From Geissler Tubes to Cathode Ray Tubes (Crookes Tubes, Physics & History
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Date: 2022-12-27
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Comments and reviews: 20
John
The ideas by Crookes in his letter to Stokes (presumably George Gabriel Stokes who worked on the radiometer) are a revelation: his statement that one needs the corpuscular theory of light to understand what is going on (emission of light as a particle/quantum from a single electron) pre-empts Einstein's explanation of the photo-electric effect - possibly before Einstein was born? I'd disagree with the suggestion that he anticipated curved spacetime in his follow on statement about light not moving in straight lines, but this may actually point to something even more astonishing - he was predicting that the old theory of light rays in optics would not be correct. The idea of geometric optics is that light travels from one point to another by the path of shortest time (this is Fermat's principle and in a vacuum the path would be a straight line. However Hamilton had established that particles travel from one point to another by the path of least action and had developed a description of mechanics similar to geometric optics. There's a school of though that had Hamilton tried to put the principles of least time for light and least action for particles together he could have arrived at the Schroedinger equation (this would be have been in the 1830/40s) - this never happened, but it is interesting that the ideas for a wave-particle hybrid theory was already in place in the 1800's. It would be nice to know more about what Crookes actually meant!
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The ideas by Crookes in his letter to Stokes (presumably George Gabriel Stokes who worked on the radiometer) are a revelation: his statement that one needs the corpuscular theory of light to understand what is going on (emission of light as a particle/quantum from a single electron) pre-empts Einstein's explanation of the photo-electric effect - possibly before Einstein was born? I'd disagree with the suggestion that he anticipated curved spacetime in his follow on statement about light not moving in straight lines, but this may actually point to something even more astonishing - he was predicting that the old theory of light rays in optics would not be correct. The idea of geometric optics is that light travels from one point to another by the path of shortest time (this is Fermat's principle and in a vacuum the path would be a straight line. However Hamilton had established that particles travel from one point to another by the path of least action and had developed a description of mechanics similar to geometric optics. There's a school of though that had Hamilton tried to put the principles of least time for light and least action for particles together he could have arrived at the Schroedinger equation (this would be have been in the 1830/40s) - this never happened, but it is interesting that the ideas for a wave-particle hybrid theory was already in place in the 1800's. It would be nice to know more about what Crookes actually meant!
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Toby
Crookes did not mention curved spacetime. He mentioned light not moving in a straight line.
It is a fascinating philosophical question, whether space and time are metaphysical concepts or real physical things. According to basic reason, one can apply physical actions to physical things, but not to metaphysical concepts.
Thus, one can bend a stick. One can bend a rod of iron.
One cannot bend the goodwill of all unicorns, except in a metaphorical sense.
To postulate that space and time can be physically bent requires one to cease using the words to represent metaphysical concepts, and to begin using them to represent physical things.
Is it valid and sensible, to believe that time is a physical thing, and not the metaphysical concept of progression? Or that space is a physical thing, and not the metaphysical concept of 3 dimensions?
If these are things, physical things that can experience physical actions that distort their forms, then how can they also be characteristics of all other things? All sticks and rods of iron occupy occupy both space and time.
How can a physical thing occupy another physical thing, let alone all other physical things, all at once?
All unicorns may be immoral, and all unicorns may lie incessantly. Yet the unicorn with the longest horn cannot also be the unicorn with the shortest horn, as well as every other unicorn, all at once. Not unless there is only one unicorn.
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Crookes did not mention curved spacetime. He mentioned light not moving in a straight line.
It is a fascinating philosophical question, whether space and time are metaphysical concepts or real physical things. According to basic reason, one can apply physical actions to physical things, but not to metaphysical concepts.
Thus, one can bend a stick. One can bend a rod of iron.
One cannot bend the goodwill of all unicorns, except in a metaphorical sense.
To postulate that space and time can be physically bent requires one to cease using the words to represent metaphysical concepts, and to begin using them to represent physical things.
Is it valid and sensible, to believe that time is a physical thing, and not the metaphysical concept of progression? Or that space is a physical thing, and not the metaphysical concept of 3 dimensions?
