AV Geeks Lunch 7-7-2022

so so so so hi everybody i'm skip alzheimer welcome to the av geeks lunchtime streaming show where we watch old 16 millimeter films and that last film was a silent film from the mogul brothers collection about specialized lubrication now i don't know what part one had i was hoping that part one would show up when we were uh scanning more of those films but uh part two was exciting i appreciate that you guys um can at least appreciate that the variety of different things i'm showing you it's like it's all over the map and um it tickles my brain um my adhd brain to have things from all over um and so hopefully it's not too off-putting for you guys but i know the one thing that you've all been asking for um is more films about the metric system so behind me on the sintel i have learning about metric measure enjoy [Music] for his school project jim is preparing to construct the sun and the distance between the sizes and distances are shown on this chart the diameter of the earth is about 8 000 miles diameter of the sun is about 864 000 miles and the distance between them is about 93 million miles jim had planned to use a scale in which one eighth inch represents one thousand miles but jim has become so discouraged trying to convert distances like 93 million miles into the scales eight inch units he's about ready to give up the whole project then jim's father makes a suggestion instead of using a common ruler with its clumsy eighth inches inches and feet why not use this meter stick that he uses in his engineering work it too is a kind of measuring ruler jim's father also shows jim where to find more information about the meter stick jim learns that the meter is the basic unit of length in a system of measurement called the metric system the meter stick itself represents the length of one meter which is about a yard since jim has decided to do his measuring with the meter stick he wants to make a model of it to learn how it works so he cuts a strip of cardboard one meter in length jim labels the cardboard strip with the word meter followed by its abbreviation m jim notices that the meter stick is divided into several smaller units there are very tiny units there are larger numbered units and there are units that are still larger how do the sizes of these various units compare to find out jim counts the largest of the units one two three four five six seven eight nine ten there are ten because there are ten of these larger units in a meter we can think of each of them as one-tenth of a meter the word we use for one-tenth of a meter is decimeter after he has marked the cardboard strip into decimeters jim labels one of the units decimeter and writes its abbreviation dm as we have seen each decimeter is also divided into smaller units the numerals labeling these units tell us that there are 10 of the smaller units in a decimeter how many do you think there are in a meter since there are 10 of the smaller units in a decimeter and there are 10 decimeters in a meter there should be 10 times 10 or 100 of these smaller units in a meter jim counts them in groups of 10 to see 10 20 30 40 50 60 70 80 90 100. since there are 100 of these smaller units in a meter each is one one hundredth of a meter the word for one one hundredth of a meter is centimeter each centimeter on the meter stick has in turn been divided into still smaller units how many of these smaller units do you think are in a centimeter we have seen that there are ten decimeters in a meter we have also seen that there are 10 centimeters in a decimeter this makes a pattern of ten to one using the pattern ten to one we can predict that there should be ten of these very small units in a centimeter count them and see there are 10 in a centimeter the pattern 10 to 1 works jim divides one of the centimeters on the cardboard strip into 10 of the very small units if a centimeter contains 10 of these very small units how many does a decimeter contain since there are 10 centimeters in a decimeter there should be 10 times 10 or 100 of these very small units in a decimeter let's count them in groups of 10 on the meter stick and see 10 20. eighty ninety one hundred if there are one 100 of these very small units in a decimeter how many should there be in a whole meter many did we find are in a centimeter ten how many centimeters are there in a decimeter ten and how many decimeters are there in a meter ten do you see that this makes a pattern of ten times ten times ten or one thousand let's count the very small units in groups of one hundred one hundred two hundred 800 900 100 or one thousand since each of these very small units is one one thousandth of a meter each is called a millimeter a word meaning one one thousandth of a meter jim now makes a chart that shows the relationship between the decimeters centimeters and millimeters on the meter stick the chart shows that one meter is equivalent to 10 decimeters one decimeter is equivalent to 10 centimeters and one centimeter is equivalent to ten millimeters to put it another way one meter is equivalent to ten decimeters or to one hundred centimeters or to one thousand millimeters since he is using the meter stick to build his model of the earth and the sun jim has made a new scale in which one millimeter represents a thousand miles according to this new scale the diameter of the model earth is to be eight millimeters since the real earth is about eight thousand miles in diameter the diameter of the sun is to be 864 millimeters and the distance between the earth and the sun is to be ninety three thousand millimeters or ninety three meters to help him find a sphere