 megabits per watt and kilogram um the communication terminals are smaller and they are um and if you for example have a satellite pointing just down on earth with its radio footprint the radio footprint is really really large if you do laser communications you can get down your even with a small telescope of about 20 centimeter size in diameter on your on your spacecraft you can get down your footprint um on the earth to about six kilometers so this is a very very tiny spot so if you're the only one who sits in the middle of the desert observing the signal so nobody is going to be eavesdropping on you also there are some ideas how to do this interferometrically and then if you actually were to intercept the signal you would destroy the interference pattern and this is not going to work out this is how it roughly looks like what we want to do so this is what we have right now it's the radio link between a ground station also called ground segment in in space lingo and this is the satellite bus up there yeah it's called satellite bus don't be uh it's just called like that um and it has the payload and on top so if you ever read payload and satellite bus satellite bus is the satellite and payload is the stuff you put on them to do the actual thing you want to do um this is for example in geostatic stationary orbit for satellite tv but there are other things also flying around in geostationary orbit or in low earth orbit and in low earth orbit you see that the orbit just vanishes behind the horizon there so if you have maybe a satellite that looks at um earth like probing the wind like we've seen before it is only visible from your ground segment from your ground station for a brief period of time who has done uh sdr radio on the NOAA satellites anyone oh yeah okay so those people do know what i'm talking about so you have about 10 20 minutes if you have a real nice position where you can see the satellite where you can record the weather image that gets transmitted from the but after then nothing so it would be nice for example to have an optical link high data rates as said to one of the geostationary satellites and then have them maybe over a hub then talk to your low earth orbit maybe then over other hubs when it gets out of the reach of the one geostationary satellite and so on so this could be really interesting again yes maybe radio also but as said high data rates um and all the uh uh plazas that come with the lasers um so for the technically inclined uh in this audience it's uh how do we communicate uh we have three different types of modulation this is the on off keying the oh okay uh that just means you to switch your laser on and off morseing it's what you have in your fiber line card maybe at home uh it's what you do from ground to space you have pulse position modulation this is what you have in your tv remote um and actually jump jump jump jump perfect so this is what you do from uh this is what you do from ground to space uh because this is uh very very immune to um disturbances by the atmosphere you still have to look through the atmosphere um if you have nothing in your line of side you can of course go to nicer modulation uh principles like binary phase shift keying uh or or higher um modulation schemes but this means then if you modulate the the phase that you do not want to have a medium in between which is disturbing your your phase and this is the atmosphere so this is only used for space to space links this is how a laser communications terminal looks like um you have the laser and everything uh down there somewhere at the bottom you have two um mirrors reflecting it then out of the uh central aperture at the very front it's about 13 centimeters usually and this is how it looks inside so the laser is at the very bottom there and then you have diverse mirrors in there to get actually the laser out um as I said different uh modulation schemes are being used different frequencies are being used typically if you want to reuse telecommunication equipment uh of the shelf you use 1550 nanometers you get this in the normal telecommunications industry if you uh want to for example imply a neodymiac laser the infrared part you go for the um 1064 nanometer um and people are working together uh in space so for example here it's the lunar laser communication demonstrator from from NASA talking to Issa's ground station in Tenerife and this is how it then looks like from space actually there's no video online but yeah um if you look at the communications unit there is the optical module this is the just the laser but of course internally you need controller electronics you need a modem um but the nice thing as said is if you um if you do this standardized you don't have this complicated setup yet for example seen in the experiment for the wind measurements with the LiDAR looking down here you just take commercial off-the-shelf units from telecommunication industry slap it together and you're good to go um you can also do this for deep space communication this was a mission proposed by NASA said it was canceled to do this up to Mars you can do this from satellite to satellite this has been done with the terrassa satellite from Issa and the NASA um and fire satellite and right now the Europeans building a data relay system around earth it's called the EDRS the European data relay system um it's hosted on a commercial satellite from Eutelsat and a dedicated satellite that will be launched later and you see here the laser links for example in red between the satellites or in green to the international space station and then they have also radio frequency links down the next step um is already in the works it will be the so-called globe net so position