If these are things, physical things that can experience physical actions that distort their forms, then how can they also be characteristics of all other things? All sticks and rods of iron occupy occupy both space and time.
How can a physical thing occupy another physical thing, let alone all other physical things, all at once?
All unicorns may be immoral, and all unicorns may lie incessantly. Yet the unicorn with the longest horn cannot also be the unicorn with the shortest horn, as well as every other unicorn, all at once. Not unless there is only one unicorn.
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Andrew
Thank for for generating so many of these consistently informative and entertaining videos. Over the years I have discovered that I generally find it impossible to really understand science until I learn the history and the phenomena behind it. This is exactly what you are providing in these videos. To me, this is a much more effective way to learn than by simply memorizing theories, laws, and formulas. I wish I had been taught this way when I was a young man. Please keep up the good work.
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Thank for for generating so many of these consistently informative and entertaining videos. Over the years I have discovered that I generally find it impossible to really understand science until I learn the history and the phenomena behind it. This is exactly what you are providing in these videos. To me, this is a much more effective way to learn than by simply memorizing theories, laws, and formulas. I wish I had been taught this way when I was a young man. Please keep up the good work.
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David
I think the history of electricity might be better titled The Early History Of Electricity and perhaps encompass It's beginnings from video #1 to perhaps #8, and from #9 to the present be called The Lightning Tamers - The Utility Of Electricity. Just saying. I think both titles have merit, The History Of Electricity being the first half of the history, and The Lightning Tamers the later half, it being a sort of operating manual for electricity.
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I think the history of electricity might be better titled The Early History Of Electricity and perhaps encompass It's beginnings from video #1 to perhaps #8, and from #9 to the present be called The Lightning Tamers - The Utility Of Electricity. Just saying. I think both titles have merit, The History Of Electricity being the first half of the history, and The Lightning Tamers the later half, it being a sort of operating manual for electricity.
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Alan
Kathy thanks for putting these videos online. I studied Electrical Engineering in my youth at Brooklyn Polytech but after a career in sales and marketing have forgotten much of the technical stuff, and never new of the fascinating stories of the people involved with all of the human quirks we all possess. It turns out that all of this was a very important part of the progress that has been made during the 20th century. Keep up the good work.
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Kathy thanks for putting these videos online. I studied Electrical Engineering in my youth at Brooklyn Polytech but after a career in sales and marketing have forgotten much of the technical stuff, and never new of the fascinating stories of the people involved with all of the human quirks we all possess. It turns out that all of this was a very important part of the progress that has been made during the 20th century. Keep up the good work.
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M. A.
Thank you very much for this fabulous video!
I have this doubt about image at 7: 57 in the video. How is it reproduced the bending of the cathodic rays with a magnet? It's known that cathodic rays are invisible to the eye and just visible by the fluorescence they produce on fluorescing glass or minerals. Thank you in advance for your answer.
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Thank you very much for this fabulous video!
I have this doubt about image at 7: 57 in the video. How is it reproduced the bending of the cathodic rays with a magnet? It's known that cathodic rays are invisible to the eye and just visible by the fluorescence they produce on fluorescing glass or minerals. Thank you in advance for your answer.
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Count
I'd probably go with The spark, it kind of describes history and the origins of the human understanding of natures Electromagnetic phenomenon in a short snappy two word phrase. And the spark of creativity, a eureka moment is implied as well. If that is not an option then I do prefer The lightening tamers over The secret history of electricity.
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I'd probably go with The spark, it kind of describes history and the origins of the human understanding of natures Electromagnetic phenomenon in a short snappy two word phrase. And the spark of creativity, a eureka moment is implied as well. If that is not an option then I do prefer The lightening tamers over The secret history of electricity.
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Viorel
Great video. Do you by chance know of any literature on canal rays? i recall reading about them very briefly once, where a tube used a perforated cathode. The cathode generated an orange glow in the opposite direction of the cathode ray, and was apparently a stream of positive ions. I'd love to know more but can't find any info.
