So why does the water get sucked up into the glass? Simple—it doesn’t. Instead, the air pressure above the water within the glass is reduced by removing some of the air.
One might even say that this relative vacuum sucked the water up into the glass. /sigh
Ehhh… not as such. If you're talking about near-vacuum at the top of the raised portion, you're looking to measure absolute pressure, and for that you'll need [a column of water over 30 feet tall] (water is usually about 1 g/mL while everyone agrees to pretend that mercury is always exactly 13.5951 g/mL).
Now you could leave some arbitrary pressure inside the raised portion other than "hard vacuum," and that can give you an idea of the relative (or "gauge") pressure between the two surfaces of the water, but a search for the phrase "weather glass" (in quotes) on Amazon will give you options for devices that both exposes far less surface area to evaporation than a fish tank while also eliminating the problem of fish respiration/farts.
Fishics?
The "homework question" shows this guy isn't exactly a physics whiz.
Much more than the few inches shown and I'm going to say the answer is "Ye Olde Caisson Disease."
This is a theory I learned as a kid, filling a straw with fish poop from the bottom of the bowl, stick a finger over the top, and voila.
One might even say that this relative vacuum sucked the water up into the glass. /sigh
Fill it with these guys:
<img src="http://www.seabreeze.com.au/img/Content/11195082/How-do-you-catch-a-completely-invisible-fish-1.jpg"</img>
Ehhh… not as such. If you're talking about near-vacuum at the top of the raised portion, you're looking to measure absolute pressure, and for that you'll need [a column of water over 30 feet tall] (water is usually about 1 g/mL while everyone agrees to pretend that mercury is always exactly 13.5951 g/mL).
Now you could leave some arbitrary pressure inside the raised portion other than "hard vacuum," and that can give you an idea of the relative (or "gauge") pressure between the two surfaces of the water, but a search for the phrase "weather glass" (in quotes) on Amazon will give you options for devices that both exposes far less surface area to evaporation than a fish tank while also eliminating the problem of fish respiration/farts.