various satellites on a geostationary orbit around earth having intercommunication from satellite to satellite on laser based and of course the next step will be this one and my personal interest would be then to have this one is there anything else yes i know that in the abstract i did mention weird stuff communication laser based from submerged submarines to satellites in space yes this is being done um downside is you will not find any open access publications which you can show which can be streamed into the internet just google for it you will find really nice sets of information there it is that for certain frequencies in the blue and in the green actually the ocean is pretty transparent to these laser wavelength and so you don't need some uh some something floating on the surface of the ocean and then maybe have a fiber line down to your submarine and then no no no no you just shine the laser at the ocean and you do this the other way around too um just look it up it's pretty interesting some of the stuff has been declassified well actually this is the only source which i also have because i don't work in this kind of stuff and if i did i couldn't tell you um uh yeah so there's a lot of stuff going on in space above our heads right now and in the near future uh just watch out with your spaceship if you do the asteroids um we don't want to see that okay next talk thank you thank you very much for this amazing talk uh we perhaps have time for one short question a really short question so there's somebody already on the microscope he's waving uh do you get a short question number two yeah try okay it's just about how far the weather affects communication we had a company that had two locations and tried to do laser communication and it turned out fog is evil snow is even more evil so uh how is it from space to earth yeah um uh you do have these problems of course too um you do have the only thing you can do is maybe use modulation which is more immune to it otherwise if you have really dense fog you you're at some point just out and therefore uh the the ground link segments um are often still as you've seen of for example in the globe net and the european data relay system the ground links are all always at least back up with radio links so it's also getting a little too loud here to answer questions really so if you have any more questions just come here to the front and ask peter directly and now we want to end with a last big round of applause to thank our speaker peter


hey everyone welcome to figure fantasy we're here to summon both ssx and the outchan so start off with ssx here i don't have much i have 29 so this is actually pushing my luck here and let us see if i can get at least one copy of her from here if not i can get her from the event so let's do some summons here guys i'm in a mood for summoning and let us start with let's start with the nine okay single pulls single pulls nine single pulls and let us it's a rate up right so don't forget to click on the rate up don't forget that let's just do this single pulls i'm not a big fan of um this banner but um i'm gonna do it anyway not really big fans of that's two oh it's ryuka it's okay i'll get that i'll get that so another box this is four five i'll get that i'll take that i have four more four more singles i think singles is the way to go with this banner so that is three more singles this in case i wanna i'm gonna do 10 right after this one so two more singles including this okay so there we go we have 20 so let's do a 10 here and see if we're lucky okay a big box this time nothing and i'm gonna finish this off with 10 i want to take your time so let's open it up from the edge none there you go at least i got ryuka so not that bad of a pull let's start off and let's start next with uh with the outshine here and let's see how we can uh do this so let's start off with uh 10 order now so none first 10 we're gonna be just 10 summons we're gonna be getting with our gems already i haven't saved up that much for the past month so hopefully this is her this is not her it's riko i keep getting junk recently i don't know why we're already full okay let's just clean this up and promote somebody here so this is pitfall of having a limited inventory just go with it do we have a choice no there you go so what else so you have one star pinks let's let us leave them be let's go back to the summons so 20 this is for 30 but i got riko i can't believe i got riko from this banner i can't believe it it is for 30 this is for 40 with the 10 free pulls on the way okay we have another one hopefully this is her hopefully this is her okay yes the outshine is here let's skip this one and confirm let's get the reward here so at 80 we get a free copy of her but i don't think i'll reach that i don't think so probably an off-batter pull so hopefully getting another copy of her won't be you know won't be that hard i think so go too soon and i think i have one more 10 pull and that's it there you go i hope this is her another shitty pull i have uh how much is this eight pulls let's do singles here let's do singles while you guys are still single okay you might get married within this pool so let's just finish everything here if i get lucky then i get lucky if not let's gear back first so quick select let's promote again a couple of people here including vasily he's so silly mr vasily getting weird rates for the game weird rates okay let's go back back to being single okay none nada can't reach 80 anyway it's short let's check later for you know or maybe i did have your get some currency there we'll see singles nada and these are the two diamonds i'll be short with two pulls for 80 and another one okay none i'm short