5 Interesting Things

[Music] this video is sponsored by the great courses plus I'll sometimes get an idea for a video and I really like it but it's too short for its own video so I've collected a few of them together into one video so this is five interesting things I guess it's new formats potentially so if you like it I'll make more of them if you don't maybe I'll have to try it one more time because you know you've got to give these things in one go anyway he go five interesting things here's interesting thing number one image stabilisation so if you record a video on your phone or on your camera and it comes out shaky you can take the footage and load it into video editing software or you can upload it to YouTube and there'll be options to stabilize the footage and the way the software does it the way YouTube does it is to analyze the footage frame by frame to work out how the camera must have been moving to create that shot and then it tries to figure out how can we soften that movement so there's some artificial intelligence involved with that the interesting thing is that I got this phone recently it's a pixel - it has image stabilization built in but the way the phone does it is different I believe to the way the software does it the way it's done on YouTube I don't think the phone analyzes the footage as it comes in to work out what's going on instead I think it uses the sensors inside the phone so the phone has a gyroscope inside and it has an accelerometer inside those sensors tell the phone about its orientation in space and how the phone is moving so the camera should already know how it's moving it shouldn't have to try and work it out by analyzing the footage and I think I can prove that this is happening so by attaching my phone to the outside of a box with the camera looking through a hole I'm fixing the cameras position relative to the box relative to the picture of the cat there so no matter how I move the box around the picture of the cat and the camera will remain fixed relative to each other so when I hit record on this camera phone the image going into the lens will be completely stable it won't move even when I move the box but if the camera attempts to stabilize the image based on the internal sensors telling it how the camera is moving then we will see some erroneous stabilization the stable image will actually become unstable so let's let's give that a whirl you'll notice as I rotate the box like this the picture suddenly moves to one side then when I stop it kind of slowly settles back down to the middle and you can kind of see how that would stabilize an image if the phone wasn't attached to a box and like it works in going up and down as well like that so the image kind of snaps to the top and the bottom to try and compensate for the motion something I wasn't expecting to see when I put this experiment together was that the camera also seems to compensate for rolling shutter I've talked about rolling shutter in other videos but basically the sensor in a camera doesn't take an instantaneous picture instead it scans down the sensor like that so if you've got an object that's moving across your frame and the sensor is scanning down like that you can see how the object would become slanted that's called rolling shutter and pretty much all digital cameras have it's very rare to have a sensor that doesn't do that and so look if I spin round really quickly like this the the picture of the cat becomes slanted goodness wait get your balance so the the camera is compensating for that sideways motion that normally produces rolling shutter thats Nancy's trying to understand the image but because the image is not moving it ends up slanting the image the other way interesting thing number two fig pollination so a fig is a psycho neom meaning its flowers are all pointing inwards so you've got this outer shell and then all the flowers are pointing inwards hidden inside there so if all the flowers are hidden away how were they pollinated they're pollinated by a wasp a particular kind of wasp called a fig wasp creatively and here's how it goes down so you've actually got two types of fig male figs and female figs what the wasp wants to do wants to do is get inside a male fig because that's a nice place to lay your eggs it's safe in there so the crazy thing is that you've got this tiny hole and that's that's what the the pregnant female fig wasp climbs through but it's so small that the wasp loses bits of its body as it kind of shimmies through there so some of its wings go it's antennae once inside it lays its eggs and then it's trapped it can't get out again so it dies in there and then the eggs hatch so you've got a whole lot of male and female wasps inside the fig the first thing they do is mate with each other so the female figure was are pregnant before they've even left the fig that they were born in the male wasps then dig a hole out of the wasp of the females to get out of the males are blind and flightless so once they've done that they die their work is done they've already mated they've dug a hole out for the females and then they're done the pregnant females now covered in pollen from inside the male fig fly off to find another fake but here's the thing if the female wasp but that's just left the male fig flies off and then burrows into another male fig that's no good for the fig tree what the fig tree wants wants is for the female pollen carrying pregnant wasp to burrow into a female figure where it will deposit its pollen and pollinate the flowers inside the female fig but that's not good for the wasp because when what's burrows into a female fig it can't lay eggs it just dies in there it's the end of the line so the fig tree has evolved for the male and female figs at that stage in their lives to look identical it's potluck which one the wasp will burrow into it's the female ones that we eat the male ones aren't tasty so you might be thinking ah so when I eat a fig that crunchiness is because I'm crunching on dead wasps it's actually not the crunchiness is the seeds and in fact when a wasp dies inside a female they can actually that can happen several times so you might have several wasps climbing there and die the fig releases an enzyme that breaks down the body of the wasp to release those nutrients the nutrients are then absorbed into the flesh of the fig so in that sense I guess you are eating dead wasps but I mean it by that definition whenever you eat vegetables you're eating dead animals because when an animal dies it fertilizes the ground but I suppose with a fig it's a bit more direct interesting thing number three outside my window just over the River Thames there's the Ten Lost Sugar Factory and it's got these two chimneys