of the right size to represent the earth jim sets the tips of his calipers so that they are eight millimeters apart after jim has found a sphere of the right size to represent the earth he looks for the point on the meter stick that represents the size of the model sun which is to be 864 millimeters jim has found out that the measure 864 millimeters can also be thought of as eight decimeters plus six centimeters plus four millimeters just as the number 864 can be thought of as eight hundreds plus six tens plus four ones this is because the metric system works just like our decimal system of numeration by which we write numbers jim now blows up the balloon that is to represent the eight hundred sixty four thousand mile diameter of the sun when he has finished jim checks the size of the balloon on the meter stick to make sure it is 864 millimeters in diameter by comparison with the sun the eight millimeter earth model which represents the eight thousand mile diameter of the earth is very small indeed jim now drives a stake and fastens the earth model to it it just ends i don't know what happened oh no it just ends we have no idea how it's gonna end um was the reason that we didn't adopt the metric system is because explaining it was so boring uh i you know i have some theories but uh i mean they kind of made that's a much more dramatic dynamic like comparing like the fastest land speed records or you know take something that's like sports related or something that's you know super exciting and i don't know nope it's a science experiment or basically wasn't even a science experiment it was creating a model of the solar system so oh well alright uh speaking of space uh let's see how space technology improves the heart pacemaker enjoy [Music] [Applause] [Music] this is three and one half-year-old jennifer garagio since july 1973 jennifer has been using a unique rechargeable pacemaker to increase her heart rate from slow to near normal she joined some sixty thousand other americans who have heart pacemakers implanted every year developed by johns hopkins university applied physics laboratory the pacemaker makes use of power cells originally used aboard satellites in space it is half the thickness and one-third the volume of earlier models and can be painlessly recharged from outside the body for twenty years this eliminates the need for surgery every two years to remove and replace batteries mrs kathleen garagio tells what the new device has meant to her daughter jennifer this meant a lot because since jennifer's had the pacemaker there's been a complete change in her she's grown in size she's acting very normal before she really couldn't play or keep up with the other children it also means a great deal to us knowing that she doesn't have to be operated on every two years and also the size of it that it's small enough for her the other pacemakers were quite large what the pacemaker does is send an electrical impulse to the heart speeding up jennifer's heartbeat from a slow rate of 40 to a normal 72 beats a minute and normal she is she does nearly everything a healthy youngster can do and especially enjoys playing with her brothers cousins and friends it's over her routine is different for only 90 minutes a week when she recharges the pacemaker batteries pacemaker charger is very simple it's convenient enough to carry you can take it anywhere necessary to charge her it's also very good if we were on a week's vacation we wouldn't have to take it with us if you miss a week you can catch up on it but there'll be no harm to jennifer if we should not do it [Music] that alarm means that the charging head is not meeting up it lets us know that it's not charging when it stops the green light goes on and that means that she's being charged and when the whole charging period is finished a blue light goes on and let us know that it's the end of the charge this means that she's charged for another week we won't have to do it until next week we asked mrs garagio about the outlook for jennifer's future the outlook for jennifer's future is very good the doctors say that she can live to be a ripe old age and she could grow up to to be anything she wants to be [Music] the basic concept for the long life battery in jennifer's pacemaker has been proven in over 10 years of space use a good example of technology for space now being used to help people this has been an aeronautics and space report presented by nasa the national aeronautics and space administration oh yeah the nasa meatball logo it's the big thing the meatball um so that that film was from that time period when uh electronics had to have wood or at least wood grain um very odd time you know to kind of i guess that was kind of related to televisions and like consoles of like stereos that had wood this is more furniture-ish but like why would you have a [Music] pace you know a pacemaker charger that had wood on it like is it cheaper i it's just weird anyways that was that of that time and that's why like even the original atari looks like it's wood it's it's so strange anyways um finish eating uh i my assistant uh keshawn uh scanned this and he was like yeah it was fascinating footage but it's a little on the growth side so here is a housefly third edition enjoy [Music] to most of us the housefly is little more than an annoying insect that buzzes around in the warmth and shelter of our homes it bothers us especially when we find it in the kitchen on dishes and food but otherwise it seems simple and insignificant yet the house flies amazingly complex and it can be a deadly menace a master of flight the housefly is agile and fast and