of two i'll be back and check if see i have more you know more pulls to get at least two okay guys i forgot we have i have 30 here so i gotta leave you hanging from this one i don't think i have more in terms of diamonds so let's go with this one and just summon these 10 and hopefully as you can see here i have please do update your wishlist because um the outchan can be added to galatea already while you're pulling for this and who knows you might get her here so i'll do 10 i'll do 30 oh hopefully this is her hopefully this is her no it's xanthacane it's okay okay so another can't do back to back skip and our last 10 for this one so far that is it i am kind of disappointed uh won't be able to give you the ending that you guys deserve but more or less let's see let's see if uh can get more gems here i don't think so so that is it guys so thank you very much for staying this far take care stay safe this is the warden and i'm out of here


What is going on everybody, Astos here. Welcome back to another video. So in today's video, just like every Sunday, we're going to be talking about 10 stocks that I'm personally watching and looking to trade here in the fourth week, this upcoming week in May of 2019. And out of those 10 stocks, some of them are actually ones that you ended up calling out, either in the comment section on Friday's video or in the call-out section in our Discord group chat. So if you did end up shouting one of those out, thank you for the call-out and I will get to that in this video. And for all you new viewers out there, typically every single Sunday, pretty much every single Sunday over the past couple of months now, I've been making videos like this, kind of going over my watch list, my thoughts on these couple of stocks, and my mindset for the upcoming week. Because typically on Sundays, this is when I'm planning out stocks I'm trading, my plan for the upcoming week, what my thoughts are on the market. And I take a little bit, you know, sometimes an hour, sometimes a couple of hours, just doing some research and planning because I find doing this on the weekend is how you get ahead of other people, you know, get ahead of the competition in terms of trading. And you just get to learn more, you speed up your learning and you get better at trading quite frankly, right, and understanding movement in the stock market. So that's what I'm typically doing every Sunday. And if you want to see further content like this from me and you're not yet subscribed to the channel, feel free to subscribe to the channel, hit that notification bell so you're notified every single time that I do make a video, hit that like button. It really does support me and supports the channel in general. And let's get right into it, guys. So the S&P 500, it was kind of on a roller coaster for these past couple of weeks, right? Let's just do a quick little 60-second gist here, a breakdown of what ended up happening this past week. We noticed over the past two weeks we've been seeing selling off and now the past week mostly has been a recovery, right? We noticed the bottoming out at about $2,800. We recovered up to about $2,885 here. And on Friday, we ended up getting rejected a bit by this 180 simple moving average here on the 10-day 30-minute chart as well as this 20-day one-hour chart. So we had a couple of recovery days here. We're looking like we're pulling back here. This could be the start of potentially a downwards trend or the continuation of the overall downwards trend here. And if we see a break below the 50-SMA here tomorrow on the SPX, that's going to be pretty confirming that we're heading back down in the S&P 500. And let's say we pop above here. Let's say we end up trending back up. Let's say we get back into the $2,900 level. We end up breaking above this 180-SMA resistance. That would be probably most likely, really on a technical basis here, definitely would be the continuation of this uptrend. We'll be pushing up at that point. And who knows, we might be hitting all-time highs again. We may be testing 2950 again, which is a resistance from a couple of trading weeks ago. These are just a couple of different scenarios. And if you guys want to see a further breakdown on the market's performance last week, just go check out a couple of videos from last week I'm uploading every single day during the week, breaking down the market's movements. In the beginning of those videos, I'm typically going over the market's movement for that particular day in around 5, 10 minutes. So if you want to see a specific day of the market's movement and my analysis of it, just go check out those old videos. So let's just kind of get right into it, guys. Right now, my mindset is to just be cautious. The market's in a funky spot, very, very volatile. I'm mostly cash as of right now, but I'm still watching stocks. Of course, I'm still looking to trade. I'm still looking to hop in. But during different times, during volatile times like this, my strategy tends to shift. I'm not really focusing on one, two, three weeks swing trades. I'm mostly focusing on day trading, the swings of the market to be quite frank, because when it's volatile out there, the S&Ps up 2%, one day down 2%, the next, and there's just a bunch of big swings. So this brings me to the top 10 stocks that I'm personally watching. And of course, some that you guys are watching in there that I personally see potential in as well, with the first one being Johnson and Johnson guys, ticker symbol JNJ. Johnson and Johnson is one that is looking pretty quite attractive right now on a technical basis, right? We noticed a couple of months ago, this is probably, this is really old news at this point. But for those of