with spiral fins around the outside and you may have seen that on chimneys before there's a good reason for them to be there so when air passes over a cylinder it sets up this oscillation in the air downwind it's called a vortex shedding because it produces these alternating vortices that are spinning one way and then the other and the reason you get this is because of fluid dynamics like fluid dynamics is complicated so you get vortex shedding for complicated reasons but but there it is it's it's fluid dynamics but the important thing is if you've got this oscillation in the air this backwards and forwards motion well every action has an equal and opposite reaction Newton's third law so the chimney must be feeling a side-to-side force as well opposite to the force that the air is feeling and that's okay just make sure your chimney is sturdy enough to resist that side-to-side force except that the the frequency of vortex shedding like how quickly does it go back and forth is related to the wind speed if you increase the wind speed you increase the frequency of vortex shedding what that means is if by some bad luck the wind speed is just right you'll get the resonating frequency of your chimney I've talked about resonating frequency before but the important thing is if you hit the resonating frequency of the system the energy that you put in adds to the energy that's already there and the amplitude goes up dramatically so suddenly your chimneys doing this which is bad news and I can illustrate this effect actually with an elastic band and a hairdryer it's similar to when you put a blade of grass between your thumbs and blow through you don't want that to happen to your chimney because it will fall over so you put these fins around it and they direct the air downwards on one side outputs on the other side and that's enough to disrupt the flow of air to the point where you don't get vortex shedding interesting thing number four Lima beans lima bean plants have evolved this amazing defense against caterpillars basically they call in the meta predator like if you can find a way to summon your predators predator you might be able to survive an attack and the meta predator in this case is a wasp different wasps to the other one we talked about this one is a caterpillar wasp obviously and this one injects its eggs into caterpillars so you know when you think of wasp you think about it's an insect that stings you but I mean that's a type of wasp another type is a wasp that uses its stinger to inject eggs into things in this case caterpillars so the egg hatches inside the caterpillar the newly hatched wasp eats the caterpillar from the inside out and the cat's butter dies of that obviously so what the lima bean plant does is when a cathode comes along and bites into a leaf that's detected chemically by the plant and it reacts by releasing a scent and this scent is like an advert it's like the signs outside the Krispy kream you know they light up when there are fresh donuts it's like this scent is saying hey we've got fresh caterpillars come again so the the wasps fly on over and inject their eggs the caterpillars die and the lima bean survives it's amazing and it's a coordinated thing as well like one caterpillar takes a bite and the whole plant releases a scent and neighboring plants release the scent as well it's really amazing interesting think number five Tower of string I've got this tower of string sort of sculpture it's slightly mind-bending because you know string isn't rigid it's flexible so it should fall over and while this tower thing has rigid parts these plastic bits are rigid they're not attached to each other directly they're attached via bits of string and string is flexible I mean think about it for a bit you can see how it works like the the bits of plastic are under tension and they're holding the string in tension as well string is strong and attention and that's what makes the tower stand but still it's a little bit mind-bending when you first look at it which is fun thanks to us in angle for bringing that to my attention he sent me a picture of one that he'd seen on Twitter which inspired me to build my own so there you go five interesting things one more bonus detail at the end of the video but before that I just want to say we have covered a few different topics in this video biology engineering technology if you want to learn more about those subjects and maybe learn in a more structured way then I can recommend the great courses plus it's a subscription on-demand video learning service with great courses and lectures from top professors at Ivy League universities and other noble institutions from around the world you get unlimited access to 9000 video lectures about the subjects you find interesting from engineering and biology to cooking and playing chess I really recommend the course called do-it-yourself engineering because you can get your hands dirty as you're working through the course you can build the things along at home with the professor building them on screen by the end you'll be a really accomplished maker interesting fact for my UK viewers the great courses price has always been optimized for the US but it's now optimized for the UK as well and Australia so there you go they're offering a free trial right now for subscribers to my channel so go to the great courses plus com4 slash Steve moles or click on the link in the description and start your free trial today here's the bonus fact it's about the fig wasps a female fig can be pollinated by many female fig wasps so you might have a few crawling in there with that with the pollen covered heads and if you're a fig farmer that's a problem because if too many of those internal flowers there get pollinated then the fig bursts open and the figs are harder to sell I guess when they're burst open so the farmers keep the male fig trees and the female fig trees completely separates there'll be two completely separate plantations or orchards maybe and you know the distance is too great for the wasps to just kind of find themselves crossing between the two and so what the farmers then do is they they collect the wasps from the male orchard and carry them over and just release exactly the right number that they want to perfectly fertilize the fig without it burning that's it I hope you enjoyed the video if you did don't forget to hit subscribe [Music]

Channel: Steve Mould

Views: 769,605

Rating: 4.9490857 out of 5

Keywords: Explained, understand, fig, wasp, image stabilization, fluid dynamics, vortex shedding, lima beans, caterpillar, evolution, string tower

Id: a6jJzOc9gaE

Length: 16min 12sec (972 seconds)

Published: Fri Mar 16 2018

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