My textbook says that facts or truths which do not change can be present tense, even when the whole sentence is in the past.
Example sentence from my textbook;
Galileo Galilei KNEW that the earth GOES around the sun.
The station master TOLD me that the first train STARTS at five.
In contrast, another example;
DID you say you ARE/WERE Japanese?
My textbook says "were" is commonly used because of the tense consistency although the person's nationality never changes.
Is this true?
Galileo KNEW + WENT and the station master TOLD + STARTED; do these also work?
I noticed that this machine did/does not work.
In this case, "did" or "does"? (*I know that this machine still does not work, so this fact is still lasting)