wch4999

"transform into each other" would be more appropriate. The gauge choice you mentioned is not totally wrong. The gauge freedom can be used to set the electric field to zero, but only once at a single point.

You need to read the paragraph prior to the quote. He is talking about which one of field and mechanical stress is more "fundamental" or less "direct". If one measure the force exerted by electric field using a unit charge, one measures the field by measuring the mechanical stress first.

Of course, the context matters. Often if one compares potential and field, field would be the one directly measured. It is just semantics really.

Well, reading the first part I just realized this is japanese/chinese! In Chinese all characters are like 口 or 食. Sometimes we can also break the character down to several parts to understand its meaning.

Because the government doesn't consider this as crime.

Seriouly, does EVERYONE need dev tools in their browsers? As a casual web-developer, I use it quite often. It is questionable for most people if they are using the dev tools in Chrome or Firefox. Not to mention when someone accidentally press F12, something scary for them will appear. Personally thining, Making dev tools as an add-on would be more appropriate.