The stories you put together is amazing...that connections you make between different great minds, their experiments and learnings simply awestruck me.
Great video as always. Little imprecision: the building in Rome you show in the picture is the Pantheon, not the Parthenon. The latter is located in Greece. Regards,
Kathy, I love you and your videos! Having had the honor of visiting both, I confirm you showed the Pantheon 😜 ("both" meaning not you and the videos, Parthenon and Pantheon!)
I WAS LOOKING FOR SOMETHING JUST LIKE THIS!!! I'm so glad I found your videos, Kathy. So far the only thing I could find like this was a book called "Electrodynamics from Ampere to Einstein", but it didn't go in depth at the beginning like you do. Edit: You WROTE A BOOK?!?! This is a like miracle! Like an answered prayer! Yes!
The Inquisition, what a show, The Inquisition, here we go, I bet you're wishing that we'd go away... but The Inquisition is here and it's here to stay!!
The first xerox, was made by exposing sulphur plates to light. They realized it lost its static electric charge when exposed. Carlson pitched this idea and they improved the proof of concept. The idea was to charge the paper, expose it, cover it with powder with tiny flakes of plastics, and melt the ‘toner’ to the paper. They knew about sulphur and its interesting electric properties back then so it makes sense he would use a sulphur ball, even though it’s funny to make fun of and call stinky.
These are called electrostatic photocopiers. And were multiple separate machines set up in stages so making a copy was a a full process. But less than that of negatives and chemical like Prussian blueprints. I highly recommend watching Tim Hunkin’s Secret Life of Machines photocopier episode for more info
2:30 - reminds me of the words of James Burke’s Connections series when he said “ there was time when you could not talk about nothing. That’s not a double negative, you couldn’t talk about nothing, nothing as in the vacuum.”
I've learned more in a few weeks of watching your channel then years of school. You do well showing how all these concepts fit together to make one understanding! Thank you
I think I can shed some light on the sulphur ball. I have no idea why S was chosen but I know it doesn’t stink. I regularly use it as a fungicide and it hardly has any smell at all. What stinks are most sulphur COMPOUNDS, such as Hydrogen sulfide (formula H ₂S a colorless gas with the characteristic foul odor of rotten eggs) and Sulfur dioxide (formula SO ₂ a toxic gas responsible for the smell of burnt matches). Sulphur compounds are also responsible for the strong smell of a lot of food such as onions, garlic, cabbages, cauliflower, Bruxelles sprouts, kale and so on. Btw, Great series of videos. 👍 Somebody recommended the channel on the comment section of an astronomy video and here I am, working my way through the back catalogue. 😀
But if you let sulfur get a little damp, it will disproportionate with water into oxides and hydrogen sulfide, and it's primarily the hydrogen sulfide that you smell. Fresh sulfur is bright yellow, but it darkens to a tan color on exposure. So I wouldn't so easily dismiss the stinkiness of a ball of sulfur.
Given the technology of the era, with no plastics, how else would you make an insulating sphere? Sulphur is a good insulator that easily takes a static charge and melts at ordinary lab temperatures so can be readily moulded into shape. Strictly the sphere doesn't have to insulate, only the string does, but that would have been harder. A blown glass sphere or marble would probably have worked, but it's harder to charge.
These are super. I feel like I'm learning something about the motivation behind scientific discovery. Well, at least one perspective from the 21st Century. You might enjoy David Barron's book on the American Eclipse (1878). He looks at Edison, and to a lesser extent Bell and the development of the National Academy of Science, and the first publication by the AAAS, all within the context of eclipse astronomy.
There used to be this show on public television when i was a kid called “connections”. Anybody remember that one? These videos remind me a lot of that show. The host would take a lot of seemingly random and unconnected historical events and concepts usually within a scientific framework and weave them together into a nice little package that was both entertaining and informative.
Kathy! Recently discovered your fideos....I'm retirted after 40 years of teaching Chemistry and Physics, high school level. SULFUR, the yellow element has almost no detectible smell. Most of it's compounds are just the opposite.....H2S,...hydrogen sulfide is the rotten egg smell (and incidentally an order of magnitude more toxic than cyanide) SO2, sulfur dioxide is the burned match smell...etc
I searched; you didn't make a video on Gasparo Berti. The tube Torcelli used was of the design that Gasparo Berti used first. I hope you'd make a video on Berti's work as well, or at least you’d mention him in some other video. I find your list the most complete one and useful on youtube. Jim Al-khalili's doc is great but short and with a lot of missed points. Thanks for putting such effort untiringly for everybody.
Enjoy your videos,you have a charming personality that suits the subject,and it makes me think of all the experiments we did at school,great times,thanks again please keep teaching reminding us..