you guys that don't know, the stock went from 150 down to about 121 due to asbestos being one of their products has kind of freaked everybody out. It dropped the stock 10%, 15%. But since then, it's been on a very nice, slow recovery with an upward, projected pattern here, right? The bottom at 120, the next one's a higher low at 127. Next one's at 134, which is a higher low. The uptrend's intact. We popped up to a higher high at about 143-ish a couple of trading weeks ago. We pulled down to about 136, which is a higher low from the previous, which means the uptrend is still intact. And now we're looking to fight up and continue this uptrend. So JNJ is a value play out there, meaning it doesn't swing as crazy as some of these growth stocks when the markets are volatile. So this could be a quote unquote safer play over the next couple of trading weeks as these markets get volatile. And if JNJ continues to confirm its push to the upside, right? So as of now, we're seeing higher highs, higher lows on a smaller term basis here. Since we bottomed out on Johnson and Johnson, and we can see this on the 10-day 30 minute, we're noticing since we pulled back, right, we've actually broken out of the moving average resistances. And now it's looking like we're holding those levels as new support. So on a smaller term basis, I would love to see JNJ get back into the 140s at that point. If we're in the 140s, guys, we're going to be trending above the 50 SMA here on the 184-hour chart. And that's going to be the last confirming factor, in my opinion, for this continuation of the uptrend. And at that point, JNJ is going to be looking very solid as a play. The RSI is looking pretty solid right now as well. They reported earnings a couple of weeks ago. So we don't really have to worry about an earnings play shifting the movement heavily to the upside or the downside, which would affect our decision making. Everything is just looking pretty good. All we need to see is that confirming signs. So JNJ is the number one stock that I'm watching. And there's honestly no particular order in how much I like the stock for this upcoming week in terms of 1 to 10. I kind of just throw them in there randomly and just talk about them in this little order that I have on my piece of paper right here. So TVIX slash SQQQ are two kind of volatility short market ETFs that I'm watching. And by short market ETFs, I mean, these two do well when the markets are doing poorly and when the markets are very volatile. So TVIX typically goes up when the overall market is selling off and when the VIX is going crazy to the upside, right? When the VIX, the volatility index is pushing up heavily and the markets are selling off. TVIX is usually doing amazing, right? We saw literally when the markets sold off heavily last week or two weeks ago, whenever that ended up being, you know, TVIX had a 40% day. And at that point, you know, the VIX was up like four or five dollars, you know, it was just going crazy, right? So TVIX is one that I'm always watching when the markets are volatile and when the markets are typically selling off, which is where we kind of are, you know, right now in the current state of the market.  If the if the markets are volatile this week, this is going to be a very good play as well. So SQQQ is one that is also a market short ETF. This one doesn't really rely on the VIX. This is more one that tracks directly actually the NASDAQ 100, which is the NASDAQ index here. When the NASDAQ is going down, SQQQ is going up. So that's all you need to know pretty much, right? If the SQQQQ is really up pre-market, if we're seeing NASDAQ markets in general are selling off, this would be a very good play. So SQQQ, definitely on my watch list. And I'm really just looking to trade this if I see signs that the markets are going to push down, right? That's just the honest truth about this. So TQQQ on the flip side is the third one that I'm watching for this upcoming week. And this is in case, let's say the markets go up in price, right? SQQQQ, like we just said, tracks the NASDAQ 100. It's going up when the NASDAQ is selling off. But on the flip side, TQQQ, which is actually one I traded on Friday, does well. It goes up in price. When the NASDAQ 100, the NQ here, is actually going up in price, right? So this follows the direction of the market, hence why it's been doing well over these past couple of trading weeks, right? The market's been recovering really the past couple of months at this point. It's been doing very, very well. So if you guys want to see a more in-depth video on these three market ETFs that I just talked about, go check out Friday's video. I uploaded a video called Four Market ETFs to Trade When the Markets Are Volatile. I go deeper into these three and an additional one that I didn't mention in this video. So those are really important during volatile times, guys, because they're just really, really useful to hop in and out of when sometimes individual stocks are more difficult to find in terms of trades. You can always rely on these ones to do well. If you pick the right side, when the markets are volatile, right? So the fourth one that I want to talk about is Jnug, JDST, the gold ETFs that we trade, that I trade and talk about on this channel. So Jnug, these are gold ETFs. They go by slash GC. You can also look at GDX, which is a ETF Trust Gold Miners ETF. This is a bit more accurate in terms of tracking Jnug and JDST, and how these work, guys, is pretty much Jnug. Whenever it's going up in price, that means gold GDX is going up in price, right? Whenever GDX gold is going down in price, JDST is going up in price, and Jnug is going down. So typically, Jnug just follows the movement of