I have read that it is a myth that you can see stars in daylight if you stood at the bottom of a well, however, if you stood at the bottom of a well at night, or built a long non reflective tube and pointed it to the sky, would you be able to see more stars through the tube in a light polluted area?
I have not heard of this myth, but you can find it on Snopes:
Based on the discussion there, I would think that yes, you might be able to see more stars through a tube. You would be blocking some light sources, particularly local ones (depending on the size of the tube), but as discussed in the Snopes post, most of the skyglow would still be present. Like the daytime case, I doubt the effect would be significant enough for you to actually notice. Perhaps, if you knew a particular star was just below the level of your local observation conditions, you migth be able to increase the chance of observing that particular star with a long enough tube. However, I don't think the experiment is really worth performing.