Not necessarily. Scoria and pumice are forms of volcanic glass that contain air spaces, while obsidian, another volcanic glass, contains minimal air spaces if any.
a rock that is full of tiny, connected air spaces is PERMEABLE
vesicular
a rock that is full of tiny, connected air spaces is PERMEABLE
To measure the air in a glass full of stones, you can first fill the glass with water. Then, carefully submerge the glass into a larger container of water, making sure no air escapes. The volume of water displaced by the glass will indicate the total volume of the glass, including the volume of air in between the stones. By subtracting the volume of water from the total volume of the glass, you can determine the volume of air present.
Porous material.
The Water
Permeable
Pumice has a low density because it is full of small holes and cavities that are created during its formation due to the rapid cooling and depressurization of volcanic magma. These empty spaces make pumice very porous and lightweight, allowing it to float on water.
By Haurn Mo. It depends on your perception. If the glass was already empty and you starting filling it up but stoped halfway, the glass is half full, If you started drink it but stoped halfway, the glass is half empty.
You are probably thinking of pumice, and igneous rock.
Water cannot fill the glass because the glass is already ~lled with air. The "empty" glass is full of air. So, air takes up space. Air is a gas. It has no size or shape of its own but will fill every space it can.
Wine needs to combine with air to open up its full flavor potential so filling a glass to the half-way point (and refilling as necessary) is best.