First thank you very much for your videos. It has made learning about a topic that I was already very curious in that much more exciting. I know I may be late to the party so this information may have already been but that stinky ball comment was always a bit funny to me as it as it was for proabably may others well while doing some research here and there Otto von Guericke very basic sulfur static crank powered generator came up. Apparently after he spun the ball he could take it off the machine and show your hair stand on end once he brings his stinky magic wand close to it
Starting from the inquisition reminded me of the late science historian James Burke who wrote of just such odd connections in his book and endearing BBC series, "Connections". Physics is filled with - and I hope you narrate other such stories.
@@Kathy_Loves_Physics - Yes, to the best of my knowledge JB is still with us. However, we lost David Kennard last year to cancer. He was the producer (and occasional director) of "Connections" plus the original "Cosmos" with Carl Sagan, "Hal's Legacy" with AC Clarke, and other science documentaries. He also produced documentaries on the arts and history like "Keeping Score" with Michael Tilson Thomas and the San Francisco Symphony. His last films were a trilogy on the European wine industry, "A Year in Burgundy," "A Year in Champagne" and "A Year in Port." I had the honor of working with him a little trying to do a three-part series on the importance of having a vigorous space program based on a couple of my books. I did some treatments that we shopped around, but, as usual, we couldn't find the funding.
Theories that are technically incorrect can actually teach us more than theories that tested correct the first time. I can tell you, I have learned more from my mistakes than from my successes. The fact that the sulfur ball did not actually model gravity was very lucky indeed. Does anyone else experience religious levels of ecstasy when they learn from a mistake? Oh. Just me, huh?
We definitely learn more from our failures but I wouldn’t call Guericke’s ball a failure as much as an old fashioned method of using science as a philosophic model which isn’t science but can certainly lead to scientific discoveries despite that.
This is the most enlightening RU-vid I have ever seen, but before I give my reason for saying why, I say this, let me give you an insight into the Sulphur. Sulphur is a semiconductor and it was used sulphur as the surface coating in the first generations of photocopiers. The sulphur surface coating would be charged up, then light reflected from the paper of the document being copied would discharge the surface. On the surface where no light fell because dark ink on the copied paper, the sulphur surface coating would remain charged, and that charge would not migrate into the surrounding surface. We now have a charge image on the sulphur surface coating that matches the dark ink on the document being copied. This charge image attacks charged toner onto the copy paper, where it is baked on. What has this to do with this RU-vid clip? It slows down the process of charging of the attracted feather. So that we see that the feather becoming charged to the same voltage as the sulphur sphere takes some time. Back to my first point. Early in the clip we learned that it is not the vacuum pulling things together, it is the pressure of the surrounding air, which pushes them together. A vacuum is zero pressure, it displays the reality of the surrounding air pressure. Yet we fail to see this when we look at electrostatics. When the voltage difference between the feather and the sulphur sphere falls to zero the feather is attracted by the voltage gradient between it and the surroundings, away from the sulphur sphere. We have for hundreds of years accepted that a zero air pressure does not attract, yet we still hold on to the notion that a zero voltage between two charged objects pushes them apart. A zero value does nothing, except expose the effects of the surroundings. As Rutherford said “We didn’t have the money so we had to think.”
Love your channel! But Galileo didn't "prostate" himself (though that might be interesting...) but he did 'prostrate' himself. I listened closely and... yeah, ya did... And that's not the Parthenon. That's a domed cathedral. 3:02 You said "water pumps cannot pump more than 33 feet" which is a misrepresentation. A perfect vacuum at the top of a tube cannot pull water up more than 33 feet at sea level. Water pumps can push water uphill readily depending on the power applied, but always fail at pulling it upwards. Still, I love this channel and sub'd.
Jack D. Ripper eek after all that I’m not sure *I* should follow myself! 🤣 I know my pronunciation is a little, ahem, off. It was worse in the early videos I think. Sorry about that. Speaking of mistakes I meant the Pantheon not the Parthenon. Eek. Thanks for subbing despite my many mistakes.
@@osmanfb1 I noticed the mistake immediately, then saw your comment from two hours ago... btw I spent New Years eve 1969 at the base of the Acropolis in Athens, hoping to go up to the Parthenon, but it was closed for the evening. A few weeks later I was standing under the oculus in the Pantheon... thank you US Navy.
He wasn't the only one who drew a connection, real or not, between electricity and gravity. Faraday also thought as much as did many others. This theoretical force called gravity which cannot be measured in the same direct way electric or magnetic forces are. It is calculated based on density of an object and the gravitational constant for which Newton knew no mechanism for. And then Einstein made it a geometry of a 4D spacetime matrix. Still, not directly measurable. GC was the first God of Modernity as it is an anomaly without explanation and therefore just an effect. I also love the quote, "We live at the bottom of an ocean of air". Of course I don't know what I am talking about. ;)
Enjoy your videos. Correction is needed for this one. Sulfur does not smell like a rotten egg. It barely smells at all. What does smell like a rotten egg is a sulfur compound called hydrogen sulfide.
