I saw a schematic for building a NOT gate, it worked, but there's something I don't understand.
Here is a pic of what I did (sorry about my finger hiding the push button)
If I push the button, the LED at the bottom gets turned off, even though there is a path between Resistor 2, the LED and ground (which is a bit strange to me).
I played around and realized that, if I put a resistor between the emitter terminal and the ground terminal, the NOT gate stops working, so I came to the conclusion that the path between Resistor 2, Collector, Emitter and ground, has less total resistance than if it had to go from Resistor 2 to the LED and ground.
I read that the transistor causes a drop of 0.7V, just like the LED, so why wouldn't the led shine even just a little ?