How does a drinking straw work?

Me and my friend "R" came home from our trip to the art museum. It was a hot day, so I offered her a glass of juice  with a straw in it and poured myself  too. As we were drinking  the juice we remembered our childhood days of how we enjoyed drinking  milk, juice,water and anything we could drink with a straw.



 During our conversation, she asked me "do you know how a straw works?" and the immediate reply I wanted to give was " I am sucking the juice up the straw". I paused for a minute and thought about it.

 When I leave the straw sitting inside the glass, the juice fills up the straw up to the level of the juice outside of the straw. So, the atmospheric pressure is same inside the glass and the little bit of place inside the straw too.

But, when I suck the air out of the straw, the pressure inside the straw decreases compared to the rest of the glass. And the high pressure outside of the straw pushes the juice up the straw and into my mouth. Actually, the high atmospheric pressure does the work of pushing the liquid up the straw.

This can be explained easily if you think of the atmospheric pressure on one side of the seesaw and air inside the straw on the other side of the seesaw. Since the atmospheric pressure is high the seesaw will go down and push up the side of the seesaw with air inside the straw.


In this case the force down on the inside part of the see-saw is weaker than the push on the outside side of the see-saw. As a result of the unbalanced forces, the water (the see-saw) will move. So, the water outside of the straw will be pushed down and the water in the straw will be pushed up.



Now that you know how the straw works, do you think it will work in space?.

 Probably not. You should stand out completely in space with liquid and straw. In space, there isn't any atmospheric pressure so the straw wouldn't work at all. Surely, inside the space shuttle it will work because there is pressure inside the cabin.