How did new weapons help create areas known as "No-man's land"?

Question

How did new weapons help create areas known as "No-man's land"?

Answer 1

The invention of the machine gun in WW1 created no-man's-lands by being able to lay down suppressive and killing fire between the trenches on a continuous basis.  Cannons took time to reload, were difficult to direct effectively, were heavy and expensive and required a highly trained crew whereas a machine gun could be operated by a couple of men.

  Cannon were used extensively prior to the invention of the machine gun, but fast, horse cavalry could close inside the cannon's range and attack the gun crews during reloading operations.  Not true with the machine gun.  A single machine gunner in a fortified position could cover vast tracts of land and fire on anything that moved.  They were so effective when they were introduced that the battle lines in WW1 stagnated and became the trench warfare WW1 is famous for.  It was a hard lesson for the generals to learn.  They were still doing the infantry charges across the open areas between the opposing forces only to see thousands of their men get mowed down like wheat.  No man could survive such a manuever, thus the name: No Man's Land