And with 1960's thinking, x-rays can detect explosives in shoes, hence why we remove our shoes for "screening".

Back to the topic... a laptop placed on top of or below a gun will show a very high density area where the gun is located. If the screener was trained well, they'd scan the object again, get a second opinion, and/or have it swabbed for explosives.

Since these x-rays are based on an object's density and its shape is displayed on screen, why bother removing the laptop from the bag? Other countries screening process does not require the removal of the laptop from the bag. Is it because their screeners are better trained than ours? Or is it that we want to make our screeners job as easy as possible so that they can search for other threats like water, pies, or mayonnaise?

Also, why not put the explosives puffer inline with the x-ray machine? This way, all objects that pass through are screened for guns and mayonnaise at the same time? @:-)