very difficult to catch when it flies its wings beat more than 200 times every second the up and down motion of the wings is controlled indirectly by flight muscles in the fly's midsection or thorax the thorax moves up and down a mere fraction of a millimeter these tiny movements are transferred to the wings along a series of hinge-like joints and amplified several hundred times by the wings the number of winged beats can be measured by the tone of the hum the higher it sounds the faster the wings are beating during flight the legs are held close to the body to decrease air resistance the wings constantly change their angle of thrust this wing motion lifts and propels the fly through the air the fly's wings are translucent and well adapted for rapid flight the efficiency of each wing is increased by bristles on the leading edge my nude hairs on the winged surface probably contribute to efficient airflow over the wing the row of hairs on the trailing edge of the wing enlarges the surface slightly behind each wing is a halter a vestigial wing that acts as a flight stabilizer the halters relay information about the fly's position in flight the delicate antennae sensed the airstream during flight enabling the fly to control its airspeed the many faceted compound eyes aid flight by providing the fly with a panoramic view of its surroundings the fly also has three acelly simple eyes that sense differences in light intensity rapid extension of its legs enables the fly to land on any available surface instantly to land upside down the fly first extends its four legs upward to make contact and then swings the rest of its body into place but how does the fly stay upside down if we look at the fly from below through a pane of glass we see on the tip of each foot or tarsus a pair of claws which enable the fly to cling to rough surfaces and a pair of tarsal pads for adhering to smooth surfaces the tarsal pads are covered with many fine hairs the ends of which hold a sticky fluid when the fly removes its foot from the glass the droplets remain as we've seen the housefly is well adapted for flight it is also well adapted for feeding in ways that seem unusual to us to find and recognize its food the fly has scent and taste organs the scent organs are on its antennae which are covered with sensory hair and olfactory pits we often see flies standing on their food flies not only can taste with their mouths but with their feet as well the tarcy of the front legs have taste organs the flies proboscis or feeding organ extends from the head when the fly finds food the end of the proboscis expands into two lobes here we see the lobes from below each lobe contains a system of channels stiffened by thin braces by means of the channels liquid food like this drop of sugar solution can be quickly absorbed okay some solids like this grain of sugar must be dissolved first the fly secretes saliva onto the food the liquefied food can be sucked up pumped by a special set of muscles in the head because the fly can liquefy many substances with its saliva it can find nourishment almost everywhere the house line not only feeds on our food but also on garbage it also feeds on manure fly larvae help us by breaking these wastes down however disease germs from the wastes stick to the body of the adult fly because of this the fly contributes to the spread of disease the housefly and close relatives like the face fly spread disease to livestock fly-borne diseased germs can easily infect the body through an open wound flies transmit germs of cholera typhoid dysentery polio and many other deadly diseases millions of microbes are excreted with the fly's feces using a microscope we discover a variety of fungal spores and bacteria in the feces microbes also stick to the fly itself in fact it is covered with them when a fly walks over a suitable culture medium it leaves a trail of bacteria which soon develop into colonies using time-lapse photography we can watch the growth of a bacterial colony that develops in the trail of a fly the adult house fly feeds on garbage and waste so do its offspring which begin life in their source of food the housefly begins as an egg laid by an adult female she probes for a suitable location for her eggs the female extends her ovipositor like a telescope to deposit the eggs in a source of food for her young she lays them under the surface to safeguard them from enemies and dehydration the tip of the ovipositor carries sense organs which enable the female to lay her eggs side by side and in the right place she lays about 120 to 150 eggs in a single batch and four to five batches during her short life after about 24 hours the fly larvae called maggots hatch from the eggs a slit at one end of the eggshell eases hatching maggots have no legs they crawl by using powerful muscles which contract and extend the body by using hook-shaped mouthparts at the pointed anterior end and with the assistance of spines on their bodies that give traction the maggot has no eyes on the blunt posterior end are two dark spots the spots are breathing pores or spiracles that lead into a complex system of air tubes delicate hairs keep out dust and liquid by keeping garbage near our homes we offer the fly a most favorable environment for its offspring virtually on our doorsteps depending on the availability of food and on temperature after about five to six days and two molts the mature maggots are ready to pupate a major step in their transformation into adults this process takes several hours but is shown here in several seconds through time-lapse photography the pupa case which is formed by the hardening of the