Scanners have gotten better recently, meaning they can tell the difference between water and explosives, but these restrictions weren’t pulled out of thin air like many others.

https://en.m.wikipedia.org/wiki/Security_repercussions_due_to_the_2006_transatlantic_aircraft_plot

There was a thwarted terrorist plot to use drink bottles to hold explosives.

Most grinders you have to screw together (threaded). The Brilliant Cut Grinder uses magnets to keep the grounds compartment attached. Similar to how most grinders keep the mid plate and top plate together

Continuous.

Instead of jumping from 1 to 2 to 3, we move smoothly across all (typically real) numbers. Obviously this would go to infinity almost every time because there are infinite real numbers between any two distinct real numbers. So instead, we merge it into a bunch of skinny rectangles with their bottom on the x axis and the top at the value of the function for the start of the rectangle. As we shrink the width of the rectangles, it approaches the continuous notion.

Continuous means “smooth” - there are no jumps Discrete means there are jump