What happens to how bright light bulbs are when you add more of them in a series circuit?

Placing cells in series increases the voltage in the circuit by 1.5 V for each cell. Increasing the voltage increases the brightness of the bulb. When a bulb in a series circuit is unscrewed all bulbs in the circuit go out. Increasing the number of bulbs in a series circuit decreases the brightness of the bulbs.

it would either make it pop or make it dimmer

Explanation:

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.