gold. And we're noticing here, Jnug is kind of on a support at about $6.72. This general area of about 6 to 650 has been a support for Jnug here stemming back a couple of months ago, actually, towards the end of 2018. We saw that big run, and now we're pulling back down to these levels again, where it's kind of making Jnug attractive. And if we're looking at GDX very quickly, it's the same thing. And we're noticing a slight breakout to the upside here on a shorter-term basis. We're kind of noticing a potential breakout, right? Higher or low, higher or low, and now we're popping up. Now I would want to see if GDX ends up getting back up to, let's say, $20.95. If it breaks out of $21 flat, that could be a huge move to the upside for GDX, which would end up shooting up. Jnug, and of course, at that point, gold is probably going to be pushing up. It is going to be going up as well. So I would say at this point, guys, GDX, especially if it breaks out of this 180S SMA resistance here, that's going to be a pretty bullish move. And if we break out of 21, that could be the first bullish move we need to see before we get to the 180S SMA. And I see a bunch of margin there, honestly. If GDX gets up to 21 and breaks and maybe tests up to 21.50, Jnug is going to be at a huge green up. It's going to have huge green upside at that point. So Jnug is looking good. But on the flip side, if GDX, let's say it sells off and starts to get back down to the 19 level, maybe high 19s, maybe we break this $20 support, JDST is going to be the better play at that point. Because at that point, GDX is going to be just continuing its downtrend. Gold in general is most likely it is going to be downtrending at that point as well. And that's something that we wouldn't want to hop in on the Jnug side. We might as well just flip to the JDST and play the bare ETF. So the fifth stock I want to talk about in today's video. I talked about it in last video as well is Tesla guys. So Tesla, this is a stock that's been monstrously beaten down with a baseball bat from $380 down to $200 right now nearly. This stock has almost lost half of its value in about less than a year. This is absolutely unbelievable. And I've been getting a bunch of questions on Tesla stocks. Are you looking to swing trade Tesla? Are you buying Tesla? Are you day trading Tesla? And the truth is guys, I don't want to buy more shares of Tesla until we get to under the $200 level, to be honest. That's what I'm personally waiting for in my long-term portfolio. In terms of swing trading, I'm not looking to swing trade Tesla until we see a break out of these moving averages here on the 184-hour chart to the upside. I would need to see at least a break out of like 250, 260, 270 to even consider swing trading Tesla at this point. Or if we end up getting low enough and we start to see a push back up towards the resistance of the 50SMA, that could be maybe a short two, three-day swing trade. But again, that's kind of going against my own rules of trade or swing trading stocks rather that are downtrending. I don't really do that. But maybe a day trade on Tesla would be applicable here if we were able to maybe bottom out and slowly start to push up and test that 50SMA. So right now, the way I'm viewing Tesla is it's a pretty good day tradeable stock. If we do end up finding a bottom, which could happen this week, honestly, guys, and we start to see a bit of recovery to the upside here, right? If we maybe bottom out hypothetically here, not saying this is going to happen, let's say we bottom out at 205, right? We start to see some consolidation and then we start to see a pop back up. Just take a look at how much margin would be open at that point, right? From 205, maybe up to the 50SMA at that point would be maybe like 225 if this continues just downwards push. That would give us an 8% potential on Tesla, guys. So I'm watching it mainly as a day trade or maybe a very short swing trade, but probably not because that's going against my rules, not saying you shouldn't swing trade it. But for me, I'm not going to swing trade it mostly looking to day trade it because we've seen Tesla, like we've seen it fall $17 here on one day, we've seen it go up that amount in one day, right? Which is a very, very nice move for a day trade, right? Imagine a stock going up 8%, you day trade it, that would be nice if you got like 3%, 4% out of that, right? So that's what I'm looking for in Tesla stock. So the next one I want to talk about today is Disney stock, guys. D-I-S. So Disney right now, you know, this is one that was what's it called, recommended or shouted out by one of the subscribers. And I'm not really liking Disney at these levels right now. It's kind of to me looking like it wants to continue to fall and maybe retest this 180SMA. And let me explain why, guys. Take a look at this. We're noticing the big pop up to 143. We sold off to 131 and we struggled to really retest the 140s, right? We actually popped up to about 136, which take a look at the pattern is actually a lower high from the previous, right? We sold off to 130, which was a lower low from the previous. We popped up to 136-ish, 135. And now it seems like we're selling off again. So this does kind of seem like the beginning of a downwards trending lower high, lower low pattern on Disney, right? If we were to, let's say, sell off and maybe get back down to 130, crack 130 and get into the 120s, and then we slowly test this 180SMA, which at that point, right, might be at around 128, and we hold that level, that could be a pretty good entry point on Disney. But from what I'm seeing right now, I honestly think the hype is slowly starting to shift away from Disney, because we saw a bunch of hype regarding their streaming service, pushed the stock up a ton. And typically, guys, when that happens, the stock gets pushed up a ton. Sometimes, after a couple of weeks, maybe a month or two, the hype around that push-up slowly starts to die down. And this is probably what's happening right now, right?  