Why don't ghosts swing their arm while 'walking'

Have you ever wondered why ghosts are depicted to be motionless while 'moving' around. Note the '' '' here which I will explain later as well. Some would probably say that this is just something scriptwriters and movie directors came up with to differentiate real living people from those dead ones. But if you think about it from the scientific aspects, it actually make some sense.

There are actually 2 problems here... 1) Why don't they swing their arms? 2) Do they even walk?

The only way for someone to travel from place to place without any mechanical aid(eg. skateboard, roller blades, etc) is to walk. We all agree that right? Then again, we don't really classify them as people, but let's assume they are for now. So why don't they swing their arms like us? Scientifically it is accurate, let me show you. Firstly, we don't assume ghosts have any weight, isn't it? They can float and do other funny stuff so let's assume they are weightless, or rather mass-less. But what makes people swing their arms is actually due to the moment generated by our legs as we walk, so to counter this moment, our arms swing or else we will be turning as we walk and can never reach our destination. To generate moment, we need a force and a perpendicular distance from the force to the pivot(from one leg to the other).

Then we go back to our 2nd question, do they ghosts really walk?? Let's first assume they do, so with each step they generate a moment and so on... but wait, they were mass-less, right? So by Newton's 2nd law, F = ma, they cannot generate any force so no moment and no counter-moment from the arms. Question 1, check!

Then we go back to our first assumption that they walk, so now we assume they don't, if you watched enough movies they actually float around since they can defy gravity with their lack of mass(sometimes they crawl too, think THE RING). So they move, but their arms still don't swing, why? Remember I said the swing of arm is due to the moment from the movement of the legs, so since their legs don't move, why the hell you get that moment you need to swing those arms??

Then back to Qn 2, do they walk? We need to go back to Newton's 2nd law to explain this. If you paid enough attention in your physics class in secondary school, you should know you need a force to move, since ghosts are mass-less, they generate no force and thus they cannot walk. Therefore the notion that they float is more accurate than say Sadako crawling out of the TV.
Question 2, check!

**Explaining the Paranormal with Science is proudly brought to you by LAMESHIT School of Thought, any truth is purely coincidental**

Hope you guys managed to de-stress in this exam period!

PS: LAMESHIT School of Thought is looking for more myths and legends that need explaining with science.

Bonus Qn : 用什么抹窗最干净?? Answer will be out with the next post.