system
Given the following post, respond as if you're commenting on Reddit:
human
How, on a physical level, do transistors/vacuum tubes work, and how do they produce logic gates?
gpt
Electrons are charged particles, and in a vacuum tube, they are the only particles available to move. If there is a positively charged plate, the negative electrons will move towards the plate, the electron movement is called current. the Tube is now conducting. 

If the plate is then charged negatively, the negative electrons will be repelled, and no electrical energy will flow, as the electron movement has stopped or reversed. the Tube is now off. 

this effect allows current to flow only in one direction, selectively allowing current to flow based on the charge on the plates in the tube. Diodes achieve the same selective effect. transistors, working off the same principles, will allow the control of when to allow current, injecting electrons into a region which would allow conduction based again on the polarity of the regions surrounding.

This creates a switching mechanism, which allows implementation of very complex functions build from individual switches turning on/off. 

edit:formatting
A simple OR gate can be implemented with two diodes. Modern gates are implemented with CMOS as it uses much less power. If your interested further the book microelectronic circuit design by jaeger takes you from simple circuits to RAM memory.