And if we get to these levels here, I think that could be a good entry point on DIS. So the next one is BABA, ticker symbol B-A-B-A. And BABA is actually another one of these stocks that's gotten pretty beaten down here over the past couple of weeks. We're noticing right now, excuse me, we're noticing right now, BABA is actually at about a 168, 169, 170-ish level of support, right? We're noticing how the level we're at right now. If we're bringing out my drawing tool very quickly here, we're noticing this level was a support back in what day was this, the 10th of May. So about 10 days ago, this was a support. We ended up closing on Friday above that support from 10 days ago. And also, it was a resistance from back in the beginning of December in 2018. And we all know at this point, when a stock breaks out of a resistance, it becomes a new support. It becomes a support again, right? So we're testing two separate levels of support. I guess you can really say multiple more because this was a resistance again in the beginning of towards the middle of September. Again, we broke out of it becoming a new support level, right? We're noticing it was a resistance back in the end of January. So this is a pretty strong level here, a technical level over the past couple of months for Alibaba. I would say if we broke this level, which I think is very possible because the pattern right now is still a falling knife in my personal opinion, especially with the trade tensions with China affecting the Chinese stocks and companies very heavily as we've seen with some other stocks. I think this could definitely fall further here to be completely honest, guys. And this is a reason why I'm most likely not going to touch Baba unless it does somehow hold above here. But again, if we see a break, even a sudden break, that can cause more selling on a technical level here on Baba because again, it's like we're moving to a different tier of the stock, right? We're noticing, you know, once we got out of this level, that was us breaking out of the resistances from a couple of months ago and getting into a new tier, right? The 170 level, once we broke out of that, it got us to near the $200 level on the stock, right? Which again is a new tier. And now that we're selling off, if we break this level, it's like we're going back down to the tier that we just came from, which is the 130 to the 170-ish level. And that might issue more selling, right? And again, the tensions with China, you know, all this stuff that's going on regarding the trade war, I think this would put more, will put more pressure on the Chinese companies and Baba, which is why I'm really just a spectator on the sidelines right now with this company. But let's say again, miraculously, we break up and so the 180s, we break these moving average resistances here. You know, this could be a good trade, but I'm personally not seeing that happening as of right now. So the next one we're going to talk about is Home Depot ticker symbol HD. And HD, I really like this call out right now due to its pullback that we're seeing here. We're noticing a pullback on HD from about 207 down to about 190. We're noticing that this pullback opened up, I would say off the top of my head, probably like 10%, right? About 8-9% margin of profit here on HD. This pullback is also a higher or low from the previous. And if we just draw a trend line here, we can see how the market, or you know, this is really the markets still holding this one on an uptrend from a higher low from the previous, right? So this is not really a hard, difficult pattern to understand. One thing that I am a bit worried about is we're seeing the beginning right here of a bearish cross. And a bearish cross is when the 50SMA or whatever smaller increment level of moving average that you use crosses below the 180SMA, in this case, the yellow line or whatever larger increment of moving average that you use, right? Typically when the smaller SMA crosses below the larger SMA, that's a bearish sign, right? So that kind of worries me especially because the candlesticks are still trending under these moving averages, right? If we do get rejected tomorrow, we end up selling off, this gets further deeper into the bearish cross that can issue more selling. And that's also breaking the trend line, which in turn would shy me away from trading HD to be completely honest with you guys. But if we end up popping above here, let's say we break the 50SMA and the 180SMA, we start to get maybe back up to the 196s, 197s, 198s, that's going to be good in my opinion for Home Depot HD. So the next one is Verizon guys ticker symbol VZ Verizon communications. And this is kind of similar to HD in a sense, right? But Verizon broke out of those moving average resistances unlike HD has or has yet, right? We're noticing here, Verizon broke above the 180SMA, we're pulling back now actually, and we're retesting that 180SMA. So I would think at this point, a huge sign for the continuation of this bullish reversal would be if Verizon successfully maintained this 180SMA and continued to push up starting to break out of other levels of resistance that we're seeing here that are coming up, right? Take a look at this one right here. It's at about $58, right? We're noticing a bit of a rejection there. If we broke out of this one this week, we could be testing upwards of $61 in the next couple of weeks because that