eli5 – how does the weight of the liquid in a hummingbird feeder not just push all the liquid out of the little holes? The openings of little holes are upturned, but still way below the water level.

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eli5 – how does the weight of the liquid in a hummingbird feeder not just push all the liquid out of the little holes? The openings of little holes are upturned, but still way below the water level.

In: Physics

There is less air above the water. When some water is drank from below, the water level in the dish gets lower and allows some air in. This air then increases the pressure above the water and allows it to drop a tiny bit.

After dropping, the air has been once again lowered in pressure (as it has expanded) and so the water does not continue to move down.

If you want to see the way it works, upend an open water bottle into a glass of water (over a sink, probably). A little water will drop out of the water, then it’ll stop. You can dribble the water out by raising the bottle a little bit, or do like the hummingbirds and suck or spill water out of the glass.