Pouring water from a bottle into a glass under gravity, but in a vaccum.

I have a beer bottle full of liquid with viscosity, density and surface tension similar to that of water - for the purposes of this experiment, it’s a liquid - hypothetical if necessary - that will not boil at room temperature in a vaccum.

I’m holding this bottle in my spacesuit-gloved hand in a vaccum chamber on Earth - there is as near to a complete vacuum as possible in the chamber.

I invert the bottle over a glass held in my other glove. What happens?

I think what happens is that the water pours out of the bottle in a fairly orderly fashion, and an empty space appears above the remaining liquid in the bottle as it goes, but without the necessity of any bubbles glugging in through the bottle’s mouth to create that empty space as I pour. Am I right?

What’s the temperature of a vacuum?

I would like to suggest we look at it as being mercury, and the temperature is in the range of it staying a liquid.

It the thrust of the question is whether the glug-glug effect is gone, then you are correct. This can be replicated in an atmosphere simply by cutting off the bottom of the bottle to make a funnel (or by putting a big enough hole in it.)

This is for a bottle that can not move closer to the gravity source and the opening is facing the same source.

I would think the mercury would be drawn to the gravity source in one mass the diameter of the neck of the bottle. The mercury would then try to form into a sphere, which is the best shape that molecular cohesion allows for. What it eventual looks like before reaching the gravity source, would depend on how long it has to turn into a sphere. A cone shaped container would allow a cone shaped mass to leave the jar, but it too would try to turn into a sphere.

vacuum doesn’t have one, but the liquid is at room temperature and because it’s magic hypothetical liquid, it doesn’t boil and lose heat that way, so it doesn’t freeze dusing the experiment either.

You’re describing the behaviour of the liquid as it falls from the bottle, but before it reaches the glass?


The change to a sphere wouldn’t be noticed with something like this being done on earth. The change would be noticed if we could do this over a long distance.

Do it on something like a two foot distance and you would only see a unbroken column between the bottle and glass. Tip the bottle sideways and you see an arc form. Air doesn’t put up a resistance against the flow so no gluging.

Not quite. Depending on the surface tension and cohesion of the liquid, and on how far you pour it, the stream of liquid will either have a trumpet shape (widest at the opening of the bottle), or it’ll break up into individual droplets. The bottom part of the stream is falling faster than the top part, due to acceleration from gravity, so it can’t just all fall as a single uniform column.

I was hoping somebody else would comment on this thread. I was just using the best I could think of.