would be the channel that we're trading in at that point in time if we were to break out of that resistance in terms of Verizon, but everything is looking solid right now in terms of the reversal trend to the upside, right? It's looking pretty good on VZ Verizon communications. So the next one, the last one that I want to talk about is PG Proctor and Gamble. This one, guys, has been doing very well while the market has been selling off like crazy. We're noticing, like I talked about in last week's video, PG, I was about to say VZ, PG ended up breaking the 107 level of resistance, and now we're all the way up to 108, and we're looking to retest that level of resistance, previous resistance, as a new support, right? So typically, I talked about this in a video, but typically, when the markets are volatile, when growth stocks are selling off, a lot of people are flooding their money into value plays like Proctor and Gamble, Coca-Cola, Pepsi, J&J, and a bunch of others, and you notice how these stocks end up doing better than the growth stocks during volatile times, and PG is no exception to that, or yeah, no exception to that, right? This stock does very well during volatile times, and I do plan on trading this one if the markets do get volatile again this week, and especially if we do end up just maintaining 107, guys. I would love to see us hold this resistance, old resistance as a new support, and for us to continue to truck up maybe into the 110. So that's it for this video, guys. If you enjoy this video, feel free to go down below and hit the Like button. Again, it really supports me and supports the channel in general. If you want to see more content from me, feel free to subscribe and hit that notification bell so you're notified every single time that I do make a video, and drop a comment down below. Let me know what you guys think about these stocks. What are your plans for this upcoming week? I would love to know. So I appreciate it. As always, all you guys watching, it means a lot for you to take time out of your busy days. Come to the channel, watch me, it means a lot to me, and I will cherish that forever. So I'll catch you all in the next video. Have a good one, guys. Peace out.


So, in order to understand how databases work on the internet, we need to understand what internet is. We need to understand how internet works. We need to understand what are the different mechanisms of exchanging data over the internet. All of this will help you better understand and better develop the web-based database applications. And it will help you understand the issues and how to take care of those issues to be a successful web-based database application developer. So, when you are chatting with somebody, your friend using your phone, smartphone or using your computer and your friend is also using a smartphone or a computer at the other end maybe at other part of the world. So, in between there are maybe a dozen or so computers which are bridging that gap between yourself and between your friend. That network of computers, that group of connected computers, those computers which bridge the gap running the TCP IP protocol, those computers running those protocols over a telecommunication network, that network is the internet. Internet is like a network of roads. It is like a network of telephone lines. It is like a network of electrical wires in a building. So, over the network, the traffic flows. In the context of roads, over the road network, vehicles move. In the context of telecommunication network, calls are moving and so on. So, internet is just like a network. Of course, it is a network of networks. It is a network of networks and it is running the TCP IP protocol which I will discuss in more detail. So, I believe up till now you have gotten the picture. So, this lecture or this module will consist of two parts. One part is this, the other part I will tell you totally. So, in this module, I will talk about what is internet and what internet does. So, when I say what is internet, of course, I will explaining to you how internet works very, very briefly because the more details are in the next module which is how data moves on the internet. And very briefly, there are two methods of using or moving the data which is the circuit switching and packet switching. I will go into a lot of details. The circuit switching is between the two points, a path is set. It is dedicated to be exclusively used by person A, person B, computer A, computer B. That is circuit switching. Packet switching is that the data at A and B is divided into packets which can use different paths, routes over the internet and arrive at destination may be lost during the process also and resend and reassemble and generate the message or whatever. And how computers do different jobs on the internet. So, that is part of the next module. So, let us now go into what is the internet. So, internet is a global system of interconnected computer, interconnected computer networks. It is a network of networks not of road networks but a network of computer networks which share the same protocol which is the TCPIP protocol. And of course, this protocol may be a supporting non-computing devices also because now we have something called as the IoT internet of things. We have sensors, we have different things which are also connected over the internet. So, the primary precursor of the internet is ARPANET. The ARPANET was developed in the 1970s to connect the university campuses and the defense establishments in the United States and that ARPANET formed the backbone of the interconnection in the 1970s. And then it evolved over the period of time and Vincent Cerf is the inventor of you can say is the