final larval skin is a small barrel shaped container inside the pupa case the metamorphosis from maggot to fly occurs special photography enables us to see the fly's heartbeat inside the pupa case when the metamorphosis is complete the adult bursts the lid of the pupa case aided by a balloon-like tylenol on its head when this sack expands the head swells to about twice its normal size the tilinum acts like a bulldozer pushing open a path to the surface by alternating expansion and contraction of the tilinum the fly can reach the surface its spindly legs are of little help in this process once on the surface the fly immediately begins to groom itself the tilinum disappears withdrawn into the head never to be used again as is true of all insects the behavior of the housefly is purely instinctive the fly is taught nothing its every act is an innate mechanism on the average females will live about four to five weeks males only three to four the adult pumps blood into its crumpled wings to expand them then the wings stiffen the exoskeleton soon hardens and darkens the fly is ready to take to the air i love sean's comment why doesn't this film end properly uh you guys are cracking me up you're hilarious um so i i just saw that uh james clown had has passed and i was i thought that i had a film it was kind of a preview for one of his movies thief but then i realized it's to catch a thief which is not james cotton it's a tv show so unfortunately i don't have something um sometimes i'm able to do tributes sometimes i can't it just kind of depends on what i can find but i do have behind me another film set up and hopefully this will make up for the metric system film i don't know i have not seen this this is very exciting so this is lab safety uh accident at jefferson high uh enjoy [Music] some kid had gotten hurt at jefferson high school last week and of all places the chemistry lab my partner bruno and i were conducting the follow-up investigation my name's grumman and i have to admit this is the first time i'd ever been called into a high school chem lab but i have investigated my fair share of accidents and one thing i've learned is that there's nothing accidental about him somebody goofed let's go bruno uh lieutenant can i talk to you for a second hey not now bruno i'm busy okay you're the boss the office sent us up to see mr petry the chemistry teacher he had an open period so i figured he had plenty of time to talk with us bruno may not have been the brightest guy in the department but he was a good man to have around may i help you morning i'm lieutenant grumman this is sergeant bruno i think you know why we're here the place looked real nice it was all neat and orderly clean floors and uncluttered table tops the guy even had safety posters on the walls hard to imagine an accident happening here it's very rare but you know a chem lab can be a dangerous place the hazards everywhere you're kidding where let me show you around uh lieutenant can i talk to you a second not now bruno i'm busy still busy you see this yeah nitric acid one drop can burn a hole through your skin hydrochloric acid breathe too much of the fumes and you could end up with permanent lung damage and in here we have white phosphorus handle this the wrong way watch out sodium mix this with water boom typical chem lab has hundreds of different chemicals in it if you're not careful with them use some the wrong way mix two that shouldn't be mixed yeah i see what you mean mr petrie told us how each and every chemical in his lab had been completely and properly labeled and stored in the proper manner flammable and volatile liquids were placed in a special storage cupboard caustic materials were on the lowest shelves less chance of their falling but they were off the floor in order to avoid contact with water incompatible chemicals those that should be separated were in different storage areas it may have been a high school chem lab but i could see this wasn't kid stuff then there are all the other dangers there's more afraid so smell a chemical the wrong way you could be out for the day drink out of a beaker i don't care how clean it looks you never know what could happen squeeze bottles squeeze them too hard somebody might not like it sorry light a gas printer the wrong way and it could be lights out [Music] hey you got some matches oh no sorry [Applause] rebecca you got some matches oh no no i'm sorry you got some matches yeah hey thanks a lot yeah then they're spilled [Music] this place is a death trap no not at all it's perfectly safe as long as you pay attention and do things the right way it's like i always tell my students be alert and proceed with caution makes sense while it's extremely unlikely accidents can happen and people can get hurt and they must take the proper precautions to see that they don't like what by coming to class prepared for lab work that means tying back long hair so it doesn't get in the way rolling up long shirt sleeves for the same reason removing loose and dangling jewelry shoes are important students should never wear sandals or other open-toed shoes using a lab apron is always a good idea it not only protects clothing but the skin as well splash proof goggles are an absolute must especially during experiments involving caustic or corrosive chemicals here's a little demonstration i show my students this balloon contains acetone red dye and hydrogen the head's a styrofoam one has a pair of safety goggles the other does not i'm going to simulate a small explosion one you might encounter in a lab if this were a kid he'd probably be blind this one maybe some minor facial burns