Fill a glass bottle with enough water so when its on its side it won’t spill out. Then microwave for a 1:30 on high. The bottle is going to be VERY HOT! Use caution and use hot pads. Make sure to wear safety glasses!
Already with a bowl of water on the table, pour the water out of the bottle into the bowl, then put the tip of the bottle into the bowl of water straight up. Hold on tight as the vacuum has a huge amount of force.
When we microwave the bottle and water it becomes steam in the bottle which is a gas. Dunking the bottle in water, causes the steam to condense back into a liquid, creating a large vacuum (steam is a lot less dense than water), the large vacuum then draws water into the bottle with the force of the atmosphere pushing down on the surface of the water. This pushes it into the vacuum.