inventor of internet. So, as I discussed earlier that because of the software architecture evolution and the revolution what has happened that I will discuss in the next slides you see that we have this network of networks and I have this machine over here this machine over here and I have this connection over here it can be a dial up connection over here I have the service provider and of course I can communicate with this device also from here to here or from here to here and so on. So this is what internet is. So, there is no central body, there is no established structure because these links these links can go down also, these links can go down also and maybe new links come up also and so on. This is what internet is. So what I was discussing that because of the architecture software architecture because of the proliferation and so many things there has been a tremendous adaption of the internet and you can see that there is almost an exponential rise in the number of countries which are getting online and we can see that about 210 countries getting online in about 20 years. So that is a lot of countries in a very small amount of time. Now this adoption of internet is not limited to rich countries but also not so rich countries also as shown in the next slide as you can see over here roughly more than half of the world population over here. They don't have kind of internet access in 2015 right or not in terms of percentage in terms of percentage per whatever right or not. So the point over here is that there is a divide over here between the have and have nots a digital divide. So of course it takes money it costs money but the point is still there has been a tremendous proliferation of internet. Now let's briefly look at what internet does so very very basically internet moves data. Now what data it can be audio it can be video it could be text it could be anything else it could be combination also when we say data it means digital data. So as the traffic moves cars move over a traffic network or a road network data moves over the internet that's one purpose of internet internet is like a postal service meaning that the data moves from one point to other point the responsibility of the postal service is to ensure that the letter is delivered at the given address they are not concerned about the contents of the letter as long as the certain tickets are on that envelope they are not concerned about the contents as long as it's paper same as true for the internet. The big difference is that postal service is governed by certain rules regulations owned by the government but internet is decentralized so it's not totally like a postal service. It is neutral to data as I told you before that data could be any data it is just ones and zeros it could be audio it could be video it could be a combination it could be email it could be chat messages whatever and finally it is neutral to applications I could be running any application as a matter of fact let me give you an example of Skype. Now Skype was developed by two European developers okay they didn't had to change internet they didn't have to change any protocols they developed Skype on top of the internet protocols they developed Skype on top of the standard internet that is one example of openness of internet also and another example of neutrality of applications over the internet Skype using internet then WhatsApp using internet and of course there will be many more applications to the benefit to our benefit okay which will be running on the internet because internet is neutral to applications that is one purpose of internet thanks for your time.


So, what are HTML tags? In this video, we're going to show you HTML tags in their most basic form, so you can get a good idea of how to write them. We'll also look at a website where you'll see how these HTML tags look from behind the scenes. And in the end of the video, we're going to take you to burntorlearn.com where you can practice writing these HTML tags. Let's take a look at this sample website. Here we have a header and we have a section. We also have an aside and here at the bottom we have a footer. Each of these are HTML elements which we can make using HTML tags. Let's do that now. Let's take a look at the syntax of an HTML tag. It's pretty straightforward. We have a less than sign and a greater than sign. That makes an opening HTML tag. A less than sign followed by a forward slash and a greater than sign make a closing HTML tag. Together, they create an HTML element. Now let's take a look at these different elements. We have a header element and we can create that by creating a header opening tag and a header closing tag. Once we have these two elements, we can add or these two sections or two areas we can create or put content inside of this element. Now let's test our skills. If you'd like to try this out, visit burntorlearn.com forward slash HTML. So let's create some HTML tags. We're going to start with our header tag and we'll add some content. We'll call it header just to help us to distinguish it. We'll create the section tag, the aside tag, and lastly our footer tag.  But I want you to notice and see if you can find the difference between our simple website that we showed you here and the way that the tags look when they show up here on the page. So here we go. You'll notice we have the header tag, the section tag, the aside and the footer, but it doesn't look like our simple website that we're going to build. So why not? Well the simple answer is that HTML tags need attributes in order to give style and to give height and width to these different elements. We're going to show you how to give your HTML tags attributes in our very next video.