but nothing compared to losing your sight this guy seemed to have his acids and bases covered so i decided to interview a few of his students what do you want to talk to me for i didn't do anything well just a few questions here i understand you were doing some kind of experiment today that's right i was making a preparation of hydrogen which as you know calls for mossy zinc and sulfuric acid diluted to a three molar solution yeah yeah that's what it calls for all right uh so tell me about it well let's see first i had to dilute the acid how did you do that very carefully acids should only be diluted by pouring them into water never water into acid why is that it'll mix better that way with less chance of it splashing in your face i poured the acid slowly stirring at the same time [Music] then i rinsed the stirring rod in water and placed it on the bench you're not going to believe this but once i saw a guy put a stirring rod in his mouth a good rule in the lab is to put nothing in your mouth you should never touch the chemicals with your hands either how do you know you were diluting sulfuric acid and not something else mix-ups can happen that's why everything we use is labeled and then we check and double check those labels before we use them it's kind of like what mr petrie's always telling us be alert and proceed with caution i've heard that i figured it was time to give the kid a quick test so what would you have done had you spilled some of that spilled acid can really be dangerous and should be cleaned up right away the best thing to use is a sodium bicarbonate solution which mr petri keeps handy whenever we're working with acids [Music] what if you spilled a base use the same stuff heck no if you spill a base you should clean it up with a vinegar solution that's an acid you see how it works if you spill an acid you clean it up with a base you spill a base you clean it up with an acid okay now i know you were careful and all but let's just suppose just supposing that you would spill some of that acid on your skin what then acids and alkalize will burn your skin you gotta get it off fast using plenty of running water and if you should ever get some in your eyes you should rinse them for 15 straight minutes i could see this kid wasn't going to fall for any cheap tricks anything else no that's about it the experiment went okay and then i cleaned up making sure to dump all the chemicals in the right containers never down the sink unless mr petrie tells us it's okay then i cleaned everything i used and put it back in his proper place okay kid you can go that's it i'm off the hook yeah yeah you're clean great it was time to move on to somebody else uh lieutenant can i talk to you for a second uh not now bruno i'm busy i understand you were working with a gas burner today that's right pretty dangerous isn't it well it can be if you don't know what you're doing but mr petrie gave us complete instructions go on well the first thing i did was to make sure that the burner hose was properly connected to the gas jet and not the compressed air outlet then i lit the match first and then turned the burner on you got to remember to light the match first otherwise gas could build up in the air then i made sure to throw the match into the right container and not the waste basket what would you do if there were some volatile materials around like uh alcohol or ether well i make sure there's none of that around before i like the burner okay so what happened next let's see i had to bend some glass tubing for an experiment i was doing first i cut the tubing to the right length i did this by making a deep scratch in the glass with a file then i covered it with a tile and bent it away from me using my thumbs i fire polish the rough ends then i heated the bin spot with the tip of the flame and bent it away from me then i set it down to cool how do you know when it's cool well you can't tell by looking at it a good way to tell is to bring the back of the hand down just above it what'd you do with the tubing i was setting up an experiment and i needed to run into a rubber stopper sounds like that could get tricky yeah it can be what you have to do is lubricate it first glycerin is best then you use a tile to protect your hand and insert the tooth slowly using a rotating motion you got to be real careful the stuff breaks easy then what i had to heat some chemicals in a test tube as always i made sure the open end of the tube was pointed away from me why is that for safety when chemicals are heated they can boil over very quickly and shoot out especially when they're in a test tube so what you got to do is keep the open end of the tube pointed away from you and anyone else and you should move the flame along the length of the test tube not just at the bottom the kid was sharp i thought i'd find out just how sharp let's just say for the sake of example that you did something wrong and you wound up with a fire on your hands uh an alcohol fire what would you do throw water on it no way water would only make that kind of fire spread what would you do then come on quick you got a fire on your hands first i tell everyone to move away then i grab the fire extinguisher you know how to use it sure dude mr feature showed us how and what if someone's clothing caught on fire would you use the fire extinguisher oh no a fire extinguisher should never be used on a person then what would you do i'd smother it using the fire blanket located where right over there okay kid you can go thanks a lot hope i helped yeah sure it was one dead end after another the first case i couldn't figure there was no evidence of