Throw-able entities, such as eggs, snowballs, enderpearls, defy Minecraft's physics and do not float in bubble columns. If you stand in water and throw a ender pearl towards the sky according to Minecraft's physics it should float up to the surface and float there. Instead it goes up a little bit, loses all momentum, and then goes straight down. This makes no sense since "heavier" entities float no problem, such as boats, minecarts, anvils, sand, etc.