Water left overnight

[mst3k]

When I go to bed I fill a glass with water with no bubbles and when I wake in the morning there is tiny bubbles on the side of the glass, what are the bubbles and where did they come from? Thanks

[Clanad]

When you run water from the tap into the glass, you'll see several large bubbles floating to the top immediatley. Thing is, many small air bubbles incorporated by the water running into the glass take a while to percolate out... this is some of what your'e seeing. In addition, the water was probably colder, coming out of the faucet, than the glass and surrounding air. This temperature difference will also cause small bubbles of oxygen and nitrogen to condense on the side of the glass. Even falling barometric pressure can cause a few bubbles...

[heathfield]

Also, the water will have been under pressure in the water main. Once it's left the tap, it will be at normal atmospheric pressure and dissolved gases will be released. There will still be some residual gases that will be released over time to form those bubbles on the glass next morning.
It's like an opened bottle of fizzy drink left open overnight. If you taste it next morning, you'll notice that there will still be some fizz left in it.

[mst3k]

Cool,

Thanks

[Ridcully]

I sneak into your house and blow into the drink through a straw.

A clean straw, obviously.