Was producing parts for the war effort. And so in England, after they had retrofitted this factory and turned it into a war production facility, German intelligence became aware of it. And so they decided that they wanted to destroy that factory in order to, you know, hurt their production capabilities. So the only problem was, is that England had enacted, you know, sufficient air defense systems to be able to shoot down any planes that they saw flying during the day. And there was no way that they were going to be able to fly all the way from Germany to to England during the day and drop bombs on this factory. So they decided, well, if we fly at night and we fly, you know, high like 15, 20 zero zero zero feet will be able to, uh, you know, do it without them seeing us. And they also won't be able to get us with radar. So that's what they did. But the only problem was, is flying at night. In order to be stealthy, they would have to be flying blind. Basically no lights or anything. And also they wouldn't have any way to reference where they were because they also would turn the lights off, um, at certain places in, in England so that they wouldn't be able to to track it that way either. And so they needed a navigation system to be able to guide these bomb planes there in order to be able to drop the bombs accurately at night. So the German engineers came up with this idea. They said, hey, why don't we just triangulate the position? What we can do is we can build these radio towers, and what we'll do is we'll send two different beams. And based on, you know, we know where the map says that the location is. You know, they plug in the location, lat long, all that stuff. They point the beams directly towards Derby, towards the factory. And what we'll do is we'll have the planes fly inside one of the beams. They'll have receivers inside of the plane so that they can tell when they're in it. You know, it'll it'll go off, the receiver will go off and make a noise or whatever as long as they stay within the beam. So if, if at any point, you know, it goes off and it, you know, they stop receiving the signal, they know they've flown out of the beam, so they'll orient themselves in a straight path through the center of the beam, and they'll fly towards Derby. And then the other beam will intersect that beam right when they are over the bombing area, the bombing zone, so that once their receiver receives the second signal and they're receiving both signals simultaneously, they'll know now it's time to drop the bombs. So that's what they did. Now, the only problem with this is that these towers are very, very far away. Cleave is about 331, 333 miles from Derby and Stolberg hill in Nordfriesland is about 450 some odd miles away. And so what happened is, is they made a successful bombing run or two. And British intelligence is like freaking out. They're like, how are they doing this? We don't know. They're trying to figure it out. Well, they did their investigation and they figured out from a p o w they had gotten back that had been held captive, that they had word that the Germans had built radio towers, microwave towers. Uh, I guess it wouldn't be microwaves, but radio towers to, you know, target them for bombing. But the problem with it was that based on the curvature of the Earth, there's absolutely no way that these radar beams could possibly have reached the city. And so when they were presented with this information, Winston Churchill's, you know engineers, uh, kind of discarded it as dumb. They're like, that would never work because they're too far away. The curvature of the Earth would block the beams, so they just didn't look into it at first. You know, when you look into the history of it, the bombs continue dropping and they continue getting hammered and eventually they're like, okay, we're going to be forced to look into it. So they did. And when they did, they found that these towers were in fact real. And there's a whole Wikipedia page on this on battle of the beams. But it raises a strange question, because these beams were operating between 30 and 33MHz and measurements taken when they finally found it, because they after they investigated it and figured out, you know, where these towers were and what frequencies that they were operating at, they were actually able to intercept the signals with their own planes by searching in that frequency band. They found that the beams, by the time that they reached Derby, were about 400 to 500 yards wide, which is, you know, still a pretty tight bombing zone to drop when you're hitting a factory. You know, that's why they're able to be so accurate. But this is disturbing because this means that these were, number one, the fact that the planes had to fly in the beams the entire time. Right. That's how they maintain their orientation. Knowing they're going the right way shows that it was a line of sight transmission. If you even go to the Wikipedia page, it says that these were more or less line of sight transmissions. So line of sight, that means point to point. That means a straight line. So the planes were flying in a straight line from Stolberg to Darby and then or from Kleve to Darby. And then you also account for the fact that they were operating at, you know, 30MHz, 33MHz, right, in that band. That's right. At the threshold at which skywave propagation can reliably occur. So even if you said it wasn't line of sight, if you wanted to make that argument, you would have to basically state that they were doing skywaves. Now, if you could go to the next picture. Alan.