Many junior high teachers aren’t often the most knowledgable about science details. (How long it takes a light to turn on depends on how it’s made. But none of them become visible ‘instantly’. ) What (s)he (sh/c)ould have done is have you defend yourself with a reference. And then apologize.
That was the year when we were taught of the speed of light and the specific question might have been at the end of the same chapter in the text book.
Somehow I had a vague feeling that the effect of turning on the switch should not reach the light instantly.
It was much later, that I found out how it was related to the absolute speed of information that is available in current theory.
Note, that I hadn’t used the internet as much back then and it was much later, that I started diving into Wikipedia.
On the other hand, teachers are supposed to be university graduates themselves, so considering that I had the answer to that question by 12th, I would expect the teacher to at least be able to correctly answer that.
Even if the switch ‘instantly’ completed the circuit, electricity does not move along a wire at the ‘speed of light’, but only about 66% of that speed. If the light contains a filament, it has to heat up to several hundres of degrees before it’s visible. Fluorescent takes longer; even an LED does not shed light ‘instantly’. So he was wrong on multiple counts. BUT they don’t teach such details in college (except in physics classes). AFAIK,most junior high ‘science’ teachers are not all that familiar with such details.
Many junior high teachers aren’t often the most knowledgable about science details. (How long it takes a light to turn on depends on how it’s made. But none of them become visible ‘instantly’. ) What (s)he (sh/c)ould have done is have you defend yourself with a reference. And then apologize.
That was the year when we were taught of the speed of light and the specific question might have been at the end of the same chapter in the text book.
Somehow I had a vague feeling that the effect of turning on the switch should not reach the light instantly.
It was much later, that I found out how it was related to the absolute speed of information that is available in current theory.
Note, that I hadn’t used the internet as much back then and it was much later, that I started diving into Wikipedia.
On the other hand, teachers are supposed to be university graduates themselves, so considering that I had the answer to that question by 12th, I would expect the teacher to at least be able to correctly answer that.
Even if the switch ‘instantly’ completed the circuit, electricity does not move along a wire at the ‘speed of light’, but only about 66% of that speed. If the light contains a filament, it has to heat up to several hundres of degrees before it’s visible. Fluorescent takes longer; even an LED does not shed light ‘instantly’. So he was wrong on multiple counts. BUT they don’t teach such details in college (except in physics classes). AFAIK,most junior high ‘science’ teachers are not all that familiar with such details.