The reason why he used sulfur and mercury and you see all the famous scientists or philosophers following the same path, because they were mostly reading alchemy and hermetics and what they used to call 'old knowledge'
Damn you, Kathy! Your videos always end unexpectedly with "...and then...But that will be on the next episode of..." NOOOOOOOOOOOOO!!! You are an evil diva, but I still love you!
Great question, all charged objects will attract neutral objects and eventually some of the charged particles will move from the charged object to the neutral object and cause the formerly neutral object to be repelled. However, you have to wait and amber is so insulating that it takes a while for the charged particles to move.
If you look at a table of conductivities of the elements which are solid at room temperature, sulfur has the lowest electrical conductivity by far. I can’t look it up right now, but I remember it as more than an order of magnitude lower than its nearest competitor. Maybe this would help it hold onto charge when mounted on a metal shaft because it couldnt leak away easily, and when the surface of the ball was rough, since charge couldn’t migrate to points and discharge into the air. I bet the balls were stinky even though elemental sulfur is not, because being used in electricity experiments would generate sparks, and even tiny sparks would be enough to combust a tiny bit of sulfur to sulfur dioxide.
The numbers you are looking for, the resistivity for pure elements: sulfur is: 2x10²² µΩ cm followed by white phosphorous 1x10¹⁷ µΩ cm, with sulfur having a 200000x higher resistivity (source CRC Handbook) and 3/4 of the periodic table are metals. White phosphorus would not even have been an alternative here, being toxic, soft and self-igniting. Also there were not many other alternatives around at the time - amber would have been too rare and expensive, most other organic materials where to soft (tar, wax), glass is not a good insulator when exposed to humidity, glass and ceramics are more difficult to form into a perfect sphere. And as others have already pointed out, sulfur was readily available and a staple item for any researcher/alchemist at the time.
The air pressure pushes into a partial vacuum. In other words, if you pull some of the air out of a container (by expanding the container so that the air is less dense) then the air in the atmosphere will push in to replace it. Did that make sense?
Gravity...which we call "buoyance" when it's arranged to make something float. Gravity is pulling the atmosphere down, which is why we even have an atmosphere. At the bottom of the atmosphere is all that pressure caused by the weight of the air above, which has no place to escape to down here. So that column of mercury is being pulled down by gravity, but balanced by the air which is also being pulled down by gravity. Imagine an equal-arm balance with a column of mercury on one pan and a column of air on the other.
Hello Why did the objects on the sulphur ball (and ur balloon) fly off a d repel after some time? So initially the like charges are repelled on the object and it gets attracted to the ball/ balloon. What next?
So when you rub the sulphur ball (or a balloon) extra electrons are left on the ball and leave it with a net negative charge. Then some of the electrons in the feather are repelled by the ball and move away from the ball leaving a positive part of the feather near to the ball and attracting the positive side of the feather to the ball (at this point, the feather is neutral in total, with a positive side and a negative side). After a time, some electrons from the ball jump onto the positive side of the feather leaving the feather with a net negative charge. The ball still retains enough electrons to also stay negative so the negative ball repels the negative feather.
@@Kathy_Loves_Physics Thanks! I think you will like these animated videos on History of Electricity, although they are in Hindi...it is told from the point of view of Michael Faraday reading books on history of electricity...the series is under development. www.prathamopenschool.org/hn/Lesson/LES941
If the Inquisitors had had it explained to them how to torture someone by putting them in a chamber and drawing down the air pressure, they probably would have done it.
The Parthenon is in Athens. This is the Pantheon.🤣 Parthenon means "The (temple) of the virgin (= the godess Athena parthenos)" Pantheon means "The (temple) of all (pan) gods (theon)" Both in greek language. Yes roman aristocrats spoke greek.👨🎓
Scientism's endlessly repeated martyrology of Galileo makes me very tired. The story is much more complicated than they would like to have you believe. For one thing, the prediction of the planets' orbits using the Copernican system was not as accurate the current system's. We had to wait for Kepler to show that they were elliptical, not circular. And there were astronomers who were aware of this. Jesuits.
All your content is very, very good. It should be used to teach physics because it is both precise and human (people are, after all, who discovered all these things). The length is also great, given the short attention span of many of today's students.
Great great info Kathy, Id like to point out: solid sulfur barely smells, 2 solid sulfur is easily electrified by rubbing it with cloth ( think wool), 3 at that time there were not other easy obtainable matereial to electrify, could have been glass but to make a ball off glass was more difficult than making a ball of sulfur... may be wax would work but it melts as it is rubbed... wood, even is an isolator cant be electrified... should try wood covered with wax.. and more solid resin ( wich petrified is ambar) was not esily found.. bottom line: what an advanced idea to model world gravity with electrified sphere!!!
@@jhoughjr1 that´s what i said but dry wood treated with enamel or wax is a great isolator electrosrtatic machines past centuries were made with wood mostly