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Great video. Do you by chance know of any literature on canal rays? i recall reading about them very briefly once, where a tube used a perforated cathode. The cathode generated an orange glow in the opposite direction of the cathode ray, and was apparently a stream of positive ions. I'd love to know more but can't find any info.
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Kurtis
If you're a reader of science I highly recommend Isaac Asimov's book The History of Physics. I've read it twice and hope to read it a third time before my untimely demise. That book, being dead tree format and all, isn't as entertaining as Kathy's videos but covers a lot of the same ground and is extremely informative.
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If you're a reader of science I highly recommend Isaac Asimov's book The History of Physics. I've read it twice and hope to read it a third time before my untimely demise. That book, being dead tree format and all, isn't as entertaining as Kathy's videos but covers a lot of the same ground and is extremely informative.
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Recramorcen
Absolutely love you going over the reasons these people had & why they thought what they did. It makes understanding the technology & the physics a lot easier when you understand what went into it. Thank you so much for giving life to these characters & stories.
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Absolutely love you going over the reasons these people had & why they thought what they did. It makes understanding the technology & the physics a lot easier when you understand what went into it. Thank you so much for giving life to these characters & stories.
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On
Another amazing video. A list of all of them with links would be useful - perhaps I haven't found it yet.
This video is from a few years ago. I like the 'Secret History of Electrcity name' because I think that describes ithe series better.
Keep up the good work.
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Another amazing video. A list of all of them with links would be useful - perhaps I haven't found it yet.
This video is from a few years ago. I like the 'Secret History of Electrcity name' because I think that describes ithe series better.
Keep up the good work.
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Mark
I discovered your videos starting with the one you did on Tesla. I found it to be very eye opening to say the least. I have proceeded to view more of them, and you do a very good job of bringing these subjects to life! Good job and I am hooked!
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I discovered your videos starting with the one you did on Tesla. I found it to be very eye opening to say the least. I have proceeded to view more of them, and you do a very good job of bringing these subjects to life! Good job and I am hooked!
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John
Hey I like the secret history of elect. Becaue u put this great emphasis on historic details that never get covered in text books but they are the real story. Great series thankyou
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Hey I like the secret history of elect. Becaue u put this great emphasis on historic details that never get covered in text books but they are the real story. Great series thankyou
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Pixxel
No one, and I mean NO ONE, does a better job of covering these fascinating topics. I feel bad for skipping ahead to episode 36, but it was worth it. Thank you for what you do!
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No one, and I mean NO ONE, does a better job of covering these fascinating topics. I feel bad for skipping ahead to episode 36, but it was worth it. Thank you for what you do!
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star
e-l-c-tric-i-ty, reminds me of my days watching Sesami Street waiting for the the groovy animated count down pinball machine: 1, 2, 3, 4, 5, 6, 7, 8--n-i-n-e --ten!
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e-l-c-tric-i-ty, reminds me of my days watching Sesami Street waiting for the the groovy animated count down pinball machine: 1, 2, 3, 4, 5, 6, 7, 8--n-i-n-e --ten!
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Chuck
Your presentation is wonderful and provides us with an opportunity to grasp some of history's great moments. The music in the background simply distracts.
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Your presentation is wonderful and provides us with an opportunity to grasp some of history's great moments. The music in the background simply distracts.
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Lee
If it was known in 1879 that current flowed from negative to positive, why is conventional current flow positive to negative?
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If it was known in 1879 that current flowed from negative to positive, why is conventional current flow positive to negative?
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Ori
I have a chem exam tomorrow that also has a brief history section, and your videos are really helping! Thank you!
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I have a chem exam tomorrow that also has a brief history section, and your videos are really helping! Thank you!
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twistedyogert
Anyone know if they are still made and where I could get one? It would make one heck of a nightlight.
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Anyone know if they are still made and where I could get one? It would make one heck of a nightlight.
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h7opolo
i really enjoyed this video. a very good, albeit cursory, delve into the history of physics experiments.
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i really enjoyed this video. a very good, albeit cursory, delve into the history of physics experiments.
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