carelessness or neglect or improper supervision the accident just should not have happened okay i give up i just can't figure it you and your students are doing everything right what are we doing right everything your lab is clean and well organized your chemicals are properly labeled and stored your students know how to dress for lab work they wear safety goggles and aprons [Music] they know how to handle chemicals how to use a gas burner how to work with glass they know what to do in emergency situations i don't get it how could there have been an accident here accident what accident the lab accident here at jefferson high this isn't jefferson high what'd you say i said this isn't jefferson high they're right bruno this isn't jefferson i it sure isn't lieutenant that's what i've been trying to tell you good talking to you anytime lieutenant come on bruno let's go to jefferson high okay boss nice lab you got here thanks [Music] like i was saying bruno may not have been the brightest guy in the department but he was a good man to have around don't go away now there's a test coming up no you won't be graded you might even have a little fun with it okay here goes all the questions are true and false and they come from the film you've just seen so grade yourself spills can cause accidents and they should be cleaned up at the end of each period the answer is false spills should be cleaned up immediately [Music] you should smell a chemical by placing your nose directly above the test tube that's false you should never smell a chemical directly it's okay to drink out of a beaker as long as it's clean again the answer is false you should never drink out of a beaker or other lab containers splash proof safety goggles should be worn at all times the answer is true because you never know when an accident might happen long hair should be tied back as it is more stylish that way that's false long hair should be tied back to keep it out of the way lab aprons should be worn to protect clothing and skin the answer is true acids should only be diluted by pouring them into water never water into acid the answer is true if you spill an acid it should be cleaned up with a base again the answer is true when lighting a burner you should strike the match before you turn the burner on the answer is true the broken ends of glass rods should always be fire polished again that's true [Music] you can tell when a glass rod is cool by looking at it the answer is false a glass rod should be lubricated before it's inserted into a rubber stopper the answer is true when heating chemicals in a test tube the open end of the tube should be pointed away from you and anyone else again the answer is true an alcohol fire should be put out with water the answer is false an alcohol fire should be put out with a co2 fire extinguisher [Music] hope you did okay see you around sometime [Music] [Music] that was awesome um but this isn't jefferson high school um so just like yesterday when we were talking about school bus safety and all the transgressions that took place on the school bus that i was on in high school uh there were also many transgressions that took place at um my chemistry class i took two i took chemistry in advanced chemistry in high school and oh my god the things that were going on and i was i didn't really participate in them i was trying to warn people about the problems and one of them was a lot of kids loved breaking thermometers in half and playing with the mercury in their hands that's a big problem that's not very smart um and i said so much uh another time uh they would uh go um somebody who was like in charge of the lab but he was like really the worst person to be in charge of the lab he was a high school student he brought out some sodium hydroxide and he was throwing pellets at people which if you touched your eyes you'd be like ow because it's you know it's alkali and it's a big problem um this was all because our chemistry professor uh was ancient he was like in his eighties mr jeff mr jeffrey it was his name we call him mr jeff and dude had been teaching since the 50s or something like that it was ancient guy very kind soul but um the class took advantage of him uh a bunch it was very sad um because he was kind of clueless he couldn't you know he didn't know that things were being thrown behind his back and all that stuff and i'm sure at the end of the semester or the year he said wow we don't have any more thermometers what happened um anyways uh yeah you're learning more about my high school uh and how problematic it was uh growing up in rural north carolina in a rural high school in stanley county north stanley high school i somehow got out of there alive and with um much of my self-esteem intact um not everybody was so so um easily uh got through that anyways thanks for tuning in today um i love showing you guys films um we'll be back again tomorrow i think i will have a special guest who will join us and we'll be talking about computers computer films and i will be showing a computer film that i might not be able to stream on youtube we're gonna see we're gonna see what happens um but everybody have a great rest of your day if you like what you saw hit the thumbs up button you can buy us coffee at ko dash fi dot com slash av geeks thumbs up like subscribe blah blah blah um keep cool everybody and we will see you again soon i should say um the rewind devil is is real and shows up occasionally in film cans but i should also say please rewind and love each other take care of yourself um it's it's kind of rough for some people out there so um take care we will see you soon bye you