Vacuum tubes… ah yes, the venerable origin of modern electronics. Diodes, transistors, even resistors in the form of incandescent light bulbs, many important modern electronics trace their roots to vacuum tubes.
So, here’s a question I was thinking about. Exactly how hard is it to build a vacuum tube of your own? When you think about it, it really isn’t that hard. You need glass blowing and a vacuum suction pump. Once you blow glass into an cylindrical or spherical envelope shape, you give it a narrow-necked opening and you connect a hose to that and your vacuum suction pump. Then you pump all the air out to create a vacuum and keep pumping to sustain the vacuum. You can reheat the narrow neck to convert it into an enclosed nipple. Now, you can stop vacuum pumping and disconnect your hose. The vacuum will remain. It’s all simple in concept, it’s just that most modern homes don’t the necessary tools to be able to make a vacuum tube at home.
But, here’s a crucial question to answer. How do you build that vacuum suction pump and hose? Does it require rubber? If it does, then the abilityv to invent the vacuum tube was contingent on the introduction of rubber to the world at large, outside of Mesoamerica. Fortunately, vacuum suction pumps can be built without rubber. Rubber is mainly a convenience in modern designs, but it is totally possible to build a vacuum suction pump without it. In fact, the vacuum suction pump and evacuated chamber in the Magdeburg hemispheres did not use rubber at all. The hemispheres were made out of copper, and grease was used to seal the gap between them to be air-tight. Cork can also be used to seal valves in place of a rubber stopper.
So, indeed, there are means to build vacuum tubes without rubber. It’s just that, as history turns out, the invention of the vacuum tube didn’t really make much progress until well after rubber was introduced and in circulation in the world at large.
20200403/https://en.wikipedia.org/wiki/Natural_rubber#History
20200403/https://en.wikipedia.org/wiki/Vacuum_tube
20200403/https://en.wikipedia.org/wiki/Vacuum_pump
20200403/https://en.wikipedia.org/wiki/Magdeburg_hemispheres
20200403/https://en.wikipedia.org/wiki/File:Magedurger_Halbkugeln_Luftpumpe_Deutsches_Museum.jpg